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Office of Scientific and Technical Information
Global patterns of landatmosphere fluxes of carbon dioxide, latent heat, and sensible heat derived from eddy covariance,
E-Print Network [OSTI]
(NEE), latent energy (LE), and sensible heat (H) based on remote sensing indices, climateGlobal patterns of landatmosphere fluxes of carbon dioxide, latent heat, and sensible heat derived
Chen, Jiquan
A. Gershunov R. Roca Coupling of latent heat flux and the greenhouse effect by large-scale
A. Gershunov Ă? R. Roca Coupling of latent heat flux and the greenhouse effect by large Abstract Coupled variability of the greenhouse effect (GH) and latent heat flux (LHF) over the tropical of convection) form regions of strong greenhouse effect in tropical convergence zones while subtropical high
ORIGINAL ARTICLE Sensible and latent heat flux response to diurnal variation in soil
of the soil, but also the energy/water exchanges between the land surface and atmosphere (Li et al. 2002) dueORIGINAL ARTICLE Sensible and latent heat flux response to diurnal variation in soil surface temperature and moisture under different freeze/thaw soil conditions in the seasonal frozen soil region
condition of the soil, but also the energy/water exchanges between the land surface and atmosphere (Li et alORIGINAL ARTICLE Sensible and latent heat flux response to diurnal variation in soil surface temperature and moisture under different freeze/thaw soil conditions in the seasonal frozen soil region
Regional CO2 and latent heat surface fluxes in the Southern Great Plains: Measurements, modeling, and scaling
SciTech Connect (OSTI)
Characterizing net ecosystem exchanges (NEE) of CO{sub 2} and sensible and latent heat fluxes in heterogeneous landscapes is difficult, yet critical given expected changes in climate and land use. We report here a measurement and modeling study designed to improve our understanding of surface to atmosphere gas exchanges under very heterogeneous land cover in the mostly agricultural U.S. Southern Great Plains (SGP). We combined three years of site-level, eddy covariance measurements in several of the dominant land cover types with regional-scale climate data from the distributed Mesonet stations and Next Generation Weather Radar precipitation measurements to calibrate a land surface model of trace gas and energy exchanges (isotope-enabled land surface model (ISOLSM)). Yearly variations in vegetation cover distributions were estimated from Moderate Resolution Imaging Spectroradiometer normalized difference vegetation index and compared to regional and subregional vegetation cover type estimates from the U.S. Department of Agriculture census. We first applied ISOLSM at a 250 m spatial scale to account for vegetation cover type and leaf area variations that occur on hundred meter scales. Because of computational constraints, we developed a subsampling scheme within 10 km 'macrocells' to perform these high-resolution simulations. We estimate that the Atmospheric Radiation Measurement Climate Research Facility SGP region net CO{sub 2} exchange with the local atmosphere was -240, -340, and -270 gC m{sup -2} yr{sup -1} (positive toward the atmosphere) in 2003, 2004, and 2005, respectively, with large seasonal variations. We also performed simulations using two scaling approaches at resolutions of 10, 30, 60, and 90 km. The scaling approach applied in current land surface models led to regional NEE biases of up to 50 and 20% in weekly and annual estimates, respectively. An important factor in causing these biases was the complex leaf area index (LAI) distribution within cover types. Biases in predicted weekly average regional latent heat fluxes were smaller than for NEE, but larger than for either ecosystem respiration or assimilation alone. However, spatial and diurnal variations of hundreds of W m{sup -2} in latent heat fluxes were common. We conclude that, in this heterogeneous system, characterizing vegetation cover type and LAI at the scale of spatial variation are necessary for accurate estimates of bottom-up, regional NEE and surface energy fluxes.
Riley, W. J.; Biraud, S.C.; Torn, M.S.; Fischer, M.L.; Billesbach, D.P.; Berry, J.A.
Project Profile: Heat Transfer and Latent Heat Storage in Inorganic...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Heat Transfer and Latent Heat Storage in Inorganic Molten Salts for CSP Plants Project Profile: Heat Transfer and Latent Heat Storage in Inorganic Molten Salts for CSP Plants...
ARM - Measurement - Latent heat flux
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Photovoltaic roof heat flux
designs (relatively) Photovoltaic Solar P a n e l AtmosphereCALIFORNIA, SAN DIEGO Photovoltaic Roof Heat Flux A ThesisABSTRACT OF T H E THESIS Photovoltaic Roof Heat Flux by
Samady, Mezhgan Frishta
Heat-transfer coefficients in agitated vessels. Latent heat models
Latent heat models were developed to calculate heat-transfer coefficients in agitated vessels for two cases: (1) heating with a condensable fluid flowing through coils and jackets; (2) vacuum reflux cooling with an overhead condenser. In either case the mathematical treatment, based on macroscopic balances, requires no iterative schemes. In addition to providing heat-transfer coefficients, the models predict flow rates of service fluid through the coils and jackets, estimate the percentage of heat transfer due to latent heat, and compute reflux rates.
Kumpinsky, E. [Ashland Chemical Co., Columbus, OH (United States)] [Ashland Chemical Co., Columbus, OH (United States)
Experimental Research on Solar Assisted Heat Pump Heating System with Latent Heat Storage
-reaching meaning of solving energy and environment problems if new type energy conservation and environment protection heating system ? solar assisted ground-source heat pump (SAGHP) heating system with a latent heat storage tank will be practical... was established at the laboratory of construction energy conservation in Harbin Institute of Technology (HIT) in 2004. It added a latent heat storage tank in original SAGHP system. The schematic diagram of the system is shown in Figure 1. The experimental...
Han, Z.; Zheng, M.; Liu, W.; Wang, F.
Optical heat flux gauge
DOE Patents [OSTI]
A heat flux gauge is disclosed comprising first and second thermographic phosphor layers separated by a layer of a thermal insulator, wherein each thermographic layer comprises a plurality of respective thermographic sensors in a juxtaposed relationship with respect to each other. The gauge may be mounted on a surface with the first thermographic phosphor in contact with the surface. A light source is directed at the gauge, causing the phosphors to luminesce. The luminescence produced by the phosphors is collected and its spectra analyzed in order to determine the heat flux on the surface. First and second phosphor layers must be different materials to assure that the spectral lines collected will be distinguishable. 9 figures.
Noel, B.W.; Borella, H.M.; Cates, M.R.; Turley, W.D.; MacArthur, C.D.; Cala, G.C.
Physical model for the latent heat of fusion
The atomic movement induced on melting has to overcome a viscous drag resistance. It is suggested that the latent heat of fusion supplies the required energy for this physical process. The viscosity model introduced here allows computation of the latent heat from viscosity, molar volume, melting temperature, and atomic mass and diameter. The correlation between these parameters and the latent heat of 14 elements with body and face centered cubic structures was exceptional, with the correlation coefficients of 0.97 and 0.95 respectively.
Jozsef Garai
High Heat Flux Components Program
Purpose is the development of the technologies necessary to design, build and operate high heat flux components such as actively cooled limiters, divertor collector plates, R.F. antennas, mirror end cells, mirror halo collectors, direct convertor collectors, and neutral beam dumps. These components require an integrated design that considers the plasma-materials interaction (PMI) issues, heat removal problems and materials issues (including possible low Z coatings and claddings). As a general definition, high heat flux components see heat fluxes ranging from 1 to 100 MW/m/sup 2/. Suitable materials include copper and copper alloys.
Whitley, J.B.
The Effects of Latent Heating on The Extratropical Transition of Typhoon Sinlaku
The Effects of Latent Heating on The Extratropical Transition of Typhoon Sinlaku Dr. Jenni Evans and completion to latent heating from the storm and surrounding area. Two sets of simulations using the Weather Research and Forecasting (WRF) model are examined to clarify the role of latent heating during ET
Bjørnstad, Ottar Nordal
under the offset unit's solar panel, the hf formula (16) wasdrop below the angle unit's solar panel at night time. D u rfor both the units, the solar panel covered roof was a heat
Heat flux limiting sleeves
A heat limiting tubular sleeve extending over only a portion of a tube having a generally uniform outside diameter, the sleeve being open on both ends, having one end thereof larger in diameter than the other end thereof and having a wall thickness which decreases in the same direction as the diameter of the sleeve decreases so that the heat transfer through the sleeve and tube is less adjacent the large diameter end of the sleeve than adjacent the other end thereof.
Harris, William G. (Tampa, FL)
Heat flux solarimeter
The solarimeter presented in this work is easy to assemble. It is calibrated and its performance is validated by means of Hottel's method. Finally, the curves obtained with this solarimeter are compared to the ones obtained with a commercial solarimeter. This device is based on the evaluation of the heat flow in a metal rod. In consequence, measurements are not affected by ambient temperature variations. On the other hand, there is a linear relationship between the temperatures measured at the rod ends and the incident radiation, as can be concluded both from the theory of its operation and the calibration lines obtained. The results obtained from the global irradiance measurements in the area of Los Polvorines (Buenos Aires Province), together with a preliminary evaluation of the solarimeter's response time, are presented in this work. (author)
Sartarelli, A.; Vera, S.; Cyrulies, E. [Instituto de Desarrollo Humano, Univ. Nac. de Gral. Sarmiento (IDH, UNGS), Los Polvorines (Argentina); Echarri, R. [Instituto de Desarrollo Humano, Univ. Nac. de Gral. Sarmiento (IDH, UNGS), Los Polvorines (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET) (Argentina); Samson, I. [INTEC (Instituto Tecnologico Santo Domingo), Santo Domingo (Dominican Republic)
Isentropic Slopes, Downgradient Eddy Fluxes, and the Extratropical Atmospheric Circulation Response to Tropical Tropospheric Heating
to Tropical Tropospheric Heating AMY H. BUTLER NOAA/NWS/NCEP/Climate Prediction Center, Camp Springs, Maryland of the midlatitude jets and their associated eddy fluxes of heat and potential vorticity (PV). Experiments run latent heating and thus locally enhanced warming in the tropical troposphere. Here the authors provide
High Heat Flux Thermoelectric Module Using Standard Bulk Material...
Heat Flux Thermoelectric Module Using Standard Bulk Material High Heat Flux Thermoelectric Module Using Standard Bulk Material Presents high heat flux thermoelectric module design...
An investigation into the thermal properties of selected sensible and latent heat storage materials
in the latent heat of fusion. Considerable work has been done in analyzing latent heat storage systems. Telkes and Raymond [lj did early work with a sodium sulfate system using sealed drums. iVore recent experimental work was conducted with other salt...
Wood, Stanley Clayton
ARM Energy Balance Bowen Ratio (EBBR) station: surf. heat flux and related data, 30-min
DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]
The Energy Balance Bowen Ratio (EBBR) system produces 30-min estimates of the vertical fluxes of sensible and latent heat at the local surface. Flux estimates are calculated from observations of net radiation, soil surface heat flux, and the vertical gradients of temperature and relative humidity. Meteorological data collected by the EBBR are used to calculate bulk aerodynamic fluxes, which are used in the Bulk Aerodynamic Technique (BA) EBBR value-added product (VAP) to replace sunrise and sunset spikes in the flux data. A unique aspect of the system is the automatic exchange mechanism (AEM), which helps to reduce errors from instrument offset drift.
Cook, David
On the Interaction between Marine Boundary Layer Cellular Cloudiness and Surface Heat Fluxes
The interaction between marine boundary layer cellular cloudiness and surface uxes of sensible and latent heat is investigated. The investigation focuses on the non-precipitating closed-cell state and the precipitating open-cell state at low geostrophic wind speed. The Advanced Research WRF model is used to conduct cloud-system-resolving simulations with interactive surface fluxes of sensible heat, latent heat, and of sea salt aerosol, and with a detailed representation of the interaction between aerosol particles and clouds. The mechanisms responsible for the temporal evolution and spatial distribution of the surface heat fluxes in the closed- and open-cell state are investigated and explained. It is found that the horizontal spatial structure of the closed-cell state determines, by entrainment of dry free tropospheric air, the spatial distribution of surface air temperature and water vapor, and, to a lesser degree, of the surface sensible and latent heat flux. The synchronized dynamics of the the open-cell state drives oscillations in surface air temperature, water vapor, and in the surface fluxes of sensible and latent heat, and of sea salt aerosol. Open-cell cloud formation, cloud optical depth and liquid water path, and cloud and rain water path are identified as good predictors of the spatial distribution of surface air temperature and sensible heat flux, but not of surface water vapor and latent heat flux. It is shown that by enhancing the surface sensible heat flux, the open-cell state creates conditions by which it is maintained. While the open-cell state under consideration is not depleted in aerosol, and is insensitive to variations in sea-salt fluxes, it also enhances the sea-salt flux relative to the closed-cell state. In aerosol-depleted conditions, this enhancement may replenish the aerosol needed for cloud formation, and hence contribute to the perpetuation of the open-cell state as well. Spatial homogenization of the surface fluxes is found to have only a small effect on cloud properties in the investigated cases. This indicates that sub-grid scale spatial variability in the surface flux of sensible and latent heat and of sea salt aerosol may not be required in large scale and global models to describe marine boundary layer cellular cloudiness.
Kazil, J.; Feingold, G.; Wang, Hailong; Yamaguchi, T.
A model for the latent heat of melting in free standing metal nanoparticles
Nanoparticles of many metals are known to exhibit scale dependent latent heats of melting. Analytical models for this phenomenon have so far failed to completely capture the observed phenomena. Here we present a thermodynamic analysis for the melting of metal nanoparticles in terms of their internal energy and a scale dependent surface tension proposed by Tolman. The resulting model predicts the scale dependence of the latent heat of melting and is confirmed using published data for tin and aluminum.
Shin, Jeong-Heon; Deinert, Mark R., E-mail: email@example.com [Department of Mechanical Engineering, The University of Texas at Austin, Austin, Texas 78715 (United States)
Comparison of the high temperature heat flux sensor to traditional heat flux gages under high heat flux conditions.
Four types of heat flux gages (Gardon, Schmidt-Boelter, Directional Flame Temperature, and High Temperature Heat Flux Sensor) were assessed and compared under flux conditions ranging between 100-1000 kW/m2, such as those seen in hydrocarbon fire or propellant fire conditions. Short duration step and pulse boundary conditions were imposed using a six-panel cylindrical array of high-temperature tungsten lamps. Overall, agreement between all gages was acceptable for the pulse tests and also for the step tests. However, repeated tests with the HTHFS with relatively long durations at temperatures approaching 1000%C2%B0C showed a substantial decrease (10-25%) in heat flux subsequent to the initial test, likely due to the mounting technique. New HTHFS gages have been ordered to allow additional tests to determine the cause of the flux reduction.
Blanchat, Thomas K.; Hanks, Charles R.
Heat Transfer and Latent Heat Storage in Inorganic Molten Salts for Concentrating Solar Power Plants
A key technological issue facing the success of future Concentrating Solar Thermal Power (CSP) plants is creating an economical Thermal Energy Storage (TES) system. Current TES systems use either sensible heat in fluids such as oil, or molten salts, or use thermal stratification in a dual-media consisting of a solid and a heat-transfer fluid. However, utilizing the heat of fusion in inorganic molten salt mixtures in addition to sensible heat , as in a Phase change material (PCM)-based TES, can significantly increase the energy density of storage requiring less salt and smaller containers. A major issue that is preventing the commercial use of PCM-based TES is that it is difficult to discharge the latent heat stored in the PCM melt. This is because when heat is extracted, the melt solidifies onto the heat exchanger surface decreasing the heat transfer. Even a few millimeters of thickness of solid material on heat transfer surface results in a large drop in heat transfer due to the low thermal conductivity of solid PCM. Thus, to maintain the desired heat rate, the heat exchange area must be large which increases cost. This project demonstrated that the heat transfer coefficient can be increase ten-fold by using forced convection by pumping a hyper-eutectic salt mixture over specially coated heat exchanger tubes. However,only 15% of the latent heat is used against a goal of 40% resulting in a projected cost savings of only 17% against a goal of 30%. Based on the failure mode effect analysis and experience with pumping salt at near freezing point significant care must be used during operation which can increase the operating costs. Therefore, we conclude the savings are marginal to justify using this concept for PCM-TES over a two-tank TES. The report documents the specialty coatings, the composition and morphology of hypereutectic salt mixtures and the results from the experiment conducted with the active heat exchanger along with the lessons learnt during experimentation.
Mathur, Anoop [Terrafore Inc.] [Terrafore Inc.
Longitudinal variation of tides in the MLT region: 2. Relative effects of solar radiative and latent heating
of solar radiative and latent heating Xiaoli Zhang,1 Jeffrey M. Forbes,1 and Maura E. Hagan2 Received 11 study examines the relative importance of radiative heating and latent heating in accounting (GSWM) and new tidal heating rates derived from International Satellite Cloud Climatology Project (ISCCP
Forbes, Jeffrey
Critical heat flux test apparatus
An apparatus for testing, in situ, highly irradiated specimens at high temperature transients is provided. A specimen, which has a thermocouple device attached thereto, is manipulated into test position in a sealed quartz heating tube by a robot. An induction coil around a heating portion of the tube is powered by a radio frequency generator to heat the specimen. Sensors are connected to monitor the temperatures of the specimen and the induction coil. A quench chamber is located below the heating portion to permit rapid cooling of the specimen which is moved into this quench chamber once it is heated to a critical temperature. A vacuum pump is connected to the apparatus to collect any released fission gases which are analyzed at a remote location.
Welsh, Robert E. (West Mifflin, PA); Doman, Marvin J. (McKeesport, PA); Wilson, Edward C. (West Mifflin, PA)
The effect of nonuniform axial heat flux distribution on the critical heat flux
A systematic experimental and analytic investigation of the effect of nonuniform axial heat flux distribution on critical heat rilux was performed with water in the quality condition. Utilizing a model which ascribes the ...
Todreas, Neil E.
Effects of urban land cover modifications in a mesoscale meteorological model on surface temperature and heat fluxes in the Phoenix metropolitan area.
and latent heat fluxes and therefore the ground temperature, Tg. Evaporation, E, for each grid cell temperature and heat fluxes in the Phoenix metropolitan area. S. Grossman-Clarke1, J.A. Zehnder2, and W) satellite images [2]. The data were upscaled to a 30-second grid and used to augment and correct
Hall, Sharon J.
Vacuum energy and the latent heat of AdS-Kerr black holes
Phase transitions for rotating asymptotically anti-de Sitter black holes in four dimensions are described in the $P-T$ plane, in terms of the Hawking temperature and the pressure provided by the cosmological constant. The difference between constant angular momentum and constant angular velocity is highlighted, the former has a second order phase transition while the latter does not. If the angular momentum is fixed there a line of first order phase transitions terminating at a critical point with a second order phase transition and vanishing latent heat, while if the angular velocity is fixed there is a line of first order phase transitions terminating at a critical point with infinite latent heat. For constant angular velocity the analytic form of the phase boundary is determined, latent heats derived and the Clapeyron equation verified.
Brian P. Dolan
Latent heat fluxes through nano-engineered porous materials
Micro- and nano-scale truss architectures provide mechanical strength, light weight, and breatheability in polymer barriers. Liquid evaporation and transport of resulting vapor through truss voids (pores) cools surfaces ...
Traum, Matthew J. (Matthew Jason), 1977-
Determination of solid fractiontemperature relation and latent heat using full scale
on five such corrosion resistant alloys: superaustenitic stainless steel CN3MN, duplex stainless steels CD available. The alloys selected consist of three stainless steels (super- austenitic CN3MN and duplexes CD3MN, Latent heat, Stainless steels, Nickel based alloys Introduction Casting simulation is routinely used
Beckermann, Christoph
Heat flux dynamics in dissipative cascaded systems
We study the dynamics of heat flux in the thermalization process of a pair of identical quantum system that interact dissipatively with a reservoir in a {\\it cascaded} fashion. Despite the open dynamics of the bipartite system S is globally Lindbladian, one of the subsystems "sees" the reservoir in a state modified by the interaction with the other subsystem and hence it undergoes a non-Markovian dynamics. As a consequence, the heat flow exhibits a non-exponential time behaviour which can greatly deviate from the case where each party is independently coupled to the reservoir. We investigate both thermal and correlated initial states of $S$ and show that the presence of correlations at the beginning can considerably affect the heat flux rate. We carry out our study in two paradigmatic cases -- a pair of harmonic oscillators with a reservoir of bosonic modes and two qubits with a reservoir of fermionic modes -- and compare the corresponding behaviours. In the case of qubits and for initial thermal states, we find that the trace distance discord is at any time interpretable as the correlated contribution to the total heat flux.
Salvatore Lorenzo; Alessandro Farace; Francesco Ciccarello; G. Massimo Palma; Vittorio Giovannetti
Contactless heat flux control with photonic devices
The ability to control electric currents in solids using diodes and transistors is undoubtedly at the origin of the main developments in modern electronics which have revolutionized the daily life in the second half of 20th century. Surprisingly, until the year 2000 no thermal counterpart for such a control had been proposed. Since then, based on pioneering works on the control of phononic heat currents new devices were proposed which allow for the control of heat fluxes carried by photons rather than phonons or electrons. The goal of the present paper is to summarize the main advances achieved recently in the field of thermal energy control with photons.
Ben-Abdallah, Philippe
Quarterly Journal of the Royal Meteorological Society Q. J. R. Meteorol. Soc. 140: 139150, January 2014 A The role of latent heating in warm frontogenesis
2014 A The role of latent heating in warm frontogenesis Adele L. Igel* and Susan C. van den email@example.com The role of latent heating from individual cloud processes associated with one part of a springtime droplet nucleation are the largest sources of latent heat along the frontal surface and together produce
Collett Jr., Jeffrey L.
Assessment and Prediction of the Thermal Performance of a Centralized Latent Heat Thermal Energy Storage Utilizing Artificial Neural Network
A simulation tool is developed to analyze the thermal performance of a centralized latent heat thermal energy storage system (LHTES) using computational fluid dynamics (CFD). The LHTES system is integrated with a mechanical ventilation system...
El-Sawi, A.; Haghighat, F.; Akbari, H.
Gas Flux Sampling At Long Valley Caldera Geothermal Area (Lewicki...
Open Energy Info (EERE)
statistical regression of EC energy fluxes (sensible and latent heat) against available energy (net radiation, less soil heat flux). While incomplete (R2 0.77 for 1:1 line),...
Transient critical heat flux and blowdown heat-transfer studies
Objective of this study is to give a best-estimate prediction of transient critical heat flux (CHF) during reactor transients and hypothetical accidents. To accomplish this task, a predictional method has been developed. Basically it involves the thermal-hydraulic calculation of the heated core with boundary conditions supplied from experimental measurements. CHF predictions were based on the instantaneous ''local-conditions'' hypothesis, and eight correlations (consisting of round-tube, rod-bundle, and transient correlations) were tested against most recent blowdown heat-transfer test data obtained in major US facilities. The prediction results are summarized in a table in which both CISE and Biasi correlations are found to be capable of predicting the early CHF of approx. 1 s. The Griffith-Zuber correlation is credited for its prediction of the delay CHF that occurs in a more tranquil state with slowly decaying mass velocity. In many instances, the early CHF can be well correlated by the x = 1.0 criterion; this is certainly indicative of an annular-flow dryout-type crisis. The delay CHF occurred at near or above 80% void fraction, and the success of the modified Zuber pool-boiling correlation suggests that this CHF is caused by flooding and pool-boiling type hydrodynamic crisis.
Leung, J.C.
Tracking heat flux sensors for concentrating solar applications
Innovative tracking heat flux sensors located at or near the solar collector's focus for centering the concentrated image on a receiver assembly. With flux sensors mounted near a receiver's aperture, the flux gradient near the focus of a dish or trough collector can be used to precisely position the focused solar flux on the receiver. The heat flux sensors comprise two closely-coupled thermocouple junctions with opposing electrical polarity that are separated by a thermal resistor. This arrangement creates an electrical signal proportional to heat flux intensity, and largely independent of temperature. The sensors are thermally grounded to allow a temperature difference to develop across the thermal resistor, and are cooled by a heat sink to maintain an acceptable operating temperature.
Andraka, Charles E; Diver, Jr., Richard B
High flux heat transfer in a target environment
High flux heat transfer in a target environment T. Davenne High Power Targets Group Rutherford Valid for: Consider turbulent heat transfer in a 1.5mm diameter pipe  Dittus Boelter correlation Achenbach correlation for heat transfer in a packed bed of spheres Max power density for a sphere
McDonald, Kirk
Full-scale study of a building equipped with phase change material wallboards and a multi-layer rack latent heat thermal energy store system
-layer rack latent heat thermal energy store system Julien Borderon1 , Joseph Virgone2 , Richard Cantin1 installed as wallboard and as latent heat thermal energy storage system coupled with the ventilation system for the ventilation air is efficient. INTRODUCTION Nowadays, thermal energy storage systems are one way for reducing
Paris-Sud XI, Université de
MERLOT: a model for flow and heat transfer through porous media for high heat flux applications
MERLOT: a model for flow and heat transfer through porous media for high heat flux applications A Abstract Fusion power plant studies have found helium to be an attractive coolant based on its safety tend to provide modest heat transfer performance due to their inherently low heat capacity and heat
Raffray, A. René
Six-Week Time Series Of Eddy Covariance CO2 Flux At Mammoth Mountain...
Determination of pool boiling Critical Heat Flux enhancement in nanofluids
Nanofluids are engineered colloids composed of nano-size particles dispersed in common fluids such as water or refrigerants. Using an electrically controlled wire heater, pool boiling Critical Heat Flux (CHF) of Alumina ...
Truong, Bao H. (Bao Hoai)
Model of critical heat flux in subcooled flow boiling
The physical phenomenon occurring before and at the critical heat flux (CHF) for subcooled flow boiling has been investigated. The first phase of this study established the basic nature of the flow structure at CHF. A ...
Fiori, Mario P.
Divertor Heat Flux Mitigation in the National Spherical Torus Experiment
Steady-state handling of divertor heat flux is a critical issue for both ITER and spherical torus-based devices with compact high power density divertors. Significant reduction of heat flux to the divertor plate has been achieved simultaneously with favorable core and pedestal confinement and stability properties in a highly-shaped lower single null configuration in the National Spherical Torus Experiment (NSTX) [M. Ono et al., Nucl. Fusion 40, 557 2000] using high magnetic flux expansion at the divertor strike point and the radiative divertor technique. A partial detachment of the outer strike point was achieved with divertor deuterium injection leading to peak flux reduction from 4-6 MW m{sup -2} to 0.5-2 MW m{sup -2} in small-ELM 0.8-1.0 MA, 4-6 MW neutral beam injection-heated H-mode discharges. A self-consistent picture of outer strike point partial detachment was evident from divertor heat flux profiles and recombination, particle flux and neutral pressure measurements. Analytic scrape-off layer parallel transport models were used for interpretation of NSTX detachment experiments. The modeling showed that the observed peak heat flux reduction and detachment are possible with high radiated power and momentum loss fractions, achievable with divertor gas injection, and nearly impossible to achieve with main electron density, divertor neutral density or recombination increases alone.
Soukhanovskii, V A; Maingi, R; Gates, D A; Menard, J E; Paul, S F; Raman, R; Roquemore, A L; Bell, M G; Bell, R E; Boedo, J A; Bush, C E; Kaita, R; Kugel, H W; LeBlanc, B P; Mueller, D
Nano-engineering the boiling surface for optimal heat transfer rate and critical heat flux
The effects on pool boiling characteristics such as critical heat flux and the heat transfer coefficient of different surface characteristics such as surface wettability, roughness, morphology, and porosity are not well ...
Phillips, Bren Andrew
Development of dual temperature ammines for heat pump latent heat storage application. Final report
Ammoniated Complex Compounds can be used as working fluids in space heating and cooling heat pumps and storage systems. This report describes the theoretical and experimental development of complex compound working fluids for a heat pump-storage system. A computerized data base was developed for the preliminary selection of candidate working fluids. The selected substances were experimentally investigated. Several concepts using two ammoniated complex compounds or one complex compound and the plain ligand were developed. A subscale prototype was built using the NaBr-n NH/sub 3/ complex and NH/sub 3/ as the ligand. Two heat exchanger designs were tested and compared in terms of optimum reaction rates. A computer simulation was written to predict the performance of a complex compound heat pump-storage system. The results were compared with a simulation of a conventional R22 heat pump cycle. The influence of additives in the NaBr-n NH/sub 3/ complex was investigated with respect to the adsorption and desprption rates.
Rockenfeller, U.
Thermal response of a flat heat pipe sandwich structure to a localized heat flux
Thermal response of a flat heat pipe sandwich structure to a localized heat flux G. Carbajal a , C The temperature distribution across a flat heat pipe sandwich structure, subjected to an intense localized thermal to the evaporator side of the flat heat pipe, while the condenser side was cooled via natural convective
Wadley, Haydn
Characterizing the combustion behaviors of energetic materials requires diagnostic tools that are often not readily or commercially available. For example, a jet of thermite spray provides a high temperature and pressure reaction that can also be highly corrosive and promote undesirable conditions for the survivability of any sensor. Developing a diagnostic to quantify heat flux from a thermite spray is the objective of this study. Quick response sensors such as thin film heat flux sensors can not survive the harsh conditions of the spray, but more rugged sensors lack the response time for the resolution desired. A sensor that will allow for adequate response time while surviving the entire test duration was constructed. The sensor outputs interior temperatures of the probes at known locations and utilizes an inverse heat conduction code to calculate heat flux values. The details of this device are discussed and illustrated. Temperature and heat flux measurements of various thermite spray conditions are reported. Results indicate that this newly developed energetic material heat flux sensor provides quantitative data with good repeatability.
Eric Nixon; Michelle Pantoya
Downstream Heat Flux Profile vs. Midplane T Profile in Tokamaks
The relationship between the midplane scrape-off-layer electron temperature profile and the parallel heat flux profile at the divertor in tokamaks is investigated. A model is applied which takes into account anisotropic thermal diffusion, in a rectilinear geometry with constant density. Eigenmode analysis is applied to the simplified problem with constant thermal diffusivities. A self-similar nonlinear solution is found for the more realistic problem with anisotropically temperature-dependent thermal diffusivities. Numerical solutions are developed for both cases, with spatially dependent heat flux emerging from the plasma. For both constant and temperature-dependent thermal diffusivities it is found that, below about one-half of its peak, the heat flux profile shape at the divertor, compared with the midplane temperature profile shape, is robustly described by the simplest two-point model. However the physical processes are not those assumed in the simplest two-point model, nor is the numerical coefficient relating q||div to Tmp ?||mp/L|| as predicted. For realistic parameters the peak in the heat flux, moreover, can be reduced by a factor of two or more from the two-point model scaling which fits the remaining profile. For temperature profiles in the SOL region above the x-point set by marginal stability, the heat flux profile to the divertor can be largely decoupled from the prediction of the two-point model. These results suggest caveats for data interpretation, and possibly favorable outcomes for divertor configurations with extended field lines.
Robert J. Goldston
Remote high-temperature insulatorless heat-flux gauge
A remote optical heat-flux gauge for use in extremely high temperature environments is described. This application is possible because of the use of thermographic phosphors as the sensing media, and the omission of the need for an intervening layer of insulator between phosphor layers. The gauge has no electrical leads, but is interrogated with ultraviolet or laser light. The luminescence emitted by the two phosphor layers, which is indicative of the temperature of the layers, is collected and analyzed in order to determine the heat flux incident on the surface being investigated. The two layers of thermographic phosphor must be of different materials to assure that the spectral lines collected will be distinguishable. Spatial heat-flux measurements can be made by scanning the light across the surface of the gauge. 3 figures.
Noel, B.W.
A remote optical heat-flux gauge for use in extremely high temperature environments is described. This application is possible because of the use of thermographic phosphors as the sensing media, and the omission of the need for an intervening layer of insulator between phosphor layers. The gauge has no electrical leads, but is interrogated with ultraviolet or laser light. The luminescence emitted by the two phosphor layers, which is indicative of the temperature of the layers, is collected and analyzed in order to determine the heat flux incident on the surface being investigated. The two layers of thermographic phosphor must be of different materials to assure that the spectral lines collected will be distinguishable. Spatial heat-flux measurements can be made by scanning the light across the surface of the gauge.
Noel, Bruce W. (Espanola, NM)
Laboratory experiments show a linear relationship between the total heat flux from a water surface to air and the standard deviation of the surface temperature field, {sigma}, derived from thermal images of the water surface over a range of heat fluxes from 400 to 1800 Wm{sup -2}. Thermal imagery and surface data were collected at two power plant cooling lakes to determine if the laboratory relationship between heat flux and {sigma} exists in large heated bodies of water. The heat fluxes computed from the cooling lake data range from 200 to 1400 Wm{sup -2}. The linear relationship between {sigma} and Q is evident in the cooling lake data, but it is necessary to apply band pass filtering to the thermal imagery to remove camera artifacts and non-convective thermal gradients. The correlation between {sigma} and Q is improved if a correction to the measured {sigma} is made that accounts for wind speed effects on the thermal convection. Based on more than a thousand cooling lake images, the correlation coefficients between {sigma} and Q ranged from about 0.8 to 0.9.
Garrett, A; Eliel Villa-Aleman, E; Robert Kurzeja, R; Malcolm Pendergast, M; Timothy Brown, T; Saleem Salaymeh, S
Micro and nanostructured surfaces for enhanced phase change heat transfer
Two-phase microchannel heat sinks are of significant interest for thermal management applications, where the latent heat of vaporization offers an efficient method to dissipate large heat fluxes in a compact device. However, ...
Chu, Kuang-Han, Ph. D. Massachusetts Institute of Technology
Sea surface exchanges of momentum, heat, and freshwater determined by satellite remote sensing
1 Sea surface exchanges of momentum, heat, and freshwater determined by satellite remote sensing Freshwater flux Latent heat flux Longwave radiation Satellite remote sensing Sea surface flux estimation Sensible heat flux Shortwave radiation Surface wind fields 2 #12;Sea surface exchanges of momentum, heat
Yu, Lisan
Determining heat fluxes from temperature measurements made in massive walls
A technique is described for determining heat fluxes at the surfaces of masonry walls or floors using temperature data measured at two points within the wall, usually near the surfaces. The process consists of solving the heat diffusion equation in one dimension using finite difference techniques given two measured temperatures as input. The method is fast and accurate and also allows for an in-situ measurement of wall thermal diffusivity if a third temperature is measured. The method is documented in sufficient detail so that it can be readily used by the reader. Examples are given for heat flow through walls. Annual results for two cases are presented. The method has also been used to determine heat flow into floors.
Balcomb, J.D.; Hedstrom, J.C.
Method of fission heat flux determination from experimental data
A method is provided for determining the fission heat flux of a prime specimen inserted into a specimen of a test reactor. A pair of thermocouple test specimens are positioned at the same level in the holder and a determination is made of various experimental data including the temperature of the thermocouple test specimens, the temperature of bulk water channels located in the test holder, the gamma scan count ratios for the thermocouple test specimens and the prime specimen, and the thicknesses of the outer clads, the fuel fillers, and the backclad of the thermocouple test specimen. Using this experimental data, the absolute value of the fission heat flux for the thermocouple test specimens and prime specimen can be calculated.
Paxton, Frank A. (Schenectady, NY)
An experimental investigation of critical heat flux in subcooled internal flow
An experimental investigation has been conducted to determine the critical heat flux for subcooled refrigerant-11 and refrigerant-113 flowing upward in a vertical cylindrical tube. Critical heat flux (CHF) values are determined for a range of tube...
Shatto, Donald Patrick
E-Print Network 3.0 - axial heat flux Sample Search Results
is provided by Elsevier for the Summary: pipe, such as working temperature, heat flux, inclination angle, working fluid fill ratio (defined... , heat flux 5.0 kwm2 -40 kwm2 ,...
PUBLISHED VERSION Characterization of local heat fluxes around ICRF antennas on JET
) to characterize the heat fluxes on the protection of the JET ICRF antennas, using Infra-Red (IR) thermography
Spatial variability in soil heat flux at three Inner Mongolia steppe ecosystems
April 2008 Accepted 18 April 2008 Keywords: Energy balance Soil heat flux Available energy Eddy variability in soil heat flux contributing to energy balance closure (EBC), by deploying a mobile energySpatial variability in soil heat flux at three Inner Mongolia steppe ecosystems Changliang Shao a
Mean and Variability of Air-Sea Heat Fluxes in the Indian Ocean
-sea heat Fluxes) Project: blended product planned activity: daily, 1º-grid, mid 1950's  present currently available: daily, 1º-grid, 1988-2003 #12;OAFlux (Objectively Analyzed Air-sea Heat Fluxes) For the GlobalMean and Variability of Air-Sea Heat Fluxes in the Indian Ocean Lisan Yu Woods Hole Oceanographic
Sensitivity of Cenozoic Antarctic ice sheet variations to geothermal heat flux
Sensitivity of Cenozoic Antarctic ice sheet variations to geothermal heat flux David Pollard a sheet to geothermal heat flux is investigated, using a coupled climateÂice sheet model with various prescribed values and patterns of geothermal heat flux. The sudden growth of major ice across the Eocene
The Effect of Diurnal Sea Surface Temperature Warming on Climatological Air–Sea Fluxes
Diurnal sea surface warming affects the fluxes of latent heat, sensible heat, and upwelling longwave radiation. Diurnal warming most typically reaches maximum values of 3°C, although very localized events may reach 7°–8°C. ...
Clayson, Carol Anne
Calculation of Heating Values for the High Flux Isotope Reactor
Calculating the amount of energy released by a fission reaction (fission Q value) and the heating rate distribution in a nuclear reactor is an important part of the safety analysis. However, these calculations can become very complex. One of the codes that can be used for this type of analyses is the Monte Carlo transport code MCNP5. Currently it is impossible to calculate the Q value and heating rate disposition for delayed beta and delayed gamma particles directly from MCNP5. The purpose of this paper is to outline a rigorous method for indirectly calculating the Q values and heating rates in the High Flux Isotope Reactor (HFIR), based on previous similar studies carried out for very high-temperature reactor configurations. This method has been applied in this study to calculate heating rates for the beginning of cycle (BOC) and end-of-cycle (EOC) states of HFIR. In addition, the BOC results obtained for HFIR are compared with corresponding results for the Advanced Test Reactor. The fission Q value for HFIR was calculated as 200.2 MeV for the BOC and 201.3 MeV for the EOC. It was also determined that 95.1% and 95.4% of the heat was deposited within the HFIR fuel plates for the BOC and EOC models, respectively. This methodology can also be used for heating rate calculations for HFIR experiments.
Peterson, Joshua L [ORNL] [ORNL; Ilas, Germina [ORNL] [ORNL
Structural design criteria for high heat flux components.
The high temperature design rules of the ITER Structural Design Criteria (ISDC), are applied to first wall designs with high heat flux. The maximum coolant pressure and surface heat flux capabilities are shown to be determined not only by the mechanical properties of the first wall material but also by the details of the blanket design. In a high power density self-cooled lithium blanket, the maximum primary stress in the first wall is controlled by many of the geometrical parameters of the blanket, such as, first wall span, first wall curvature, first wall thickness, side wall thickness, and second wall thickness. The creep ratcheting lifetime of the first wall is also shown to be controlled by many of the same geometrical parameters as well as the coolant temperature. According to most high temperature design codes, the time-dependent primary membrane stress allowable are based on the average temperature (ignoring thermal stress). Such a procedure may sometimes be unconservative, particularly for embrittled first walls with large temperature gradients. The effect of secondary (thermal) stresses on the accumulation of creep deformation is illustrated with a vanadium alloy flat plate first wall design.
Majumdar, S.
Effect of combined nanoparticle and polymeric dispersions on critical heat flux, nucleate boiling heat transfer coefficient, and coating adhesion
An experimental study was performed to determine thermal performance and adhesion effects of a combined nanoparticle and polymeric dispersion coating. The critical heat flux (CHF) values and nucleate boiling heat transfer ...
Edwards, Bronwyn K
Spatially Distributed CO2, Sensible, and Latent Heat Fluxes Over the
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administrationcontroller systemsBiSiteNeutron Scattering Facilities »Southern Great Plains
Estimation of turbulent surface heat fluxes using sequences of remotely sensed land surface temperature
Fluxes of heat and moisture at the land-surface play a significant role in the climate system. These fluxes interact with the overlying atmosphere and influence the characteristics of the planetary boundary layer (e.g. ...
Bateni, Sayed Mohyeddin
Effects of Temperature Gradients and Heat Fluxes on High-Temperature Oxidation
The effects of a temperature gradient and heat flux on point defect diffusion in protective oxide scales were examined. Irreversible thermodynamics were used to expand Fick's first law of diffusion to include a heat-flux term—a Soret effect. Oxidation kinetics were developed for the oxidation of cobalt and of nickel doped with chromium. Research is described to verify the effects of a heat flux by oxidizing pure cobalt in a temperature gradient at 900 °C, and comparing the kinetics to isothermal oxidation. No evidence of a heat flux effect was found.
Holcomb, G.R.
Quantitative method for measuring heat flux emitted from a cryogenic object
The present invention is a quantitative method for measuring the total heat flux, and of deriving the total power dissipation, of a heat-fluxing object which includes the steps of placing an electrical noise-emitting heat-fluxing object in a liquid helium bath and measuring the superfluid transition temperature of the bath. The temperature of the liquid helium bath is thereafter reduced until some measurable parameter, such as the electrical noise, exhibited by the heat-fluxing object or a temperature-dependent resistive thin film in intimate contact with the heat-fluxing object, becomes greatly reduced. The temperature of the liquid helum bath is measured at this point. The difference between the superfluid transition temperature of the liquid helium bath surrounding the heat-fluxing object, and the temperature of the liquid helium bath when the electrical noise emitted by the heat-fluxing object becomes greatly reduced, is determined. The total heat flux from the heat-fluxing object is determined as a function of this difference between these temperatures. In certain applications, the technique can be used to optimize thermal design parameters of cryogenic electronics, for example, Josephson junction and infra-red sensing devices.
Duncan, Robert V. (Tijeras, NM)
The present invention is a quantitative method for measuring the total heat flux, and of deriving the total power dissipation, of a heat-fluxing object which includes the steps of placing an electrical noise-emitting heat-fluxing object in a liquid helium bath and measuring the superfluid transition temperature of the bath. The temperature of the liquid helium bath is thereafter reduced until some measurable parameter, such as the electrical noise, exhibited by the heat-fluxing object or a temperature-dependent resistive thin film in intimate contact with the heat-fluxing object, becomes greatly reduced. The temperature of the liquid helum bath is measured at this point. The difference between the superfluid transition temperature of the liquid helium bath surrounding the heat-fluxing object, and the temperature of the liquid helium bath when the electrical noise emitted by the heat-fluxing object becomes greatly reduced, is determined. The total heat flux from the heat-fluxing object is determined as a function of this difference between these temperatures. In certain applications, the technique can be used to optimize thermal design parameters of cryogenic electronics, for example, Josephson junction and infrared sensing devices.
Duncan, R.V.
autoinmune latente del: Topics by E-print Network
We describe algorithms for estimating binary latent known, understood, and used tool, multivariate nor- mal distributions, not always applicable Kirshner, Sergey 9 Latent heat...
Numerical Simulation of a Latent Heat Storage System of a Solar-Aided Ground Source Heat Pump
In this study, the rectangular phase change storage tank (PCST) linked to a solar-aided ground source heat pump (SAGSHP) system is investigated experimentally and theoretically. The container of the phase change material (PCM) is the controlling...
Wang, F.; Zheng, M.; Li, Z.; Lei, B.
Conceptual design selection and development of a latent-heat thermal-energy-storage subsystem for a saturated-steam solar receiver and load
The following latent heat storage concepts are described and evaluated in comparison with each other and with an oil/rock sensible heat storage system: (1) passive tube intensive (shell-and-tube heat exchanger) with and without heat transfer enhanced by fins; (2) phase change material cans (or chubbs) with a biphenyl intermediate heat transfer fluid; (3) phase change material macroencapsulation in a containment tank full of tubes; (4) microencapsulation in a porous carrier; (5) direct contact heat exchange; and (6) systems using mechanical scrapers for removing solidified phase change material from container surfaces. A tube intensive system with heat transfer enhancement was selected, and the conceptual design and cost/performance estimates are given for it. A commercial scale unit is assessed, and design changes and corresponding costs are presented that would be required to make the system meet changed requirements. (LEW)
Not Available
INNOVATIVE DESIGN AND MATERIAL SOLUTIONS OF THERMAL CONTACT LAYERS FOR HIGH HEAT FLUX APPLICATIONS of sacrificial plasma facing components that have to handle the high heat and particle fluxes in ITER armour thermal and electrical contact with the cooled sub-structure while promoting remote, in
Tillack, Mark
forced convection micro-channel heat sinks for minimum pump power at high heat fluxes. Results gained orders of magnitude, especially for high heat flux devices. Using water and air as coolants, designs for heat fluxes of >10 kW/cm2 and >100 W/cm2 respectively with pump/fan power expenses less than 1
MĂĽller, Norbert
Convective currents in nucleate pool boiling and their effects on the heat flux from varying diameter flat plate heating elements
investigation was conducred to amine the effects of convection currents in nucleate oool boil ing and to determine the changes in critical heat flux caused by varying the diameter of horizontal flat olate heating surfaces. Freon 113 (Trichlorotrifluoroethane... by high energy costs and thc need to economize in industrial heat transfer applications . I'nucleate boiling is a very efficient neans of heat transfer because of the large sur ace areas involved in vaporization of the bulk fluid. as bubbles form...
Morford, Peter Stephen
Countercurrent flow limited (CCFL) heat flux in the high flux isotope reactor (HFIR) fuel element
The countercurrent flow (CCF) performance in the fuel element region of the HFIR is examined experimentally and theoretically. The fuel element consists of two concentric annuli filled with aluminum clad fuel plates of 1.27 mm thickness separated by 1.27 mm flow channels. The plates are curved as they go radially outward to accomplish constant flow channel width and constant metal-to-coolant ratio. A full-scale HFIR fuel element mock-up is studied in an adiabatic air-water CCF experiment. A review of CCF models for narrow channels is presented along with the treatment of CCFs in system of parallel channels. The experimental results are related to the existing models and a mechanistic model for the annular'' CCF in a narrow channel is developed that captures the data trends well. The results of the experiment are used to calculate the CCFL heat flux of the HFIR fuel assembly. It was determined that the HFIR fuel assembly can reject 0.62 Mw of thermal power in the CCFL situation. 31 refs., 17 figs.
Ruggles, A.E.
Subcooled flow boiling heat transfer and critical heat flux in water-based nanofluids at low pressure
A nanofluid is a colloidal suspension of nano-scale particles in water, or other base fluids. Previous pool boiling studies have shown that nanofluids can improve the critical heat flux (CHF) by as much as 200%. In this ...
Kim, Sung Joong, Ph. D. Massachusetts Institute of Technology
Sandia National Laboratories: Beryllium High Heat Flux Testing at PMTF
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Designing, testing, and analyzing coupled, flux transformer heat
of identical effective length, this research shows that sufficient heat can be transferred across the system to work effectively in situations where the single heat pie will fail to operate. The thermal resistance in the condenser and evaporator sections need...
Renzi, Kimberly Irene
The effects of orientation angle, subcooling, heat flux, mass flux, and pressure on bubble growth and detachment in subcooled flow boiling
The effects of orientation angle, subcooling, heat flux, mass flux, and pressure on bubble growth and detachment in subcooled flow boiling were studied using a high-speed video camera in conjunction with a two-phase flow ...
Sugrue, Rosemary M
Surface energy budget over the South Pole and turbulent heat fluxes as a function of an empirical bulk Richardson number
Surface energy budget over the South Pole and turbulent heat fluxes as a function of an empirical in the monthly mean surface energy budget and to investigate the behavior of turbulent heat fluxes under stable and one as the residual of the surface energy budget (i.e., subsurface heat fluxes minus net radiation
Walden, Von P.
RF-sheath heat flux estimates on Tore Supra and JET ICRF antennae. Extrapolation to ITER
RF-sheath induced heat loads are identified from infrared thermography measurements on Tore Supra ITER-like prototype and JET A2 antennae, and are quantified by fitting thermal calculations. Using a simple scaling law assessed experimentally, the estimated heat fluxes are then extrapolated to the ITER ICRF launcher delivering 20 MW RF power for several plasma scenarios. Parallel heat fluxes up to 6.7 MW/m{sup 2} are expected very locally on ITER antenna front face. The role of edge density on operation is stressed as a trade-off between easy RF coupling and reasonable heat loads. Sources of uncertainty on the results are identified.
Colas, L.; Portafaix, C.; Goniche, M. [CEA, IRFM, F-13108 Saint-Paul-lez-Durance (France); Jacquet, Ph. [EURATOM/UKAEA Fusion Association, Culham, OX14 3DB (United Kingdom); Agarici, G. [Fusion for Energy, C/Josep Pla 2, E-08019 Barcelona (Spain)
Alumina Nanoparticle Pre-coated Tubing Ehancing Subcooled Flow Boiling Cricital Heat Flux
Nanofluids are engineered colloidal dispersions of nano-sized particle in common base fluids. Previous pool boiling studies have shown that nanofluids can improve critical heat flux (CHF) up to 200% for pool boiling and ...
Truong, Bao H.
Separate effects of surface roughness, wettability, and porosity on the boiling critical heat flux
The separate effects of surface wettability, porosity, and roughness on the critical heat flux (CHF) of water were examined using engineered surfaces. Values explored were 0, 5, 10, and 15??m for Rz (roughness), <5°, ?75°, ...
O'Hanley, Harry
The role of the geothermal heat flux in driving the abyssal ocean circulation
The results presented in this paper demonstrate that the geothermal heat flux (GHF) from the solid Earth into the ocean plays a non-negligible role in determining both abyssal stratification and circulation strength. Based ...
Mashayek, A.
Estimating air-sea fluxes of heat, freshwater, and momentum through global ocean data assimilation
Estimating air-sea fluxes of heat, freshwater, and momentum through global ocean data assimilation of surface flux adjustments made to the initial NCEP re-analysis-1 products. During the state estimation the boundary current regions, they are consistent with known large-scale deficiencies in the NCEP products
Spatially resolved temperature and heat flux measurements for slow evaporating droplets heated by a microfabricated heater array
flux datum per one droplet. No spatial or temporal heat flux information was given. Klassen et al. [12] and di Marzo et al. [13] were the first to use an infrared thermography technique to attempt to measure the spatially and temporally resolved... infrared thermography. Because of the aforementioned limitation of the IR thermography, measurements were only possible outside of the droplets. Michiyoshi and Makino [15] used a dual beam synchroscope to measure the variation of the heater supply...
Paik, Sokwon
High Heat Flux Interactions and Tritium Removal from Plasma Facing Components by a Scanning Laser'
its promise as an attractive, environmentally acceptable energy source[2]. Carbon based materials have-mechanical response o f graphite and carbon fiber composite (CFC) to very high heat flux includes sublimation, heating of carbon tiles. These tiles were previously used in the TFTR inner limiter and have a surface layer
Harilal, S. S.
Identification of boundary heat fluxes in a falling film experiment using
, regularization, conjugate gradient method, falling film, heat flux estimation, anisotropic finite elements, model problems must be solved. We apply a one step -method and piecewise linear finite elements on a tetrahedral of Process Systems Engineering, RWTH Aachen University c Chair of Heat Transfer and Air Conditioning, RWTH
Inferring surface heat flux distributions guided by a global seismic model: particular application to Antarctica
-flow measurements are rare or entirely absent. This will result in a smooth global heat-flow map that may proveInferring surface heat flux distributions guided by a global seismic model: particular application to Antarctica Nikolai M. Shapiro*, Michael H. Ritzwoller Department of Physics, Center for Imaging the Earth
Shapiro, Nikolai
High heat flux testing capabilities at Sandia National Laboratories - New Mexico
High heat flux testing for the United States fusion power program is the primary mission of the Plasma Materials Test Facility (PMTF) located at Sandia National Laboratories - New Mexico. This facility, which is owned by the United States Department of Energy, has been in operation for over 17 years and has provided much of the high heat flux data used in the design and evaluation of plasma facing components for many of the world`s magnetic fusion, tokamak experiments. In addition to domestic tokamaks such as Tokamak Fusion Test Reactor (TFTR) at Princeton and the DIII-D tokamak at General Atomics, components for international experiments like TEXTOR, Tore-Supra, and JET also have been tested at the PMTF. High heat flux testing spans a wide spectrum including thermal shock tests on passively cooled materials, thermal response and thermal fatigue tests on actively cooled components, critical heat flux-burnout tests, braze reliability tests and safety related tests. The objective of this article is to provide a brief overview of the high heat flux testing capabilities at the PMTF and describe a few of the experiments performed over the last year.
Youchison, D.L.; McDonald, J.M.; Wold, L.S.
Sensitivity of Radiative Fluxes and Heating Rates to Cloud Microphysics
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Two-Layer Baroclinic Eddy Heat Fluxes: Zonal Flows and Energy Balance ANDREW F. THOMPSON AND WILLIAM R. YOUNG
Two-Layer Baroclinic Eddy Heat Fluxes: Zonal Flows and Energy Balance ANDREW F. THOMPSON of these drag- less heat-flux parameterizations relies on the ability of to direct energy into zonal flows, California (Manuscript received 27 September 2006, in final form 13 December 2006) ABSTRACT The eddy heat
Young, William R.
A multi-site analysis of random error in tower-based measurements of carbon and energy fluxes
A multi-site analysis of random error in tower-based measurements of carbon and energy fluxes Hampshire, Morse Hall, 39 College Road, Durham, NH 03824, USA b NE Research Station, USDA Forest Service 2006 Abstract Measured surface-atmosphere fluxes of energy (sensible heat, H, and latent heat, LE
High Heat Flux Thermoelectric Module Using Standard Bulk Material |
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Remote Measurement of Heat Flux from Power Plant Cooling Lakes
Laboratory experiments have demonstrated a correlation between the rate of heat loss q? from an experimental fluid to the air above and the standard deviation ? of the thermal variability in images of the fluid surface. These experimental results imply that q? can be derived directly from thermal imagery by computing ?. This paper analyses thermal imagery collected over two power plant cooling lakes to determine if the same relationship exists. Turbulent boundary layer theory predicts a linear relationship between q? and ? when both forced (wind driven) and free (buoyancy driven) convection are present. Datasets derived from ground- and helicopter-based imagery collections had correlation coefficients between ? and q? of 0.45 and 0.76, respectively. Values of q? computed from a function of ? and friction velocity u* derived from turbulent boundary layer theory had higher correlations with measured values of q? (0.84 and 0.89). This research may be applicable to the problem of calculating losses of heat from the ocean to the atmosphere during high-latitude cold-air outbreaks because it does not require the information typically needed to compute sensible, evaporative, and thermal radiation energy losses to the atmosphere.
Garrett, A.; Kurzeja, R.; Villa-Aleman, E.; Bollinger, J.
Method and apparatus for determining vertical heat flux of geothermal field
A method and apparatus for determining vertical heat flux of a geothermal field, and mapping the entire field, is based upon an elongated heat-flux transducer (10) comprised of a length of tubing (12) of relatively low thermal conductivity with a thermopile (20) inside for measuring the thermal gradient between the ends of the transducer after it has been positioned in a borehole for a period sufficient for the tube to reach thermal equilibrium. The transducer is thermally coupled to the surrounding earth by a fluid annulus, preferably water or mud. A second transducer comprised of a length of tubing of relatively high thermal conductivity is used for a second thermal gradient measurement. The ratio of the first measurement to the second is then used to determine the earth's thermal conductivity, k.sub..infin., from a precalculated graph, and using the value of thermal conductivity thus determined, then determining the vertical earth temperature gradient, b, from predetermined steady state heat balance equations which relate the undisturbed vertical earth temperature distributions at some distance from the borehole and earth thermal conductivity to the temperature gradients in the transducers and their thermal conductivity. The product of the earth's thermal conductivity, k.sub..infin., and the earth's undisturbed vertical temperature gradient, b, then determines the earth's vertical heat flux. The process can be repeated many times for boreholes of a geothermal field to map vertical heat flux.
Poppendiek, Heinz F. (LaJolla, CA)
Separate effects of surface roughness, wettability and porosity on boiling heat transfer and critical heat flux and optimization of boiling surfaces
The separate effects of surface wettability, porosity, and roughness on critical heat flux (CHF) and heat transfer coefficient (HTC) were examined using carefully-engineered surfaces. All test surfaces were prepared on ...
O'Hanley, Harrison Fagan
Nanoscale modification of key surface parameters to augment pool boiling heat transfer and critical heat flux in water and dielectric fluids
Surface effects on pool boiling heat transfer and the critical heat flux are well documented but poorly understood. This study investigates the pool boiling characteristics of various fluids, and demonstrates that surface ...
Forrest, Eric Christopher
New charged shear-free relativistic models with heat flux
We study shear-free spherically symmetric relativistic gravitating fluids with heat flow and electric charge. The solution to the Einstein-Maxwell system is governed by the generalised pressure isotropy condition which contains a contribution from the electric field. This condition is a highly nonlinear partial differential equation. We analyse this master equation using Lie's group theoretic approach. The Lie symmetry generators that leave the equation invariant are found. The first generator is independent of the electromagnetic field. The second generator depends critically on the form of the charge, which is determined explicitly in general. We provide exact solutions to the gravitational potentials using the symmetries admitted by the equation. Our new exact solutions contain earlier results without charge. We show that other charged solutions, related to the Lie symmetries, may be generated using the algorithm of Deng. This leads to new classes of charged Deng models which are generalisations of conformally flat metrics.
Y. Nyonyi; S. D. Maharaj; K. S. Govinder
Review of current status of high flux heat transfer techniques. Volume I. Text + Appendix A
The scope of this work comprised two tasks. The first was to review high heat flux technology with consideration given to heat transfer panel configuration, diagnostics techniques and coolant supply. The second task was to prepare a report describing the findings of the review, to recommend the technology offering the least uncertainty for scale-up for the MFTF-B requirement and to recommend any new or perceived requirements for R and D effort.
Bauer, W.H.; Gordon, H.S.; Lackner, H.; Mettling, J.R.; Miller, J.E.
The deterioration in heat transfer to fluids at supercritical pressure and high heat fluxes
At slightly supercritical pressure and in the neighborhood of the pseudo-critical temperature (defined as the temperature corresponding to the peak in specific heat at the operating pressure), the heat transfer coefficient ...
Shiralkar, B. S.
Heat transfer to impacting drops and post critical heat flux dispersed flow
Heat transfer to drops impacting on a hot surface is examined in context of dispersions of flowing, boiling fluids. The liquid contribution to heat transfer from a hot tube to a two-phase dispersion is formulated in terms ...
Kendall, Gail E.
High Heat Flux Erosion of Carbon Fibre Composite Materials in the TEXTOR Tokamak*
,. 1. * . High Heat Flux Erosion of Carbon Fibre Composite Materials in the TEXTOR Tokamak Erosion of Carbon Fibre composite Materials in the TEXTOR Tokamak H. Bolt, T. Scholz, J. Boedo*, KH. The materials tested were carbon fibre reinforced materials w"th and without Si-addition. The probe w
The Total Meridional Heat Flux and Its Oceanic and Atmospheric Partition CARL WUNSCH
model residual is done to permit calculation of a preliminary uncertainty estimate for the atmospheric the oceanic flux drops rapidly, but does not actually vanish until the oceanic surface area goes to zero The partitioning and fluctuations in the net poleward transport of heat (energy, actually enthalpy; see War- ren
Wunsch, Carl
Local heat flux and energy loss in a 2D vibrated granular gas
We performed event-driven simulations of a two-dimensional granular gas between two vibrating walls and directly measured the local heat flux and energy dissipation rate in the stationary state. Describing the local heat flux as a function of the coordinate x in the direction perpendicular to the driving walls, we use a generalization of Fourier's law, q_x(x) = kappa d_x T(x) + mu d_x rho(x), to relate the local heat flux to the local gradients of the temperature and density. This ansatz accounts for the fact that density gradients also generate heat flux, not only temperature gradients. The transport coefficients kappa and mu are assumed to be independent of x, and we check the validity of this assumption in the simulations. Both kappa and mu are determined for different system parameters, in particular, for a wide range of coefficients of restitution. We also compare our numerical results to existing hydrodynamic theories. Agreement is found for kappa for very small inelasticities only. Beyond this region, kappa and mu exhibit a striking non-monotonic behavior.
Olaf Herbst; Peter Müller; Annette Zippelius
On the heat flux and entropy produced by thermal fluctuations S. Ciliberto1
by an elastic force. Our results set strong constrains on the energy exchanged between coupled nano-systems held kept at different temperatures and coupled by an elastic force [13, 19]. Thus it gives more insight into the properties of the heat flux produced by mechanical coupling, in the famous Feymann ratchet [2224] widely
Paris-Sud XI, Université de
Eddy Correlation Flux Measurement System (ECOR) Handbook
The eddy correlation (ECOR) flux measurement system provides in situ, half-hour measurements of the surface turbulent fluxes of momentum, sensible heat, latent heat, and carbon dioxide (CO2) (and methane at one Southern Great Plains extended facility (SGP EF) and the North Slope of Alaska Central Facility (NSA CF). The fluxes are obtained with the eddy covariance technique, which involves correlation of the vertical wind component with the horizontal wind component, the air temperature, the water vapor density, and the CO2 concentration.
Cook, DR
Effect of ocean surface currents on wind stress, heat flux, and wind power input to the ocean
Effect of ocean surface currents on wind stress, heat flux, and wind power input to the ocean, J. T., and L. Thompson (2006), Effect of ocean surface currents on wind stress, heat flux, and wind power input to the ocean, Geophys. Res. Lett., 33, L09604, doi:10.1029/2006GL025784. 1. Introduction [2
Thompson, LuAnne
Heat Flux Analysis of a Reacting Thermite Spray Impingent on a Substrate
Spray combustion from a thermite reaction is a new area of research relevant to localized energy generation applications, such as welding or cutting. In this study, we characterized the heat flux of combustion spray impinging on a target from a nozzle for three thermite mixtures. The reactions studied include aluminum (Al) with iron oxide (Fe2O3), Al with copper oxide (CuO), and Al with molybdenum oxide (MoO3). Several standoff distances (i.e., distance from the nozzle exit to the target) were analyzed. A fast response heat flux sensor was engineered for this purpose and is discussed in detail. Results correlated substrate damage to a threshold heat flux of 4550 W/cm2 for a fixed-nozzle configuration. Also, higher gas-generating thermites were shown to produce a widely dispersed spray and be less effective at imparting kinetic energy damage to a target. These results provide an understanding of the role of thermal and physical properties (i.e., such as heat of combustion, gas generation, and particle size) on thermite spray combustion performance measured by damaging a target substrate.
Eric S. Collins; Michelle L. Pantoya; Michael A. Daniels; Daniel J. Prentice; Eric D. Steffler; Steven P. D'Arche
Ultrahigh heat flux plasma-facing components for magnetic fusion energy
Sandia and Ultramet partnered to design and test refractory metal plasma-facing components and heat exchangers for advanced, high-temperature power conversion systems. These devices consisted of high-temperature helium-to-helium and lithium-to-helium heat exchangers that operate with high efficiency due to the porous foam inserts used in the gas stream, which promote turbulence and provide extended surface area for enhanced convection. Single- and multi-channel helium panels and the Li-He heat exchanger were fabricated from either pure molybdenum, TZM, or tungsten. The design was carried out through an Ultramet subcontractor. The flow path was carefully tailored to minimize the pressure drop while maximizing the heat transfer. The single- and multi-channel helium panels were tested at Sandia's PMTF using an electron beam system and the closed helium flow loop. In 2006, a single-channel tungsten tube was successfully tested to an average heat flux of 14 MW/m{sup 2} with a localized peak of 22 MW/m{sup 2} along the axial centerline at the outer radius. Under this CRADA, multiple square-channel molybdenum components were successfully tested to heat flux levels approaching 8.5 MW/m{sup 2}. The three multi-channel prototypes experienced mechanical failure due to issues related to the design of the large unsupported span of the heated faceplates in combination with prototype material and braze selection. The Li-He heat exchanger was both designed and partially tested at the PMTF for helium and lithium flow.
Youchison, D. L.
Simplified model for determining local heat flux boundary conditions for slagging wall
In this work, two models for calculating heat transfer through a cooled vertical wall covered with a running slag layer are investigated. The first one relies on a discretization of the velocity equation, and the second one relies on an analytical solution. The aim is to find a model that can be used for calculating local heat flux boundary conditions in computational fluid dynamics (CFD) analysis of such processes. Two different cases where molten deposits exist are investigated: the black liquor recovery boiler and the coal gasifier. The results show that a model relying on discretization of the velocity equation is more flexible in handling different temperature-viscosity relations. Nevertheless, a model relying on an analytical solution is the one fast enough for a potential use as a CFD submodel. Furthermore, the influence of simplifications to the heat balance in the model is investigated. It is found that simplification of the heat balance can be applied when the radiation heat flux is dominant in the balance. 9 refs., 7 figs., 10 tabs.
Bingzhi Li; Anders Brink; Mikko Hupa [Aabo Akademi University, Turku (Finland). Process Chemistry Centre
Striation pattern of target particle and heat fluxes in three dimensional simulations for DIII-D
The application of resonant magnetic perturbations results in a non-axisymmetric striation pattern of magnetic field lines from the plasma interior which intersect the divertor targets. The impact on related particle and heat fluxes is investigated by three dimensional computer simulations for two different recycling conditions (controlled via neutral gas pumping). It is demonstrated that a mismatch between the particle and heat flux striation pattern (splitting vs. no splitting), as is repeatedly observed in ITER similar shape H-mode plasmas at DIII-D, can be reproduced by the simulations for high recycling conditions at the onset of partial detachment. These results indicate that a detailed knowledge of the particle and energy balance is at least as important for realistic simulations as the consideration of a change in the magnetic field structure by plasma response effects.
Frerichs, H.; Schmitz, O.; Reiter, D. [Institute of Energy and Climate Research—Plasma Physics, Forschungszentrum Jülich GmbH, Association EURATOM-FZJ, Partner in the Trilateral Euregio Cluster, Jülich (Germany)] [Institute of Energy and Climate Research—Plasma Physics, Forschungszentrum Jülich GmbH, Association EURATOM-FZJ, Partner in the Trilateral Euregio Cluster, Jülich (Germany); Evans, T. E. [General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States)] [General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States); Feng, Y. [Max-Planck Institute for Plasma Physics, Greifswald (Germany)] [Max-Planck Institute for Plasma Physics, Greifswald (Germany)
Parallel heat flux and flow acceleration in open field line plasmas with magnetic trapping
The magnetic field strength modulation in a tokamak scrape-off layer (SOL) provides both flux expansion next to the divertor plates and magnetic trapping in a large portion of the SOL. Previously, we have focused on a flux expander with long mean-free-path, motivated by the high temperature and low density edge anticipated for an absorbing boundary enabled by liquid lithium surfaces. Here, the effects of magnetic trapping and a marginal collisionality on parallel heat flux and parallel flow acceleration are examined. The various transport mechanisms are captured by kinetic simulations in a simple but representative mirror-expander geometry. The observed parallel flow acceleration is interpreted and elucidated with a modified Chew-Goldberger-Low model that retains temperature anisotropy and finite collisionality.
Guo, Zehua; Tang, Xian-Zhu; McDevitt, Chris [Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
Evaluation of heat flux through blast furnace shell with attached sensors
Plant trials to evaluate heat fluxes through a lining/cooling system of a blast furnace were conducted in order to realize the cooling efficiency of the blast furnace under operation. For this purpose, several experiments to measure the in-furnace gas temperatures were cautiously made, and numerical simulations for the temperature distributions over the blast furnace shell and cooling/lining systems were also carried out.
Han, J.W. [Kyonggi Univ., Suwon, Kyonggi (Korea, Republic of). Dept. of Materials Engineering; Lee, J.H.; Suh, Y.K. [POSCO, Kwangyang, Cheonnam (Korea, Republic of). Technical Research Labs.
Elementary Heating Events - Magnetic Interactions Between Two Flux Sources. III Energy Considerations
The magnetic field plays a crucial role in heating the solar corona, but the exact energy release mechanism(s) is(are) still unknown. Here, we investigate in detail, the process of magnetic energy release in a situation where two initially independent flux systems are forced into each other. Work done by the foot point motions goes in to building a current sheet in which magnetic reconnection takes place. The scaling relations of the energy input and output are determined as functions of the driving velocity and the strength of fluxes in the independent flux systems. In particular, it is found that the energy injected into the system is proportional to the distance travelled not the rate of travel. Similarly, the rate of Joule dissipation is related to the distance travelled. Hence, rapidly driven foot points lead to bright, intense, but short-lived events, whilst slowly driven foot points produce weaker, but longer-lived brightenings. Integrated over the lifetime of the events both would produce the same heating if all other factors were the same. A strong overlying field has the affect of creating compact flux lobes from the sources. These appear to lead to a more rapid injection of energy, as well as a more rapid release of energy. Thus, the stronger the overlying field the more compact and more intense the heating. This means observers must know the rate of movement of the magnetic fragments involved in an events, as well as determine the strength and orientation of the surrounding field to be able to predict anything about the energy dissipated.
K. Galsgaard; C. E. Parnell
Development of probes for assessment of ion heat transport and sheath heat flux in the boundary of the Alcator C-Mod Tokamak
Progress towards a viable fusion reactor will require comprehensive understanding of boundary plasma physics. Knowledge in this area has been growing, yet there are critical gaps. Measurements of the sheath heat flux ...
Brunner, Daniel Frederic
Investigation of downward facing critical heat flux with water-based nanofluids for In-Vessel Retention applications
In-Vessel Retention ("IVR") is a severe accident management strategy that is power limiting to the Westinghouse AP1000 due to critical heat flux ("CHF") at the outer surface of the reactor vessel. Increasing the CHF level ...
DeWitt, Gregory L
Subsurface Temperature, Moisture, Thermal Conductivity and Heat Flux, Barrow, Area A, B, C, D
Subsurface temperature data are being collected along a transect from the center of the polygon through the trough (and to the center of the adjacent polygon for Area D). Each transect has five 1.5m vertical array thermistor probes with 16 thermistors each. This dataset also includes soil pits that have been instrumented for temperature, water content, thermal conductivity, and heat flux at the permafrost table. Area C has a shallow borehole of 2.5 meters depth is instrumented in the center of the polygon.
Cable, William; Romanovsky, Vladimir
Relativistic heat flux for a single component charged fluid in the presence of an electromagnetic field
Transport properties in gases are significantly affected by temperature. In previous works it has been shown that when the thermal agitation in a gas is high enough, such that relativistic effects become relevant, heat dissipation is driven not solely by a temperature gradient but also by other vector forces. In the case of relativistic charged fluids, a heat flux is driven by an electrostatic field even in the single species case. The present work generalizes such result by considering also a magnetic field in an arbitrary inertial reference frame. The corresponding constitutive equation is explicitly obtained showing that both electric and magnetic forces contribute to thermal dissipation. This result may lead to relevant effects in plasma dynamics.
Garcia-Perciante, A L; Brun-Battistini, D
High-heat-flux removal by phase-change fluid and particulate flow
A new concept based on particulate flow in which either or both the particulates and the fluid could undergo phase changes is proposed. The presence of particulates provides not only a mechanism for additional heat removal through phase change but also the potential for increasing the rate of heat transfer by enhancing convection through surface region/bulk [open quotes]mixing[close quotes], by enhancing radiation, particularly for high-temperature cases; and for the case of multiphase fluid, by enhancing the boiling process. One particularly interesting coolant system based on this concept is [open quotes]subcooled boiling water-ice particulate[close quotes] flow. A preliminary analysis of this coolant system is presented, the results of which indicate that such a coolant system is better applied for cooling of relatively small surface areas with high local heat fluxes, where a conventional cooling system would come short of providing the required heat removal at acceptable coolant pressure levels. 14 refs., 8 figs.
Gorbis, Z.R.; Raffray, A.R.; Abdou, M.A. (Univ. of California, Los Angeles (United States))
Reduced model simulations of the scrape-off-layer heat-flux width and comparison with experiment
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Reduced model simulations of turbulence in the edge and scrape-off-layer (SOL) region of a spherical torus or tokamak plasma are employed to address the physics of the scrape-off-layer heat flux width. The simulation model is an electrostatic two-dimensional fluid turbulence model, applied in the plane perpendicular to the magnetic field at the outboard midplane of the torus. The model contains curvature-driven-interchange modes, sheath losses, and both perpendicular turbulent diffusive and convective (blob) transport. These transport processes compete with classical parallel transport to set the SOL width. Midplane SOL profiles of density, temperature and parallel heat flux are obtained from the simulation and compared with experimental results from the National Spherical Torus Experiment (NSTX) [S. M. Kaye, et al., Phys. Plasmas 8, 1977 (2001)] to study the scaling of the heat flux width with power and plasma current. It is concluded that midplane turbulence is the main contributor to the SOL heat flux width for the low power H-mode discharges studied, while additional physics is required to explain the plasma current scaling of the SOL heat flux width observed experimentally in higher power discharges. Intermittent separatrix spanning convective cells are found to be the main mechanism that sets the near-SOL width in the simulations. The roles of sheared flows and blob trapping vs. emission are discussed.
Myra, J. R. [Lodestar Research Corporation, Boulder, CO (United States); Russell, D. A. [Lodestar Research Corporation, Boulder, CO (United States); D'Ippolito, D. A. [Lodestar Research Corporation, Boulder, CO (United States); Ahn, J- W [Oak Ridge National Lab., TN (United States); Maingi, R. [Oak Ridge National Lab., TN (United States); Maqueda, R. J. [Princeton Plasma Physics Lab., NJ (United States); Lundberg, D. P. [Princeton Plasma Physics Lab., NJ (United States); Stotler, D. P. [Princeton Plasma Physics Lab., NJ (United States); Zweben, S. J. [Princeton Plasma Physics Lab., NJ (United States); Boedo, J. [Univ. of California at San Diego, CA (United States); Umansky, M. [Lawrence Livermore National Lab., Livermore, CA (United States)
The Surface Energy Balance System (SEBS) for estimation of turbulent heat fluxes Hydrology and Earth System Sciences, 6(1), 8599 (2002) EGS
, turbulent heat flux, evaporation, remote sensing Introduction The estimation of atmospheric turbulent fluxes because of the heterogeneity of land surfaces and the dynamic nature of heat transfer processes. Remote be represented by point measurements only. Methods using remote sensing information to estimate heat exchange
International Lige Colloquium on Ocean Dynamics, GAS TRANSFER AT WATER SURFACES, May 2 -6 2005 Estimation of air-sea gas and heat fluxes from infrared imagery and
2005 Estimation of air-sea gas and heat fluxes from infrared imagery and surface wave measurements and much higher heat fluxes. In addition, the infrared imagery analysis reveals potentially significant the infrared images. It is also shown that the difference in the surface boundary conditions for heat and gas
Jaehne, Bernd
Investigating the use of nanofluids to improve high heat flux cooling systems
The thermal performance of high heat flux components in a fusion reactor could be enhanced significantly by the use of nanofluid coolants, suspensions of a liquid with low concentrations of solid nanoparticles. However, before they are considered viable for fusion, the long-term behaviour of nanofluids must be investigated. This paper reports an experiment which is being prepared to provide data on nanofluid stability, settling and erosion in a HyperVapotron device. Procedures are demonstrated for nanofluid synthesis and quality assessment, and the fluid sample analysis methods are described. The end results from this long-running experiment are expected to allow an initial assessment of the suitability of nanofluids as coolants in a fusion reactor.
Barrett, T R; Flinders, K; Sergis, A; Hardalupas, Y
Oxidation and Volatilization from Tungsten Brush High Heat Flux Armor During High Temperature Steam Exposure
Tungsten brush accommodates thermal stresses and high heat flux in fusion reactor components such as plasma facing surfaces or armor. However, inherently higher surface areas are introduced with the brush design. We have tested a specific design of tungsten brush in steam between 500 and 1100°C. Hydrogen generation and tungsten volatilization rates were determined to address fusion safety issues. The brush prepared from 3.2-mm diameter welding rods had a packing density of 85 percent. We found that both hydrogen generation and tungsten volatilization from brush, fixtured to represent a unit within a larger component, were less than projections based upon the total integrated surface area (TSA). Steam access and the escape of hydrogen and volatile oxide from void spaces within the brush are restricted compared to specimens with more direct diffusion pathways to the test environment. Hydrogen generation rates from restrained specimens based on normal surface area (NSA) remain about five times higher than rates based on total surface areas from specimens with direct steam access. Volatilization rates from restrained specimens based upon normal surface area (NSA) were only 50 percent higher than our historic cumulative maximum flux plot (CMFP) for tungsten. This study has shown that hydrogen generation and tungsten volatilization from brush do not scale according to predictions with previously determined rates, but in fact, with higher packing density could approach those from flat surfaces.
Smolik, Galen Richard; Pawelko, Robert James; Anderl, Robert Andrew; Petti, David Andrew
US-Japan workshop Q-181 on high heat flux components and plasma-surface interactions for next devices: Proceedings
This report contain viewgraphs of papers from the following sessions: plasma facing components issues for future machines; recent PMI results from several tokamaks; high heat flux technology; plasma facing components design and applications; plasma facing component materials and irradiation damage; boundary layer plasma; plasma disruptions; conditioning and tritium; and erosion/redeposition.
McGrath, R.T. [ed.] [Sandia National Labs., Albuquerque, NM (United States)] [ed.; Sandia National Labs., Albuquerque, NM (United States); Yamashina, T. [ed.] [Hokkadio Univ. (Japan)] [ed.; Hokkadio Univ. (Japan)
Pressure tensor and heat flux vector for inhomogeneous nonequilibrium fluids under the influence of three-body forces
coupled with the Axilrod-Teller three-body force. Our method of planes calculations agree perfectlyPressure tensor and heat flux vector for inhomogeneous nonequilibrium fluids under the influence of three-body forces Junfang Zhang and B. D. Todd* Centre for Molecular Simulation, Swinburne University
Low heat flux and large variations of lithospheric thickness in the Canadian Shield
and require variations of heat supply to the lithosphere and/or radiogenic heat production in the lithospheric
Long, Bernard
Proceedings of US/Japan workshop, Q219 on high heat flux components and plasma surface interactions for next fusion devices
This report contains the viewgraphs from the proceedings of US/Japan Workshop on High Heat Flux Components and Plasma Surface Interactions for Next Fusion Devices. Some of the general topics covered by this report are: PFC/PSI in tokamak and helical devices; development of high heat flux components; PSIS and plasma facing materials;tritium; and material damage.
Ulrickson, M.A.; Stevens, P.L.; Hino, T.; Hirohata, Y. [eds.] [eds.
Estimation of the thin ice thickness and heat flux for the Chukchi Sea Alaskan coast polynya from Special Sensor Microwave/Imager data,
Estimation of the thin ice thickness and heat flux for the Chukchi Sea Alaskan coast polynya from shows that the SSM/I thicknesses and heat fluxes are valid for ice thicknesses less than 10Â20 cm, comparison with other numerical and satellite estimates of the ice production shows that although our ice
Washington at Seattle, University of
Study on premixed combustion in cylindrical micro combustors: Transient flame behavior and wall heat flux
The micro combustor is a key component of the micro thermophotovoltaic (TPV) system. Improving the wall temperature of the micro combustor is an effective way to elevate the system efficiency. An experimental study on the wall temperature and radiation heat flux of a series of cylindrical micro combustors (with a backward-facing step) was carried out. For the micro combustors with d = 2 mm, the regime of successful ignition (under the cold wall condition) was identified for different combustor lengths. Acoustic emission was detected for some cases and the emitted sound was recorded and analyzed. Under the steady-state condition, the effects of the combustor diameter (d), combustor length (L), flow velocity (u{sub 0}) and fuel-air equivalence ratio ({phi}) on the wall temperature distribution were investigated by measuring the detailed wall temperature profiles. In the case that the micro combustor is working as an emitter, the optimum efficiency was found at {phi} {approx} 0.8, independent of the combustor dimensions (d and L) and the flow velocity. Under the experimental conditions employed in the present study, the positions of the peak wall temperature were found to be about 8-11 mm and 4-6 mm from the step for the d = 3 mm and d = 2 mm micro combustors, respectively, which are 8-11 and 8-12 times of their respective step heights. This result suggests that the backward-facing step employed in the combustor design is effective in stabilizing the flame position. (author)
Li, J.; Chou, S.K.; Huang, G.; Yang, W.M. [Department of Mechanical Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117576 (Singapore); Li, Z.W. [SSLS, National University of Singapore, 5 Research Link, Singapore 117603 (Singapore)
Testing above-and below-canopy representations of turbulent fluxes in an energy balance snowmelt model
Testing above- and below-canopy representations of turbulent fluxes in an energy balance snowmelt and latent heat are important processes in the surface energy balance that drives snowmelt. Modeling in an energy balance snowmelt model, Water Resour. Res., 49, doi:10.1002/wrcr.20073. 1. Introduction [2
Tarboton, David
The role of parallel heat transport in the relation between upstream scrape-off layer widths and target heat flux width in H-mode plasmas of NSTX.
The physics of parallel heat transport was tested in the Scrape-off Layer (SOL) plasma of the National Spherical Torus Experiment (NSTX) [M. Ono, et al., Nucl. Fusion 40, 557 (2000) and S. M. Kaye, et al., Nucl. Fusion 45, S168 (2005)] tokamak by comparing the upstream electron temperature (T{sub e}) and density (n{sub e}) profiles measured by the mid-plane reciprocating probe to the heat flux (q{sub {perpendicular}}) profile at the divertor plate measured by an infrared (IR) camera. It is found that electron conduction explains the near SOL width data reasonably well while the far SOL, which is in the sheath limited regime, requires an ion heat flux profile broader than the electron one to be consistent with the experimental data. The measured plasma parameters indicate that the SOL energy transport should be in the conduction-limited regime for R-R{sub sep} (radial distance from the separatrix location) < 2-3 cm. The SOL energy transport should transition to the sheath-limited regime for R-R{sub sep} > 2-3cm. The T{sub e}, n{sub e}, and q{sub {perpendicular}} profiles are better described by an offset exponential function instead of a simple exponential. The conventional relation between mid plane electron temperature decay length ({lambda}{sub Te}) and target heat flux decay length ({lambda}{sub q}) is {lambda}{sub Te} = 7/2{lambda}{sub q}, whereas the newly-derived relation, assuming offset exponential functional forms, implies {lambda}{sub Te} = (2-2.5){lambda}{sub q}. The measured values of {lambda}{sub Te}/{lambda}{sub q} differ from the new prediction by 25-30%. The measured {lambda}{sub q} values in the far SOL (R-R{sub sep} > 2-3cm) are 9-10cm, while the expected values are 2.7 < {lambda}{sub q} < 4.9 cm (for sheath-limited regime). We propose that the ion heat flux profile is substantially broader than the electron heat flux profile as an explanation for this discrepancy in the far SOL.
Ahn, J W; Boedo, J A; Maingi, R; Soukhanovskii, V A
Critical heat flux predictions based on the BODYFIT-2PE computer code and Columbia University CHF correlation. [PWR; BWR
The BODYFIT-2PE (Boundary-Fitted Coordinate, 2-Phase Flow with Partially Elliptic) computer code has been developed and was employed to simulate the critical heat flux experiment in a General Electric 3 x 3 rod bundle by using a CHF correlation recently developed at Columbia University under EPRI sponsorship. CHF predictions are important in analyzing rod bundle performance in nuclear reactor operation. The results of the BODYFIT calculations compared favorably with the experimental measurements.
Chen, B.C.J.; Chien, T.H.; Sha, W.T.; Kim, J.H.
Heat transfer and pressure drop data for high heat flux densities to water at high subcritical pressures
Local surface ooeffioients of heat t-ansfer, overall pressure drop data and mean friction factor are presented for heat flamms up to 3.52106 BtuAr ft2 for water flowing in a nickel tabe isder the following conditions: mass ...
Rohsenow, Warren M.
Division of Development and Technology Plasma/Materials Interaction and High Heat Flux Materials and Components Task Groups: Report on the joint meeting, July 9, 1986
This paper contains a collection of viewgraphs from a joint meeting of the Division of Development and Technology Plasma/Materials Interaction and High Heat Flux Materials and Components Task Groups. A list of contributing topics is: PPPL update, ATF update, Los Alamos RFP program update, status of DIII-D, PMI graphite studies at ORNL, PMI studies for low atomic number materials, high heat flux materials issues, high heat flux testing program, particle confinement in tokamaks, helium self pumping, self-regenerating coatings technical planning activity and international collaboration update. (LSP)
Watson, R.D. (ed.)
Report on the joint meeting of the Division of Development and Technology Plasma/Wall Interaction and High Heat Flux Materials and Components Task Groups
This report of the Joint Meeting of the Division of Development and Technology Plasma/Wall Interaction and High Heat Flux Materials and Components Task Groups contains contributing papers in the following areas: Plasma/Materials Interaction Program and Technical Assessment, High Heat Flux Materials and Components Program and Technical Assessment, Pumped Limiters, Ignition Devices, Program Planning Activities, Compact High Power Density Reactor Requirements, Steady State Tokamaks, and Tritium Plasma Experiments. All these areas involve the consideration of High Heat Flux on Materials and the Interaction of the Plasma with the First Wall. Many of the Test Facilities are described as well. (LSP)
Wilson, K.L. (ed.)
Natural convection in high heat flux tanks at the Hanford Waste Site / [by] Mark van der Helm and Mujid S. Kazimi
A study was carried out on the potential for natural convection and the effect of natural convection in a High Heat Flux Tank, Tank 241-C-106, at the Hanford Reservation. To determine the existence of natural convection, ...
Van der Helm, Mark Johan, 1972-
The Critical Heat Flux (CHF) of water with dispersed alumina nanoparticles was measured for the geometry and flow conditions relevant to the In-Vessel Retention (IVR) situation which can occur during core melting sequences ...
Park, R.J.
Control of temperature and heat flux in a combustor using coal-derived gas of varying heat content. [Patent application
The present invention is directed to a fuel-air control system for a combustor in which coal-derived gas of varying heat content is used. To maintain the temperature in the combustor at an essentially constant value the fuel-to-air ratio is adjusted by using a temperature actuated variable pressure regulator in the gas feed line to compensate for the variability of the heat content of the gas. The velocity of the products of combustion is maintained at an essentially constant flow rate by controlling the mass flow of the air and fuel through linked valves on the gas and air feed lines.
Loth, J.L.; Nakaishi, C.V.; Carpenter, L.K.; Bird, J.D.
Constant-flux discrete heating in a unit aspect-ratio annulus This article has been downloaded from IOPscience. Please scroll down to see the full text article.
Constant-flux discrete heating in a unit aspect-ratio annulus This article has been downloaded from to the journal homepage for more Home Search Collections Journals About Contact us My IOPscience #12;IOP.1088/0169-5983/44/6/065507 Constant-flux discrete heating in a unit aspect-ratio annulus J M Lopez1,2 , M Sankar3 and Younghae Do2 1
Lopez, John M.
A comparison of the heat transfer capabilities of two manufacturing methods for high heat flux water-cooled devices
An experimental program was undertaken to compare the heat transfer characteristics of water-cooled copper devices manufactured via conventional drilled passage construction and via a technique whereby molten copper is cast over a network of preformed cooling tubes. Two similar test blocks were constructed; one using the drilled passage technique, the other via casting copper over Monel pipe. Each test block was mounted in a vacuum system and heated uniformly on the top surface using a swept electron beam. From the measured absorbed powers and resultant temperatures, an overall heat transfer coefficient was calculated. The maximum heat transfer coefficient calculated for the case of the drilled passage test block was 2534 Btu/hr/ft/sup 2///sup 0/F. This corresponded to an absorbed power density of 320 w/cm/sup 2/ and resulted in a maximum recorded copper temperature of 346/sup 0/C. Corresponding figures for the cast test block were 363 Btu/hr/ft/sup 2///sup 0/F, 91 w/cm/sup 2/, and 453/sup 0/C.
McKoon, R.H.
Deep-Sea Research I 52 (2005) 519542 Davis Strait volume, freshwater and heat fluxes
cycle is a complex combination of land runoff, precipitation, ice freezingmelting and input of salty that the freshwater flux coming out of Baffin Bay asso- ciated with the sea ice melting in that area repre- sents 70 to the melting of ice drifting with the shelf Labrador Current (Khatiwala et al., 2002). Hud- son Bay runoff
GEOPHYSICAL RESEARCH LETTERS, VOL. 40, 16, doi:10.1002/grl.50640, 2013 The role of the geothermal heat flux in driving the abyssal
. Peltier1 Received 24 April 2013; revised 4 June 2013; accepted 5 June 2013. [1] The results presented-induced circulation and the Antarctic bottom water cell. The enhanced circulation ven- tilates the GHF derived heating. R. Peltier (2013), The role of the geothermal heat flux in driving the abyssal ocean circulation
Ferrari, Raffaele
Simulated and observed fluxes of sensible and latent heat and CO2 at the WLEF-TV tower using SiB2.5
, water, momentum, and trace gases to the atmosphere. A parameterized representa- tion of these exchanges prediction (NWP) models to forecast weather under extreme climatic conditions such as droughts (Atlas et al
by an elastic force. Our results set strong constrains on the energy exchanged between coupled nano-systems kept on systems in contact with a single heat bath and driven out-of-equilibrium by external forces or fields [3 Brownian particles kept at different temperatures and coupled by an elastic force [11, 12]. Thus it gives
Multi-scale Control and Enhancement of Reactor Boiling Heat Flux by Reagents and Nanoparticles
The phenomenological characterization of the use of non-invasive and passive techniques to enhance the boiling heat transfer in water has been carried out in this extended study. It provides fundamental enhanced heat transfer data for nucleate boiling and discusses the associated physics with the aim of addressing future and next-generation reactor thermal-hydraulic management. It essentially addresses the hypothesis that in phase-change processes during boiling, the primary mechanisms can be related to the liquid-vapor interfacial tension and surface wetting at the solidliquid interface. These interfacial characteristics can be significantly altered and decoupled by introducing small quantities of additives in water, such as surface-active polymers, surfactants, and nanoparticles. The changes are fundamentally caused at a molecular-scale by the relative bulk molecular dynamics and adsorption-desorption of the additive at the liquid-vapor interface, and its physisorption and electrokinetics at the liquid-solid interface. At the micro-scale, the transient transport mechanisms at the solid-liquid-vapor interface during nucleation and bubblegrowth can be attributed to thin-film spreading, surface-micro-cavity activation, and micro-layer evaporation. Furthermore at the macro-scale, the heat transport is in turn governed by the bubble growth and distribution, macro-layer heat transfer, bubble dynamics (bubble coalescence, collapse, break-up, and translation), and liquid rheology. Some of these behaviors and processes are measured and characterized in this study, the outcomes of which advance the concomitant fundamental physics, as well as provide insights for developing control strategies for the molecular-scale manipulation of interfacial tension and surface wetting in boiling by means of polymeric reagents, surfactants, and other soluble surface-active additives.
R.M. Manglik; A. Athavale; D.S. Kalaikadal; A. Deodhar; U. Verma
Floating Refrigerant Loop Based on R-134a Refrigerant Cooling of High-Heat Flux Electronics
The Oak Ridge National Laboratory (ORNL) Power Electronics and Electric Machinery Research Center (PEEMRC) have been developing technologies to address the thermal issues associated with hybrid vehicles. Removal of the heat generated from electrical losses in traction motors and their associated power electronics is essential for the reliable operation of motors and power electronics. As part of a larger thermal control project, which includes shrinking inverter size and direct cooling of electronics, ORNL has developed U.S. Patent No. 6,772,603 B2, ''Methods and Apparatus for Thermal Management of Vehicle Systems and Components'' [1], and patent pending, ''Floating Loop System for Cooling Integrated Motors and Inverters Using Hot Liquid Refrigerant'' [2]. The floating-loop system provides a large coefficient of performance (COP) for hybrid-drive component cooling. This loop (based on R-134a) is integrated with a vehicle's existing air-conditioning (AC) condenser, which dissipates waste heat to the ambient air. Because the temperature requirements for cooling of power electronics and electric machines are not as low as that required for passenger compartment air, this adjoining loop can operate on the high-pressure side of the existing AC system. This arrangement also allows the floating loop to run without the need for the compressor and only needs a small pump to move the liquid refrigerant. For the design to be viable, the loop must not adversely affect the existing system. The loop should also provide a high COP, a flat-temperature profile, and low-pressure drop. To date, the floating-loop test prototype has successfully removed 2 kW of heat load in a 9 kW automobile passenger AC system with and without the automotive AC system running. The COP for the tested floating-loop system ranges from 40-45, as compared to a typical AC system COP of about 2-4. The estimated required waste-heat load for future hybrid applications is 5.5 kW and the existing system could be easily scaleable for this larger load.
Lowe, K.T.
Latent effects decision analysis
Latent effects on a system are broken down into components ranging from those far removed in time from the system under study (latent) to those which closely effect changes in the system. Each component is provided with weighted inputs either by a user or from outputs of other components. A non-linear mathematical process known as `soft aggregation` is performed on the inputs to each component to provide information relating to the component. This information is combined in decreasing order of latency to the system to provide a quantifiable measure of an attribute of a system (e.g., safety) or to test hypotheses (e.g., for forensic deduction or decisions about various system design options).
Cooper, J. Arlin (Albuquerque, NM); Werner, Paul W. (Albuquerque, NM)
High heat flux testing of a two-tube copper panel specimen for LLNL at ASURF
This letter documents the results of the test program conducted for Lawrence Livermore National Laboratory (LLNL) by Westinghouse Advanced Energy Systems Division (AESD) in fulfillment of the Third Amendment to Subcontract 9125401. The original test matrix of 20,000 heating cycles on two test articles called for in the contract was not technically feasible due to the inability of the test articles supplied by LLNL to perform successfully at the required test conditions. Burnout occurred in one of the tubes of a two-tube target during the first series of tests. As a result, the work scope was changed by LLNL such that the tests on the milled copper plate panel specimen were replaced by a second set of heating tests on the second tube of the two-tube copper panel specimen to confirm the conditions for burnout failure. The testing requirements were completed following failure of the second tube at nominally identical conditions under which the first tube failed, and verification of these conditions. This letter completes all contractual obligations by serving as the final report on the test program.
Easoz, J.R.; Sink, D.A.
Plasma-Materials Interactions (PMI) and High-Heat-Flux (HHF) component research and development in the US Fusion Program
Plasma particle and high heat fluxes to in-vessel components such as divertors, limiters, RF launchers, halo plasma scrapers, direct converters, and wall armor, and to the vacuum chamber itself, represent central technical issues for fusion experiments and reactors. This is well recognized and accepted. It is also well recognized that the conditions at the plasma boundary can directly influence core plasma confinement. This has been seen most dramatically, on the positive side, in the discovery of the H-mode using divertors in tokamaks. It is also reflected in the attention devoted worldwide to the problems of impurity control. Nowadays, impurities are controlled by wall conditioning, special discharge cleaning techniques, special coatings such as carbonization, the use of low-Z materials for limiters and armor, a careful tailoring of heat loads, and in some machines, through the use of divertors. All programs, all experiments, and all designers are now keenly aware that PMI and HHF issues are key to the successful performance of their machines. In this brief report we present general issues in Section 2, critical issues in Section 3, existing US PMI/HHF experiments and facilities in Section 4, US International Cooperative PMI/HHF activities in Section 5, and conclude with a discussion on major tasks in PMI/HHF in Section 6.
Conn, R.W.
Higher dimensional charged shear-free relativistic models with heat flux
We analyse shear-free spherically symmetric relativistic models of gravitating fluids with heat flow and electric charge defined on higher dimensional manifolds. The solution to the Einstein-Maxwell system is governed by the pressure isotropy condition which depends on the spacetime dimension. We study this highly nonlinear partial differential equation using Lie's group theoretic approach. The Lie symmetry generators that leave the equation invariant are determined. We provide exact solutions to the gravitational potentials using the first symmetry admitted by the equation. Our new exact solutions contain the earlier results for the four-dimensional case. Using the other Lie generators, we are able to provide solutions to the gravitational potentials or reduce the order of the master equation to a first order nonlinear differential equation. We derive the temperature transport equation in higher dimensions and find expressions for the causal and Eckart temperatures showing their explicit dependance on the dimension. We analyse a particular solution, obtained via group techniques, to show its physical applicability.
Numerical prediction of heat-flux to massive calorimeters engulfed in regulatory fires with the cask analysis fire environment (CAFE) model
Recent observations show that the thermal boundary conditions within large-scale fires are significantly affected by the presence of thermally massive objects. These objects cool the soot and gas near their surfaces, and these effects reduce the incoming radiant heat-flux to values lower than the levels expected from simple {sigma}T{sub fire}{sup 4} models. They also affect the flow and temperature fields in the fire far from their surfaces. The Cask Analysis Fire Environment (CAFE) code has been developed at Sandia National Laboratories to provide an enhanced fire boundary condition for the design of radioactive material packages. CAFE is a set of computer subroutines that use computational fluid mechanics methods to predict convective heat transfer and mixing. It also includes models for fuel and oxygen transport, chemical reaction, and participating-media radiation heat transfer. This code uses two-dimensional computational models so that it has reasonably short turnaround times on standard workstations and is well suited for design and risk studies. In this paper, CAFE is coupled with a commercial finite-element program to model a large cylindrical calorimeter fully engulfed in a pool fire. The time-dependent heat-flux to the calorimeter and the calorimeter surface temperature are determined for several locations around the calorimeter circumference. The variation of heat-flux with location is determined for calorimeters with different diameters and wall thickness, and the observed effects discussed.
Subantarctic Mode Water formation : air-sea fluxes and cross-frontal exchange
remote sensing data. The Kelly latent and sensible heatRemote Sensing Obser- vations (J-OFURO), Kelly, OAFlux, and the Southern Ocean State Estimate (SOSE). The heat
Holte, James
Validation/Uncertainty Quantification for Large Eddy Simulations of the heat flux in the Tangentially Fired Oxy-Coal Alstom Boiler Simulation Facility
The objective of this task is to produce predictive capability with quantified uncertainty bounds for the heat flux in commercial-scale, tangentially fired, oxy-coal boilers. Validation data came from the Alstom Boiler Simulation Facility (BSF) for tangentially fired, oxy-coal operation. This task brings together experimental data collected under Alstom's DOE project for measuring oxy-firing performance parameters in the BSF with this University of Utah project for large eddy simulation (LES) and validation/uncertainty quantification (V/UQ). The Utah work includes V/UQ with measurements in the single-burner facility where advanced strategies for O2 injection can be more easily controlled and data more easily obtained. Highlights of the work include: • Simulations of Alstom's 15 megawatt (MW) BSF, exploring the uncertainty in thermal boundary conditions. A V/UQ analysis showed consistency between experimental results and simulation results, identifying uncertainty bounds on the quantities of interest for this system (Subtask 9.1) • A simulation study of the University of Utah's oxy-fuel combustor (OFC) focused on heat flux (Subtask 9.2). A V/UQ analysis was used to show consistency between experimental and simulation results. • Measurement of heat flux and temperature with new optical diagnostic techniques and comparison with conventional measurements (Subtask 9.3). Various optical diagnostics systems were created to provide experimental data to the simulation team. The final configuration utilized a mid-wave infrared (MWIR) camera to measure heat flux and temperature, which was synchronized with a high-speed, visible camera to utilize two-color pyrometry to measure temperature and soot concentration. • Collection of heat flux and temperature measurements in the University of Utah's OFC for use is subtasks 9.2 and 9.3 (Subtask 9.4). Several replicates were carried to better assess the experimental error. Experiments were specifically designed for the generation of high-fidelity data from a turbulent oxy-coal flame for the validation of oxy-coal simulation models. Experiments were also conducted on the OFC to determine heat flux profiles using advanced strategies for O2 injection. This is important when considering retrofit of advanced O2 injection in retrofit configurations.
Smith, P.J.; Eddings, E.G.; Ring, T.; Thornock, J.; Draper, T.; Isaac, B.; Rezeai, D.; Toth, P.; Wu, Y.; Kelly, K.
A TWO-PHASE HEAT SPREADER FOR COOLING HIGH HEAT FLUX SOURCES Mitsuo Hashimoto, Hiroto Kasai, Yuichi Ishida, Hiroyuki Ryoson, a
-sectional area, m2 d mesh wire diameter, m pD particle diameter, m gD channel depth, m h heat transferQ condensation heat, W effr effective pore radius, m t thickness, m T' temperature differential, K W mesh opening heat transfer [23-27]. Few passively cooled devices offer heat dissipation levels approaching 5 W/mm2
t y (2009). 11. Pacific Gas &Electric, Go Solar California:California Solar Initiative (2008). A consumer's guide toprograms such as the California Solar Initiative (CSI) to
d b y t h e a n g l e d solar panel F i g u r e 62: C a l cK l e i s s l , C h a i r Solar panels were mounted w i t hthe optimal angles for solar panels [9], i n this study both
Pressure drop, heat transfer, critical heat flux, and flow stability of two-phase flow boiling of water and ethylene glycol/water mixtures - final report for project "Efficent cooling in engines with nucleate boiling."
Because of its order-of-magnitude higher heat transfer rates, there is interest in using controllable two-phase nucleate boiling instead of conventional single-phase forced convection in vehicular cooling systems to remove ever increasing heat loads and to eliminate potential hot spots in engines. However, the fundamental understanding of flow boiling mechanisms of a 50/50 ethylene glycol/water mixture under engineering application conditions is still limited. In addition, it is impractical to precisely maintain the volume concentration ratio of the ethylene glycol/water mixture coolant at 50/50. Therefore, any investigation into engine coolant characteristics should include a range of volume concentration ratios around the nominal 50/50 mark. In this study, the forced convective boiling heat transfer of distilled water and ethylene glycol/water mixtures with volume concentration ratios of 40/60, 50/50, and 60/40 in a 2.98-mm-inner-diameter circular tube has been investigated in both the horizontal flow and the vertical flow. The two-phase pressure drop, the forced convective boiling heat transfer coefficient, and the critical heat flux of the test fluids were determined experimentally over a range of the mass flux, the vapor mass quality, and the inlet subcooling through a new boiling data reduction procedure that allowed the analytical calculation of the fluid boiling temperatures along the experimental test section by applying the ideal mixture assumption and the equilibrium assumption along with Raoult's law. Based on the experimental data, predictive methods for the two-phase pressure drop, the forced convective boiling heat transfer coefficient, and the critical heat flux under engine application conditions were developed. The results summarized in this final project report provide the necessary information for designing and implementing nucleate-boiling vehicular cooling systems.
Yu, W.; France, D. M.; Routbort, J. L. (Energy Systems)
E-Print Network 3.0 - accurate heat capacity Sample Search Results
Mathematics, University of California at Santa Barbara Collection: Mathematics 4 Heat Capacity and Latent Heat The objective of this laboratory is for you to explore the heat...
An Experimental Study of Upward and Downward Flow of Supercritical Carbon Dioxide in a Straight Pipe Heat Exchanger with Constant Wall Heat Flux
An experimental analysis was conducted on a single circular tube heat exchanger using supercritical carbon dioxide as the working fluid. The heat exchanger was operated in two different orientations: vertically upward and downward. The experimental...
Umrigar, Eric Dara
Advanced Heat Transfer Fluids and Novel Thermal Storage Concepts...
Systems Lehigh University: Novel Thermal Storage Technologies for Concentrating Solar Power Generation Terrafore: Heat Transfer and Latent Heat Storage in Inorganic Molten...
Experimental investigations of uncovered-bundle heat transfer and two-phase mixture-level swell under high-pressure low heat-flux conditions. [PWR
Results are reported from a series of uncovered-bundle heat transfer and mixture-level swell tests. Experimental testing was performed at Oak Ridge National Laboratory in the Thermal Hydraulic Test Facility (THTF). The THTF is an electrically heated bundle test loop configured to produce conditions similar to those in a small-break loss-of-coolant accident. The objective of heat transfer testing was to acquire heat transfer coefficients and fluid conditions in a partially uncovered bundle. Testing was performed in a quasi-steady-state mode with the heated core 30 to 40% uncovered. Linear heat rates varied from 0.32 to 2.22 kW/m.rod (0.1 to 0.68 kW/ft.rod). Under these conditions peak clad temperatures in excess of 1050 K (1430/sup 0/F) were observed, and total heat transfer coefficients ranged from 0.0045 to 0.037 W/cm/sup 2/.K (8 to 65 Btu/h.ft/sup 2/./sup 0/F). Spacer grids were observed to enhance heat transfer at, and downstream of, the grid. Radiation heat transfer was calculated to account for as much as 65% of total heat transfer in low-flow tests.
Anklam, T. M.; Miller, R. J.; White, M. D.
The Conserved Penrose-Fife Phase Field Model with Special Heat Flux Laws and Memory E ects.
of one of the phases). The data g and h stand for the heat supply and the outer temperature; the function
Rocca, Elisabetta
Chaotic flow in a 2D natural convection loop with heat flux boundaries William F. Louisos a,b,
the nonlinear dynamics of unstable convection in a 2D thermal convection loop (i.e., thermosyphon) with heat behavior and residence time in a cir- culatory direction are explored and described for the various thermal-storms depicted as a classic `bow echo' on radar [3]; land and sea breezes as a result of differential heating
Danforth, Chris
On the Sensitivity of Atmospheric Model Implied Ocean Heat Transport to the Dominant Terms of the Surface Energy Balance
The oceanic meridional heat transport (T{sub o}) implied by an atmospheric General Circulation Model (GCM) can help evaluate a model's readiness for coupling with an ocean GCM. In this study we examine the T{sub o} from benchmark experiments of the Atmospheric Model Intercomparison Project, and evaluate the sensitivity of T{sub o} to the dominant terms of the surface energy balance. The implied global ocean TO in the Southern Hemisphere of many models is equatorward, contrary to most observationally-based estimates. By constructing a hybrid (model corrected by observations) T{sub o}, an earlier study demonstrated that the implied heat transport is critically sensitive to the simulated shortwave cloud radiative effects, which have been argued to be principally responsible for the Southern Hemisphere problem. Systematic evaluation of one model in a later study suggested that the implied T{sub o} could be equally as sensitive to a model's ocean surface latent heat flux. In this study we revisit the problem with more recent simulations, making use of estimates of ocean surface fluxes to construct two additional hybrid calculations. The results of the present study demonstrate that indeed the implied T{sub o} of an atmospheric model is very sensitive to problems in not only the surface net shortwave, but the latent heat flux as well. Many models underestimate the shortwave radiation reaching the surface in the low latitudes, and overestimate the latent heat flux in the same region. The additional hybrid transport calculations introduced here could become useful model diagnostic tests as estimates of implied ocean surface fluxes are improved.
Gleckler, P J
Definition of Total Energy budget equation in terms of moist-air Enthalpy surface flux
Uncertainty exists concerning the proper formulation of surface heat fluxes, namely the sum of "sensible" and "latent" heat fluxes, and in fact concerning these two fluxes if they are considered as separate fluxes. In fact, eddy flux of moist-air energy must be defined as the eddy transfer of moist-air specific enthalpy ($\\overline{w' h'}$), where the specific enthalpy ($h$) is equal to the internal energy of moist air plus the pressure divided by the density (namely $h = e_{\\rm int} + p/\\rho$). The fundamental issue is to compute this local (specific) moist-air enthalpy ($h$), and in particular to determine absolute reference value of enthalpies for dry air and water vapour $(h_d)_{\\rm ref}$ and $(h_v)_{\\rm ref}$. New results shown in Marquet (QJRMS 2015, arXiv:1401.3125) are based on the Third-law of Thermodynamics and can allow these computations. In this note, this approach is taken to show that Third-law based values of moist-air enthalpy fluxes is the sum of two terms. These two terms are similar to wha...
Marquet, Pascal
Experimental investigations of two-phase mixture level swell and axial void fraction distribution under high pressure, low heat flux conditions in rod bundle geometry
Experimental data is reported from a series of quasi-steady-state two-phase mixture level swell and void fraction distribution tests. Testing was performed at ORNL in the Thermal Hydraulic Test Facility - a large electrically heated test loop configured to produce conditions similar to those expected in a small break loss of coolant accident. Pressure was varied from 2.7 to 8.2 MPa and linear power ranged from 0.33 to 1.95 kW/m. Mixture swell was observed to vary linearly with the total volumetric vapor generation rate over the power range of primary interest in small break analysis. Void fraction data was fit by a drift-flux model and both the drift-velocity and concentration parameter were observed to decrease with increasing pressure.
Anklam, T.M.; White, M.D.
Measurement of gas species, temperatures, coal burnout, and wall heat fluxes in a 200 MWe lignite-fired boiler with different overfire air damper openings
Measurements were performed on a 200 MWe, wall-fired, lignite utility boiler. For different overfire air (OFA) damper openings, the gas temperature, gas species concentration, coal burnout, release rates of components (C, H, and N), furnace temperature, and heat flux and boiler efficiency were measured. Cold air experiments for a single burner were conducted in the laboratory. The double-swirl flow pulverized-coal burner has two ring recirculation zones starting in the secondary air region in the burner. As the secondary air flow increases, the axial velocity of air flow increases, the maxima of radial velocity, tangential velocity and turbulence intensity all increase, and the swirl intensity of air flow and the size of recirculation zones increase slightly. In the central region of the burner, as the OFA damper opening widens, the gas temperature and CO concentration increase, while the O{sub 2} concentration, NOx concentration, coal burnout, and release rates of components (C, H, and N) decrease, and coal particles ignite earlier. In the secondary air region of the burner, the O{sub 2} concentration, NOx concentration, coal burnout, and release rates of components (C, H, and N) decrease, and the gas temperature and CO concentration vary slightly. In the sidewall region, the gas temperature, O{sub 2} concentration, and NOx concentration decrease, while the CO concentration increases and the gas temperature varies slightly. The furnace temperature and heat flux in the main burning region decrease appreciably, but increase slightly in the burnout region. The NOx emission decreases from 1203.6 mg/m{sup 3} (6% O{sub 2}) for a damper opening of 0% to 511.7 mg/m{sup 3} (6% O{sub 2}) for a damper opening of 80% and the boiler efficiency decreases from 92.59 to 91.9%. 15 refs., 17 figs., 3 tabs.
Jianping Jing; Zhengqi Li; Guangkui Liu; Zhichao Chen; Chunlong Liu [Harbin Institute of Technology, Harbin (China). School of Energy Science and Engineering
Heat transfer in porous media with fluid phase changes
A one-dimensional experimental apparatus was built to study the heat pipe phenomenon. Basically, it consists of a 25 cm long, 2.5 cm I.D. Lexane tube packed with Ottawa sand. The two ends of the tube were subjected to different tempratures, i.e., one above the boiling temperature and the other below. The tube was well insulated so that a uniform one-dimensional heat flux could pass through the sand pack. Presence of the heat pipe phenomenon was confirmed by the temperature and saturation profiles of the sand pack at the final steady state condition. A one-dimensional steady state theory to describe the experiment has been developed which shows the functional dependence of the heat pipe phenomenon on liquid saturation gradient, capillary pressure, permeability, fluid viscosity, latent heat, heat flux and gravity. Influence of the heat pipe phenomenon on wellbore heat losses was studied by use of a two-phase two-dimensional cylindrical coordinate computer model.
Su, H.J.
Industrial Heat Pump Case Study
with operating the evaporator. The open-cycle heat pump design uses an electrically driven centrifugal compressor to recover the latent heat of the water vapor generated by the evaporator. (Steam was the original heat source but is now only needed for start...
Wagner, J. R.; Brush, F. C.
Proceedings of 1999 U.S./Japan Workshop (99FT-05) On High Heat Flux Components and Plasma Surface Interactions for Next Fusion Devices
The 1999 US-Japan Workshop on High Heat Flux Components and Plasma Surface Interactions in Next Step Fusion Devices was held at the St. Francis Hotel in Santa Fe, New Mexico, on November 1-4, 1999. There were 42 presentations as well as discussion on technical issues and planning for future collaborations. The participants included 22 researchers from Japan and the United States as well as seven researchers from Europe and Russia. There have been important changes in the programs in both the US and Japan in the areas of plasma surface interactions and plasma facing components. The US has moved away from a strong focus on the ITER Project and has introduced new programs on use of liquid surfaces for plasma facing components, and operation of NSTX has begun. In Japan, the Large Helical Device began operation. This is the first large world-class confinement device operating in a magnetic configuration different than a tokamak. In selecting the presentations for this workshop, the organizers sought a balance between research in laboratory facilities or confinement devices related to plasma surface interactions and experimental research in the development of plasma facing components. In discussions about the workshop itself, the participants affirmed their preference for a setting where ''work-in-progress'' could be informally presented and discussed.
Intercomparison of Sensible Heat Flux from Large Aperture Scintillometer and Eddy Covariance Methods: Field Experiment over a Homogeneous Semi-arid Region
of satellite remote sensing sensible heat-?ux estimates dueremote sensing algorithms. A typical approach identi?es spectral bands particularly sensitive to surface heat ?
Zeweldi, Dawit A.; Gebremichael, Mekonnen; Wang, Junming; Sammis, Theodore; Kleissl, Jan; Miller, David
Sensitivity of Surface Flux Simulations to Hydrologic Parameters Based on an Uncertainty Quantification Framework Applied to the Community Land Model
Uncertainties in hydrologic parameters could have significant impacts on the simulated water and energy fluxes and land surface states, which will in turn affect atmospheric processes and the carbon cycle. Quantifying such uncertainties is an important step toward better understanding and quantification of uncertainty of integrated earth system models. In this paper, we introduce an uncertainty quantification (UQ) framework to analyze sensitivity of simulated surface fluxes to selected hydrologic parameters in the Community Land Model (CLM4) through forward modeling. Thirteen flux tower footprints spanning a wide range of climate and site conditions were selected to perform sensitivity analyses by perturbing the parameters identified. In the UQ framework, prior information about the parameters was used to quantify the input uncertainty using the Minimum-Relative-Entropy approach. The quasi-Monte Carlo approach was applied to generate samples of parameters on the basis of the prior pdfs. Simulations corresponding to sampled parameter sets were used to generate response curves and response surfaces and statistical tests were used to rank the significance of the parameters for output responses including latent (LH) and sensible heat (SH) fluxes. Overall, the CLM4 simulated LH and SH show the largest sensitivity to subsurface runoff generation parameters. However, study sites with deep root vegetation are also affected by surface runoff parameters, while sites with shallow root zones are also sensitive to the vadose zone soil water parameters. Generally, sites with finer soil texture and shallower rooting systems tend to have larger sensitivity of outputs to the parameters. Our results suggest the necessity of and possible ways for parameter inversion/calibration using available measurements of latent/sensible heat fluxes to obtain the optimal parameter set for CLM4. This study also provided guidance on reduction of parameter set dimensionality and parameter calibration framework design for CLM4 and other land surface models under different hydrologic and climatic regimes.
Hou, Zhangshuan; Huang, Maoyi; Leung, Lai-Yung R.; Lin, Guang; Ricciuto, Daniel M.
ARM - Measurement - Sensible heat flux
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc Documentation RUC : XDCResearch Relatedcontent ARMnumberDoppler ARM
ARM - Measurement - Soil heat flux
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc Documentation RUC : XDCResearch Relatedcontentcharacteristics ARM Data Discovery Browse Dataheat
A Latent Time-Budget Model
DE L E E U W (1989), Latent budget analysis, in: A. DECARLI,DER H E U D E N (1988), The analysis of time- budgets with alatent-time-budget model, in E. Diday et al. (eds. ), Data
Jan de Leeuw; Peter G.M. van der Heijden; Peter Verboon
E-Print Network 3.0 - artificially heated waters Sample Search...
Oklahoma State University (www.hvac.okstate.edu) Summary: exchanger, and water-to-water heat pumps have been developed and validated separately... from precipitation, and latent...
Consistent and efficient reconstruction of latent tree models
We study the problem of learning a latent tree graphical model where samples are available only from a subset of variables. We propose two consistent and computationally efficient algorithms for learning minimal latent ...
Choi, Myung Jin
Lab I - 1 LABORATORY I: CONSERVATION OF ENERGY AND HEAT In 1101 labs, you used conservation are in thermal equilibrium · Use the latent heat to determine the internal energy change of a system during conservation of energy, you can then determine the metal's specific heat. However, you know that some energy
Minnesota, University of
Development of an air-cooled, loop-type heat pipe with multiple condensers
Thermal management challenges are prevalent in various applications ranging from consumer electronics to high performance computing systems. Heat pipes are capillary-pumped devices that take advantage of the latent heat ...
Kariya, H. Arthur (Harumichi Arthur)
Complex Compound Chemical Heat Pumps
-Vapor Energy Storage Systems," Final Report, ORNL, under contract No. 86X-57432'J, in print. 4. Rockenfeller, U., et. al., "Development of Dual Temperature Ammines for Heat Pump latent Storage Application," Final Report, ORNL, under Contract No. 86X-4'i...
Rockenfeller, U.; Langeliers, J.; Horn, G.
Sandia National Laboratories: BASF latent curing epoxy
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 -the Mid-Infrared0Energy Advanced NuclearBASF latent curing epoxy Fabrication of AMI
Journalof EnhaneaiHeat T r w e r 1996,Vol. 3, No. 2, pp. 119-127
Transfer Enhancementin Latent Heat Thermal Energy Storage System by Using an External Radial Finned Key Words Thermalenergy storage; Finned tube The thermal energy storage system using a Phase Change inside the tube. This type of latent heat storage system has been studied by a number of authors
Zhang, Yuwen
Coronal mass ejections and magnetic flux buildup in the heliosphere
electron heat flux. The first panel shows the preeruption heliospheric flux, which consists of the an open the observed doubling in the magnetic field intensity at 1 AU over the solar cycle. Such timescales signatures; no flux buildup results. The dynamic simulation yields a solar cycle flux variation with high
California at Berkeley, University of
Solar heating system
An improved solar heating system in which the incident radiation of the sun is absorbed on collector panels, transferred to a storage unit and then distributed as heat for a building and the like. The improvement is obtained by utilizing a storage unit comprising separate compartments containing an array of materials having different melting points ranging from 75.degree. to 180.degree. F. The materials in the storage system are melted in accordance with the amount of heat absorbed from the sun and then transferred to the storage system. An efficient low volume storage system is provided by utilizing the latent heat of fusion of the materials as they change states in storing and releasing heat for distribution.
Schreyer, James M. (Oak Ridge, TN); Dorsey, George F. (Concord, TN)
Improved solar heating systems
An improved solar heating system is described in which the incident radiation of the sun is absorbed on collector panels, transferred to a storage unit and then distributed as heat for a building and the like. The improvement is obtained by utilizing a storage unit comprising separate compartments containing an array of materials having different melting points ranging from 75 to 180/sup 0/F. The materials in the storage system are melted in accordance with the amount of heat absorbed from the sun and then transferred to the storage system. An efficient low volume storage system is provided by utilizing the latent heat of fusion of the materials as they change states in storing ad releasing heat for distribution.
Schreyer, J.M.; Dorsey, G.F.
Segmentation and Enhancement of Latent Fingerprints: A Coarse to Fine Ridge
a latent fingerprint image, a total variation (TV) decomposition model with L1 fidelity regularization INTRODUCTION LATENT fingerprints (or simply latents or finger marks) refer to fingerprints lifted from the sur
The effect of post-fire stand age on the boreal forest energy balance
solar radiation (S), albedo, sensible heat flux density (H), and latent heat flux density (LE), above the vegetation canopy from towers,
Rank/sparsity minimization and latent variable graphical model selection
Rank/sparsity minimization and latent variable graphical model selection Pablo A. Parrilo · Complication: latent variables · Rank/sparsity decomposition, and generalizations · Convex optimization cond. on other vars. 1 3 2 4 Sparse Low-rank Concentration matrix #12;Proposal for modeling · Decompose
Parrilo, Pablo A.
Please cite this article in press as: S. Banetta, et al., Manufacturing of small-scale mock-ups and of a semi-prototype of the ITER Normal Heat Flux First Wall, Fusion Eng. Des. (2014), http://dx.doi.org/10.1016/j.fusengdes.2014.04.020
Please cite this article in press as: S. Banetta, et al., Manufacturing of small-scale mock-ups homepage: www.elsevier.com/locate/fusengdes Manufacturing of small-scale mock-ups and of a semi the manufacturing development and fabrication of reduced scale ITER First Wall (FW) mock-ups of the Normal Heat Flux
Raffray, A. René
antineutrino flux measurements: Topics by E-print Network
with Terrestrial Antineutrino Flux Measurements CERN Preprints Summary: Uranium and thorium are the main heat producing elements in the earth. Their quantities and...
Disaggregating Cooling Energy Use of Commercial Buildings Into Sensible and Latent Fractions From Whole-Building Monitored Data: Methodology and Advantages
In hot and humid climates, where summers are both warm and humid, the latent cooling can be a significant portion of the total cooling load (as much as 40%). Typically the monitored data only includes whole-building heating and cooling energy use...
Katipamula, S.; Reddy, T. A.; Claridge, D. E.
Cloud Processes: Insights over a Decade into the Links between
Cloud Resolving Models Satellite and radar data Field Campaigns Radar Simulators (image: C. McGee) Grid Diffuse Sensible heat flux Latent heat flux Latent heat flux Aerosol direct effects Incoming solar radiation Direct Diffuse Sensible heat flux SiB RAMS CO2 Fluxes: Photosynthesis Respiration CO2 Radiative
Multi-Label Informed Latent Semantic Indexing , Shipeng Yu
Multi-Label Informed Latent Semantic Indexing Kai Yu , Shipeng Yu , Volker Tresp Siemens AG, University of Munich, Germany email@example.com, firstname.lastname@example.com, spyu
Tresp, Volker
3, 681705, 2006 Measurement and
and latent heat flux over the heterogeneous surface. Since 1970s, remote sensing technology has brought superiority to estimate areal sensible and latent heat flux over heterogenrous surface. For remote sensing temperature retrieved from remote sensing data and air temperature. Then latent heat flux can be calculated
Boyer, Edmond
The latent effect of cogency in the minority influence process
THE LATENT EFFECT OF COGENCY IN THE MINORITY INFLUENCE PROCESS A Thesis by JUDITH ANN OUELLETTE Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER... OF SCIENCE May 1993 Major subject: Psychology THE LATENT EFFECT OF COGENCY IN THE MINORITY INFLUENCE PROCESS A Thesis by JUDITH ANN OUELLETTE Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment...
Ouellette, Judith A
PUBLISHED ONLINE: 17 JULY 2011 | DOI: 10.1038/NGEO1205 Partial radiogenic heat model for Earth revealed
half of Earth's total heat flux. We therefore conclude that Earth's primordial heat supply has not yet
Piepke, Andreas G.
Temperature profile of the infrared image Heat exchange between
T Temperature profile of the infrared image Heat exchange between atmosphere and ocean References coefficient of heat in water determine the heat transfer velocity: *t Infrared images of the water surface: a-Karls-Universität Heidelberg www.uni-heidelberg.de Active controlled flux technique (ACFT) Continuous heat flux Periodic heat
Project Profile: Heat Transfer and Latent Heat Storage in Inorganic Molten
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious RankCombustion | Department ofT ib l L d FNEPA/309DepartmentDepartment of EnergyFlexibleSalts for CSP
Plume heat flow is much lower than CMB heat flow Eric Mittelstaedt a,*, Paul J. Tackley a,b
to follow a power-law size distribution, estimated a plume heat flux as high as 35% of surface heat fluxPlume heat flow is much lower than CMB heat flow Eric Mittelstaedt a,*, Paul J. Tackley a, of the heat conducted across the CMB. Here this assumption is explored using numerical convection models
Tackley, Paul J.
Transient-heat-transfer and stress analysis of a thermal-storage solar cooker module
This paper details the analysis carried out in Solidworks to determine the best material and configuration of a thermal-storage solar cooker module.The thermal-storage solar cooker utilizes the high-latent-heat lithium ...
Zengeni, Hazel C
Using Cool Roofs to Reduce Energy Use, Greenhouse Gas Emissions, and Urban Heat-island Effects: Findings from an India Experiment
heat fluxes, solar radiation, and electric power consumed byheat fluxes, solar radiation, and electric power consumed byheat fluxes, solar radiation, and electric power consumed by
Akbari, Hashem
Fast flux locked loop
A flux locked loop for providing an electrical feedback signal, the flux locked loop employing radio-frequency components and technology to extend the flux modulation frequency and tracking loop bandwidth. The flux locked loop of the present invention has particularly useful application in read-out electronics for DC SQUID magnetic measurement systems, in which case the electrical signal output by the flux locked loop represents an unknown magnetic flux applied to the DC SQUID.
Ganther, Jr., Kenneth R. (Olathe, KS); Snapp, Lowell D. (Independence, MO)
Proceedings of HT'03 2003 Summer Heat Transfer Conference
Proceedings of HT'03 2003 Summer Heat Transfer Conference July 21Â23, 2003, Las Vegas, Nevada, USA HT2003-47016 A NEW TECHNIQUE FOR HEAT FLUX DETERMINATION D.G. Walker Department of email@example.com ABSTRACT A new method for estimating heat fluxes from heating rate measurements and an approach to measure
Walker, D. Greg
Botryosphaeriaceae as endophytes and latent pathogens of woody plants: diversity, ecology and impact
Review Botryosphaeriaceae as endophytes and latent pathogens of woody plants: diversity, ecology Keywords: Botryosphaeria Botryosphaeriaceae Emerging tree diseases Endophyte Latent pathogen Quarantine to general patterns observed for the collective of endophytes of woody plants. These include high levels
Pulse flux measuring device
A device for measuring particle flux comprises first and second photodiode detectors for receiving flux from a source and first and second outputs for producing first and second signals representing the flux incident to the detectors. The device is capable of reducing the first output signal by a portion of the second output signal, thereby enhancing the accuracy of the device. Devices in accordance with the invention may measure distinct components of flux from a single source or fluxes from several sources.
Riggan, William C. (Albuquerque, NM)
A critical evaluation of the upper ocean heat budget in the Climate Forecast System Reanalysis data for the south central equatorial Pacific
Coupled ocean-atmospheric models suffer from the common bias of a spurious rain belt south of the central equatorial Pacific throughout the year. Observational constraints on key processes responsible for this bias are scarce. The recently available reanalysis from a coupled model system for the National Centers for Environmental Prediction (NCEP) Climate Forecast System Reanalysis (CFSR) data is a potential benchmark for climate models in this region. Its suitability for model evaluation and validation, however, needs to be established. This paper examines the mixed layer heat budget and the ocean surface currents - key factors for the sea surface temperature control in the double Inter-Tropical Convergence Zone in the central Pacific - from 5{sup o}S to 10{sup o}S and 170{sup o}E to 150{sup o}W. Two independent approaches are used. The first approach is through comparison of CFSR data with collocated station observations from field experiments; the second is through the residual analysis of the heat budget of the mixed layer. We show that the CFSR overestimates the net surface flux in this region by 23 W m{sup -2}. The overestimated net surface flux is mainly due to an even larger overestimation of shortwave radiation by 44 W m{sup -2}, which is compensated by a surface latent heat flux overestimated by 14 W m{sup -2}. However, the quality of surface currents and the associated oceanic heat transport in CFSR are not compromised by the surface flux biases, and they agree with the best available estimates. The uncertainties of the observational data from field experiments are also briefly discussed in the present study.
Liu H.; Lin W.; Liu, X.; Zhang, M.
Heat Transfer Derivation of differential equations for heat transfer conduction
) or kW *h or Btu. U is the change in stored energy, in units of kW *h (kWh) or Btu. qx is the heat conducted (heat flux) into the control volume at surface edge x, in units of kW/m2 or Btu/(h-ft2). qx volume is positive), in kW/m3 or Btu/(h-ft3) (a heat sink, heat drawn out of the volume, is negative
Veress, Alexander
World IMACS / MODSIM Congress, Cairns, Australia 13-17 July 2009 http://mssanz.org.au/modsim09
. Keywords: Land surface models, evapotranspiration, latent heat flux, satellite remote sensing Comparison of latent heat flux estimates over Australia Matthew F. McCabe1 , Yi Y. Liu1 , Raghuveer Vinukollu from such data do not contribute to model assessment and calibration. This study compares latent heat
Evans, Jason
Relationship between gradient and EM steps in latent variable models.
includes random search, standard gradientbased algorithms, line search methods such as conjugate gradient to to first order method operat ing on the gradient of a locally reshaped likelihood function. DirectRelationship between gradient and EM steps in latent variable models. Ruslan Salakhutdinov Sam
Roweis, Sam
includes random search, standard gradient-based algorithms, line search methods such as conjugate gradient to to first order method operat- ing on the gradient of a locally reshaped likelihood function. DirectRelationship between gradient and EM steps in latent variable models. Ruslan Salakhutdinov Sam
Reliability-Constrained Latent Structure Peter Westfall and Kevin Henning
Reliability-Constrained Latent Structure Models Peter Westfall and Kevin Henning Texas Tech allow you to estimate reliability of your measure of the fuzzy concept · LSMs allow you to estimate cannot identify reliability. · LSMs cannot identify relationships between fuzzy concepts. · LSMs cannot
Westfall, Peter H.
Latent extinction risk and the future battlegrounds of mammal conservation
or where many species are thought to be at imminent risk of extinction. However, these strategies may identify such areas for the world's mammals using latent extinction risk, the discrepancy between a species' current extinction risk and that predicted from models on the basis of biological traits. Species
Wilmers, Chris
Latent-Descriptor Clustering for Unsupervised POS Induction Michael Lamar
Latent-Descriptor Clustering for Unsupervised POS Induction Michael Lamar Department of Mathematics; Lamar et al., 2010; Reichart et al., 2010; Berg-Kirkpatrick et al., 2010). Some of these methods use papers advocate non- disambiguating models (Abend et al., 2010; Lamar et al., 2010): these assign
Bienenstock, Elie
Simplified numerical description of latent storage characteristics for phase change wallboard
Cooling of residential California buildings contributes significantly to electrical consumption and peak power demand. Thermal mass can be utilized to reduce the peak-power demand, down-size the cooling systems and/or switch to low-energy cooling sources. Large thermal storage devices have been used in the past to overcome the short-comings of alternative cooling sources or to avoid high demand charges. With the advent of phase change material (PCM) implemented in gypsum board, plaster or other wall-covering material, thermal storage can be part of the building structure even for light-weight buildings. PCMs have two important advantages as storage media: they can offer an order-of-magnitude increase in thermal storage capacity and their discharge is almost isothermal. This allows to store large amounts of energy without significantly changing the temperature of the sheathing. As heat storage takes place in the building part where the loads occur, rather than externally (e.g., ice or chilled water storage), additional transport energy is not needed. To numerically evaluate the latent storage performance of treated wallboard, RADCOOL, a thermal building simulation model based on the finite difference approach, will be used. RADCOOL has been developed in the SPARK environment in order to be compatible with the new family of simulation tools being developed at Lawrence Berkeley Laboratory. As logical statements are difficult to use in SPARK, a continuous function for the specific heat and the enthalpy had to be found. This report covers the development of a simplified description of latent storage characteristics for wallboard treated with phase change material.
Feustel, H.E.
Gas heat transfer in a heated vertical channel under deteriorated turbulent heat transfer regime
Passive cooling via natural circulation of gas after a loss of coolant (LOCA) accident is one of the major goals of the Gas-cooled Fast Reactor (GFR). Due to its high surface heat flux and low coolant velocities under ...
Lee, Jeongik
Gas Heat Transfer in a Heated Vertical Channel under Deteriorated Turbulent Heat Transfer Regime
Heat pipe array heat exchanger
A heat pipe arrangement for exchanging heat between two different temperature fluids. The heat pipe arrangement is in a ounterflow relationship to increase the efficiency of the coupling of the heat from a heat source to a heat sink.
Reimann, Robert C. (Lafayette, NY)
Biogeosciences, 5, 421431, 2008 www.biogeosciences.net/5/421/2008/
, into the fluxes of sensible and latent heat and heat storage con- trols the degree of coupling between the land covariance flux measurements of sensible and latent heat, soil heat flux, net radiation, above-ground phytomass and meteorological driv- ing forces energy partitioning was investigated at a temperate mountain
Ground Surface Heat Flux Histories, Beltrami 1 Global Ground Surface and Heat Flux Histories from Geothermal
Geothermal Measurements: Inferences from Inversion of the Global Data Set Hugo Beltrami,1 1 Department and temperature anomalies detected in the shallow sub- surface. Results from the analysis of Canada's geothermal. Application of this method to the global geothermal data base allowed for a quantification of the global
Beltrami, Hugo
affecting carbon fluxes: Topics by E-print Network
(IFN) (2 Paris-Sud XI, Universit de 43 High Heat Flux Erosion of Carbon Fibre Composite Materials in the TEXTOR Tokamak* Plasma Physics and Fusion Websites Summary: ,. 1. *...
Waste-heat recovery in batch processes using heat storage
The waste-heat recovery in batch processes has been studied using the pinch-point method. The aim of the work has been to investigate theoretical and practical approaches to the design of heat-exchanger networks, including heat storage, for waste-heat recovery in batch processes. The study is limited to the incorporation of energy-storage systems based on fixed-temperature variable-mass stores. The background for preferring this to the alternatives (variable-temperature fixed-mass and constant-mass constant-temperature (latent-heat) stores) is given. It is shown that the maximum energy-saving targets as calculated by the pinch-point method (time average model, TAM) can be achieved by locating energy stores at either end of each process stream. This theoretically large number of heat-storage tanks (twice the number of process streams) can be reduced to just a few tanks. A simple procedure for determining a number of heat-storage tanks sufficient to achieve the maximum energy-saving targets as calculated by the pinch-point method is described. This procedure relies on combinatorial considerations, and could therefore be labeled the combinatorial method for incorporation of heat storage in heat-exchanger networks. Qualitative arguments justifying the procedure are presented. For simple systems, waste-heat recovery systems with only three heat-storage temperatures (a hot storage, a cold storage, and a heat store at the pinch temperature) often can achieve the maximum energy-saving targets. Through case studies, six of which are presented, it is found that a theoretically large number of heat-storage tanks (twice the number of process streams) can be reduced to just a few tanks. The description of these six cases is intended to be sufficiently detailed to serve as benchmark cases for development of alternative methods.
Stoltze, S.; Mikkelsen, J.; Lorentzen, B.; Petersen, P.M.; Qvale, B. [Technical Univ. of Denmark, Lyngby (Denmark). Lab. for Energetics
PUBLISHED VERSION ICRF heating in JET during initial operations with the ITER-like wall
. Heat-fluxes on the protecting limiters close the antennas quantified using Infra-Red (IR) thermography
Metrological tool for the characterization of flame fronts based on the coupling of heat
° flame inclination angle due to wind [ ]th i W theoretical radiative heat flux received by the ith target
Are ghost surfaces and quadratic-flux-minimizing surfaces the same?
12 2 2 10 || parallel diffusion dominates perpendicular diffusio solved numerically on grid 2 2 heat, 1 Nov 2009, Atlanta, GA, USA ( ) -10 || ||heat transport is anisotropic: 0 with / =10 if nested flux
Hudson, Stuart
Regional climate effects of irrigation and urbanization in the western united states: a model intercomparison
In the two northern grid cells, sensible heat flux decreasedthe two southern grid cells sensible heat flux increased andgrid cells that were irrigated in Figure 5. January and August latent heat
Atmospheric Neutrino Fluxes
Starting with an historical review, I summarize the status of calculations of the flux of atmospheric neutrinos and how they compare to measurements.
Thomas K. Gaisser
Varying trends in surface energy fluxes and associated climatebetween 1960-2002 based on transient climate simulations
The observed reduction in land surface radiation over the last several decades (1960-1990)---the so-called ''dimming effect''--- and the more recent evidence of a reversal in ''dimming'' over some locations beyond 1990 suggest several consequences on climate, notably on the hydrological cycle. Such a reduction in radiation should imply reduced surface temperature (Ts) and precipitation, which have not occurred. We have investigated the possible causes for the above climate features using a climate model coupled to a dynamic ocean model under natural and anthropogenic conditions. To isolate the aerosol influence on surface radiation trends, we have analyzed transient climate simulations from1960 to 2002 with and without anthropogenic aerosols. Based on a linear trend with aerosol effects included, the global mean change in the surface solar radiation absorbed over land is -0.021+-0.0033 Wm-2yr-1. Although the overall trend is negative, we do note a reversal in dimming after 1990, consistent with observations. Without aerosol effects, the surface solar radiation absorbed over land increases throughout 1960 to 2002, mainly due to the decrease in cloud cover associated with increased greenhouse warming. In spite of a simulated increase in Ts of 0.012 Kyr-1 for 1960 to 2002, the global mean latent heat flux and associated intensity of the hydrological cycle decrease overall, however with increases over some land locations due mainly to moisture advection. Simulated changes correspond more closely to observed changes when accounting for aerosol effects on climate.
Nazarenko, Larissa; Menon, Surabi
Spheromak reactor with poloidal flux-amplifying transformer
An inductive transformer in the form of a solenoidal coils aligned along the major axis of a flux core induces poloidal flux along the flux core's axis. The current in the solenoidal coil is then reversed resulting in a poloidal flux swing and the conversion of a portion of the poloidal flux to a toroidal flux in generating a spheromak plasma wherein equilibrium approaches a force-free, minimum Taylor state during plasma formation, independent of the initial conditions or details of the formation. The spheromak plasma is sustained with the Taylor state maintained by oscillating the currents in the poloidal and toroidal field coils within the plasma-forming flux core. The poloidal flux transformer may be used either as an amplifier stage in a moving plasma reactor scenario for initial production of a spheromak plasma or as a method for sustaining a stationary plasma and further heating it. The solenoidal coil embodiment of the poloidal flux transformer can alternately be used in combination with a center conductive cylinder aligned along the length and outside of the solenoidal coil. This poloidal flux-amplifying inductive transformer approach allows for a relaxation of demanding current carrying requirements on the spheromak reactor's flux core, reduces plasma contamination arising from high voltage electrode discharge, and improves the efficiency of poloidal flux injection.
Furth, Harold P. (Princeton, NJ); Janos, Alan C. (East Windsor, NJ); Uyama, Tadao (Osaka, JP); Yamada, Masaaki (Lawrenceville, NJ)
Enhanced heat transfer for thermionic power modules
The thermionic power module is capable of operating at very high heat fluxes, which in turn serve to reduce capital costs. The most efficient operation also requires uniform heat fluxes. The development of enhanced heat transfer systems is required to meet the demand for high heat fluxes (>20 w/cm/sup 2/) at high temperatures (>1500K) which advanced thermionic power modules place upon combustion systems. Energy transfer from the hot combustion gases may take place by convection, radiation, or a combination of radiation and convection. Enhanced convective heat transfer with a jet impingement system has been demonstrated in a thermionic converter. The recently-developed cellular ceramic radiative heat transfer system has also been applied to a thermionic converter. By comparing the jet impingement and cellular ceramic radiative heat transfer systems, an appropriate system may be selected for utilization in advanced thermionic power modules. Results are reported.
Johnson, D.C.
Plasma momentum meter for momentum flux measurements
Invention comprises an instrument in which momentum flux onto a biasable target plate is transferred via a suspended quartz tube onto a sensitive force transducer--a capacitance-type pressure gauge. The transducer is protected from thermal damage, arcing and sputtering, and materials used in the target and pendulum are electrically insulating, rigid even at elevated temperatures, and have low thermal conductivity. The instrument enables measurement of small forces (10.sup.-5 to 10.sup.3 N) accompanied by high heat fluxes which are transmitted by energetic particles with 10's of eV of kinetic energy in a intense magnetic field and pulsed plasma environment.
Zonca, Fulvio (Rome, IT); Cohen, Samuel A. (Hopewell, NJ); Bennett, Timothy (Princeton, NJ); Timberlake, John R. (Allentown, NJ)
Heat Content Changes in the Pacific Ocean
Heat Content Changes in the Pacific Ocean The Acoustic Thermometry of Ocean Cli- mate (ATOC assimilating ocean observations and changes expected from surface heat fluxes as measured by the daily National are a result of advection of heat by ocean currents. We calculate that the most likely cause of the discrepancy
Frandsen, Jannette B.
Atmospheric State, Cloud Microphysics and Radiative Flux
Atmospheric thermodynamics, cloud properties, radiative fluxes and radiative heating rates for the ARM Southern Great Plains (SGP) site. The data represent a characterization of the physical state of the atmospheric column compiled on a five-minute temporal and 90m vertical grid. Sources for this information include raw measurements, cloud property and radiative retrievals, retrievals and derived variables from other third-party sources, and radiative calculations using the derived quantities.
Mace, Gerald
Rank-r latent models for cross-covariance Jacob A. Wegelin
Rank-r latent models for cross-covariance Jacob A. Wegelin Thomas S. Richardson University of Gaussian rank-r latent models for cross-covariance. We show by construction that any variance-covariance matrix for the ob- served variables induced by rank-r reduced-rank regression can be induced by a rank
Bayesian latent variable modelling in studies of air pollution and health
Bayesian latent variable modelling in studies of air pollution and health Duncan Lee, Gavin://www.bath.ac.uk/math-sci/BICS #12;Bayesian latent variable modelling in studies of air pollution and health. Duncan Lee (1), Gavin to the approach adopted for modelling the trend and correlation. KEYWORDS: Air pollution and health; Bayesian
Burton, Geoffrey R.
An Investigation of the Latent Semantic Analysis Technique for Document Retrieval
An Investigation of the Latent Semantic Analysis Technique for Document Retrieval STUDENT PROJECT;_________________________________________________________________________ An Investigation of the Latent Semantic Analysis Technique for Document Retrieval. Report by: David Mugo Page 2. These term-matching techniques have always relied on matching query terms with document terms to retrieve
Identification of Segments of French Urban Public Transport with a Latent Class Frontier Model
Identification of Segments of French Urban Public Transport with a Latent Class Frontier Model from 1995 to 2002 with unbalanced panel data. The latent class frontier model is used allowing the identification of different segments in the production frontier. We find that there are three statistically
Determining Reactor Neutrino Flux
Flux is an important source of uncertainties for a reactor neutrino experiment. It is determined from thermal power measurements, reactor core simulation, and knowledge of neutrino spectra of fuel isotopes. Past reactor neutrino experiments have determined the flux to (2-3)% precision. Precision measurements of mixing angle $\\theta_{13}$ by reactor neutrino experiments in the coming years will use near-far detector configurations. Most uncertainties from reactor will be canceled out. Understanding of the correlation of uncertainties is required for $\\theta_{13}$ experiments. Precise determination of reactor neutrino flux will also improve the sensitivity of the non-proliferation monitoring and future reactor experiments. We will discuss the flux calculation and recent progresses.
Jun Cao
Industrial Heat Recovery - 1982
like: "Vertical, natural circulation boilers are intrinsically mbre reliable than horizontal, forced circula tion boilers.",4 and " it will be seen that horizontal tubes have much lower heat fluxes at burnout than do vertical ones, though...-steam density difference dia gram (Figure 1) has been presented repeat edly in order to indicate a significant density difference between the two phases (even close to the critical pressure) which induces natural circulation. However, this diagra...
Csathy, D.
Pool boiling heat transfer characteristics of nanofluids
Nanofluids are engineered colloidal suspensions of nanoparticles in water, and exhibit a very significant enhancement (up to 200%) of the boiling Critical Heat Flux (CHF) at modest nanoparticle concentrations (50.1% by ...
EXPERIMENTAL INVESTIGATION OF BOILING HEAT CONVECTION IN A FRACTURE A REPORT SUBMITTED between heat conduction and heat convection with boiling flow in a rock fracture. An experimental coefficient. This coefficient is the proportionality factor between the heat flux to a fracture surface
Stanford University
Solar Magnetic Flux Ropes
The most probable initial magnetic configuration of a CME is a flux rope consisting of twisted field lines which fill the whole volume of a dark coronal cavity. The flux ropes can be in stable equilibrium in the coronal magnetic field for weeks and even months, but suddenly they loose their stability and erupt with high speed. Their transition to the unstable phase depends on the parameters of the flux rope (i.e., total electric current, twist, mass loading etc.), as well as on the properties of the ambient coronal magnetic field. One of the major governing factors is the vertical gradient of the coronal magnetic field which is estimated as decay index (n). Cold dense prominence material can be collected in the lower parts of the helical flux tubes. Filaments are therefore good tracers of the flux ropes in the corona, which become visible long before the beginning of the eruption. The perspectives of the filament eruptions and following CMEs can be estimated by the comparison of observed filament heights with...
Filippov, Boris; Srivastava, Abhishek K; Uddin, Wahab
NOVEMBER 1997 2847L O F G R E N Simulated Effects of Idealized Laurentian Great Lakes on
cycle of latent and sensible heat flux. Very high upward sensible heat flux occurs over these idealized noted remote effects of the Great Lakes in the form of different precipitation patterns over
Formation of nanometer-size wires using infiltration into latent nuclear tracks
Nanometer-size wires having a cross-sectional dimension of less than 8 nm with controllable lengths and diameters are produced by infiltrating latent nuclear or ion tracks formed in trackable materials with atomic species. The trackable materials and atomic species are essentially insoluble in each other, thus the wires are formed by thermally driven, self-assembly of the atomic species during annealing, or re-crystallization, of the damage in the latent tracks. Unlike conventional ion track lithography, the inventive method does not require etching of the latent tracks.
Musket, Ronald G. (Danville, CA); Felter, Thomas E. (Livermore, CA)
Radiative Flux Analysis
The Radiative Flux Analysis is a technique for using surface broadband radiation measurements for detecting periods of clear (i.e. cloudless) skies, and using the detected clear-sky data to fit functions which are then used to produce continuous clear-sky estimates. The clear-sky estimates and measurements are then used in various ways to infer cloud macrophysical properties.
Long, Chuck [NOAA
Acoustic emission from magnetic flux tubes in the solar network
We present the results of three-dimensional numerical simulations to investigate the excitation of waves in the magnetic network of the Sun due to footpoint motions of a magnetic flux tube. We consider motions that typically mimic granular buffeting and vortex flows and implement them as driving motions at the base of the flux tube. The driving motions generates various MHD modes within the flux tube and acoustic waves in the ambient medium. The response of the upper atmosphere to the underlying photospheric motion and the role of the flux tube in channeling the waves is investigated. We compute the acoustic energy flux in the various wave modes across different boundary layers defined by the plasma and magnetic field parameters and examine the observational implications for chromospheric and coronal heating.
Vigeesh, G
Model Specification Searches in Latent Growth Modeling: A Monte Carlo Study
This dissertation investigated the optimal strategy for the model specification search in the latent growth modeling. Although developing an initial model based on the theory from prior research is favored, sometimes researchers may need to specify...
Kim, Min Jung
Specific heat in two-dimensional melting
We report the specific heat $c_N$ around the melting transition(s) of micrometer-sized superparamagnetic particles confined in two dimensions, calculated from fluctuations of positions and internal energy, and corresponding Monte Carlo simulations. Since colloidal systems provide single particle resolution, they offer the unique possibility to compare the experimental temperatures of peak position of $c_N(T)$ and symmetry breaking, respectively. While order parameter correlation functions confirm the Kosterlitz-Thouless-Halperin-Nelson-Young melting scenario where translational and orientational order symmetries are broken at different temperatures with an intermediate so called hexatic phase, we observe a single peak of the specific heat within the hexatic phase, with excellent agreement between experiment and simulation. Thus, the peak is not associated with broken symmetries but can be explained with the total defect density, which correlates with the maximum increase of isolated dislocations. The absence of a latent heat strongly supports the continuous character of both transitions.
Sven Deutschländer; Antonio M. Puertas; Georg Maret; Peter Keim
Anisotropic Heat and Water Transport in a PEFC Cathode Gas Diffusion Layer
PEFCs , owing to their high en- ergy efficiency, low emission, and low noise, are widely considered. In addition, the latent heat effects due to condensation/evaporation of water on the temperature and water ohmic losses. Along with water man- agement, thermal management is also a key to high performance
Heat transfer in katabatic flow Measurements on the Morteratsch glacier, Switzerland
Heat transfer in katabatic flow Measurements on the Morteratsch glacier, Switzerland M. de Graaf #12;Heat transfer in katabatic flow Measurements on the Morteratsch glacier, Switzerland Martin de is used to calculate surface heat fluxes over glaciers. As determination of surface fluxes still
Graaf, Martin de
Urban Energy Fluxes in Built-Up Downtown Areas and Variations across the Urban Area, for Use in Dispersion Models
Surface energy fluxes, at averaging times from 10 min to 1 h, are needed as inputs to most state-of-the-art dispersion models. The sensible heat flux is a major priority, because it is combined with the momentum flux to ...
Hanna, Steven
Total Space Heating Water Heating Cook-
Gasoline and Diesel Fuel Update (EIA)
Released: September, 2008 Total Space Heating Water Heating Cook- ing Other Total Space Heating Water Heating Cook- ing Other All Buildings* ... 1,602 1,397...
Released: September, 2008 Total Space Heating Water Heating Cook- ing Other Total Space Heating Water Heating Cook- ing Other All Buildings* ... 1,870 1,276...
Energy Consumption Survey: Energy End-Use Consumption Tables Total Space Heating Water Heating Cook- ing Other Total Space Heating Water Heating Cook- ing Other All...
Released: September, 2008 Total Space Heating Water Heating Cook- ing Other Total Space Heating Water Heating Cook- ing Other All Buildings ... 2,037...
Susanville District Heating District Heating Low Temperature...
Susanville District Heating District Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Susanville District Heating District Heating Low Temperature...
HIGS Flux Performance Projection
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-SeriesFlickr FlickrGuided Self-Assembly of GoldHAWCHIGS flux performance table
Mixed Layer Lateral Eddy Fluxes Mediated by Air-Sea Interaction
The modulation of air–sea heat fluxes by geostrophic eddies due to the stirring of temperature at the sea surface is discussed and quantified. It is argued that the damping of eddy temperature variance by such air–sea ...
Shuckburgh, Emily
509 RECENT ADVANCES IN HEAT TRANSFER TO HELIUM 1 C. JOHANNES Service de Recherches Appliquées, L boiling, forced convection heat transfer. Relations between critical nucleate flux and some parameters confronted with the problem of calculating the heat transfer from the helium to the superconducting material
Heating system
A heating system utilizing solar panels and buried ground conduits to collect and store heat which is delivered to a heatpump heat exchanger. A heat-distribution fluid continuously circulates through a ground circuit to transfer heat from the ground to the heat exchanger. The ground circuit includes a length of buried ground conduit, a pump, a check valve and the heat exchanger. A solar circuit, including a solar panel and a second pump, is connected in parallel with the check valve so that the distribution fluid transfers solar heat to the heat exchanger for utilization and to the ground conduit for storage when the second pump is energized. A thermostatically instrumented control system energizes the second pump only when the temperature differential between the solar panel inlet and outlet temperatures exceeds a predetermined value and the ground temperature is less than a predetermined value. Consequently, the distribution fluid flows through the solar panel only when the panel is capable of supplying significant heat to the remainder of the system without causing excessive drying of the ground.
Nishman, P.J.
E-Print Network 3.0 - additional direct heat Sample Search Results
transfer. The specific design is directed toward the cooling of a prototypical optoelectronic... SUPERCOOLER FOR HIGH HEAT FLUX COOLING IN OPTOELECTRONIC PACKAGES Walter W....
Traveling-wave device with mass flux suppression
A traveling-wave device is provided with the conventional moving pistons eliminated. Acoustic energy circulates in a direction through a fluid within a torus. A side branch may be connected to the torus for transferring acoustic energy into or out of the torus. A regenerator is located in the torus with a first heat exchanger located on a first side of the regenerator downstream of the regenerator relative to the direction of the circulating acoustic energy; and a second heat exchanger located on an upstream side of the regenerator. The improvement is a mass flux suppressor located in the torus to minimize time-averaged mass flux of the fluid. In one embodiment, the device further includes a thermal buffer column in the torus to thermally isolate the heat exchanger that is at the operating temperature of the device.
Swift, Gregory W. (Santa Fe, NM); Backhaus, Scott N. (Los Alamos, NM); Gardner, David L. (White Rock, NM)
A study of the minimum meniscus radius as a function of vapor temperature using heat pipes
/sec 2 latent heat of vaporization, BTU/lb m wick permeability, ft 2 length, ft molecular weight, ibm water parameter, hf pfof/uf fgff f pressure, lbf/ft 2 desorption pressure, lbf/ft 2 saturation pressure, lbf/ft 2 heat transfer rate, BTU... into Cosgrove's equation, assuming the temperature is uni- form inside the heat pipe, replacing the sum of the section lengths by the total length of the heat pipe, and combining the fluid prop- erties into one var1able there is obtained N = hf pfof/uf...
Sonnier, Ronald James
Sandia National Laboratories: Beryllium High Heat Flux Testing...
system, controls, and blast gun) is now used for electron beam test system vacuum vessel beryllium decontamination and has shortened the beryllium clean-up procedure from...
Systematic errors in ground heat flux estimation and their correction
Incoming radiation forcing at the land surface is partitioned among the components of the surface energy balance in varying proportions depending on the time scale of the forcing. Based on a land-atmosphere analytic continuum ...
Gentine, P.
Technical Sessions Measurements of Surface Heat Flux Over Contrasting Surfaces
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security AdministrationcontrollerNanocrystallineForeign ObjectOUR8, 2013Battelle:Technical
Boosted Fast Flux Loop Final Report
The Boosted Fast Flux Loop (BFFL) project was initiated to determine basic feasibility of designing, constructing, and installing in a host irradiation facility, an experimental vehicle that can replicate with reasonable fidelity the fast-flux test environment needed for fuels and materials irradiation testing for advanced reactor concepts. Originally called the Gas Test Loop (GTL) project, the activity included (1) determination of requirements that must be met for the GTL to be responsive to potential users, (2) a survey of nuclear facilities that may successfully host the GTL, (3) conceptualizing designs for hardware that can support the needed environments for neutron flux intensity and energy spectrum, atmosphere, flow, etc. needed by the experimenters, and (4) examining other aspects of such a system, such as waste generation and disposal, environmental concerns, needs for additional infrastructure, and requirements for interfacing with the host facility. A revised project plan included requesting an interim decision, termed CD-1A, that had objectives of' establishing the site for the project at the Advanced Test Reactor (ATR) at the Idaho National Laboratory (INL), deferring the CD 1 application, and authorizing a research program that would resolve the most pressing technical questions regarding GTL feasibility, including issues relating to the use of booster fuel in the ATR. Major research tasks were (1) hydraulic testing to establish flow conditions through the booster fuel, (2) mini-plate irradiation tests and post-irradiation examination to alleviate concerns over corrosion at the high heat fluxes planned, (3) development and demonstration of booster fuel fabrication techniques, and (4) a review of the impact of the GTL on the ATR safety basis. A revised cooling concept for the apparatus was conceptualized, which resulted in renaming the project to the BFFL. Before the subsequent CD-1 approval request could be made, a decision was made in April 2006 that further funding for the project would be suspended. Remaining funds have been used to prepare and irradiate mini-plates of the proposed booster fuel. The current baseline design is for a set of three test positions inside an in-pile tube with a thermal neutron absorber and heat sink made of aluminum mixed with hafnium. Operating the ATR at power levels needed to achieve the required fast flux will result in an estimated increase in ATR fuel consumption between 15 and 20% above present rates and a reduction in the time between fuel replacements. Preliminary safety analyses conducted have indicted safe operation of the ATR with the GTL under normal, abnormal, and postulated accident conditions. More comprehensive analyses are needed.
Boosted Fast Flux Loop Project Staff
Micro- and Nanoscale Measurement Methods for Phase Change Heat Transfer on Planar and Structured Surfaces
In this opinion piece, we discuss recent advances in experimental methods for characterizing phase change heat transfer. We begin with a survey of techniques for high-resolution measurements of temperature and heat flux ...
Buongiorno, Jacopo
Independent Control of Sensible and Latent Cooling in Small Buildings
util impact. INTRODUCTION Dehumidification has become an increasingly large fraction of the total cooling load in many new buildings, as heat gains through the envelope have been reduced but internal moisture generation and the need... to be coincident with maximum air-conditioning loads. The possibility was suggested that by independently controlling temperature and humidity ways might be found to ameliorate the peak electrical loads imposed on utilities by the residential and small...
Andrews, J.; Lamontagne, J.; Piraino, M.
Physics of String Flux Compactifications
We provide a qualitative review of flux compactifications of string theory, focusing on broad physical implications and statistical methods of analysis.
Frederik Denef; Michael R. Douglas; Shamit Kachru
Fluxes, Gaugings and Gaugino Condensates
Based on the correspondence between the N = 1 superstring compactifications with fluxes and the N = 4 gauged supergravities, we study effective N = 1 four-dimensional supergravity potentials arising from fluxes and gaugino condensates in the framework of orbifold limits of (generalized) Calabi-Yau compactifications. We give examples in heterotic and type II orientifolds in which combined fluxes and condensates lead to vacua with small supersymmetry breaking scale. We clarify the respective roles of fluxes and condensates in supersymmetry breaking, and analyze the scaling properties of the gravitino mass.
J. -P. Derendinger; C. Kounnas; P. M. Petropoulos
Materials Compatibility and Aging for Flux and Cleaner Combinations.
A materials study of high reliability electronics cleaning is presented here. In Phase 1, mixed type substrates underwent a condensed contaminants application to view a worst- case scenario for unremoved flux with cleaning agent residue for parts in a silicone oil filled environment. In Phase 2, fluxes applied to copper coupons and to printed wiring boards underwent gentle cleaning then accelerated aging in air at 65% humidity and 30 O C. Both sets were aged for 4 weeks. Contaminants were no-clean (ORL0), water soluble (ORH1 liquid and ORH0 paste), and rosin (RMA; ROL0) fluxes. Defluxing agents were water, solvents, and engineered aqueous defluxers. In the first phase, coupons had flux applied and heated, then were placed in vials of oil with a small amount of cleaning agent and additional coupons. In the second phase, pairs of copper coupons and PWB were hand soldered by application of each flux, using tin-lead solder in a strip across the coupon or a set of test components on the PWB. One of each pair was cleaned in each cleaning agent, the first with a typical clean, and the second with a brief clean. Ionic contamination residue was measured before accelerated aging. After aging, substrates were removed and a visual record of coupon damage made, from which a subjective rank was applied for comparison between the various flux and defluxer combinations; more corrosion equated to higher rank. The ORH1 water soluble flux resulted in the highest ranking in both phases, the RMA flux the least. For the first phase, in which flux and defluxer remained on coupons, the aqueous defluxers led to worse corrosion. The vapor phase cleaning agents resulted in the highest ranking in the second phase, in which there was no physical cleaning. Further study of cleaning and rinsing parameters will be required.
Archuleta, Kim; Piatt, Rochelle
Heat Transfer -1 A satellite in space orbits the sun. The satellite can be approximated as a flat plate with
Heat Transfer - 1 A satellite in space orbits the sun. The satellite can be approximated as a flat plate with dimensions and properties given below. (a) Calculate the solar heat flux (W/m2 is at a distance where the solar heat flux (as defined above) is 500 W/m2 , and the flat plate is oriented
Virginia Tech
Effects of Radiative Diffusion on Thin Flux Tubes in Turbulent Solar-like Convection
We study the combined effects of convection and radiative diffusion on the evolution of thin magnetic flux tubes in the solar interior. Radiative diffusion is the primary supplier of heat to convective motions in the lower convection zone, and it results in a heat input per unit volume of magnetic flux tubes that has been ignored by many previous thin flux tube studies. We use a thin flux tube model subject to convection taken from a rotating spherical shell of turbulent, solar-like convection as described by Weber, Fan, and Miesch (2011, Astrophys. J., 741, 11; 2013, Solar Phys., 287, 239), now taking into account the influence of radiative heating on flux tubes of large-scale active regions. Our simulations show that flux tubes of less than or equal to 60 kG subject to solar-like convective flows do not anchor in the overshoot region, but rather drift upward due to the increased buoyancy of the flux tube earlier in its evolution as a result of the inclusion of radiative diffusion. Flux tubes of magnetic fie...
Weber, Maria A
Heat Transfer to the Structure during the Fire
The post-flashover Fire Test One of a furnished room in Dalmarnock provides a wealth of information including measurements in both the gas phase and on compartment boundaries (Chapter 3). Total heat fluxes at a number ...
Jowsey, Allan; Torero, Jose L; Lane, Barbara
Influence of Infrared Radiation on Attic Heat Transfer
roof temperatures. It was found that a radiant barrier such as aluminum foil can reduce the heat flux significantly. Experimental results were compared to a Three-Region approximate solution developed at Oak Ridge National Laboratories (ORNL). The model...
Katipamula, S.; Turner, W. D.; Murphy, W. E.; O'Neal, D. L.
Heat collector
A heat collector and method suitable for efficiently and cheaply collecting solar and other thermal energy are provided. The collector employs a heat pipe in a gravity-assist mode and is not evacuated. The collector has many advantages, some of which include ease of assembly, reduced structural stresses on the heat pipe enclosure, and a low total materials cost requirement. Natural convective forces drive the collector, which after startup operates entirely passively due in part to differences in molecular weights of gaseous components within the collector.
Merrigan, Michael A. (Santa Cruz, NM)
Merrigan, M.A.
Inverse estimation of surface heating condition in a three-dimensional object using conjugate gradient method
heat conduction Laser Gaussian profile Conjugate gradient method a b s t r a c t Temperature and heat gradient method Jianhua Zhou, Yuwen Zhang *, J.K. Chen, Z.C. Feng Department of Mechanical and Aerospace gradient method (CGM) with temperature and heat flux measured on back surface (opposite to the heated
1 NUMERICAL SIMULATION OF POOL BOILING FOR STEADY STATE AND TRANSIENT HEATING Ying He, Masahiro role in nucleate and transition boiling heat transfer at high heat flux. Many experiments have been in the numerical simulation of boiling heat transfer. In this study, based on the macrolayer evaporation model
Maruyama, Shigeo
Corrosive resistant heat exchanger
A corrosive and errosive resistant heat exchanger which recovers heat from a contaminated heat stream. The heat exchanger utilizes a boundary layer of innocuous gas, which is continuously replenished, to protect the heat exchanger surface from the hot contaminated gas. The innocuous gas is conveyed through ducts or perforations in the heat exchanger wall. Heat from the heat stream is transferred by radiation to the heat exchanger wall. Heat is removed from the outer heat exchanger wall by a heat recovery medium.
Richlen, Scott L. (Annandale, VA)
BUILDING BLOCKS FOR HIERARCHICAL LATENT VARIABLE MODELS Harri Valpola, Tapani Raiko and Juha Karhunen
BUILDING BLOCKS FOR HIERARCHICAL LATENT VARIABLE MODELS Harri Valpola, Tapani Raiko and Juha, Espoo, Finland EÂmail: {Harri.Valpola, Tapani.Raiko, firstname.lastname@example.com URL: http; and the approximation of the true posterior p(#18; j X) by q(#18;). The cost function C used in ensemble learning is C
Karhunen, Juha
Tuberculosis and Latent TB Treatment Approved by the UHS Patient Education Committee
health care Who abuse drugs and/or alcohol Who work or are residents of long-term care facilities return to the health care worker who will check to see if there is a reaction to the test. A positive tell the health care worker prior to having the test repeated. #12;Tuberculosis and Latent TB Treatment
Yener, Aylin
integrating both a hierarchical regression model of biases and a structural equation model of the answers : hierarchical model, latent variables, structural equations, shared variables, experts knowledge, uncertainty 1 sont précisément définis dans un guide international, le VIM (2007). Des normes proposent des méthodes
Condensation Risk in a Room with High Latent Load and Chilled Ceiling
proposed a new ventilation system with radiant cooling panel and air supplied from a liquid desiccant dehumidification system, which provided very dry supply air and chilled water for radiant cooling. This study usedCondensation Risk in a Room with High Latent Load and Chilled Ceiling Panel and with Air Supplied
Chen, Qingyan "Yan"
Efficient Energy Management and Data Recovery in Sensor Networks using Latent Variables Based Tensor
Efficient Energy Management and Data Recovery in Sensor Networks using Latent Variables Based factor in a successful sensor network deployment is finding a good balance between maximizing the number of measurements taken (to maintain a good sampling rate) and minimizing the overall energy consumption (to extend
Simunic, Tajana
Author's personal copy Slower postnatal motor development in infants of mothers with latent toxoplasmosis
a , Jaroslav Flegr a a Department of Philosophy and History of Science, Faculty of Science, Charles University and an associated risk of a sieve effect, our results should be considered as preliminary and performing a large effects of latent toxoplasmosis on the risk of abortion; however, this speculation was not confirmed
Flegr, Jaroslav
Latent-to-full palmprint comparison based on radial triangulation under forensic conditions
Latent-to-full palmprint comparison based on radial triangulation under forensic conditions Ruifang In forensic applications the evidential value of palmprints is obvious according to surveys of law enforcement. Consequently, developing forensic automatic palmprint identification technology is an urgent and challenging
Autonoma de Madrid, Universidad
Development of an Air-Source Heat Pump Integrated with a Water Heating / Dehumidification Module
A residential-sized dual air-source integrated heat pump (AS-IHP) concept is under development in partnership between ORNL and a manufacturer. The concept design consists of a two-stage air-source heat pump (ASHP) coupled on the air distribution side with a separate novel water heating/dehumidification (WH/DH) module. The motivation for this unusual equipment combination is the forecast trend for home sensible loads to be reduced more than latent loads. Integration of water heating with a space dehumidification cycle addresses humidity control while performing double-duty. This approach can be applied to retrofit/upgrade applications as well as new construction. A WH/DH module capable of ~1.47 L/h water removal and ~2 kW water heating capacity was assembled by the manufacturer. A heat pump system model was used to guide the controls design; lab testing was conducted and used to calibrate the models. Performance maps were generated and used in a TRNSYS sub-hourly simulation to predict annual performance in a well-insulated house. Annual HVAC/WH energy savings of ~35% are predicted in cold and hot-humid U.S. climates compared to a minimum efficiency baseline.
Rice, C Keith [ORNL] [ORNL; Uselton, Robert B. [Lennox Industries, Inc] [Lennox Industries, Inc; Shen, Bo [ORNL] [ORNL; Baxter, Van D [ORNL] [ORNL; Shrestha, Som S [ORNL] [ORNL
Acoustically Enhanced Boiling Heat Transfer
An acoustic field is used to increase the critical heat flux (CHF) of a flat-boiling-heat-transfer surface. The increase is a result of the acoustic effects on the vapor bubbles. Experiments are performed to explore the effects of an acoustic field on vapor bubbles in the vicinity of a rigid-heated wall. Work includes the construction of a novel heater used to produce a single vapor bubble of a prescribed size and at a prescribed location on a flatboiling surface for better study of an individual vapor bubble's reaction to the acoustic field. Work also includes application of the results from the single-bubble heater to a calibrated-copper heater used for quantifying the improvements in CHF.
Z. W. Douglas; M. K. Smith; A. Glezer
Heating System Specification Specification of Heating System
Appendix A Heating System Specification /* Specification of Heating System (loosely based */ requestHeat : Room Â? bool; 306 #12; APPENDIX A. HEATING SYSTEM SPECIFICATION 307 /* user inputs */ livingPattern : Room Â? behaviour; setTemp : Room Â? num; heatSwitchOn, heatSwitchOff, userReset : simple
Day, Nancy
The Solar Wind Energy Flux
The solar-wind energy flux measured near the ecliptic is known to be independent of the solar-wind speed. Using plasma data from Helios, Ulysses, and Wind covering a large range of latitudes and time, we show that the solar-wind energy flux is independent of the solar-wind speed and latitude within 10%, and that this quantity varies weakly over the solar cycle. In other words the energy flux appears as a global solar constant. We also show that the very high speed solar-wind (VSW > 700 km/s) has the same mean energy flux as the slower wind (VSW < 700 km/s), but with a different histogram. We use this result to deduce a relation between the solar-wind speed and density, which formalizes the anti-correlation between these quantities.
Chat, G Le; Meyer-Vernet, N
Heating 7. 2 user's manual
HEATING is a general-purpose conduction heat transfer program written in Fortran 77. HEATING can solve steady-state and/or transient heat conduction problems in one-, two-, or three-dimensional Cartesian, cylindrical, or spherical coordinates. A model may include multiple materials, and the thermal conductivity, density, and specific heat of each material may be both time- and temperature-dependent. The thermal conductivity may also be anisotropic. Materials may undergo change of phase. Thermal properties of materials may be input or may be extracted from a material properties library. Heat-generation rates may be dependent on time, temperature, and position, and boundary temperatures may be time- and position-dependent. The boundary conditions, which may be surface-to-environment or surface-to-surface, may be specified temperatures or any combination of prescribed heat flux, forced convection, natural convection, and radiation. The boundary condition parameters may be time- and/or temperature-dependent. General gray-body radiation problems may be modeled with user-defined factors for radiant exchange. The mesh spacing may be variable along each axis. HEATING uses a runtime memory allocation scheme to avoid having to recompile to match memory requirements for each specific problem. HEATING utilizes free-form input. Three steady-state solution techniques are available: point-successive-overrelaxation iterative method with extrapolation, direct-solution, and conjugate gradient. Transient problems may be solved using any one of several finite-difference schemes: Crank-Nicolson implicit, Classical Implicit Procedure (CIP), Classical Explicit Procedure (CEP), or Levy explicit method. The solution of the system of equations arising from the implicit techniques is accomplished by point-successive-overrelaxation iteration and includes procedures to estimate the optimum acceleration parameter.
Childs, K.W.
AOSC 621AOSC 621 Radiative Heating/CoolingRadiative Heating/Cooling
? Why drop off near sfc? 4 #12;Net flux Net flux: F = F+ - F- 1 2 F-(1) F+(1) F-(2) F+(2) Net energy at the top of the atmosphere is zero. Then we can write 1' ' )',( )'()0,()( 0 * dz dz zzdT zBzTBzF z z F F · The heating rate at z is defined as follows: )( )( d zdF zH net four termsofconsistwilland dz A
Li, Zhanqing
Heat Exchanger Fouling- Prediction, Measurement and Mitigation
wall. The fouling probe has been successfully tested in the laboratory at flue gas temperatures up to 2200°F and a local heat flux up to 41,000 BTU/hr-ft2. The probe has been field tested at a coal-fired boiler plant. Future tests at a municipal waste...
Peterson, G. R.
PMEL Ocean Climate Station Program Meghan Cronin, Chris Sabine, Chris Meinig
. Papa HOT MBARI Cold dry air blowing over warm Kuroshio Extension causes large sensible and latent heat for climate reference) Net Surface Heat Flux = TurbPMEL Ocean Climate Station Program Meghan Cronin, Chris Sabine, Chris Meinig NOAA Pacific Marine
High-Latitude Ocean and Sea Ice Surface Fluxes: Challenges for Climate Research Mark A. Bourassa1
, the Wilkins Ice Shelf collapsed equally quickly (Scambos et al. 2009). Ocean heat content is rising rapidlyHigh-Latitude Ocean and Sea Ice Surface Fluxes: Challenges for Climate Research Mark A. Bourassa1 conditions for the measurement and estimation of airÂsea and ice fluxes, limiting understanding of related
Gille, Sarah T.
High-Latitude Ocean and Sea Ice Surface Fluxes: Challenges for Climate Research1 Mark A. Bourassa1
), and in 2008, the Wilkins Ice Shelf51 collapsed equally quickly (Scambos et al. 2009). Ocean heat content1 High-Latitude Ocean and Sea Ice Surface Fluxes: Challenges for Climate Research1 2 Mark A conditions for the measurement and estimation of airÂ27 sea and ice fluxes, limiting understanding of related
), and in 2008, the Wilkins Ice Shelf51 collapsed equally quickly (Scambos et al. 2009). Ocean heat content1 High-Latitude Ocean and Sea Ice Surface Fluxes: Challenges for Climate Research1 2 Mark A-latitude surface fluxes will require close collaboration among meteorologists,33 oceanographers, ice physicists
HEAT BUMP MODELING IN HIGH HEAT-LOAD X-RAY OPTICS* E. Windisch IV, Wayne State, Detroit, MI, 48201, U.S.A.
HEAT BUMP MODELING IN HIGH HEAT-LOAD X-RAY OPTICS* E. Windisch IV, Wayne State, Detroit, MI, 48201, U.S.A. Abstract Thermal deformation in high heat load X-Ray optics limits coherence and reduces flux-equipped MATLAB program designed to calculate three dimensional energy depostion in a solid. It uses an executable
Cinabro, David
Triaxial thermopile array geo-heat-flow sensor
A triaxial thermopile array geothermal heat flow sensor is designed to measure heat flow in three dimensions in a reconstituted or unperturbed subsurface regime. Heat flow can be measured in conductive or permeable convective media. The sensor may be encased in protective pvc tubing and includes a plurality of thermistors and an array of heat flow transducers produce voltage proportional to heat flux along the subsurface regime and permit direct measurement of heat flow in the subsurface regime. The presence of the thermistor array permits a comparison to be made between the heat flow estimates obtained from the transducers and heat flow calculated using temperature differences and Fourier's Law. The device is extremely sensitive with an accuracy of less than 0.1 Heat Flow Units (HFU) and may be used for long term readings. 6 figs.
Carrigan, C.R.; Hardee, H.C.; Reynolds, G.D.; Steinfort, T.D.
A triaxial thermopile array geothermal heat flow sensor is designed to measure heat flow in three dimensions in a reconstituted or unperturbed subsurface regime. Heat flow can be measured in conductive or permeable convective media. The sensor may be encased in protective pvc tubing and includes a plurality of thermistors and an array of heat flow transducers arranged in a vertical string. The transducers produce voltage proportional to heat flux along the subsurface regime and permit direct measurement of heat flow in the subsurface regime. The presence of the thermistor array permits a comparison to be made between the heat flow estimates obtained from the transducers and heat flow calculated using temperature differences and Fourier's Law. The device is extremely sensitive with an accuracy of less than 0.1 Heat Flow Units (HFU) and may be used for long term readings.
Carrigan, Charles R. (Tracy, CA); Hardee, Harry C. (Albuquerque, NM); Reynolds, Gerald D. (Tijeras, NM); Steinfort, Terry D. (Tijeras, NM)
Including radiative heat transfer and reaction quenching in modeling a Claus plant waste heat boiler
Due to increasingly stringent sulfur emission regulations, improvements are necessary in the modified Claus process. A recently proposed model by Nasato et al. for the Claus plant waste heat boiler (WHB) is improved by including radiative heat transfer, which yields significant changes in the predicted heat flux and the temperature profile along the WHB tube, leading to a faster quenching of chemical reactions. For the WHB considered, radiation accounts for approximately 20% of the heat transferred by convection alone. More importantly, operating the WHB at a higher gas mass flux is shown to enhance reaction quenching, resulting in a doubling of the predicted hydrogen flow rate. This increase in hydrogen flow rate is sufficient to completely meet the hydrogen requirement of the H[sub 2]S recovery process considered, which would eliminate the need for a hydrogen plant.
Karan, K.; Mehrotra, A.K.; Behie, L.A. (Univ. of Calgary, Alberta (Canada). Dept. of Chemical and Petroleum Engineering)
Micro loop heat pipe evaporator coherent pore structures
and 5360 K for water, Pv is vapor pressure, sigma is surface tension, Rc is the radius of curvature, Psat(Tl) is water saturation pressure at liquid temperature for flat interface, A is Hamaker constant, delta is liquid film thickness, )vib... is the vibrational partion function, w s pore wall temperature, hfg is water latent heat of vaporization, kl is liquid conductivity. The FPEM was developed by Ward1 and applied by Oinuma2 in order to eliminate the need for empirical constants required by Kinetic...
Alexseev, Alexandre Viktorovich
Finite ballooning angle effects on ion temperature gradient driven mode in gyrokinetic flux tube simulations
This paper presents effects of finite ballooning angles on linear ion temperature gradient (ITG) driven mode and associated heat and momentum flux in Gyrokinetic flux tube simulation GENE. It is found that zero ballooning angle is not always the one at which the linear growth rate is maximum. The ITG mode acquires a short wavelength (SW) branch (k{sub ?}?{sub i}?>?1) when growth rates maximized over all ballooning angles are considered. However, the SW branch disappears on reducing temperature gradient showing characteristics of zero ballooning angle SWITG in case of extremely high temperature gradient. Associated heat flux is even with respect to ballooning angle and maximizes at nonzero ballooning angle while the parallel momentum flux is odd with respect to the ballooning angle.
Singh, Rameswar, E-mail: email@example.com [Institute for Plasma Research, Bhat Gandhinagar, Gujarat 2382 428 (India) [Institute for Plasma Research, Bhat Gandhinagar, Gujarat 2382 428 (India); Laboratoire de Physique des Plasmas, Ecole Polytechnique, Route de Saclay, 91128 Palaiseau Cedex (France); Brunner, S. [CRPP, Ecole Polytechnique Federale de Lausanne, CH-1015 Lausanne (Switzerland)] [CRPP, Ecole Polytechnique Federale de Lausanne, CH-1015 Lausanne (Switzerland); Ganesh, R. [Institute for Plasma Research, Bhat Gandhinagar, Gujarat 2382 428 (India)] [Institute for Plasma Research, Bhat Gandhinagar, Gujarat 2382 428 (India); Jenko, F. [Max-Planck-Institut fur Plasmaphysik, EURATOM Association, D-85748 Garching (Germany)] [Max-Planck-Institut fur Plasmaphysik, EURATOM Association, D-85748 Garching (Germany)
Geothermal heating
The aim of the study is to demonstrate the viability of geothermal heating projects in energy and economic terms and to provide nomograms from which an initial estimate may be made without having to use data-processing facilities. The effect of flow rate and temperature of the geothermal water on drilling and on the network, and the effect of climate on the type of housing are considered.
Aureille, M.
Berry-Phase-Induced Heat Pumping and Its Impact on the Fluctuation Theorem Jie Ren (),1,2,* Peter Hanggi,2,3,
Berry-Phase-Induced Heat Pumping and Its Impact on the Fluctuation Theorem Jie Ren (),1,2,* Peter heat baths. We demonstrate that the pumped heat typically exhibits a Berry-phase effect in providing-dependent manipulations various molecular heat pumps have been proposed to efficiently control heat flux against thermal
Li, Baowen
High flux solar energy transformation
Disclosed are multi-stage systems for high flux transformation of solar energy allowing for uniform solar intensification by a factor of 60,000 suns or more. Preferred systems employ a focusing mirror as a primary concentrative device and a non-imaging concentrator as a secondary concentrative device with concentrative capacities of primary and secondary stages selected to provide for net solar flux intensification of greater than 2000 over 95 percent of the concentration area. Systems of the invention are readily applied as energy sources for laser pumping and in other photothermal energy utilization processes. 7 figures.
Winston, R.; Gleckman, P.L.; O'Gallagher, J.J.
Beta ray flux measuring device
A beta ray flux measuring device in an activated member in-core instrumentation system for pressurized water reactors. The device includes collector rings positioned about an axis in the reactor's pressure boundary. Activated members such as hydroballs are positioned within respective ones of the collector rings. A response characteristic such as the current from or charge on a collector ring indicates the beta ray flux from the corresponding hydroball and is therefore a measure of the relative nuclear power level in the region of the reactor core corresponding to the specific exposed hydroball within the collector ring.
Impink, Jr., Albert J. (Murrysville, PA); Goldstein, Norman P. (Murrysville, PA)
Disclosed are multi-stage systems for high flux transformation of solar energy allowing for uniform solar intensification by a factor of 60,000 suns or more. Preferred systems employ a focusing mirror as a primary concentrative device and a non-imaging concentrator as a secondary concentrative device with concentrative capacities of primary and secondary stages selected to provide for net solar flux intensification of greater than 2000 over 95 percent of the concentration area. Systems of the invention are readily applied as energy sources for laser pumping and in other photothermal energy utilization processes.
Winston, Roland (Chicago, IL); Gleckman, Philip L. (Chicago, IL); O'Gallagher, Joseph J. (Flossmoor, IL)
The development of a latent heat thermal energy storage system using a phase change material for solar energy application.
??This investigation forms part of an attempt to provide an alternative to conventional power generation technologies that use fossil fuels which have impact on global… (more)
Zulu, Njabulo Mziwandile.
Heat pump system
An air heating and cooling system for a building includes an expansion-type refrigeration circuit and a heat engine. The refrigeration circuit includes two heat exchangers, one of which is communicated with a source of indoor air from the building and the other of which is communicated with a source of air from outside the building. The heat engine includes a heat rejection circuit having a source of rejected heat and a primary heat exchanger connected to the source of rejected heat. The heat rejection circuit also includes an evaporator in heat exchange relation with the primary heat exchanger, a heat engine indoor heat exchanger, and a heat engine outdoor heat exchanger. The indoor heat exchangers are disposed in series air flow relationship, with the heat engine indoor heat exchanger being disposed downstream from the refrigeration circuit indoor heat exchanger. The outdoor heat exchangers are also disposed in series air flow relationship, with the heat engine outdoor heat exchanger disposed downstream from the refrigeration circuit outdoor heat exchanger. A common fluid is used in both of the indoor heat exchanges and in both of the outdoor heat exchangers. In a first embodiment, the heat engine is a Rankine cycle engine. In a second embodiment, the heat engine is a non-Rankine cycle engine.
Swenson, Paul F. (Cleveland, OH); Moore, Paul B. (Fedhaurn, FL)
Water and Space Heating Heat Pumps
This paper discusses the design and operation of the Trane Weathertron III Heat Pump Water Heating System and includes a comparison of features and performance to other domestic water heating systems. Domestic water is generally provided through...
Kessler, A. F.
Industrial Waste Heat Recovery Using Heat Pipes
For almost a decade now, heat pipes with secondary finned surfaces have been utilized in counter flow heat exchangers to recover sensible energy from industrial exhaust gases. Over 3,000 such heat exchangers are now in service, recovering...
Ruch, M. A.
Superconducting flux flow digital circuits
A NOR/inverter logic gate circuit and a flip flop circuit implemented with superconducting flux flow transistors (SFFTs) are disclosed. Both circuits comprise two SFFTs with feedback lines. They have extremely low power dissipation, very high switching speeds, and the ability to interface between Josephson junction superconductor circuits and conventional microelectronics. 8 figs.
Hietala, V.M.; Martens, J.S.; Zipperian, T.E.
A NOR/inverter logic gate circuit and a flip flop circuit implemented with superconducting flux flow transistors (SFFTs). Both circuits comprise two SFFTs with feedback lines. They have extremely low power dissipation, very high switching speeds, and the ability to interface between Josephson junction superconductor circuits and conventional microelectronics.
Hietala, Vincent M. (Placitas, NM); Martens, Jon S. (Sunnyvale, CA); Zipperian, Thomas E. (Albuquerque, NM)
Heating systems for heating subsurface formations
Methods and systems for heating a subsurface formation are described herein. A heating system for a subsurface formation includes a sealed conduit positioned in an opening in the formation and a heat source. The sealed conduit includes a heat transfer fluid. The heat source provides heat to a portion of the sealed conduit to change phase of the heat transfer fluid from a liquid to a vapor. The vapor in the sealed conduit rises in the sealed conduit, condenses to transfer heat to the formation and returns to the conduit portion as a liquid.
Nguyen, Scott Vinh (Houston, TX); Vinegar, Harold J. (Bellaire, TX)
Determining Reactor Flux from Xenon-136 and Cesium-135 in Spent Fuel
The ability to infer the reactor flux from spent fuel or seized fissile material would enhance the tools of nuclear forensics and nuclear nonproliferation significantly. We show that reactor flux can be inferred from the ratios of xenon-136 to xenon-134 and cesium-135 to cesium-137. If the average flux of a reactor is known, the flux inferred from measurements of spent fuel could help determine whether that spent fuel was loaded as a blanket or close to the mid-plane of the reactor. The cesium ratio also provides information on reactor shutdowns during the irradiation of fuel, which could prove valuable for identifying the reactor in question through comparisons with satellite reactor heat monitoring data. We derive analytic expressions for these correlations and compare them to experimental data and to detailed reactor burn simulations. The enrichment of the original uranium fuel affects the correlations by up to 3 percent, but only at high flux.
A. C. Hayes; Gerard Jungman
Operation of the ORNL High Particle Flux Helicon Plasma Source
A high power, high particle flux rf-based helicon plasma source has been constructed at ORNL and operated at power levels up to 30 kW. High-density hydrogen and helium plasmas have been produced. The source has been designed as the basis for a linear plasma materials interaction (PMI) test facility that will generate particle fluxes Gamma(p) > 10(23) M-3 s(-1), and utilize additional ion and electron cyclotron heating to produce high parallel (to the magnetic field) heat fluxes of similar to 10 MW/m(2). An rf-based source for PMI research is of interest because high plasma densities are generated with no internal electrodes, allowing true steady state operation with minimal impurity generation. The ORNL helicon source has a diameter of 15 cm and to-date has operated at a frequency f = 13.56 MHz, with magnetic field strength vertical bar B vertical bar in the antenna region up to similar to 0.15 T. Maximum densities of 3 x 10(19) M-3 in He and 2.5 x 10(19) m(-3) in H have been achieved. Radial density profiles have been seen to be dependent on the axial vertical bar B vertical bar profile.
Goulding, Richard Howell [ORNL; Biewer, Theodore M [ORNL; Caughman, John B [ORNL; Chen, Guangye [ORNL; Owen, Larry W [ORNL; Sparks, Dennis O [ORNL
A high power, high particle flux rf-based helicon plasma source has been constructed at ORNL and operated at power levels up to 30 kW. High-density hydrogen and helium plasmas have been produced. The source has been designed as the basis for a linear plasma materials interaction (PMI) test facility that will generate particle fluxes {Gamma}{sub p}10{sup 23} m{sup -3} s{sup -1}, and utilize additional ion and electron cyclotron heating to produce high parallel (to the magnetic field) heat fluxes of {approx}10 MW/m{sup 2}. An rf-based source for PMI research is of interest because high plasma densities are generated with no internal electrodes, allowing true steady state operation with minimal impurity generation. The ORNL helicon source has a diameter of 15 cm and to-date has operated at a frequency f = 13.56 MHz, with magnetic field strength |B| in the antenna region up to {approx}0.15 T. Maximum densities of 3x10{sup 19} m{sup -3} in He and 2.5x10{sup 19} m{sup -3} in H have been achieved. Radial density profiles have been seen to be dependent on the axial |B| profile.
Goulding, R. H.; Biewer, T. M.; Caughman, J. B. O.; Chen, G. C.; Owen, L. W.; Sparks, D. O. [Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831-6169 (United States)
Uncertainty of calorimeter measurements at NREL's high flux solar furnace
The uncertainties of the calorimeter and concentration measurements at the High Flux Solar Furnace (HFSF) at the National Renewable Energy Laboratory (NREL) are discussed. Two calorimeter types have been used to date. One is an array of seven commercially available circular foil calorimeters (gardon or heat flux gages) for primary concentrator peak flux (up to 250 W/cm{sup 2}). The second is a cold-water calorimeter designed and built by the University of Chicago to measure the average exit power of the reflective compound parabolic secondary concentrator used at the HFSF (over 3.3 kW across a 1.6cm{sup {minus}2} exit aperture, corresponding to a flux of about 2 kW/cm{sup 2}). This paper discussed the uncertainties of the calorimeter and pyrheliometer measurements and resulting concentration calculations. The measurement uncertainty analysis is performed according to the ASME/ANSI standard PTC 19.1 (1985). Random and bias errors for each portion of the measurement are analyzed. The results show that as either the power or the flux is reduced, the uncertainties increase. Another calorimeter is being designed for a new, refractive secondary which will use a refractive material to produce a higher average flux (5 kW/cm{sup 2}) than the reflective secondary. The new calorimeter will use a time derivative of the fluid temperature as a key measurement of the average power out of the secondary. A description of this calorimeter and test procedure is also presented, along with a pre-test estimate of major sources of uncertainty. 8 refs., 4 figs., 3 tabs.
Bingham, C.E.
Heat exchanger
A heat exchanger comparising a shell attached at its open end to one side of a tube sheet and a detachable head connected to the other side of said tube sheet. The head is divided into a first and second chamber in fluid communication with a nozzle inlet and nozzle outlet, respectively, formed in said tube sheet. A tube bundle is mounted within said shell and is provided with inlets and outlets formed in said tube sheet in communication with said first and second chambers, respectively.
Brackenbury, P.J.
Brackenbury, Phillip J. (Richland, WA)
Measurements of Film Flow Rate in Heated Tubes with Various Axial Power Distributions
Measurements of Film Flow Rate in Heated Tubes with Various Axial Power Distributions by Carl, Measurements of Film Flow Rate in Heated Tubes with Various Axial Power Distributions KTH Nuclear Reactor power is limited by a phenomenon called critical heat flux (CHF). It appears as a sudden detoriation
Haviland, David
Numerical modeling of heat transfer and fluid flow in rotor-stator cavities with throughflow
Numerical modeling of heat transfer and fluid flow in rotor-stator cavities with throughflow S in a rotor-stator cavity subjected to a superimposed throughflow with heat transfer. Nu- merical predictions field from the heat transfer process. The turbulent flux is approximated by a gradient hypothesis
Sensitivity of the South Asian monsoon to elevated and non-elevated heating
for the South Asian monsoon via a ``sensible-heat-driven air-pump''. In their proposed mech- anism, sensible from cold and dry extratropical air or by providing a source of elevated heating. Here we show heat fluxes from mountain slopes produce rising motion that draws surrounding air toward the mountains
Kuang, Zhiming
J1.15 PARAMETERIZING THE TURBULENT SURFACE FLUXES OVER SUMMER SEA ICE Edgar L Andreas1*
of the surface heat budget for that year at several sites around the SHEBA ice camp (Andreas et al. 1999; Persson1 of 9 J1.15 PARAMETERIZING THE TURBULENT SURFACE FLUXES OVER SUMMER SEA ICE Edgar L Andreas1* , P to study the Surface Heat Budget of the Arctic Ocean (SHEBA) lasted for a year (Uttal et al. 2002). Our
Persson, Ola
Relating magnetic reconnection to coronal heating
It is clear that the solar corona is begin heated and that coronal magnetic fields undergo reconnection all the time. Here we attempt to show that these two facts are in fact related - i.e. coronal reconnection generates heat. This attempt must address the fact that topological change of field lines does not automatically generate heat. We present one case of flux emergence where we have measured the rate of coronal magnetic reconnection and the rate of energy dissipation in the corona. The ratio of these two, $P/\\dot{\\Phi}$, is a current comparable to the amount of current expected to flow along the boundary separating the emerged flux from the pre-existing flux overlying it. We can generalize this relation to the overall corona in quiet Sun or in active regions. Doing so yields estimates for the contribution to corona heating from magnetic reconnection. These estimated rates are comparable to the amount required to maintain the corona at its observed temperature.
Longcope, Dana W
An Analysis of Fluxes by Duality
M-theory on K3xK3 with non-supersymmetry-breaking G-flux is dual to M-theory on a Calabi-Yau threefold times a 2-torus without flux. This allows for a thorough analysis of the effects of flux without relying on supergravity approximations. We discuss several dual pairs showing that the usual rules of G-flux compactifications work well in detail. We discuss how a transition can convert M2-branes into G-flux. We see how new effects can arise at short distances allowing fluxes to obstruct more moduli than one expects from the supergravity analysis.
Paul S. Aspinwall
Dual source heat pump
What is disclosed is a heat pump apparatus for conditioning a fluid characterized by a fluid handler and path for circulating the fluid in heat exchange relationship with a refrigerant fluid; at least two refrigerant heat exchangers, one for effecting heat exchange with the fluid and a second for effecting heat exchange between refrigerant and a heat exchange fluid and the ambient air; a compressor for efficiently compressing the refrigerant; at least one throttling valve for throttling liquid refrigerant; a refrigerant circuit; refrigerant; a source of heat exchange fluid; heat exchange fluid circulating device and heat exchange fluid circuit for circulating the heat exchange fluid in heat exchange relationship with the refrigerant; and valves or switches for selecting the heat exchangers and direction of flow of the refrigerant therethrough for selecting a particular mode of operation. The heat exchange fluid provides energy for defrosting the second heat exchanger when operating in the air source mode and also provides a alternate source of heat.
Ecker, Amir L. (Dallas, TX); Pietsch, Joseph A. (Dallas, TX)
Segmented heat exchanger
A segmented heat exchanger system for transferring heat energy from an exhaust fluid to a working fluid. The heat exchanger system may include a first heat exchanger for receiving incoming working fluid and the exhaust fluid. The working fluid and exhaust fluid may travel through at least a portion of the first heat exchanger in a parallel flow configuration. In addition, the heat exchanger system may include a second heat exchanger for receiving working fluid from the first heat exchanger and exhaust fluid from a third heat exchanger. The working fluid and exhaust fluid may travel through at least a portion of the second heat exchanger in a counter flow configuration. Furthermore, the heat exchanger system may include a third heat exchanger for receiving working fluid from the second heat exchanger and exhaust fluid from the first heat exchanger. The working fluid and exhaust fluid may travel through at least a portion of the third heat exchanger in a parallel flow configuration.
Baldwin, Darryl Dean (Lafayette, IN); Willi, Martin Leo (Dunlap, IL); Fiveland, Scott Byron (Metamara, IL); Timmons, Kristine Ann (Chillicothe, IL)
Geophysical and geochemical constraints on geoneutrino fluxes from Earth's mantle
Knowledge of the amount and distribution of radiogenic heating in the mantle is crucial for understanding the dynamics of the Earth, including its thermal evolution, the style and planform of mantle convection, and the energetics of the core. Although the flux of heat from the surface of the planet is robustly estimated, the contributions of radiogenic heating and secular cooling remain poorly defined. Constraining the amount of heat-producing elements in the Earth will provide clues to understanding nebula condensation and planetary formation processes in early Solar System. Mantle radioactivity supplies power for mantle convection and plate tectonics, but estimates of mantle radiogenic heat production vary by a factor of more than 20. Recent experimental results demonstrate the potential for direct assessment of mantle radioactivity through observations of geoneutrinos, which are emitted by naturally occurring radionuclides. Predictions of the geoneutrino signal from the mantle exist for several established estimates of mantle composition. Here we present novel analyses, illustrating surface variations of the mantle geoneutrino signal for models of the deep mantle structure, including those based on seismic tomography. These variations have measurable differences for some models, allowing new and meaningful constraints on the dynamics of the planet. An ocean based geoneutrino detector deployed at several strategic locations will be able to discriminate between competing compositional models of the bulk silicate Earth.
Ond?ej Šrámek; William F. McDonough; Edwin S. Kite; Vedran Leki?; Steve Dye; Shijie Zhong
The correlation of radial heat transfer data from a moving plasma
, and Str eng (4) measured the stagnation heat flux from an argon plasma jet. A plot was presented showing. the heat flux as a linear function of power supplied to the arc. No correlation was given. For predicting the stagnation heat flux to an object... temperature. Plasma temperature was assumed to be equal to the temperature at the exit of its arc chamber, and this temperature was used in the determination of Nus selt number and Reynolds number used in the above correlation. Since the gas enthalpy...
Choksi, Nitinchandra Mafatlal
HEATING 7. 1 user's manual
HEATING is a FORTRAN program designed to solve steady-state and/or transient heat conduction problems in one-, two-, or three- dimensional Cartesian, cylindrical, or spherical coordinates. A model may include multiple materials, and the thermal conductivity, density, and specific heat of each material may be both time- and temperature-dependent. The thermal conductivity may be anisotropic. Materials may undergo change of phase. Thermal properties of materials may be input or may be extracted from a material properties library. Heating generation rates may be dependent on time, temperature, and position, and boundary temperatures may be time- and position-dependent. The boundary conditions, which may be surface-to-boundary or surface-to-surface, may be specified temperatures or any combination of prescribed heat flux, forced convection, natural convection, and radiation. The boundary condition parameters may be time- and/or temperature-dependent. General graybody radiation problems may be modeled with user-defined factors for radiant exchange. The mesh spacing may be variable along each axis. HEATING is variably dimensioned and utilizes free-form input. Three steady-state solution techniques are available: point-successive-overrelaxation iterative method with extrapolation, direct-solution (for one-dimensional or two-dimensional problems), and conjugate gradient. Transient problems may be solved using one of several finite-difference schemes: Crank-Nicolson implicit, Classical Implicit Procedure (CIP), Classical Explicit Procedure (CEP), or Levy explicit method (which for some circumstances allows a time step greater than the CEP stability criterion). The solution of the system of equations arising from the implicit techniques is accomplished by point-successive-overrelaxation iteration and includes procedures to estimate the optimum acceleration parameter.
We examine heating and cooling in protostellar disks using three-dimensional radiation-MHD calculations of a patch of the Solar nebula at 1 AU, employing the shearing-box and flux-limited radiation diffusion approximations. The disk atmosphere is ionized by stellar X-rays, well coupled to magnetic fields, and sustains a turbulent accretion flow driven by magnetorotational instability, while the interior is resistive and magnetically dead. The turbulent layers are heated by absorbing the light from the central star and by dissipating the magnetic fields. They are optically thin to their own radiation and cool inefficiently. The optically thick interior in contrast is heated only weakly, by re-emission from the atmosphere. The interior is colder than a classical viscous model and isothermal. The magnetic fields support an extended atmosphere that absorbs the starlight 1.5 times higher than the hydrostatic viscous model. The disk thickness thus measures not the internal temperature, but the magnetic field strength. Fluctuations in the fields move the starlight-absorbing surface up and down. The height ranges between 13% and 24% of the radius over timescales of several orbits, with implications for infrared variability. The fields are buoyant, so the accretion heating occurs higher in the atmosphere than the stresses. The heating is localized around current sheets, caused by magnetorotational instability at lower elevations and by Parker instability at higher elevations. Gas in the sheets is heated above the stellar irradiation temperature, even though accretion is much less than irradiation power when volume averaged. The hot optically thin current sheets might be detectable through their line emission.
Hirose, S. [Institute for Research on Earth Evolution, Japan Agency for Marine-Earth Science and Technology, 3173-25 Showamachi, Kanazawa-ku, Yokohama, Kanagawa 236-0001 (Japan); Turner, N. J., E-mail: firstname.lastname@example.com, E-mail: firstname.lastname@example.com [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States)
Quantification of latent travel demand on new urban facilities in the state of Texas
for the degree of MASTER OF SCIENCE May 1989 Major Subject: Civil Engineering DUANTIFICATION OF LATENT TRAVEL DEMAND ON NEW URBAN FACILITIES IN THE STATE OF TEXAS A Thesis by RUSSELL HAROLD HENK Approved as to style and content by: eilon J an (C 'r 6f... 287 to FM 157) Radial I-20S (1-35 to US 287) Circumferential I-30W (1-20 to SH 183) Radial I-820W ( 1-20 to SH 199) Circumferential SH 121 (1-35 to 1-820) Radi al Table 6 Houston Study Sites-Facility Types Site Number Study Site I-610N (US 59...
Henk, Russell H
Stochastic volatility models with persistent latent factors: theory and its applications to asset prices
consider the nonlinear nonstationary state-space model given by yt = radicalbig f(xt,?) ut, xt+1 = ?xt +vt+1,(2.1) where I make the following assumptions: Assumption 1: The volatility function is given by (2.2) f(xt,?) = µ+ ?1+exp(??(x t ??)) , where ? = (µ.... Assumption 2: (xt) is a scalar latent volatility factor and |?| ? 1, I describe the volatility factor, (xt) explicitly in the transition equation because I am interested in the linkage between it and macro economic fundamentals. I assume that this volatility...
Lee, Hyoung Il
Center vortices as composites of monopole fluxes
We study the relation between the flux of a center vortex obtained from the center vortex model and the flux formed between monopoles obtained from the Abelian gauge fixing method. Motivated by the Monte Carlo simulations which have shown that almost all monopoles are sitting on the top of vortices, we construct the fluxes of center vortices for $SU(2)$ and $SU(3)$ gauge groups using fractional fluxes of monopoles. Then, we compute the potentials in the fundamental representation induced by center vortices and fractional fluxes of monopoles. We show that by combining the fractional fluxes of monopoles one can produce the center vortex fluxes for $SU(3)$ gauge group in a "center vortex model". Comparing the potentials, we conclude that the fractional fluxes of monopoles attract each other.
Deldar, Sedigheh
Enhanced shell-and-tube heat eschangers for the power and process industries. Final report
Single-tube pool boiling tests were performed with saturated pure refrigerants and binary mixtures of refrigerants. Generally, with pure refrigerants, the High Flux surface performed better at the higher heat fluxes compared to the Turbo-B tube, and both enhanced surfaces performed significantly better than smooth surface. In tests of R-11/R-113 mixtures, the enhanced surfaces had much less degradation in heat transfer coefficient due to mixture effects compared to smooth tubes; the largest degradation occurred at a mixture of 25% R-11/75% R-113. Under boiling in saturated aqueous solution of calcium sulfate, with a single tube, effects of fouling were more pronounced at the higher heat fluxes for all surfaces. Two staggered tube bundles were tested with tube pitch-diameter ratios of 1.17 and 1.50. For the pure refrigerant, tests on the smooth-tube bundle indicated that the effects on the heat transfer coefficient of varying mass flux, quality, and tube-bundle geometry were small, except at low heat fluxes. Neither enhanced surface showed any effect with changing mass flux or quality. The binary mixture bundle-boiling tests had results that were very similar to those obtained with the pure refrigerants. When boiling a refrigerant-oil mixture, all three surfaces (smooth, High Flux, and Turbo-B) experienced a degradation in its heat transfer coefficient; no surface studied was found to be immune or vulnerable to the presence of oil than another surface.
Bergles, A.E.; Jensen, M.K.; Somerscales, E.F.; Curcio, L.A. Jr.; Trewin, R.R.
Today's Material Gauss' Law and Flux
by the contents of the box, the box must contain zero net electric charge. Slide 27-31 #12;Gauss' Law and Flux: · The Concept of Flux · Calculating Electric Flux · Symmetry · Gauss's Law · Using Gauss's Law · Conductors that the box must contain net positive electric charge. Slide 27-29 #12;© 2013 Pearson Education, Inc
Ashlock, Dan
Numerical analysis of vapor flow in a micro heat pipe
be modeled as a classical blowing and suction problem, i. e. ?(00) = v(00) = o ?(I, p) = v(L0) = 0 ?(x, 0) = ?(x, H) = 0 i(x, 0) = v(x), v(x, H) = -i'(x) 0&x&I. , (2. 6) v(x, 0) = 0, v(x, H) = 0 I. , &x&(L, +L, ) i(x, 0) = -v(x), v(x, H) = v(x) (L, +L... are considerably smoother and appear more reasonable Figure 5. 6 presents the velocity vector which is under q=40W/cm2, H=0. 003m uniform heat flux linear heat flux 0 00 0 O'I 0 02 0. 03 0. 04 0. 05 0 06 x(m) Fig. 5. 2 Heat flux distribution influence...
Liu, Xiaoqin
Scale and deposits in high-heat-rejection engines
Scaling under conditions very similar to those of a heavy-duty diesel engine cooling system was investigated using a newly designed, versatile test stand. The parameters included flow rate, heat flux, hardness, along with bulk fluid temperatures. The hot surface temperature, a critical parameter, was also measured. Results were interpreted in terms of the conditions in the boundary layer at the hot surface. Critical values of flow rate and heat flux existed for scaling under experimental conditions. A quantitative relationship of scale with heat flux and hardness was observed. Deposits produced from testing of different types of commercial coolants, including phosphate based and nonphosphate bases, were measured and compared with results from simple beaker tests.
Chen, Y.S.; Kershisnik, E.I. [Dober Group, Glenwood, IL (United States); Hudgens, R.D. [Fleetguard, Inc., Cookeville, TN (United States); Corbeels, C.L.; Zehr, R.L. [Cummins Engine Co., Inc., Columbus, IN (United States)
Neutron imaging of alkali metal heat pipes
High-temperature heat pipes are two-phase, capillary driven heat transfer devices capable of passively providing high thermal fluxes. Such a device using a liquid-metal coolant can be used as a solution for successful thermal management on hypersonic flight vehicles. Imaging of the liquid-metal coolant inside will provide valuable information in characterizing the detailed heat and mass transport. Neutron imaging possesses an inherent advantage from the fact that neutrons penetrate the heat pipe metal walls with very little attenuation, but are significantly attenuated by the liquid metal contained inside. Using the BT-2 beam line at the National Institute of Standards and Technology (NIST) in Gaithersburg, Maryland, preliminary efforts have been conducted on a nickel-sodium heat pipe. The contrast between the attenuated beam and the background is calculated to be approximately 3%. This low contrast requires sacrifice in spatial or temporal resolution so efforts have since been concentrated on lithium (Li) which has a substantially larger neutron attenuation cross section. Using the CG-1D beam line at the High Flux Isotope Reactor (HFIR) of Oak Ridge National Laboratory (ORNL) in Oak Ridge, Tennessee, the first neutron images of high-temperature molybdenum (Mo)-Li heat pipes have been achieved. The relatively high neutron cross section of Li allows for the visualization of the Li working fluid inside the heat pipes. The evaporator region of a gravity assisted cylindrical heat pipe prototype 25 cm long was imaged from start-up to steady state operation up to approximately 900 C. In each corner of the square bore inside, the capillary action raises the Li meniscus above the bulk Li pool in the evaporator region. As the operational temperature changes, the meniscus shapes and the bulk meniscus height also changes. Furthermore, a three-dimensional tomographic image is also reconstructed from the total of 128 projection images taken 1.4o apart in which the Li had already cooled and solidified.
Kihm, Ken [University of Tennessee, Knoxville (UTK); Kirchoff, Eric [University of Tennessee, Knoxville (UTK); Golden, Matt [University of Tennessee, Knoxville (UTK); Rosenfeld, J. [Thermacore Inc.; Rawal, S. [Lockheed Martin Space Systems Company; Pratt, D. [United States Air Force Research Laboratory, Wright-Patterson Air Force Base; Bilheux, Hassina Z [ORNL; Walker, Lakeisha MH [ORNL; Voisin, Sophie [ORNL; Hussey, Dan [NIST Center for Neutron Research (NCRN), Gaithersburg, MD
Tropical Cloud Properties and Radiative Heating Profiles
We have generated a suite of products that includes merged soundings, cloud microphysics, and radiative fluxes and heating profiles. The cloud microphysics is strongly based on the ARM Microbase value added product (Miller et al., 2003). We have made a few changes to the microbase parameterizations to address issues we observed in our initial analysis of the tropical data. The merged sounding product is not directly related to the product developed by ARM but is similar in that it uses the microwave radiometer to scale the radiosonde column water vapor. The radiative fluxes also differ from the ARM BBHRP (Broadband Heating Rate Profile) product in terms of the radiative transfer model and the sampling interval.
Mather, James
Multiple source heat pump
A heat pump apparatus for conditioning a fluid characterized by a fluid handler and path for circulating a fluid in heat exchange relationship with a refrigerant fluid, at least three refrigerant heat exchangers, one for effecting heat exchange with the fluid, a second for effecting heat exchange with a heat exchange fluid, and a third for effecting heat exchange with ambient air; a compressor for compressing the refrigerant; at least one throttling valve connected at the inlet side of a heat exchanger in which liquid refrigerant is vaporized; a refrigerant circuit; refrigerant; a source of heat exchange fluid; heat exchange fluid circuit and pump for circulating the heat exchange fluid in heat exchange relationship with the refrigerant; and valves or switches for selecting the heat exchangers and directional flow of refrigerant therethrough for selecting a particular mode of operation. Also disclosed are a variety of embodiments, modes of operation, and schematics therefor.
Ecker, Amir L. (Duncanville, TX)
Integration of Novel Flux Coupling Motor and Current Source Inverter...
of Novel Flux Coupling Motor and Current Source Inverter Novel Flux Coupling Machine without Permanent Magnets John Hsu, Oak Ridge National Laboratory, Flux Coupling...
Heat Pump for High School Heat Recovery
The heat pump system used for recycling and reusing waste heat in s high school bathroom was minutely analyzed in its coefficient of performance, onetime utilization ratio of energy, economic property and so on. The results showed that this system...
Huang, K.; Wang, H.; Zhou, X.
The role of trace gas flux networks in biogeosciences
Vast networks of meteorological sensors ring the globe, providing continuous measurements of an array of atmospheric state variables such as temperature, humidity, rainfall, and the concentration of carbon dioxide [New etal., 1999; Tans etal., 1996]. These measurements provide input to weather and climate models and are key to detecting trends in climate, greenhouse gases, and air pollution. Yet to understand how and why these atmospheric state variables vary in time and space, biogeoscientists need to know where, when, and at what rates important gases are flowing between the land and the atmosphere. Tracking trace gas fluxes provides information on plant or microbial metabolism and climate-ecosystem interactions. The existence of trace gas flux networks is a relatively new phenomenon, dating back to research in 1984. The first gas flux measurement networks were regional in scope and were designed to track pollutant gases such as sulfur dioxide, ozone, nitric acid, and nitrogen dioxide. Atmospheric observations and model simulations were used to infer the depositional rates of these hazardous chemicals [Fowler etal., 2009; Meyers etal., 1991]. In the late 1990s, two additional trace gas flux measurement networks emerged. One, the United States Trace Gas Network (TRAGNET), was a short-lived effort that measured trace gas emissions from the soil and plants with chambers distributed throughout the country [Ojima etal., 2000]. The other, FLUXNET, was an international endeavor that brought many regional networks together to measure the fluxes of carbon dioxide, water vapor, and sensible heat exchange with the eddy covariance technique [Baldocchi etal., 2001]. FLUXNET, which remains active today, currently includes more than 400 tower sites, dispersed across most of the world's climatic zones and biomes, with sites in North and South America, Europe, Asia, Africa, and Australia. More recently, several specialized networks have emerged, including networks dedicated to urban areas (Urban Fluxnet), nitrogen compounds in Europe (NitroEurope), and methane (MethaneNet). Technical Aspects of Flux Networks Eddy covariance flux measurements are the preferred method by which biogeoscientists measure trace gas exchange between ecosystems and the atmosphere [Baldocchi, 2003].
Baldocch, Dennis [Department of Environmental Science, Policy and Management, University of California, Berkeley,; Reichstein, Markus [Max Planck Institute for Biogeochemistry; Papale, D. [University of Tuscia; KOTEEN, LAURIE [University of California, Berkeley; VARGAS, RODRIGO [Ensenada Center for Scientific Research and Higher Education (CICESE); Agarwal, D.A [Lawrence Berkeley National Laboratory (LBNL); Cook, Robert B [ORNL
Experimental and Numerical Investigation of Pool Boiling Heat Transfer on Engineered Nano-Finned Surfaces
Pool boiling experiments for nanocoatings (or nanostructured surfaces) show that despite the lower thermal conductivity values than carbon, silicon yielded higher values of CHF (critical heat flux). Subsequently numerical studies showed...
Yang, Hongjoo
Effect of Radiant Barrier Technology on Summer Attic Heat Load in South Texas
The objective of the study was to experimentally evaluate the performance of radiant barriers in single-family occupied housing units in South Texas. Ceiling heat fluxes, attic air temperatures, indoor air temperatures, ambient air temperatures...
Ashley, R.; Garcia, O.; Medina, M. A.; Turner, W. D.
Effects of heat and mass transfer on the kinetics of CO oxidation...
KMC simulation. The gas-phase boundary layer domain is described using the grid-based Crank-Nicolson method. At each time step, the heat and mass fluxes between two...
An experimental and theoretical study of radiative and conductive heat transfer in nongray semitransparent media
One dimensional temperature profiles and heat fluxes within a slab of molten glass were measured experimentally. The glass slab was contained in a platinum foil lined ceramic tray inside a high temperature furnace. An ...
Eryou, N. Dennis
Combined Heat and Power, Waste Heat, and District Energy | Department...
Broader source: Energy.gov (indexed) [DOE]
Combined Heat and Power, Waste Heat, and District Energy Combined Heat and Power, Waste Heat, and District Energy Presentation-given at the Fall 2011 Federal Utility Partnership...
Pagosa Springs District Heating District Heating Low Temperature...
Pagosa Springs District Heating District Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Pagosa Springs District Heating District Heating Low...
Kethcum District Heating District Heating Low Temperature Geothermal...
Kethcum District Heating District Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Kethcum District Heating District Heating Low Temperature Geothermal...
Midland District Heating District Heating Low Temperature Geothermal...
Midland District Heating District Heating Low Temperature Geothermal Facility Facility Midland District Heating Sector Geothermal energy Type District Heating Location Midland,...
San Bernardino District Heating District Heating Low Temperature...
San Bernardino District Heating District Heating Low Temperature Geothermal Facility Facility San Bernardino District Heating Sector Geothermal energy Type District Heating...
Philip District Heating District Heating Low Temperature Geothermal...
Philip District Heating District Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Philip District Heating District Heating Low Temperature Geothermal...
We investigate the effect of solar visible and infrared radiation on electrons in the Sun's atmosphere using a Monte Carlo simulation of the wave-particle interaction and conclude that sunlight provides at least 40% and possibly all of the power required to heat the corona, with the exception of dense magnetic flux loops. The simulation uses a radiation waveform comprising 100 frequency components spanning the solar blackbody spectrum. Coronal electrons are heated in a stochastic manner by low coherence solar electromagnetic radiation. The wave 'coherence time' and 'coherence volume' for each component is determined from optical theory. The low coherence of solar radiation allows moving electrons to gain energy from the chaotic wave field which imparts multiple random velocity 'kicks' to these particles causing their velocity distribution to broaden or heat. Monte Carlo simulations of broadband solar radiative heating on ensembles of 1000 electrons show heating at per particle levels of 4.0 x 10{sup -21} to 4.0 x 10{sup -20} W, as compared with non-loop radiative loss rates of {approx}1 x 10{sup -20} W per electron. Since radiative losses comprise nearly all of the power losses in the corona, sunlight alone can explain the elevated temperatures in this region. The volume electron heating rate is proportional to density, and protons are assumed to be heated either by plasma waves or through collisions with electrons.
Moran, Thomas G., E-mail: email@example.com [Physics Department, Catholic University of America, 200 Hannan Hall, Washington, DC 20064 (United States) and NASA/GSFC, Code 671, Greenbelt, MD 20771 (United States)
Method and apparatus for enhanced heat recovery from steam generators and water heaters
A heating system having a steam generator or water heater, at least one economizer, at least one condenser and at least one oxidant heater arranged in a manner so as to reduce the temperature and humidity of the exhaust gas (flue gas) stream and recover a major portion of the associated sensible and latent heat. The recovered heat is returned to the steam generator or water heater so as to increase the quantity of steam generated or water heated per quantity of fuel consumed. In addition, a portion of the water vapor produced by combustion of fuel is reclaimed for use as feed water, thereby reducing the make-up water requirement for the system.
Knight, Richard A.; Rabovitser, Iosif K.; Wang, Dexin
Absorption heat pump system
The efficiency of an absorption heat pump system is improved by conducting liquid from a second stage evaporator thereof to an auxiliary heat exchanger positioned downstream of a primary heat exchanger in the desorber of the system.
Grossman, G.
Locating Heat Recovery Opportunities
Basic concepts of heat recovery are defined as they apply to the industrial community. Methods for locating, ranking, and developing heat recovery opportunities are presented and explained. The needs for useful heat 'sinks' are emphasized as equal...
Waterland, A. F.
Grossman, Gershon (Oak Ridge, TN)
Effect of turbulent heat transfer on continuous ingot solidification
For many continuous ingot casting processes, turbulent heat transfer in the molten pool plays a critical role which, along with buoyancy and surface tension, is responsible for the quality of the end products. Based on a modified low Reynolds number K-[epsilon] two-equation closure, accounting for the phase change and mushy zone formation, the effect of turbulent heat transfer on the solidification characteristics during titanium alloy ingot casting in an electron beam melting process is investigated. The overall heat transfer rate is enhanced by turbulent transport via two sources, one through the correlated velocity and temperature fluctuations present for both single- and multi-phase flows, and the other through the correlated velocity and release of latent heat fluctuations which are unique to the flows with phase change. The roles played by both mechanisms are identified and assessed. The present turbulence model predicts that although the mushy zone defined by the mean temperature field is generally of substantial thickness as a result of the convection effect, the actual instantaneous zone thickness varies substantially due to turbulence effect. This finding is in contrast to the traditionally held viewpoint, based on the conduction analysis, of a generally thin mushy zone. The impact of turbulent heat transfer on local dendrite formation and remelting is illustrated and the issues involved in model development highlighted.
Shyy, W.; Chen, M.H. (Univ. of Florida, Gainesville, FL (United States). Dept. of Aerospace Engineering); Pang, Y.; Wei, D.Y. (GE Aircraft Engines, Engineering Materials Technology Labs., Lynn, MA (United States)); Hunter, G.B. (GE Aircraft Engines, Engineering Materials Technology Labs., Cincinnati, OH (United States))
Woven heat exchanger
This invention relates to a heat exchanger for waste heat recovery from high temperature industrial exhaust streams. In a woven ceramic heat exchanger using the basic tube-in-shell design, each heat exchanger consisting of tube sheets and tube, is woven separately. Individual heat exchangers are assembled in cross-flow configuration. Each heat exchanger is woven from high temperature ceramic fiber, the warp is continuous from tube to tube sheet providing a smooth transition and unitized construction.
Piscitella, R.R.
Total Space Heat-
Annual Energy Outlook 2013 [U.S. Energy Information Administration (EIA)]
Commercial Buildings Energy Consumption Survey: Energy End-Use Consumption Tables Total Space Heat- ing Cool- ing Venti- lation Water Heat- ing Light- ing Cook- ing Refrig- eration...
Revised: December, 2008 Total Space Heat- ing Cool- ing Venti- lation Water Heat- ing Light- ing Cook- ing Refrig- eration Office Equip- ment Com- puters Other All Buildings...
Towards Intelligent District Heating.
??A district heating system consists of one or more production units supplying energy in the form of heated water through a distribution pipe network to… (more)
Johansson, Christian
Winter Heating Fuels Update
Heating Fuels Update For: Congressional Briefings October 20, 2014 | Washington, DC By U.S. Energy Information Administration Winter Heating Fuels Update October 20, 2014 |...
Slipping Magnetic Reconnection Triggering a Solar Eruption of a Triangle-flag Flux Rope
We firstly report the simultaneous activities of a slipping motion of flare loops and a slipping eruption of a flux rope in 131 {\\AA} and 94 {\\AA} channels on 2014 February 02. The east hook-like flare ribbon propagated slippingly at a speed of about 50 km s$^{-1}$, which lasted about 40 min and extended by more than 100 Mm, but the west flare ribbon moved in the opposite direction with a speed of 30 km s$^{-1}$. At the later phase of the flare activity, a "bi-fan" system of flare loops was well developed. The east footpoints of the flux rope showed an apparent slipping motion along the hook of the ribbon, simultaneously the fine structures of the flux rope rose up rapidly at a speed of 130 km s$^{-1}$, much faster the whole flux rope. We infer that the east footpoints of the flux rope are successively heated by a slipping magnetic reconnection during the flare, which results in the apparent slippage of the flux rope. The slipping motion delineates a "triangle-flag surface" of the flux rope, implying that the...
Li, Ting
As-Run Thermal Analysis of the GTL-1 Experiment Irradiated in the ATR South Flux Trap
The GTL-1 experiment was conducted to assess corrosion the performance of the proposed Boosted Fast Flux Loop booster fuel at heat flux levels {approx}30% above the design operating condition. Sixteen miniplates fabricated from 25% enriched, high-density U3Si2/Al dispersion fuel with 6061 aluminum cladding were subjected to peak beginning of cycle (BOC) heat fluxes ranging from 411 W/cm2 to 593 W/cm2. Miniplates fabricated with three different fuel variations (without fines, annealed, and with standard powder) performed equally well, with negligible irradiation-induced swelling and a normal fission density gradient. Both the standard and the modified prefilm procedures produced hydroxide films that adequately protected the miniplates from failure. A detailed finite element model was constructed to calculate temperatures and heat flux for an as-run cycle average effective south lobe power of 25.4 MW(t). Results of the thermal analysis are given at four times during the cycle: BOC at 0 effective full power days (EFPD), middle of cycle (MOC) at 18 EFPD, MOC at 36 EFPD, and end of cycle at 48.9 EFPD. The highest temperatures and heat fluxes occur at the BOC and decrease in a linear manner throughout the cycle. Miniplate heat flux levels and fuel, cladding, hydroxide, and coolant-hydroxide interface temperatures were calculated using the average measured hydroxide thickness on each miniplate. The hydroxide layers are the largest on miniplates nearest to the core midplane, where heat flux and temperature are highest. The hydroxide layer thickness averages 20.4 {mu}m on the six hottest miniplates (B3, B4, C1, C2, C3, and C4). This tends to exacerbate the heating of these miniplates, since a thicker hydroxide layer reduces the heat transfer from the fuel to the coolant. These six hottest miniplates have the following thermal characteristics at BOC: (1) Peak fuel centerline temperature >300 C; (2) Peak cladding temperature >200 C; (3) Peak hydroxide temperature >190 C; (4) Peak hydroxide-water interface temperature >140 C; and (5) Peak heat flux >565 W/cm2.
Donna P. Guillen
A Framework for Incorporating General Domain Knowledge into Latent Dirichlet Allocation using First-Order Logic
Topic models have been used successfully for a variety of problems, often in the form of application-specific extensions of the basic Latent Dirichlet Allocation (LDA) model. Because deriving these new models in order to encode domain knowledge can be difficult and time-consuming, we propose the Fold-all model, which allows the user to specify general domain knowledge in First-Order Logic (FOL). However, combining topic modeling with FOL can result in inference problems beyond the capabilities of existing techniques. We have therefore developed a scalable inference technique using stochastic gradient descent which may also be useful to the Markov Logic Network (MLN) research community. Experiments demonstrate the expressive power of Fold-all, as well as the scalability of our proposed inference method.
Andrzejewski, D; Zhu, X; Craven, M; Recht, B
Efficient Heat Storage Materials: Metallic Composites Phase-Change Materials for High-Temperature Thermal Energy Storage
HEATS Project: MIT is developing efficient heat storage materials for use in solar and nuclear power plants. Heat storage materials are critical to the energy storage process. In solar thermal storage systems, heat can be stored in these materials during the day and released at night—when the sun's not out—to drive a turbine and produce electricity. In nuclear storage systems, heat can be stored in these materials at night and released to produce electricity during daytime peak-demand hours. MIT is designing nanostructured heat storage materials that can store a large amount of heat per unit mass and volume. To do this, MIT is using phase change materials, which absorb a large amount of latent heat to melt from solid to liquid. MIT's heat storage materials are designed to melt at high temperatures and conduct heat well—this makes them efficient at storing and releasing heat and enhances the overall efficiency of the thermal storage and energy-generation process. MIT's low-cost heat storage materials also have a long life cycle, which further enhances their efficiency.
Numerical investigation of the convection of heat-emitting liquid reactor materials taking stratification into account
Convective heat transfer to a reactor vessel following core destruction is analyzed. Fuel fragment and structural materials are assumed to melt either mix uniformly or stratify. The Navier-Stokes equations were solved numerically with a rectangular coarse difference grid, neglecting the negligibly small contribution of the laminar boundary layer. Calculations for different levels of volume heat release showed that integral heat fluxes at the lateral and top surfaces of the melt are virtually independent of the convective flow scenario. However, the maximum heat flux on the lateral surface is approximately 1.5 times higher for the homogeneous case than for the stratified case. The higher heat flux could result in larger mechanical loads on the reactor vessel, requiring more cooling of the reactor vessel outer surface. 12 refs., 4 figs.
Likhanskii, V.V.; Loboiko, A.I.; Khoruzhii, O.V.
Heat-pipe gas-combustion system endurance test for Stirling engine. Final report, May 1990-September 1990
Stirling Thermal Motors, Inc., (STM) has been developing a general purpose Heat Pipe Gas Combustion System (HPGC) suitable for use with the STM4-120 Stirling engine. The HPGC consists of a parallel plate recuperative preheater, a finned heat pipe evaporator and a film cooled gas combustor. A principal component of the HPGC is the heat pipe evaporator which collects and distributes the liquid sodium over the heat transfer surfaces. The liquid sodium evaporates and flows to the condensers where it delivers its latent heat. The report presents test results of endurance tests run on a Gas-Fired Stirling Engine (GFSE). Tests on a dynamometer test stand yielded 67 hours of engine operation at power levels over 10 kW (13.5 hp) with 26 hours at power levels above 15 kW (20 hp). Total testing of the engine, including both motoring tests and engine operation, yielded 245 hours of engine run time.
Mahrle, P.
The Effects of Great Plains Irrigation on the Surface Energy Balance, Regional Circulation, and Precipitation
the net radiation at the surface, channeling that energy into additional latent heat flux, which increases convective available potential energy and provides downstream convective systems with additional energy and moisture. Most noteworthy in this study...
Huber, David B.; Brunsell, Nathaniel A.; Mechem, David B.
On solar neutrino fluxes in radiochemical experiments
We analyze fluctuations of the solar neutrino flux using data from the Homestake, GALLEX, GNO, SAGE and Super Kamiokande experiments. Spectral analysis and direct quantitative estimations show that the most stable variation of the solar neutrino flux is a quasi-five-year periodicity. The revised values of the mean solar neutrino flux are presented in Table 4. They were used to estimate the observed pp-flux of the solar electron neutrinos near the Earth. We consider two alternative explanations for the origin of a variable component of the solar neutrino deficit.
R. N. Ikhsanov; Yu. N. Gnedin; E. V. Miletsky
Fluxing agent for metal cast joining
A method of joining an aluminum cast member to an aluminum component. The method includes the steps of coating a surface of an aluminum component with flux comprising cesium fluoride, placing the flux coated component in a mold, filling the mold with molten aluminum alloy, and allowing the molten aluminum alloy to solidify thereby joining a cast member to the aluminum component. The flux preferably includes aluminum fluoride and alumina. A particularly preferred flux includes about 60 wt. % CsF, about 30 wt. % AlF.sub.3, and about 10 wt. % Al.sub.2 O.sub.3.
Gunkel, Ronald W. (Lower Burrell, PA); Podey, Larry L. (Greensburg, PA); Meyer, Thomas N. (Murrysville, PA)
Rotary magnetic heat pump
A rotary magnetic heat pump constructed without flow seals or segmented rotor accomplishes recuperation and regeneration by using split flow paths. Heat exchange fluid pumped through heat exchangers and returned to the heat pump splits into two flow components: one flowing counter to the rotor rotation and one flowing with the rotation. 5 figs.
Kirol, L.D.
Mass and Heat Recovery
In the last few years heat recovery was under spot and in air conditioning fields usually we use heat recovery by different types of heat exchangers. The heat exchanging between the exhaust air from the building with the fresh air to the building...
Hindawai, S. M.
Direct fired heat exchanger
A gas-to-liquid heat exchanger system which transfers heat from a gas, generally the combustion gas of a direct-fired generator of an absorption machine, to a liquid, generally an absorbent solution. The heat exchanger system is in a counterflow fluid arrangement which creates a more efficient heat transfer.
Reimann, Robert C. (Lafayette, NY); Root, Richard A. (Spokane, WA)
A rotary magnetic heat pump constructed without flow seals or segmented rotor accomplishes recuperation and regeneration by using split flow paths. Heat exchange fluid pumped through heat exchangers and returned to the heat pump splits into two flow components: one flowing counter to the rotor rotation and one flowing with the rotation.
Kirol, Lance D. (Shelly, ID)
Thulium-170 heat source
An isotopic heat source is formed using stacks of thin individual layers of a refractory isotopic fuel, preferably thulium oxide, alternating with layers of a low atomic weight diluent, preferably graphite. The graphite serves several functions: to act as a moderator during neutron irradiation, to minimize bremsstrahlung radiation, and to facilitate heat transfer. The fuel stacks are inserted into a heat block, which is encased in a sealed, insulated and shielded structural container. Heat pipes are inserted in the heat block and contain a working fluid. The heat pipe working fluid transfers heat from the heat block to a heat exchanger for power conversion. Single phase gas pressure controls the flow of the working fluid for maximum heat exchange and to provide passive cooling.
Walter, Carl E. (Pleasanton, CA); Van Konynenburg, Richard (Livermore, CA); VanSant, James H. (Tracy, CA)
Heat Treating Apparatus
Apparatus for heat treating a heat treatable material including a housing having an upper opening for receiving a heat treatable material at a first temperature, a lower opening, and a chamber therebetween for heating the heat treatable material to a second temperature higher than the first temperature as the heat treatable material moves through the chamber from the upper to the lower opening. A gas supply assembly is operatively engaged to the housing at the lower opening, and includes a source of gas, a gas delivery assembly for delivering the gas through a plurality of pathways into the housing in countercurrent flow to movement of the heat treatable material, whereby the heat treatable material passes through the lower opening at the second temperature, and a control assembly for controlling conditions within the chamber to enable the heat treatable material to reach the second temperature and pass through the lower opening at the second temperature as a heated material.
De Saro, Robert (Annandale, NJ); Bateman, Willis (Sutton Colfield, GB)
Anisotropic turbulent model for solar coronal heating
Context : We present a self-consistent model of solar coronal heating, originally developed by Heyvaert & Priest (1992), in which we include the dynamical effect of the background magnetic field along a coronal structure by using exact results from wave MHD turbulence (Galtier et al. 2000). Aims : We evaluate the heating rate and the microturbulent velocity for comparison with observations in the quiet corona, active regions and also coronal holes. Methods :The coronal structures are assumed to be in a turbulent state maintained by the slow erratic motions of the magnetic footpoints. A description for the large-scale and the unresolved small-scale dynamics are given separately. From the latter, we compute exactly (or numerically for coronal holes) turbulent viscosites that are finally used in the former to close self-consistently the system and derive the heating flux expression. Results : We show that the heating rate and the turbulent velocity compare favorably with coronal observations. Conclusions : Although the Alfven wave turbulence regime is strongly anisotropic, and could reduce a priori the heating efficiency, it provides an unexpected satisfactory model of coronal heating for both magnetic loops and open magnetic field lines.
B. Bigot; S. Galtier; H. Politano
Thermoelectric heat exchange element
A thermoelectric heat exchange module includes a first substrate including a heat receptive side and a heat donative side and a series of undulatory pleats. The module may also include a thermoelectric material layer having a ZT value of 1.0 or more disposed on at least one of the heat receptive side and the heat donative side, and an electrical contact may be in electrical communication with the thermoelectric material layer.
Callas, James J. (Peoria, IL); Taher, Mahmoud A. (Peoria, IL)
Heat Integrate Heat Engines in Process Plants
of forcing a good fit between a heat engine and process T', H profiles extends the ideas of appropriate and inappropriate placement to give bet ter overall integration schemes [7] . The new 'and powerful representations of the thermodynamics of a process... HEAT INTEGRATE HEAT ENGINES IN PROCESS PLANTS E. Hindmarsh, D. Boland and D.W. Townsend TENSA Technology, Houston, Texas Shorter Version Appeared in Chemical Engineering Copyright McGraw Hill, 1985 ABSTRACT This paper presents a novel method...
Hindmarsh, E.; Boland, D.; Townsend, D. W.
Process for reducing series resistance of solar cell metal contact systems with a soldering flux etchant
Disclosed is a process for substantially reducing the series resistance of a solar cell having a thick film metal contact assembly thereon while simultaneously removing oxide coatings from the surface of the assembly prior to applying solder therewith. The process includes applying a flux to the contact assembly and heating the cell for a period of time sufficient to substantially remove the series resistance associated with the assembly by etching the assembly with the flux while simultaneously removing metal oxides from said surface of said assembly.
Coyle, R. T. (Lakewood, CO); Barrett, Joy M. (Eldorado Springs, CO)
PHELIX for flux compression studies
PHELIX (Precision High Energy-density Liner Implosion eXperiment) is a concept for studying electromagnetic implosions using proton radiography. This approach requires a portable pulsed power and liner implosion apparatus that can be operated in conjunction with an 800 MeV proton beam at the Los Alamos Neutron Science Center. The high resolution (< 100 micron) provided by proton radiography combined with similar precision of liner implosions driven electromagnetically can permit close comparisons of multi-frame experimental data and numerical simulations within a single dynamic event. To achieve a portable implosion system for use at high energy-density in a proton laboratory area requires sub-megajoule energies applied to implosions only a few cms in radial and axial dimension. The associated inductance changes are therefore relatively modest, so a current step-up transformer arrangement is employed to avoid excessive loss to parasitic inductances that are relatively large for low-energy banks comprising only several capacitors and switches. We describe the design, construction and operation of the PHELIX system and discuss application to liner-driven, magnetic flux compression experiments. For the latter, the ability of strong magnetic fields to deflect the proton beam may offer a novel technique for measurement of field distributions near perturbed surfaces.
Turchi, Peter J [Los Alamos National Laboratory; Rousculp, Christopher L [Los Alamos National Laboratory; Reinovsky, Robert E [Los Alamos National Laboratory; Reass, William A [Los Alamos National Laboratory; Griego, Jeffrey R [Los Alamos National Laboratory; Oro, David M [Los Alamos National Laboratory; Merrill, Frank E [Los Alamos National Laboratory
URANIUM MILL TAILINGS RADON FLUX CALCULATIONS PIĂ?ON RIDGE PROJECT MONTROSE COUNTY, COLORADO Inc. (Golder) was commissioned by EFRC to evaluate the operations of the uranium mill tailings storage in this report were conducted using the WISE Uranium Mill Tailings Radon Flux Calculator, as updated on November
Ozone heating and the destabilization of traveling waves during summer
The effects of ozone heating on the linear stability of lower stratospheric traveling waves of the summertime, extratropical circulation are examined. Based on coupled equations for the quasigeostrophic potential vorticity and ozone volume mixing ratio, it is shown that the diabatic heating arising from ozone advection can offset the damping due to Newtonian cooling, leading to wave amplification and significant changes in the structure and zonally rectified fluxes of the wave fields in both the lower stratosphere and troposphere. The vertical profile of the zonal mean wind plays a crucial role in determining whether the ozone heating destabilizes eastward and/or westward traveling disturbances.
Nathan, T.R.; Cordero, E.C.; Li, L. [Univ. of California, Davis, CA (United States)] [Univ. of California, Davis, CA (United States)
Cloud properties and associated radiative heating rates in the tropical western Pacific
Cloud properties and associated radiative heating rates in the tropical western Pacific James H set of atmospheric remote sensing instruments at sites around the world, including three radiative fluxes and heating rates. Maxima in cloud occurrence are found in the boundary layer and the upper
Heat transfer system
A heat transfer system for a nuclear reactor. Heat transfer is accomplished within a sealed vapor chamber which is substantially evacuated prior to use. A heat transfer medium, which is liquid at the design operating temperatures, transfers heat from tubes interposed in the reactor primary loop to spaced tubes connected to a steam line for power generation purposes. Heat transfer is accomplished by a two-phase liquid-vapor-liquid process as used in heat pipes. Condensible gases are removed from the vapor chamber through a vertical extension in open communication with the chamber interior.
McGuire, Joseph C. (Richland, WA)
A heat transfer system for a nuclear reactor is described. Heat transfer is accomplished within a sealed vapor chamber which is substantially evacuated prior to use. A heat transfer medium, which is liquid at the design operating temperatures, transfers heat from tubes interposed in the reactor primary loop to spaced tubes connected to a steam line for power generation purposes. Heat transfer is accomplished by a two-phase liquid-vapor-liquid process as used in heat pipes. Condensible gases are removed from the vapor chamber through a vertical extension in open communication with the chamber interior.
Consolidated Electric Cooperative- Heat Pump and Water Heating Rebates
Broader source: Energy.gov [DOE]
Consolidated Electric Cooperative provides rebates to residential customers who install electric water heaters, dual-fuel heating system or geothermal heat pumps. A dual-fuel heating systems...
The choice of heat transfer fluids has significant effects on the performance, cost, and reliability of solar thermal systems. In this chapter, we evaluate existing heat transfer fluids such as oils and molten salts based ...
Lenert, Andrej
Berry-Phase induced Heat Pumping and its Impact on the Fluctuation Theorem
Applying adiabatic, cyclic two parameter modulations we investigate quantum heat transfer across an anharmonic molecular junction contacted with two heat baths. We demonstrate that the pumped heat typically exhibits a Berry phase effect in providing an additional geometric contribution to heat flux. Remarkably, a robust fractional quantized geometric phonon response is identified as well. The presence of this geometric phase contribution in turn causes a breakdown of the fluctuation theorem of the Gallavotti-Cohen type for quantum heat transfer. This can be restored only if (i) the geometric phase contribution vanishes and if (ii) the cyclic protocol preserves the detailed balance symmetry.
Ren, Jie; Li, Baowen
Final Technical Report for "Radiative Heating Associated with Tropical Convective Cloud Systems: Its Importance at Meso and Global Scales"
Heating associated with tropical cloud systems drive the global circulation. The overall research objectives of this project were to i) further quantify and understand the importance of heating in tropical convective cloud systems with innovative observational techniques, and ii) use global models to determine the large-scale circulation response to variability in tropical heating profiles, including anvil and cirrus cloud radiative forcing. The innovative observational techniques used a diversity of radar systems to create a climatology of vertical velocities associated with the full tropical convective cloud spectrum along with a dissection of the of the total heating profile of tropical cloud systems into separate components (i.e., the latent, radiative, and eddy sensible heating). These properties were used to validate storm-scale and global climate models (GCMs) and were further used to force two different types of GCMs (one with and one without interactive physics). While radiative heating was shown to account for about 20% of the total heating and did not have a strong direct response on the global circulation, the indirect response was important via its impact on convection, esp. in how radiative heating impacts the tilt of heating associated with the Madden-Julian Oscillation (MJO), a phenomenon that accounts for most tropical intraseasonal variability. This work shows strong promise in determining the sensitivity of climate models and climate processes to heating variations associated with cloud systems.
Schumacher, Courtney
Abrasion resistant heat pipe
A specially constructed heat pipe for use in fluidized bed combustors. Two distinct coatings are spray coated onto a heat pipe casing constructed of low thermal expansion metal, each coating serving a different purpose. The first coating forms aluminum oxide to prevent hydrogen permeation into the heat pipe casing, and the second coating contains stabilized zirconium oxide to provide abrasion resistance while not substantially affecting the heat transfer characteristics of the system.
Ernst, Donald M. (Leola, PA)
MA HEAT Loan Overview
Presents information on the success of Massachusetts's HEAT loan offerings and how the financing tool is funded.
A specially constructed heat pipe is described for use in fluidized bed combustors. Two distinct coatings are spray coated onto a heat pipe casing constructed of low thermal expansion metal, each coating serving a different purpose. The first coating forms aluminum oxide to prevent hydrogen permeation into the heat pipe casing, and the second coating contains stabilized zirconium oxide to provide abrasion resistance while not substantially affecting the heat transfer characteristics of the system.
Ernst, D.M.
Solar heat receiver
A receiver is described for converting solar energy to heat a gas to temperatures from 700 to 900/sup 0/C. The receiver is formed to minimize impingement of radiation on the walls and to provide maximum heating at and near the entry of the gas exit. Also, the receiver is formed to provide controlled movement of the gas to be heated to minimize wall temperatures. The receiver is designed for use with gas containing fine heat absorbing particles, such as carbon particles.
Hunt, A.J.; Hansen, L.J.; Evans, D.B.
Nonlocal fluxes at a plasma sheath
The particle and energy fluxes of electrons at the boundary of a plasma in contact with a perfectly absorbing plate are considered. In general, the fluxes are shown not to be determined by the plasma temperature and density at the plate but rather by a convolution of the plasma profiles in the vicinity of the plate. A simple empirical expression is proposed for the nonlocal fluxes, which approximately reproduces the results of a full kinetic calculation. The implications of this, to divertor plasmas near the neutralizer plate, are discussed.
Marchand, R.; Abou-Assaleh, Z.; Matte, J.P. (INRS-Energie, C. P. 1020, Varennes, Quebec, J3X 1S2, Canada (CA))
High-Flux Microchannel Solar Receiver
This fact sheet describes a high-flux, microchannel solar receiver project awarded under the DOE's 2012 SunShot Concentrating Solar Power R&D award program. The team, led by Oregon State University, is working to demonstrate a microchannel-based solar receiver capable of absorbing high solar flux, while using a variety of liquid and gaseous working fluids. High-flux microchannel receivers have the potential to dramatically reduce the size and cost of a solar receiver by minimizing re-radiation and convective losses.
Modeling threat assessments of water supply systems using markov latent effects methodology.
Recent amendments to the Safe Drinking Water Act emphasize efforts toward safeguarding our nation's water supplies against attack and contamination. Specifically, the Public Health Security and Bioterrorism Preparedness and Response Act of 2002 established requirements for each community water system serving more than 3300 people to conduct an assessment of the vulnerability of its system to a terrorist attack or other intentional acts. Integral to evaluating system vulnerability is the threat assessment, which is the process by which the credibility of a threat is quantified. Unfortunately, full probabilistic assessment is generally not feasible, as there is insufficient experience and/or data to quantify the associated probabilities. For this reason, an alternative approach is proposed based on Markov Latent Effects (MLE) modeling, which provides a framework for quantifying imprecise subjective metrics through possibilistic or fuzzy mathematics. Here, an MLE model for water systems is developed and demonstrated to determine threat assessments for different scenarios identified by the assailant, asset, and means. Scenario assailants include terrorists, insiders, and vandals. Assets include a water treatment plant, water storage tank, node, pipeline, well, and a pump station. Means used in attacks include contamination (onsite chemicals, biological and chemical), explosives and vandalism. Results demonstrated highest threats are vandalism events and least likely events are those performed by a terrorist.
Silva, Consuelo Juanita
Ammoniated salt heat pump
A thermochemical heat pump/energy storage system using liquid ammoniate salts is described. The system, which can be used for space heating or cooling, provides energy storage for both functions. The bulk of the energy is stored as chemical energy and thus can be stored indefinitely. The system is well suited to use with a solar energy source or industrial waste heat.
Haas, W.R.; Jaeger, F.J.; Giordano, T.J.
Heat Transfer Guest Editorial
Journal of Heat Transfer Guest Editorial We are indeed delighted in bringing out this special issue was showcased in diverse areas such as traditional heat and mass transfer, lab-on-chip, sensors, biomedical applica- tions, micromixers, fuel cells, and microdevices. Selected papers in the field of heat transfer
Kandlikar, Satish
Acoustic Heating Peter Ulmschneider
mechanisms. 1. The acoustic heating theory Only a few years after Edlen's (1941) discovery that the solar acoustic wave radiation- · b. field acoustic wave Figure 1. Panel a: Acoustic heating in late-type stars: effective temperature TeJ f, gravity g and mixing length parameter fr. Panel b: Acoustic heating in early
Ulmschneider, Peter
Liquid heat capacity lasers
The heat capacity laser concept is extended to systems in which the heat capacity lasing media is a liquid. The laser active liquid is circulated from a reservoir (where the bulk of the media and hence waste heat resides) through a channel so configured for both optical pumping of the media for gain and for light amplification from the resulting gain.
Comaskey, Brian J. (Walnut Creek, CA); Scheibner, Karl F. (Tracy, CA); Ault, Earl R. (Livermore, CA)
Pioneering Heat Pump Project
Project objectives: To install and monitor an innovative WaterFurnace geothermal system that is technologically advanced and evolving; To generate hot water heating from a heat pump that uses non-ozone depleting refrigerant CO2. To demonstrate the energy efficiency of this system ground source heat pump system.
A corrosive resistant heat exchanger
A corrosive and erosive resistant heat exchanger which recovers heat from a contaminated heat stream. The heat exchanger utilizes a boundary layer of innocuous gas, which is continuously replenished, to protect the heat exchanger surface from the hot contaminated gas. The innocuous gas is pumped through ducts or perforations in the heat exchanger wall. Heat from the heat stream is transferred by radiation to the heat exchanger wall. Heat is removed from the outer heat exchanger wall by a heat recovery medium. 3 figs., 3 tabs.
Richlen, S.L.
Simplified Numerical Description of Latent Storage Characteristics for Phase Change Wallboard
the discharge of thermal energy storage without "dumping"thermal mass, and • utilize low-energy heating and cooling sources. Large thermal storagelow- energy cooling sources. Large thermal storage devices
Fuestel, H.E.
Experimental investigation of piston heat transfer under conventional diesel and reactivity-controlled compression ignition combustion regimes
The piston of a heavy-duty single-cylinder research engine was instrumented with 11 fast-response surface thermocouples, and a commercial wireless telemetry system was used to transmit the signals from the moving piston. The raw thermocouple data were processed using an inverse heat conduction method that included Tikhonov regularization to recover transient heat flux. By applying symmetry, the data were compiled to provide time-resolved spatial maps of the piston heat flux and surface temperature. A detailed comparison was made between conventional diesel combustion and reactivity-controlled compression ignition combustion operations at matched conditions of load, speed, boost pressure, and combustion phasing. The integrated piston heat transfer was found to be 24% lower, and the mean surface temperature was 25 C lower for reactivity-controlled compression ignition operation as compared to conventional diesel combustion, in spite of the higher peak heat release rate. Lower integrated piston heat transfer for reactivity-controlled compression ignition was found over all the operating conditions tested. The results showed that increasing speed decreased the integrated heat transfer for conventional diesel combustion and reactivity-controlled compression ignition. The effect of the start of injection timing was found to strongly influence conventional diesel combustion heat flux, but had a negligible effect on reactivity-controlled compression ignition heat flux, even in the limit of near top dead center high-reactivity fuel injection timings. These results suggest that the role of the high-reactivity fuel injection does not significantly affect the thermal environment even though it is important for controlling the ignition timing and heat release rate shape. The integrated heat transfer and the dynamic surface heat flux were found to be insensitive to changes in boost pressure for both conventional diesel combustion and reactivity-controlled compression ignition. However, for reactivity-controlled compression ignition, the mean surface temperature increased with changes in boost suggesting that equivalence ratio affects steady-state heat transfer.
Splitter, Derek A [ORNL; Hendricks, Terry Lee [Sandia National Laboratories (SNL); Ghandhi, Jaal B [University of Wisconsin
CORQUENCH: A model for gas sparging-enhanced, melt-water, film-boiling heat transfer
In evaluation of severe-accident sequences for water-cooled nuclear reactors, molten core materials may be postulated to be released into the containment and accumulate on concrete. The heatup and decomposition of concrete is accompanied by the release of water vapor and carbon dioxide gases. Gases flowing through the melt upper surface can influence the rates of heat transfer to water overlying the melt. In particular, the gas flow through the interface can be envisioned to enhance the heat removal from the melt. A mechanistic model (CORQUENCH) has been developed to describe film-boiling heat transfer between a molten pool and an overlying coolant layer in the presence of sparging gas. The model favorably predicts the lead-Feron 11 data of Greene and Greene et al. for which the calculations indicate that area enhancement in the conduction heat transfer across the film is the predominant mechanism leading to augmentation in the heat flux as the gas velocity increases. Predictions for oxidic corium indicate a rapid increase in film-boiling heat flux as the gas velocity rises. The predominant mode of heat transfer for this case is radiation, and the increase in heat flux with gas velocity is primarily a result of interfacial area enhancement of the radiation component of the overall heat transfer coefficient. The CORQUENCH model has been incorporated into the MELTSPREAD-1 computer code{sup 6} for the analysis of transient spreading in containments.
Farmer, M.T.; Sienicki, J.J.; Spencer, B.W.
Chemical heat pump
A chemical heat pump system is disclosed for use in heating and cooling structures such as residences or commercial buildings. The system is particularly adapted to utilizing solar energy, but also increases the efficiency of other forms of thermal energy when solar energy is not available. When solar energy is not available for relatively short periods of time, the heat storage capacity of the chemical heat pump is utilized to heat the structure as during nighttime hours. The design also permits home heating from solar energy when the sun is shining. The entire system may be conveniently rooftop located. In order to facilitate installation on existing structures, the absorber and vaporizer portions of the system may each be designed as flat, thin wall, thin pan vessels which materially increase the surface area available for heat transfer. In addition, this thin, flat configuration of the absorber and its thin walled (and therefore relatively flexible) construction permits substantial expansion and contraction of the absorber material during vaporization and absorption without generating voids which would interfere with heat transfer. The heat pump part of the system heats or cools a house or other structure through a combination of evaporation and absorption or, conversely, condensation and desorption, in a pair of containers. A set of automatic controls change the system for operation during winter and summer months and for daytime and nighttime operation to satisfactorily heat and cool a house during an entire year. The absorber chamber is subjected to solar heating during regeneration cycles and is covered by one or more layers of glass or other transparent material. Daytime home air used for heating the home is passed at appropriate flow rates between the absorber container and the first transparent cover layer in heat transfer relationship in a manner that greatly reduce eddies and resultant heat loss from the absorbant surface to ambient atmosphere.
Greiner, Leonard (2750-C Segerstrom Ave., Santa Ana, CA 92704)
New configurations of a heat recovery absorption heat pump integrated with a natural gas boiler for boiler efficiency improvement
Conventional natural gas-fired boilers exhaust flue gas direct to the atmosphere at 150 200 C, which, at such temperatures, contains large amount of energy and results in relatively low thermal efficiency ranging from 70% to 80%. Although condensing boilers for recovering the heat in the flue gas have been developed over the past 40 years, their present market share is still less than 25%. The major reason for this relatively slow acceptance is the limited improvement in the thermal efficiency of condensing boilers. In the condensing boiler, the temperature of the hot water return at the range of 50 60 C, which is used to cool the flue gas, is very close to the dew point of the water vapor in the flue gas. Therefore, the latent heat, the majority of the waste heat in the flue gas, which is contained in the water vapor, cannot be recovered. This paper presents a new approach to improve boiler thermal efficiency by integrating absorption heat pumps with natural gas boilers for waste heat recovery (HRAHP). Three configurations of HRAHPs are introduced and discussed. The three configurations are modeled in detail to illustrate the significant thermal efficiency improvement they attain. Further, for conceptual proof and validation, an existing hot water-driven absorption chiller is operated as a heat pump at operating conditions similar to one of the devised configurations. An overall system performance and economic analysis are provided for decision-making and as evidence of the potential benefits. These three configurations of HRAHP provide a pathway to achieving realistic high-efficiency natural gas boilers for applications with process fluid return temperatures higher than or close to the dew point of the water vapor in the flue gas.
Qu, Ming [Purdue University, West Lafayette, IN; Abdelaziz, Omar [ORNL; Yin, Hongxi [Southeast University, Nanjing, China
A low cost high flux solar simulator
A low cost, high flux, large area solar simulator has been designed, built and characterized for the purpose of studying optical melting and light absorption behavior of molten salts. Seven 1500 W metal halide outdoor ...
Codd, Daniel S.
Tetrakis-amido high flux membranes
Composite RO membranes of a microporous polymeric support and a polyamide reaction product of a tetrakis-aminomethyl compound and a polyacylhalide are disclosed, said membranes exhibiting high flux and good chlorine resistance.
McCray, S.B.
High-Latitude Ocean and Sea Ice Surface Fluxes: Requirements and Challenges for Climate Mark Bourassa1
temperatures, seasonal sea ice, and the remoteness of the regions all conspire to make observations difficult latitudes - the vertical exchanges of heat, momentum and material between the ocean, atmosphere and ice1 High-Latitude Ocean and Sea Ice Surface Fluxes: Requirements and Challenges for Climate Research
An improvement in an absorption heat pump cycle is obtained by adding adiabatic absorption and desorption steps to the absorber and desorber of the system. The adiabatic processes make it possible to obtain the highest temperature in the absorber before any heat is removed from it and the lowest temperature in the desorber before heat is added to it, allowing for efficient utilization of the thermodynamic availability of the heat supply stream. The improved system can operate with a larger difference between high and low working fluid concentrations, less circulation losses, and more efficient heat exchange than a conventional system.
Grossman, Gershon (Oak Ridge, TN); Perez-Blanco, Horacio (Knoxville, TN)
Deriving Daytime Variables From the AmeriFlux Standard Eddy Covariance Data Set
A gap-filled, quality assessed eddy covariance dataset has recently become available for the AmeriFluxnetwork. This dataset uses standard processing and produces commonly used science variables. This shared dataset enables robust comparisons across different analyses. Of course, there are many remaining questions. One of those is how to define 'during the day' which is an important concept for many analyses. Some studies have used local time ?for example 9am to 5pm; others have used thresholds on photosynthetic active radiation (PAR). A related question is how to derive quantities such as the Bowen ratio. Most studies compute the ratio of the averages of the latent heat (LE) and sensible heat (H). In this study, we use different methods of defining 'during the day' for GPP, LE, and H. We evaluate the differences between methods in two ways. First, we look at a number of statistics of GPP. Second, we look at differences in the derived Bowen ratio. Our goal is not science per se, but rather informatics in support of the science.
Ingen, Catharine van; Agarwal, Deborah A; Humphrey, Marty; Li, Jie
Soft pion emission from fat flux tubes
The emission of pions from multiquark flux tubes is examined as an explanation of the soft pion puzzle. Although the soft pion spectra from the decay of fat flux tubes can account for some low {ital p}{sub {perpendicular}} enhancement, the dependence on the number of involved quarks is too weak to provide a plausible explanation of the observed enhancement in the pion spectrum at low transverse momenta.
Kusnezov, D.; Danielewicz, P. (National Superconducting Cyclotron Laboratory and Department of Physics Astronomy, Michigan State University, East Lansing, Michigan (USA))
Radial heat transfer from a moving plasma
. The plasma temperature is assumed constant axially and rad'ally and equal to the value at the exit of tl. e arc. chamber. This temperature was used in the determ'r. a- tion of the Nusselt number a, d the Reynolds number used in the above correlatior... and measured values and estimated the accuracy of the heat flux data to be within Measurements of the total continuum radiatior. or simply the energy transferred by radiation from a wall stabilized argon plasma arc were made by Barzelay (14), Comparisons...
Johnson, James Randall
Heat pump apparatus
A heat pump apparatus including a compact arrangement of individual tubular reactors containing hydride-dehydride beds in opposite end sections, each pair of beds in each reactor being operable by sequential and coordinated treatment with a plurality of heat transfer fluids in a plurality of processing stages, and first and second valves located adjacent the reactor end sections with rotatable members having multiple ports and associated portions for separating the hydride beds at each of the end sections into groups and for simultaneously directing a plurality of heat transfer fluids to the different groups. As heat is being generated by a group of beds, others are being regenerated so that heat is continuously available for space heating. As each of the processing stages is completed for a hydride bed or group of beds, each valve member is rotated causing the heat transfer fluid for the heat processing stage to be directed to that bed or group of beds. Each of the end sections are arranged to form a closed perimeter and the valve member may be rotated repeatedly about the perimeter to provide a continuous operation. Both valves are driven by a common motor to provide a coordinated treatment of beds in the same reactors. The heat pump apparatus is particularly suitable for the utilization of thermal energy supplied by solar collectors and concentrators but may be used with any source of heat, including a source of low-grade heat.
Nelson, Paul A. (Wheaton, IL); Horowitz, Jeffrey S. (Woodridge, IL)
Active microchannel heat exchanger
The present invention is an active microchannel heat exchanger with an active heat source and with microchannel architecture. The microchannel heat exchanger has (a) an exothermic reaction chamber; (b) an exhaust chamber; and (c) a heat exchanger chamber in thermal contact with the exhaust chamber, wherein (d) heat from the exothermic reaction chamber is convected by an exothermic reaction exhaust through the exhaust chamber and by conduction through a containment wall to the working fluid in the heat exchanger chamber thereby raising a temperature of the working fluid. The invention is particularly useful as a liquid fuel vaporizer and/or a steam generator for fuel cell power systems, and as a heat source for sustaining endothermic chemical reactions and initiating exothermic reactions.
Tonkovich, Anna Lee Y. (Pasco, WA) [Pasco, WA; Roberts, Gary L. (West Richland, WA) [West Richland, WA; Call, Charles J. (Pasco, WA) [Pasco, WA; Wegeng, Robert S. (Richland, WA) [Richland, WA; Wang, Yong (Richland, WA) [Richland, WA
PERFORMANCE OF A STIRLING ENGINE POWERED HEAT ACTIVATED HEAT PUMP W. D. C. Richards and W. L. Auxer General Electric Company Space Division King of Prussia, Pa. ABSTRACT A heat activated heat pump (HAHP for space heating since it directly utilizes the engine waste heat in addition to the energy obtained
Oak Ridge National Laboratory
A surface renewal model to analyze infrared image sequences of the ocean surface for the study of air-sea heat
A surface renewal model to analyze infrared image sequences of the ocean surface for the study of air-sea heat and gas exchange C. S. Garbe Interdisciplinary Center for Scientific Computing renewal, the net heat flux, and the heat transfer velocity during nighttime. The techniques are based
Garbe, Christoph S.
Control of Large-Scale Heat Transport by Small-Scale Mixing PAOLA CESSI, W. R. YOUNG, AND JEFF A. POLTON
of entropy production, mechanical energy balance, and heat trans- port. The flow is rapidly rotating- ports heat up the gradient of Ts(y); that is, the heat flux ( T, wT) is cooling where Ts(y) is a minimum
Friction in Mid-latitude Bob Plant, Stephen Belcher, Bob Beare, Andy Brown
Friction in Mid-latitude Cyclones Ian Boutle Bob Plant, Stephen Belcher, Bob Beare, Andy Brown #12;Motivation · Many studies have shown the significance of friction in formation and dissipation of cyclones Dt = + � . F . Diabatic Term: · Surface heat fluxes · Latent heat fluxes Frictional Term
Plant, Robert
IEEE GEOSCIENCE AND REMOTE SENSING LETTERS, VOL. 4, NO. 4, OCTOBER 2007 649 A Weak-Constraint-Based Data Assimilation Scheme
IEEE GEOSCIENCE AND REMOTE SENSING LETTERS, VOL. 4, NO. 4, OCTOBER 2007 649 A Weak and momentum fluxes, especially sensible and latent heat fluxes, between the land surface and the atmospheric way to achieve this goal of mapping fluxes on a regional scale is to use remote sensing techniques
Liang, Shunlin
Novel Flux Coupling Machine without Permanent Magnets - U Machine...
Novel Flux Coupling Machine without Permanent Magnets - U Machine Novel Flux Coupling Machine without Permanent Magnets - U Machine 2009 DOE Hydrogen Program and Vehicle...
CRAD, Fire Protection - Oak Ridge National Laboratory High Flux...
Fire Protection - Oak Ridge National Laboratory High Flux Isotope Reactor CRAD, Fire Protection - Oak Ridge National Laboratory High Flux Isotope Reactor February 2006 A section of...
CRAD, Engineering - Oak Ridge National Laboratory High Flux Isotope...
Oak Ridge National Laboratory High Flux Isotope Reactor CRAD, Engineering - Oak Ridge National Laboratory High Flux Isotope Reactor February 2007 A section of Appendix C to DOE G...
CRAD, Maintenance - Oak Ridge National Laboratory High Flux Isotope...
Maintenance - Oak Ridge National Laboratory High Flux Isotope Reactor CRAD, Maintenance - Oak Ridge National Laboratory High Flux Isotope Reactor February 2007 A section of...
CRAD, Nuclear Safety - Oak Ridge National Laboratory High Flux...
Nuclear Safety - Oak Ridge National Laboratory High Flux Isotope Reactor CRAD, Nuclear Safety - Oak Ridge National Laboratory High Flux Isotope Reactor February 2007 A section of...
CRAD, Safety Basis - Oak Ridge National Laboratory High Flux...
Oak Ridge National Laboratory High Flux Isotope Reactor Contractor ORR CRAD, Safety Basis - Oak Ridge National Laboratory High Flux Isotope Reactor Contractor ORR February 2007 A...
Engineering - Oak Ridge National Laboratory High Flux Isotope Reactor Contractor ORR CRAD, Engineering - Oak Ridge National Laboratory High Flux Isotope Reactor Contractor ORR...
Maintenance - Oak Ridge National Laboratory High Flux Isotope Reactor Contractor ORR CRAD, Maintenance - Oak Ridge National Laboratory High Flux Isotope Reactor Contractor ORR...
CRAD, Management- Oak Ridge National Laboratory High Flux Isotope...
Management- Oak Ridge National Laboratory High Flux Isotope Reactor CRAD, Management- Oak Ridge National Laboratory High Flux Isotope Reactor February 2007 A section of Appendix C...
High Flux Isotope Reactor system RELAP5 input model
A thermal-hydraulic computational model of the High Flux Isotope Reactor (HFIR) has been developed using the RELAP5 program. The purpose of the model is to provide a state-of-the art thermal-hydraulic simulation tool for analyzing selected hypothetical accident scenarios for a revised HFIR Safety Analysis Report (SAR). The model includes (1) a detailed representation of the reactor core and other vessel components, (2) three heat exchanger/pump cells, (3) pressurizing pumps and letdown valves, and (4) secondary coolant system (with less detail than the primary system). Data from HFIR operation, component tests, tests in facility mockups and the HFIR, HFIR specific experiments, and other pertinent experiments performed independent of HFIR were used to construct the model and validate it to the extent permitted by the data. The detailed version of the model has been used to simulate loss-of-coolant accidents (LOCAs), while the abbreviated version has been developed for the operational transients that allow use of a less detailed nodalization. Analysis of station blackout with core long-term decay heat removal via natural convection has been performed using the core and vessel portions of the detailed model.
Morris, D.G.; Wendel, M.W.
Summer HeatSummer Heat Heat stress solutions
occur (then drink a lightly salted beverage like a sports drink). The water's temperature should be cool How should gardeners avoid becoming a safety threat to themselves and others when it's hot? Start to the heat. Become a weather watcher. Set up a small weather station (with a high/low thermom eter, rain
Liskiewicz, Maciej
An air heating and cooling system for a building includes an expansion type refrigeration circuit and a vapor power circuit. The refrigeration circuit includes two heat exchangers, one of which is communicated with a source of indoor air from the building and the other of which is communicated with a source of air from outside the building. The vapor power circuit includes two heat exchangers, one of which is disposed in series air flow relationship with the indoor refrigeration circuit heat exchanger and the other of which is disposed in series air flow relationship with the outdoor refrigeration circuit heat exchanger. Fans powered by electricity generated by a vapor power circuit alternator circulate indoor air through the two indoor heat exchangers and circulate outside air through the two outdoor heat exchangers. The system is assembled as a single roof top unit, with a vapor power generator and turbine and compressor thermally insulated from the heat exchangers, and with the indoor heat exchangers thermally insulated from the outdoor heat exchangers.
Swenson, Paul F. (Shaker Heights, OH); Moore, Paul B. (Fedhaven, FL)
Swenson, Paul F.; Moore, Paul B.
Policies supporting Heat Pump Technologies
Policies supporting Heat Pump Technologies in Canada IEA Heat Pump Workshop London, UK November 13 in the world, with an average of 16,995 kilowatt-hours per annum. #12;Canada's Context for Heat Pumps Impacts avenues: Ground source heat pumps for cold climates (heating and cooling) Reversible air source heat
Radiative Heating of the ISCCP Upper Level Cloud Regimes and its Impact on the Large-scale Tropical Circulation
Radiative heating profiles of the International Satellite Cloud Climatology Project (ISCCP) cloud regimes (or weather states) were estimated by matching ISCCP observations with radiative properties derived from cloud radar and lidar measurements from the Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) sites at Manus, Papua New Guinea, and Darwin, Australia. Focus was placed on the ISCCP cloud regimes containing the majority of upper level clouds in the tropics, i.e., mesoscale convective systems (MCSs), deep cumulonimbus with cirrus, mixed shallow and deep convection, and thin cirrus. At upper levels, these regimes have average maximum cloud occurrences ranging from 30% to 55% near 12 km with variations depending on the location and cloud regime. The resulting radiative heating profiles have maxima of approximately 1 K/day near 12 km, with equal heating contributions from the longwave and shortwave components. Upper level minima occur near 15 km, with the MCS regime showing the strongest cooling of 0.2 K/day and the thin cirrus showing no cooling. The gradient of upper level heating ranges from 0.2 to 0.4 K/(day?km), with the most convectively active regimes (i.e., MCSs and deep cumulonimbus with cirrus) having the largest gradient. When the above heating profiles were applied to the 25-year ISCCP data set, the tropics-wide average profile has a radiative heating maximum of 0.45Kday-1 near 250 hPa. Column-integrated radiative heating of upper level cloud accounts for about 20% of the latent heating estimated by the Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR). The ISCCP radiative heating of tropical upper level cloud only slightly modifies the response of an idealized primitive equation model forced with the tropics-wide TRMM PR latent heating, which suggests that the impact of upper level cloud is more important to large-scale tropical circulation variations because of convective feedbacks rather than direct forcing by the cloud radiative heating profiles. However, the height of the radiative heating maxima and gradient of the heating profiles are important to determine the sign and patterns of the horizontal circulation anomaly driven by radiative heating at upper levels.
Li, Wei; Schumacher, Courtney; McFarlane, Sally A.
Fluidized bed heat treating system
Systems for heat treating materials are presented. The systems typically involve a fluidized bed that contains granulated heat treating material. In some embodiments a fluid, such as an inert gas, is flowed through the granulated heat treating medium, which homogenizes the temperature of the heat treating medium. In some embodiments the fluid may be heated in a heating vessel and flowed into the process chamber where the fluid is then flowed through the granulated heat treating medium. In some embodiments the heat treating material may be liquid or granulated heat treating material and the heat treating material may be circulated through a heating vessel into a process chamber where the heat treating material contacts the material to be heat treated. Microwave energy may be used to provide the source of heat for heat treating systems.
Ripley, Edward B; Pfennigwerth, Glenn L
Water-heating dehumidifier
A water-heating dehumidifier includes a refrigerant loop including a compressor, at least one condenser, an expansion device and an evaporator including an evaporator fan. The condenser includes a water inlet and a water outlet for flowing water therethrough or proximate thereto, or is affixed to the tank or immersed into the tank to effect water heating without flowing water. The immersed condenser design includes a self-insulated capillary tube expansion device for simplicity and high efficiency. In a water heating mode air is drawn by the evaporator fan across the evaporator to produce cooled and dehumidified air and heat taken from the air is absorbed by the refrigerant at the evaporator and is pumped to the condenser, where water is heated. When the tank of water heater is full of hot water or a humidistat set point is reached, the water-heating dehumidifier can switch to run as a dehumidifier.
Tomlinson, John J. (Knoxville, TN)
Viscoelastic Models of Tidally Heated Exomoons
Tidal heating of exomoons may play a key role in their habitability, since the elevated temperature can melt the ice on the body even without significant solar radiation. The possibility of life is intensely studied on Solar System moons such as Europa or Enceladus, where the surface ice layer covers tidally heated water ocean. Tidal forces may be even stronger in extrasolar systems, depending on the properties of the moon and its orbit. For studying the tidally heated surface temperature of exomoons, we used a viscoelastic model for the first time. This model is more realistic than the widely used, so-called fixed Q models, because it takes into account the temperature dependency of the tidal heat flux, and the melting of the inner material. With the use of this model we introduced the circumplanetary Tidal Temperate Zone (TTZ), that strongly depends on the orbital period of the moon, and less on its radius. We compared the results with the fixed Q model and investigated the statistical volume of the TTZ usi...
Dobos, Vera
Process for heating coal-oil slurries
Controlling gas to slurry volume ratio to achieve a gas holdup of about 0.4 when heating a flowing coal-oil slurry and a hydrogen containing gas stream allows operation with virtually any coal to solvent ratio and permits operation with efficient heat transfer and satisfactory pressure drops. The critical minimum gas flow rate for any given coal-oil slurry will depend on numerous factors such as coal concentration, coal particle size distribution, composition of the solvent (including recycle slurries), and type of coal. Further system efficiency can be achieved by operating with multiple heating zones to provide a high heat flux when the apparent viscosity of the gas saturated slurry is highest. Operation with gas flow rates below the critical minimum results in system instability indicated by temperature excursions in the fluid and at the tube wall, by a rapid increase and then decrease in overall pressure drop with decreasing gas flow rate, and by increased temperature differences between the temperature of the bulk fluid and the tube wall. At the temperatures and pressures used in coal liquefaction preheaters the coal-oil slurry and hydrogen containing gas stream behaves essentially as a Newtonian fluid at shear rates in excess of 150 sec[sup [minus]1]. The gas to slurry volume ratio should also be controlled to assure that the flow regime does not shift from homogeneous flow to non-homogeneous flow. Stable operations have been observed with a maximum gas holdup as high as 0.72. 29 figs.
Braunlin, W.A.; Gorski, A.; Jaehnig, L.J.; Moskal, C.J.; Naylor, J.D.; Parimi, K.; Ward, J.V.
Controlling gas to slurry volume ratio to achieve a gas holdup of about 0.4 when heating a flowing coal-oil slurry and a hydrogen containing gas stream allows operation with virtually any coal to solvent ratio and permits operation with efficient heat transfer and satisfactory pressure drops. The critical minimum gas flow rate for any given coal-oil slurry will depend on numerous factors such as coal concentration, coal particle size distribution, composition of the solvent (including recycle slurries), and type of coal. Further system efficiency can be achieved by operating with multiple heating zones to provide a high heat flux when the apparent viscosity of the gas saturated slurry is highest. Operation with gas flow rates below the critical minimum results in system instability indicated by temperature excursions in the fluid and at the tube wall, by a rapid increase and then decrease in overall pressure drop with decreasing gas flow rate, and by increased temperature differences between the temperature of the bulk fluid and the tube wall. At the temperatures and pressures used in coal liquefaction preheaters the coal-oil slurry and hydrogen containing gas stream behaves essentially as a Newtonian fluid at shear rates in excess of 150 sec.sup. -1. The gas to slurry volume ratio should also be controlled to assure that the flow regime does not shift from homogeneous flow to non-homogeneous flow. Stable operations have been observed with a maximum gas holdup as high as 0.72.
Braunlin, Walter A. (Spring, TX); Gorski, Alan (Lovington, NM); Jaehnig, Leo J. (New Orleans, LA); Moskal, Clifford J. (Oklahoma City, OK); Naylor, Joseph D. (Houston, TX); Parimi, Krishnia (Allison Park, PA); Ward, John V. (Arvada, CO)
Mechanical Compression Heat Pumps
MECHANICAL COMPRESSION HEAT PUMPS Thomas-L. Apaloo and K. Kawamura Mycom Corporation, Los Angeles, California J. Matsuda, Mayekawa Mfg. Co., Tokyo, Japan ABSTRACT Mechanical compression heat pumping is not new in industrial applications.... In fact, industry history suggests that the theoretical concept was developed before 1825. Heat pump manufacturers gained the support of consultants and end-users when the energy crisis hit this country in 1973. That interest, today, has been...
Apaloo, T. L.; Kawamura, K.; Matsuda, J.
Heat storage duration
Both the amount and duration of heat storage in massive elements of a passive building are investigated. Data taken for one full winter in the Balcomb solar home are analyzed with the aid of sub-system simulation models. Heat storage duration is tallied into one-day intervals. Heat storage location is discussed and related to overall energy flows. The results are interpreted and conclusions drawn.
Balcomb, J.D.
Solar Heating in Uppsala.
?? The housing corporation Uppsalahem has installed asolar heating system in the neighbourhood Haubitsen,which was renovated in 2011. This report examineshow much energy the solar… (more)
Blomqvist, Emelie; Häger, Klara
Solar heating in Colombia.
?? This report describes the process of a thesis implemented in Colombia concerning solar energy. The project was to install a self-circulating solar heating system,… (more)
Skytt, Johanna
Waste Heat Recovery
Office of Environmental Management (EM)
DRAFT - PRE-DECISIONAL - DRAFT 1 Waste Heat Recovery 1 Technology Assessment 2 Contents 3 1. Introduction to the TechnologySystem ......
Heat and mass exchanger
A mass and heat exchanger includes at least one first substrate with a surface for supporting a continuous flow of a liquid thereon that either absorbs, desorbs, evaporates or condenses one or more gaseous species from or to a surrounding gas; and at least one second substrate operatively associated with the first substrate. The second substrate includes a surface for supporting the continuous flow of the liquid thereon and is adapted to carry a heat exchange fluid therethrough, wherein heat transfer occurs between the liquid and the heat exchange fluid.
Lowenstein, Andrew (Princeton, NJ); Sibilia, Marc J. (Princeton, NJ); Miller, Jeffrey A. (Hopewell, NJ); Tonon, Thomas (Princeton, NJ)
HEATS: Thermal Energy Storage
HEATS Project: The 15 projects that make up ARPA-E's HEATS program, short for "High Energy Advanced Thermal Storage," seek to develop revolutionary, cost-effective ways to store thermal energy. HEATS focuses on 3 specific areas: 1) developing high-temperature solar thermal energy storage capable of cost-effectively delivering electricity around the clock and thermal energy storage for nuclear power plants capable of cost-effectively meeting peak demand, 2) creating synthetic fuel efficiently from sunlight by converting sunlight into heat, and 3) using thermal energy storage to improve the driving range of electric vehicles (EVs) and also enable thermal management of internal combustion engine vehicles.
Heat rejection system
A cooling system for rejecting waste heat consists of a cooling tower incorporating a plurality of coolant tubes provided with cooling fins and each having a plurality of cooling channels therein, means for directing a heat exchange fluid from the power plant through less than the total number of cooling channels to cool the heat exchange fluid under normal ambient temperature conditions, means for directing water through the remaining cooling channels whenever the ambient temperature rises above the temperature at which dry cooling of the heat exchange fluid is sufficient and means for cooling the water.
Smith, Gregory C. (Richland, WA); Tokarz, Richard D. (Richland, WA); Parry, Jr., Harvey L. (Richland, WA); Braun, Daniel J. (Richland, WA)
Passive solar space heating
An overview of passive solar space heating is presented indicating trends in design, new developments, performance measures, analytical design aids, and monitored building results.
Spatial variation of heat flux in Steller sea lions: evidence for consistent avenues of heat exchange along the body trunk
thermistors. Optimal sensor placement was established using infrared thermography to locate the major areas
Super-radiance and flux conservation
The theoretical foundations of the phenomenon known as super-radiance still continues to attract considerable attention. Despite many valiant attempts at pedagogically clear presentations, the effect nevertheless still continues to generate some significant confusion. Part of the confusion arises from the fact that super-radiance in a quantum field theory [QFT] context is not the same as super-radiance (super-fluorescence) in some condensed matter contexts; part of the confusion arises from traditional but sometimes awkward normalization conventions, and part is due to sometimes unnecessary confusion between fluxes and probabilities. We shall argue that the key point underlying the effect is flux conservation, (and, in the presence of dissipation, a controlled amount of flux non-conservation), and that attempting to phrase things in terms of reflection and transmission probabilities only works in the absence of super-radiance. To help clarify the situation we present a simple exactly solvable toy model exhibiting both super-radiance and damping.
Petarpa Boonserm; Tritos Ngampitipan; Matt Visser
Real Time Flux Control in PM Motors
Significant research at the Oak Ridge National Laboratory (ORNL) Power Electronics and Electric Machinery Research Center (PEEMRC) is being conducted to develop ways to increase (1) torque, (2) speed range, and (3) efficiency of traction electric motors for hybrid electric vehicles (HEV) within existing current and voltage bounds. Current is limited by the inverter semiconductor devices' capability and voltage is limited by the stator wire insulation's ability to withstand the maximum back-electromotive force (emf), which occurs at the upper end of the speed range. One research track has been to explore ways to control the path and magnitude of magnetic flux while the motor is operating. The phrase, real time flux control (RTFC), refers to this mode of operation in which system parameters are changed while the motor is operating to improve its performance and speed range. RTFC has potential to meet an increased torque demand by introducing additional flux through the main air gap from an external source. It can augment the speed range by diverting flux away from the main air gap to reduce back-emf at high speeds. Conventional RTFC technology is known as vector control [1]. Vector control decomposes the stator current into two components; one that produces torque and a second that opposes (weakens) the magnetic field generated by the rotor, thereby requiring more overall stator current and reducing the efficiency. Efficiency can be improved by selecting a RTFC method that reduces the back-emf without increasing the average current. This favors methods that use pulse currents or very low currents to achieve field weakening. Foremost in ORNL's effort to develop flux control is the work of J. S. Hsu. Early research [2,3] introduced direct control of air-gap flux in permanent magnet (PM) machines and demonstrated it with a flux-controlled generator. The configuration eliminates the problem of demagnetization because it diverts all the flux from the magnets instead of trying to oppose it. It is robust and could be particularly useful for PM generators and electric vehicle drives. Recent efforts have introduced a brushless machine that transfers a magneto-motive force (MMF) generated by a stationary excitation coil to the rotor [4]. Although a conventional PM machine may be field weakened using vector control, the air-gap flux density cannot be effectively enhanced. In Hsu's new machine, the magnetic field generated by the rotor's PM may be augmented by the field from the stationery excitation coil and channeled with flux guides to its desired destination to enhance the air-gap flux that produces torque. The magnetic field can also be weakened by reversing the current in the stationary excitation winding. A patent for advanced technology in this area is pending. Several additional RTFC methods have been discussed in open literature. These include methods of changing the number of poles by magnetizing and demagnetizing the magnets poles with pulses of current corresponding to direct-axis (d-axis) current of vector control [5,6], changing the number of stator coils [7], and controlling the air gap [8]. Test experience has shown that the magnet strengths may vary and weaken naturally as rotor temperature increases suggesting that careful control of the rotor temperature, which is no easy task, could yield another method of RTFC. The purpose of this report is to (1) examine the interaction of rotor and stator flux with regard to RTFC, (2) review and summarize the status of RTFC technology, and (3) compare and evaluate methods for RTFC with respect to maturity, advantages and limitations, deployment difficulty and relative complexity.
Otaduy, P.J.
Uniform flux dish concentrators for photovoltaic application
Researchers at the National Renewable Energy Laboratory (NREL) have designed a unique and innovative molded dish concentrator capable of producing a uniform flux profile on a flat target plane. Concentration levels of 100--200 suns, which are uniform over an area of several square inches, can be directly achieved for collection apertures of a reasonable size ({approximately}1.5-m diameter). Such performance would be immediately applicable to photovoltaic (PV) use. Economic concerns have shown that the proposed approach would be less expensive thatn Fresnel lens concepts or other dish concentrator designs that require complicated and costly receivers to mix the flux to obtain a uniform distribution. 12 refs.
Jorgensen, G; Wendelin, T
Economic analysis of wind-powered farmhouse and farm building heating systems. Final report
The study evaluated the break-even values of wind energy for selected farmhouses and farm buildings focusing on the effects of thermal storage on the use of WECS production and value. Farmhouse structural models include three types derived from a national survey - an older, a more modern, and a passive solar structure. The eight farm building applications that were analyzed include: poultry-layers, poultry-brooding/layers, poultry-broilers, poultry-turkeys, swine-farrowing, swine-growing/finishing, dairy, and lambing. These farm buildings represent the spectrum of animal types, heating energy use, and major contributions to national agricultural economic values. All energy analyses were based on hour-by-hour computations which allowed for growth of animals, sensible and latent heat production, and ventilation requirements. Hourly or three-hourly weather data obtained from the National Climatic Center was used for the nine chosen analysis sites, located throughout the United States and corresponding to regional agricultural production centers.
Stafford, R.W.; Greeb, F.J.; Smith, M.F.; Des Chenes, C.; Weaver, N.L.
Heat pipes and use of heat pipes in furnace exhaust
An array of a plurality of heat pipe are mounted in spaced relationship to one another with the hot end of the heat pipes in a heated environment, e.g. the exhaust flue of a furnace, and the cold end outside the furnace. Heat conversion equipment is connected to the cold end of the heat pipes.
Polcyn, Adam D. (Pittsburgh, PA)
Proceedings of Heat Transfer 2003: ASME Summer Heat Transfer Conference
Proceedings of Heat Transfer 2003: ASME Summer Heat Transfer Conference Las Vegas, Nevada, USA July 21-23, 2003 HT2003-47449 HEAT TRANSFER FROM A MOVING AND EVAPORATING MENISCUS ON A HEATED SURFACE meniscus with complete evaporation of water without any meniscus break-up. The experimental heat transfer
IMPLEMENTING GROUND SOURCE HEAT PUMP AND GROUND LOOP HEAT EXCHANGER MODELS IN THE ENERGYPLUS #12;ii IMPLEMENTING GROUND SOURCE HEAT PUMP AND GROUND LOOP HEAT EXCHANGER MODELS IN THE ENERGYPLUS............................................................... 2 1.3. Overview of the Parameter Estimation Water-to-Water Heat Pump Model ........... 5 1
First university owned district heating system using biomass heat
Highlights · First university owned district heating system using biomass heat · Capacity: 15 MMBtu Main Campus District Heating Performance · Avoided: 3500 tonnes of CO2 · Particulate: less than 10 mg District Heating Goals To displace 85% of natural gas used for core campus heating. Fuel Bunker Sawmill
Northern British Columbia, University of
A chemical heat pump system is disclosed for use in heating and cooling structures such as residences or commercial buildings. The system is particularly adapted to utilizing solar energy, but also increases the efficiency of other forms of thermal energy when solar energy is not available. When solar energy is not available for relatively short periods of time, the heat storage capacity of the chemical heat pump is utilized to heat the structure, as during nighttime hours. The design also permits home heating from solar energy when the sun is shining. The entire system may be conveniently rooftop located. In order to facilitate installation on existing structures, the absorber and vaporizer portions of the system may each be designed as flat, thin wall, thin pan vessels which materially increase the surface area available for heat transfer. In addition, this thin, flat configuration of the absorber and its thin walled (and therefore relatively flexible) construction permits substantial expansion and contraction of the absorber material during vaporization and absorption without generating voids which would interfere with heat transfer.
Greiner, Leonard (2853-A Hickory Pl., Costa Mesa, CA 92626)
A chemical heat pump system is disclosed for use in heating and cooling structures such as residences or commercial buildings. The system is particularly adapted to utilizing solar energy, but also increases the efficiency of other forms of thermal energy when solar energy is not available. When solar energy is not available for relatively short periods of time, the heat storage capacity of the chemical heat pump is utilized to heat the structure, as during nighttime hours. The design also permits home heating from solar energy when the sun is shining. The entire system may be conveniently rooftop located. In order to facilitate intallation on existing structures, the absorber and vaporizer portions of the system may each be designed as flat, thin wall, thin pan vessels which materially increase the surface area available for heat transfer. In addition, this thin, flat configuration of the absorber and its thin walled (and therefore relatively flexible) construction permits substantial expansion and contraction of the absorber material during vaporization and absorption without generating voids which would interfere with heat transfer.
A chemical heat pump system is disclosed for use in heating and cooling structures such as residences or commercial buildings. The system is particularly adapted to utilizing solar energy, but also increases the efficiency of other forms of thermal energy when solar energy is not available. When solar energy is not available for relatively short periods of time, the heat storage capacity of the chemical heat pump is utilized to heat the structure, as during nighttime hours. The design also permits home heating from solar energy when the sun is shining. The entire system may be conveniently rooftop located. In order to faciliate installation on existing structures, the absorber and vaporizer portions of the system may each be designed as flat, thin wall, thin pan vessels which materially increase the surface area available for heat transfer. In addition, this thin, flat configuration of the absorber and its thin walled (and therefore relatively flexible) construction permits substantial expansion and contraction of the absorber material during vaporization and absorption without generating voids which would interfere with heat transfer.
Microchannel heat sink assembly
The present invention provides a microchannel heat sink with a thermal range from cryogenic temperatures to several hundred degrees centigrade. The heat sink can be used with a variety of fluids, such as cryogenic or corrosive fluids, and can be operated at a high pressure. The heat sink comprises a microchannel layer preferably formed of silicon, and a manifold layer preferably formed of glass. The manifold layer comprises an inlet groove and outlet groove which define an inlet manifold and an outlet manifold. The inlet manifold delivers coolant to the inlet section of the microchannels, and the outlet manifold receives coolant from the outlet section of the microchannels. In one embodiment, the manifold layer comprises an inlet hole extending through the manifold layer to the inlet manifold, and an outlet hole extending through the manifold layer to the outlet manifold. Coolant is supplied to the heat sink through a conduit assembly connected to the heat sink. A resilient seal, such as a gasket or an O-ring, is disposed between the conduit and the hole in the heat sink in order to provide a watertight seal. In other embodiments, the conduit assembly may comprise a metal tube which is connected to the heat sink by a soft solder. In still other embodiments, the heat sink may comprise inlet and outlet nipples. The present invention has application in supercomputers, integrated circuits and other electronic devices, and is suitable for cooling materials to superconducting temperatures. 13 figs.
Bonde, W.L.; Contolini, R.J.
Enhanced boiling heat transfer in horizontal test bundles
Two-phase flow boiling from bundles of horizontal tubes with smooth and enhanced surfaces has been investigated. Experiments were conducted in pure refrigerant R-113, pure R-11, and mixtures of R-11 and R-113 of approximately 25, 50, and 75% of R-113 by mass. Tests were conducted in two staggered tube bundles consisting of fifteen rows and five columns laid out in equilateral triangular arrays with pitch-to-diameter ratios of 1.17 and 1.5. The enhanced surfaces tested included a knurled surface (Wolverine`s Turbo-B) and a porous surface (Linde`s High Flux). Pool boiling tests were conducted for each surface so that reference values of the heat transfer coefficient could be obtained. Boiling heat transfer experiments in the tube bundles were conducted at pressures of 2 and 6 bar, heat flux values from 5 to 80 kW/m{sup 2}s, and qualities from 0% to 80%, Values of the heat transfer coefficients for the enhanced surfaces were significantly larger than for the smooth tubes and were comparable to the values obtained in pool boiling. It was found that the performance of the enhanced tubes could be predicted using the pool boiling results. The degradation in the smooth tube heat transfer coefficients obtained in fluid mixtures was found to depend on the difference between the molar concentration in the liquid and vapor.
Trewin, R.R.; Jensen, M.K.; Bergles, A.E.
Scale/Analytical Analyses of Freezing and Convective Melting with Internal Heat Generation
Using a scale/analytical analysis approach, we model phase change (melting) for pure materials which generate constant internal heat generation for small Stefan numbers (approximately one). The analysis considers conduction in the solid phase and natural convection, driven by internal heat generation, in the liquid regime. The model is applied for a constant surface temperature boundary condition where the melting temperature is greater than the surface temperature in a cylindrical geometry. The analysis also consider constant heat flux (in a cylindrical geometry).We show the time scales in which conduction and convection heat transfer dominate.
Ali S. Siahpush; John Crepeau; Piyush Sabharwall
Comparison of ELM heat loads in snowflake and standard divertors
An analysis is given of the impact of the tokamak divertor magnetic structure on the temporal and spatial divertor heat flux from edge localized modes (ELMs). Two configurations are studied: the standard divertor where the poloidal magnetic field (B{sub p}) varies linearly with distance (r) from the magnetic null and the snowflake where B{sub p} varies quadratrically with r. Both one and two-dimensional models are used to analyze the effect of the longer magnetic field length between the midplane and the divertor plate for the snowflake that causes a temporal dilation of the ELM divertor heat flux. A second effect discussed is the appearance of a broad region near the null point where the poloidal plasma beta can substantially exceed unity, especially for the snowflake configuration during the ELM; such a condition is likely to drive additional radial ELM transport.
Rognlien, T D; Cohen, R H; Ryutov, D D; Umansky, M V
Couette flow regimes with heat transfer in rarefied gas
Based on numerical solution of the Boltzmann equation by direct statistic simulation, the Couette flow with heat transfer is studied in a broad range of ratios of plate temperatures and Mach numbers of a moving plate. Flow regime classification by the form of the dependences of the energy flux and friction stress on the Knudsen number Kn is proposed. These dependences can be simultaneously monotonic and nonmonotonic and have maxima. Situations are possible in which the dependence of the energy flux transferred to a plate on Kn has a minimum, while the dependence of the friction stress is monotonic or even has a maximum. Also, regimes exist in which the dependence of the energy flux on Kn has a maximum, while the dependence of the friction stress is monotonic, and vice versa.
Abramov, A. A., E-mail: firstname.lastname@example.com; Butkovskii, A. V., E-mail: firstname.lastname@example.com [Zhukovski Central Aerohydrodynamics Institute (Russian Federation)
Radiation from Kinetic Poynting Flux Acceleration
We derive analytic formulas for the power output and critical frequency of radiation by electrons accelerated by relativistic kinetic Poynting flux, and validate these results with Particle-In-Cell plasma simulations. We find that the in-situ radiation power output and critical frequency are much below those predicted by the classical synchrotron formulae. We discuss potential astrophysical applications of these results.
Edison Liang; Koichi Noguchi
6, 52515268, 2006 Turbulent fluxes over
´exico, 04510 Mexico City, Mexico Received: 24 March 2006  Accepted: 10 May 2006  Published: 26 June 2006 wind speed conditions (up to 25 ms -1 ). The estimates of total momentum flux and turbulent kinetic energy can be represented very5 accurately (r2 =0.99, when data are binned every 1 ms-1 ) by empirical
Recommended Procedures for Measuring Radon Fluxes from
of Waste Management Office of Nuclear Material Safety and Safeguards U.S. Nuclear Regulatory Commission#12;#12;Recommended Procedures for Measuring Radon Fluxes from Disposal Sites of Residual'nat the average annual l'elease of radon-222 from the disposal sites to t.he atmosp~1er0 by residuai radioactive
High Performance Trays and Heat Exchangers in Heat Pumped Distillation Columns
AND LIQUID now PATHS fOA IltO TltAYS I A number of engineering contractors and 1 operating companies have employed Union Carbide'\\s High Flux and Multiple Downcomer tray technolog~es to improve performance, decrease utilities and I lower operating costs... ? Fi,?'d as nll\\ximum within hf'l~ht n'!:-;tl'ie-tlon. The control scheme for a heat pump can be de signed to be no more complex than a conventional steam/cooling water system which relies on flow and level controllers to set the various column flow...
Wisz, M. W.; Antonelli, R.; Ragi, E. G.
Work and heat for two-level systems in dissipative environments: Strong driving and non-Markovian dynamics
Work, moments of work and heat flux are studied for the generic case of a strongly driven twolevel system immersed in a bosonic heat bath in domains of parameter space where perturbative treatments fail. This includes particularly the interplay between non-Markovian dynamics and moderate to strong external driving. Exact data are compared with predictions from weak coupling approaches. Further, the role of system-bath correlations in the initial thermal state and their impact on the heat flux are addressed. The relevance of these results for current experimental activities on solid state devices is discussed.
Rebecca Schmidt; M. Florencia Carusela; Jukka P. Pekola; Joachim Ankerhold
Process for reducing series resistance of solar-cell metal-contact systems with a soldering-flux etchant
Coyle, R.T.; Barrett, J.M.
Heat-Of-Reaction Chemical Heat Pumps--Possible Configurations
-807. (5) K. Kesavan. The Use of Dissociating Gases As the Working Fluid in Thermodynamic Power Conversion Cycles, Ph.D. thesis. Carnegie-Mellon University, 1978, Ann Arbor, MI: University Microfilms International, 1978. 5. Heat amplifier with a gas...ABSTRACT Chemical heat pumps utilize working fluids which undergo reversible chemical changes. Mechanically driven reactive heat pump cycles or, alternatively, hl~a: driven heat pumps in which either heat engine or heat pump working fluid...
Kirol, L. D.
Integrating preconcentrator heat controller
A method and apparatus for controlling the electric resistance heating of a metallic chemical preconcentrator screen, for example, used in portable trace explosives detectors. The length of the heating time-period is automatically adjusted to compensate for any changes in the voltage driving the heating current across the screen, for example, due to gradual discharge or aging of a battery. The total deposited energy in the screen is proportional to the integral over time of the square of the voltage drop across the screen. Since the net temperature rise, .DELTA.T.sub.s, of the screen, from beginning to end of the heating pulse, is proportional to the total amount of heat energy deposited in the screen during the heating pulse, then this integral can be calculated in real-time and used to terminate the heating current when a pre-set target value has been reached; thereby providing a consistent and reliable screen temperature rise, .DELTA.T.sub.s, from pulse-to-pulse.
Bouchier, Francis A. (Albuquerque, NM); Arakaki, Lester H. (Edgewood, NM); Varley, Eric S. (Albuquerque, NM)
Proceedings: Heat exchanger workshop
Heat transfer processes are of controlling importance in the operation of a thermal power plant. Heat exchangers are major cost items and are an important source of problems causing poor power plant availability and performance. A workshop to examine the improvements that can be made to heat exchangers was sponsored by the Electric Power Research Institute (EPRI) on June 10-11, 1986, in Palo Alto, California. This workshop was attended by 25 engineers and scientists representing EPRI-member utilities and EPRI consultants. A forum was provided for discussions related to the design, operation and maintenance of utility heat transfer equipment. The specific objectives were to identify research directions that could significantly improve heat exchanger performance, reliability and life cycle economics. Since there is a great diversity of utility heat transfer equipment in use, this workshop addressed two equipment categories: Boiler Feedwater Heaters (FWH) and Heat Recovery Steam Generators (HRSG). The workshop was divided into the following panel sessions: functional design, mechanical design, operation, suggested research topics, and prioritization. Each panel session began with short presentations by experts on the subject and followed by discussions by the attendees. This report documents the proceedings of the workshop and contains recommendations of potentially valuable areas of research and development. 4 figs.
Micro heat barrier
A highly effective, micron-scale micro heat barrier structure and process for manufacturing a micro heat barrier based on semiconductor and/or MEMS fabrication techniques. The micro heat barrier has an array of non-metallic, freestanding microsupports with a height less than 100 microns, attached to a substrate. An infrared reflective membrane (e.g., 1 micron gold) can be supported by the array of microsupports to provide radiation shielding. The micro heat barrier can be evacuated to eliminate gas phase heat conduction and convection. Semi-isotropic, reactive ion plasma etching can be used to create a microspike having a cusp-like shape with a sharp, pointed tip (<0.1 micron), to minimize the tip's contact area. A heat source can be placed directly on the microspikes. The micro heat barrier can have an apparent thermal conductivity in the range of 10.sup.-6 to 10.sup.-7 W/m-K. Multiple layers of reflective membranes can be used to increase thermal resistance.
Marshall, Albert C.; Kravitz, Stanley H.; Tigges, Chris P.; Vawter, Gregory A.
Condensing Heating and Water Heating Equipment Workshop Location...
Energy Savers [EERE]
Condensing Heating and Water Heating Equipment Workshop Location: Washington Gas Light Appliance Training Facility 6801 Industrial Road Springfield, VA Date: October 9, 2014 Time:...
City of Klamath Falls District Heating District Heating Low Temperatur...
Geothermal Facility Jump to: navigation, search Name City of Klamath Falls District Heating District Heating Low Temperature Geothermal Facility Facility City of Klamath...
Economic Options for Upgrading Waste Heat
There are at least six major types of equipment that upgrade waste heat: (1) thermocompressor; (2) electric drive compressor heat pump; (3) absorption heat pump; (4) high temperature heat powered compressor heat pump; (5) reverse absorption heat...
Erickson, D. C.
Molecular heat pump
We propose a novel molecular device that pumps heat against a thermal gradient. The system consists of a molecular element connecting two thermal reservoirs that are characterized by different spectral properties. The pumping action is achieved by applying an external force that periodically modulates molecular levels. This modulation affects periodic oscillations of the internal temperature of the molecule and the strength of its coupling to each reservoir resulting in a net heat flow in the desired direction. The heat flow is examined in the slow and fast modulation limits and for different modulation waveforms, thus making it possible to optimize the device performance.
Dvira Segal; Abraham Nitzan
Heat treatment furnace
A furnace heats through both infrared radiation and convective air utilizing an infrared/purge gas design that enables improved temperature control to enable more uniform treatment of workpieces. The furnace utilizes lamps, the electrical end connections of which are located in an enclosure outside the furnace chamber, with the lamps extending into the furnace chamber through openings in the wall of the chamber. The enclosure is purged with gas, which gas flows from the enclosure into the furnace chamber via the openings in the wall of the chamber so that the gas flows above and around the lamps and is heated to form a convective mechanism in heating parts.
Seals, Roland D; Parrott, Jeffrey G; DeMint, Paul D; Finney, Kevin R; Blue, Charles T
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