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Office of Scientific and Technical Information
Heat Transfer and Cooling Techniques at Low Temperature
E-Print Network [OSTI]
The first part of this chapter gives an introduction to heat transfer and cooling techniques at low temperature. We review the fundamental laws of heat transfer (conduction, convection and radiation) and give useful data specific to cryogenic conditions (thermal contact resistance, total emissivity of materials and heat transfer correlation in forced or boiling flow for example) used in the design of cooling systems. In the second part, we review the main cooling techniques at low temperature, with or without cryogen, from the simplest ones (bath cooling) to the ones involving the use of cryocoolers without forgetting the cooling flow techniques.
Baudouy, B
Analysis of roll gap heat transfers in hot steel strip rolling through roll temperature sensors and heat transfer models
Analysis of roll gap heat transfers in hot steel strip rolling through roll temperature sensors and heat transfer models N. Legrand1,a , N. Labbe1,b D. Weisz-Patrault2,c , A. Ehrlacher2,d , T. Luks3,e heat transfers during pilot hot steel strip rolling. Two types of temperature sensors (drilled and slot
Paris-Sud XI, Université de
High thermal power density heat transfer apparatus providing electrical isolation at high temperature using heat pipes
SciTech Connect (OSTI)
This invention is directed to transferring heat from an extremely high temperature source to an electrically isolated lower temperature receiver. The invention is particularly concerned with supplying thermal power to a thermionic converter from a nuclear reactor with electric isolation. Heat from a high temperature heat pipe is transferred through a vacuum or a gap filled with electrically nonconducting gas to a cooler heat pipe. The heat pipe is used to cool the nuclear reactor while the heat pipe is connected thermally and electrically to a thermionic converter. If the receiver requires greater thermal power density, geometries are used with larger heat pipe areas for transmitting and receiving energy than the area for conducting the heat to the thermionic converter. In this way the heat pipe capability for increasing thermal power densities compensates for the comparatively low thermal power densities through the electrically nonconducting gap between the two heat pipes.
Morris, J. F.
PTG exam 9 April 2014 short answers 123. Heat given off = surface * heat transfer coefficient * temperature = A * h * T
= Q34 = h4 h3 = 2173,3 kJ/kg d. Heat input = Q15 = h1 h5 = h1 h4 + 4 (pump power) = 2831,0 kPTG exam 9 April 2014 short answers 123. Heat given off = surface * heat transfer coefficient * temperature = A * h * T Heat transfer coefficient from Nunumber, which for natural convection
Zevenhoven, Ron
Heat transfer system
DOE Patents [OSTI]
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.
Not Available
A PC simulation of heat transfer and temperature distribution in a circulating wellbore
A PC SIMULATION OF HEAT TRANSFER AND TEMPERATURE DISTRIBUTION IN A CIRCULATING WELLBORE A Thesis by ROBERT DUANE PIERCE Submitted to the Graduate College of Texas ARM University in partial fulfillment of the requirements for the degree... of MASTER OF SCIENCE December 1987 Major Subject: Petroleum Engineering A PC SIMULATION OF HEAT TRANSFER AND TEMPERATURE DISTRIBUTION IN A CIRCULATING WELLBORE A Thesis by ROBERT DUANE PIERCE Approved as to style and content by; Hans C . Juvkam...
Pierce, Robert Duane
A new predictive dynamic model describing the effect of1 the ambient temperature and the convective heat transfer2
and the convective heat transfer2 coefficient on bacterial growth3 4 H. Ben Yaghlenea,b* , I. Leguerinela , M. Hamdib Ratkowsky "square root" model and a simplified two-parameter20 heat transfer model regarding an infinite air temperature, the convective heat transfer22 coefficient and the growth parameters of the micro
High Operating Temperature Liquid Metal Heat Transfer Fluids...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
plant. A successful candidate fluid would allow for the reduction of the levelized cost of energy by increasing the operating temperature for the CSP plant power cycle, which...
High Operating Temperature Liquid Metal Heat Transfer Fluids (Fact Sheet)
The University of California, Los Angeles, the University of California, Berkeley, and Yale University is one of the 2012 SunShot CSP R&D awardees for their Multidisciplinary University Research Initiative (MURI): High Operating Temperature (HOT) Fluids. This fact sheet explains the motivation, description, and impact of the project.
Heat transfer mechanism with thin filaments including ceramic high temperature heat exchanger
A radiative heat transfer mechanism in a furnace having burners through which pulverized coal and air are burned producing combustion gases and contaminants. A plurality of elongated conduits are positioned inside the furnace proximate to the burners generally parallel to the flow of combustion gases in the furnace. A plurality of thin filaments are inside each of the elongated hollow conduits, the filaments having diameters in the range of from about 1 micrometer to about 1,000 micrometers and having an infrared radiation cross-section sufficient to cause the filaments to heat upon exposure to infrared radiation. Blower mechanism is associated with the elongated conduits for limiting the amount of soot and ash which deposit on the conduits to preserve the radiative and convective transfer of heat energy from the combustion gases to the conduits.
Im, Kwan H. (Naperville, IL); Ahluwalia, Rajesh K. (Burr Ridge, IL)
A radiative heat transfer mechanism in a furnace is described having burners through which pulverized coal and air are burned producing combustion gases and contaminants. A plurality of elongated conduits are positioned inside the furnace proximate to the burners generally parallel to the flow of combustion gases in the furnace. A plurality of thin filaments are inside each of the elongated hollow conduits, the filaments having diameters in the range of from about 1 micrometer to about 1,000 micrometers and having an infrared radiation cross-section sufficient to cause the filaments to heat upon exposure to infrared radiation. Blower mechanism is associated with the elongated conduits for limiting the amount of soot and ash which deposit on the conduits to preserve the radiative and convective transfer of heat energy from the combustion gases to the conduits. 7 figs.
Im, K.H.; Ahluwalia, R.K.
A parametric study of shock jump chemistry, electron temperature, and radiative heat transfer models in hypersonic flows
A PARAMETRIC STUDY OF SHOCK JUMP CHEMISTRY, ELECTRON TEMPERATURE, AND RADIATIVE HEAT TRANSFER MODELS IN HYPERSONIC FLOWS A Thesis by ROBERT BRIAN GREENDYKE Submitted to the Graduate College of Texas A&M University in partial fulfillment... of the requirements for the degree of MASTER OF SCIENCE August 1988 Major Subject: Aerospace Engineering A PARAMETRIC STUDY OF SHOCK JUMP CHEMISTRY, ELECTRON TEMPERATURE, AND RADIATIVE HEAT TRANSFER MODELS IN HYPERSONIC FLOWS A Thesis by ROBERT BRIAN...
Greendyke, Robert Brian
Direct and absolute temperature mapping and heat transfer measurements in diode-end-pumped Yb:YAG
Direct and absolute temperature mapping and heat transfer measurements in diode-end-pumped Yb and heat sink grease respectively). The dynamics of thermal effects is also presented. PACS 42.55.Xi (Diode-pumped in a diode-end-pumped Yb:YAG crystal, using a calibrated infrared camera, with a 60-µm spatial resolution
Heat transfer probe
Apparatuses, systems, methods, and computer code for, among other things, monitoring the health of samples such as the brain while providing local cooling or heating. A representative device is a heat transfer probe, which includes an inner channel, a tip, a concentric outer channel, a first temperature sensor, and a second temperature sensor. The inner channel is configured to transport working fluid from an inner inlet to an inner outlet. The tip is configured to receive at least a portion of the working fluid from the inner outlet. The concentric outer channel is configured to transport the working fluid from the inner outlet to an outer outlet. The first temperature sensor is coupled to the tip, and the second temperature sensor spaced apart from the first temperature sensor.
Frank, Jeffrey I.; Rosengart, Axel J.; Kasza, Ken; Yu, Wenhua; Chien, Tai-Hsin; Franklin, Jeff
7-106 A reversible heat pump is considered. The temperature of the source and the rate of heat transfer to the sink are to be determined.
7-39 7-106 A reversible heat pump is considered. The temperature of the source and the rate of heat transfer to the sink are to be determined. Assumptions The heat pump operates steadily. Analysis Combining.5¸ ¹ · ¨ © § ¸ ¸ ¹ · ¨ ¨ © § 1.6 1 1)K300( COP 1 1 maxHP, HL TT Based upon the definition of the heat pump coefficient
Bahrami, Majid
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
Heat Transfer -2 A pure platinum wire with diameter D = 3 mm and length L = 20 mm is placed outside on a day when air temperature
Heat Transfer - 2 A pure platinum wire with diameter D = 3 mm and length L = 20 mm is placed outside on a day when air temperature T = 10o C. The heat transfer coefficient at the wire's surface h equation that includes all heat transfer mechanisms involved in this problem. Write this energy balance
Virginia Tech
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
Intermediate Heat Transfer Loop Study for High Temperature Gas-Cooled Reactor
A number of possible configurations for a system that transfers heat between the nuclear reactor and the hydrogen and/or electrical generation plants were identified. These configurations included both direct and indirect cycles for the production of electricity. Both helium and liquid salts were considered as the working fluid in the intermediate heat transport loop. Methods were developed to perform thermal-hydraulic and cycleefficiency evaluations of the different configurations and coolants. The thermal-hydraulic evaluations estimated the sizes of various components in the intermediate heat transport loop for the different configurations. This paper also includes a portion of stress analyses performed on pipe configurations.
C. H. Oh; C. Davis; S. Sherman
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
Phenylnaphthalene as a Heat Transfer Fluid for Concentrating Solar Power: High-Temperature Static Experiments
Concentrating solar power (CSP) may be an alternative to generating electricity from fossil fuels; however, greater thermodynamic efficiency is needed to improve the economics of CSP operation. One way of achieving improved efficiency is to operate the CSP loop at higher temperatures than the current maximum of about 400 C. ORNL has been investigating a synthetic polyaromatic oil for use in a trough type CSP collector, to temperatures up to 500 C. The oil was chosen because of its thermal stability and calculated low vapor and critical pressures. The oil has been synthesized using a Suzuki coupling mechanism and has been tested in static heating experiments. Analysis has been conducted on the oil after heating and suggests that there may be some isomerization taking place at 450 C, but the fluid appears to remain stable above that temperature. Tests were conducted over one week and further tests are planned to investigate stabilities after heating for months and in flow configurations. Thermochemical data and thermophysical predictions indicate that substituted polyaromatic hydrocarbons may be useful for applications that run at higher temperatures than possible with commercial fluids such as Therminol-VP1.
Bell, Jason R [ORNL; Joseph III, Robert Anthony [ORNL; McFarlane, Joanna [ORNL; Qualls, A L [ORNL
Using Thermally-Degrading, Partitioning, and Nonreactive Tracers to Determine Temperature Distribution and Fracture/Heat Transfer Surface Area in Geothermal Reservoirs
Broader source: Energy.gov [DOE]
DOE Geothermal Peer Review 2010 - Project Summary. The goal of this project is to provide integrated tracer and tracer interpretation tools to facilitate quantitative characterization of temperature distributions and surface area available for heat transfer in EGS.
General Heat Transfer Characterization and Empirical Models of Material Storage Temperatures for the Los Alamos Nuclear Materials Storage Facility
The Los Alamos National Laboratory's Nuclear Materials Storage Facility (NMSF) is being renovated for long-term storage of canisters designed to hold heat-generating nuclear materials. A fully passive cooling scheme, relying on the transfer of heat by conduction, free convection, and radiation has been proposed as a reliable means of maintaining material at acceptable storage temperatures. The storage concept involves placing radioactive materials, with a net heat-generation rate of 10 W to 20 W, inside a set of nested steel canisters. The canisters are, in placed in holding fixtures and positioned vertically within a steel storage pipe. Several hundred drywells are arranged in a linear array within a large bay and dissipate the waste heat to the surrounding air, thus creating a buoyancy driven airflow pattern that draws cool air into the storage facility and exhausts heated air through an outlet stack. In this study, an experimental apparatus was designed to investigate the thermal characteristics of simulated nuclear materials placed inside two nested steel canisters positioned vertically on an aluminum fixture plate and placed inside a section of steel pipe. The heat-generating nuclear materials were simulated with a solid aluminum cylinder containing .an embedded electrical resistance heater. Calibrated type T thermocouples (accurate to ~ O.1 C) were used to monitor temperatures at 20 different locations within the apparatus. The purposes of this study were to observe the heat dissipation characteristics of the proposed `canister/fixture plate storage configuration, to investigate how the storage system responds to changes in various parameters, and to develop and validate empirical correlations to predict material temperatures under various operating conditions
J. D. Bernardin; W. S. Gregory
Velocity and temperature distribution of air in the boundary layer of a vertical plate for free-convective heat transfer
against the nozzle and clamped to. a stand in such a way that its vertical position could be, set. as desired. Hot-Wire Anemometer A Plow Corporation Model HWB2 hot wire anemometer was used in connection with a single, filament, probe to measure...VELOCITY AND TEMPERATURE DISTRIBUTION OF AIR IN THE BOUNDARY LAYER OF A VERTICAL PLATE FOR FREE-CONVECTIVE HEAT TRANSFER A Thesis By JEAN MAXIME JOSE JULLIENNE Submitted to . the . Graduate School of the Agricultural. and Mechanical. College...
Jullienne, Jean Maxime Jose
Susanville District Heating District Heating Low Temperature...
Open Energy Info (EERE)
Susanville District Heating District Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Susanville District Heating District Heating Low Temperature...
Convective Heat Transfer and Reference Free-stream Temperature Determination near the Casing of an Axial Flow
of an Axial Flow Turbine B. Gumusel 2 and C. Camci 1 Turbomachinery Aero-Heat Transfer Laboratory Department on the casing of an axial flow turbine. The goal is to develop an accurate steady-state heat transfer method for the comparison of various casing surface and tip designs used for turbine performance improvements. The free
Camci, Cengiz
Experimental Investigation of Forced Convection Heat Transfer of Nanofluids in a Microchannel using Temperature Nanosensors
for performing the experimental measurements. TFT arrays were designed (which included design of photomask layout), microfabricated, packaged and assembled for testing with the experimental apparatus. Heat removal rates from the heated surface to the different...
Yu, Jiwon 1982-
Faculty Positions Heat Transfer and
Faculty Positions Heat Transfer and Thermal/Energy Sciences Naval Postgraduate School Monterey-track faculty position at the assistant professor level in the areas of Heat Transfer and Thermal/Fluid Sciences
5. Heat transfer Ron Zevenhoven
1/120 5. Heat transfer Ron Zevenhoven �?bo Akademi University Thermal and Flow Engineering / Värme Three heat transfer mechanisms Conduction Convection Radiation 2/120 Pic: B�?88 �?bo Akademi University | Thermal and Flow Engineering | 20500 Turku | Finland #12;3/120 5.1 Conductive heat transfer �?bo Akademi
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.
Radiative heat transfer in porous uranium dioxide
Due to low thermal conductivity and high emissivity of UO{sub 2}, it has been suggested that radiative heat transfer may play a significant role in heat transfer through pores of UO{sub 2} fuel. This possibility was computationally investigated and contribution of radiative heat transfer within pores to overall heat transport in porous UO{sub 2} quantified. A repeating unit cell was developed to model approximately a porous UO{sub 2} fuel system, and the heat transfer through unit cells representing a wide variety of fuel conditions was calculated using a finite element computer program. Conduction through solid fuel matrix as wekk as pore gas, and radiative exchange at pore surface was incorporated. A variety of pore compositions were investigated: porosity, pore size, shape and orientation, temperature, and temperature gradient. Calculations were made in which pore surface radiation was both modeled and neglected. The difference between yielding the integral contribution of radiative heat transfer mechanism to overall heat transport. Results indicate that radiative component of heat transfer within pores is small for conditions representative of light water reactor fuel, typically less than 1% of total heat transport. It is much larger, however, for conditions present in liquid metal fast breeder reactor fuel; during restructuring of this fuel type early in life, the radiative heat transfer mode was shown to contribute as much as 10-20% of total heat transport in hottest regions of fuel.
Hayes, S.L. [Texas A and M Univ., College Station, TX (United States)] [Texas A and M Univ., College Station, TX (United States)
Project Profile: Heat Transfer and Latent Heat Storage in Inorganic...
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...
Urban Sewage Delivery Heat Transfer System (2): Heat Transfer
The thimble delivery heat-transfer (TDHT) system is one of the primary modes to utilize the energy of urban sewage. Using the efficiency-number of transfer units method ( ), the heat-transfer efficiencies of the parallel-flow and reverse-flow TDTH...
Zhang, C.; Wu, R.; Li, X.; Li, G.; Zhuang, Z.; Sun, D.
Convective heat transfer model for determining quench recovery of high temperature superconducting YBCO in liquid nitrogen
Stability of a superconducting magnet is critical for reliable operation of a device in which the magnet plays a role. With the advent of high temperature superconductors (HTS), liquid nitrogen may be used to cool HTS ...
Jankowski, Joseph Edward, 1980-
Heat Transfer in Underground Rail Tunnels
The transfer of heat between the air and surrounding soil in underground tunnels ins investigated, as part of the analysis of environmental conditions in underground rail systems. Using standard turbulent modelling assumptions, flow profiles are obtained in both open tunnels and in the annulus between a tunnel wall and a moving train, from which the heat transfer coefficient between the air and tunnel wall is computed. The radial conduction of heat through the surrounding soil resulting from changes in the temperature of air in the tunnel are determined. An impulse change and an oscillating tunnel air temperature are considered separately. The correlations between fluctuations in heat transfer coefficient and air temperature are found to increase the mean soil temperature. Finally, a model for the coupled evolution of the air and surrounding soil temperature along a tunnel of finite length is given.
Sadokierski, Stefan
Modelling Heat Transfer of Carbon Nanotubes
Modelling heat transfer of carbon nanotubes is important for the thermal management of nanotube-based composites and nanoelectronic device. By using a finite element method for three-dimensional anisotropic heat transfer, we have simulated the heat conduction and temperature variations of a single nanotube, a nanotube array and a part of nanotube-based composite surface with heat generation. The thermal conductivity used is obtained from the upscaled value from the molecular simulations or experiments. Simulations show that nanotube arrays have unique cooling characteristics due to its anisotropic thermal conductivity.
Yang, Xin-She
Spring 2014 Heat Transfer -2
Spring 2014 Heat Transfer - 2 A thin electronic chip is in the shape of a square wafer, b = 1 cm surface of the chip with a heat transfer coefficient of h = 100 W/m2 -K. Assume the chip has a uniform per side with a mass of m = 0.3 grams and specific heat of C = 103 J/kg-K. The chip is mounted
Passive heat transfer means for nuclear reactors
An improved passive cooling arrangement is disclosed for maintaining adjacent or related components of a nuclear reactor within specified temperature differences. Specifically, heat pipes are operatively interposed between the components, with the vaporizing section of the heat pipe proximate the hot component operable to cool it and the primary condensing section of the heat pipe proximate the other and cooler component operable to heat it. Each heat pipe further has a secondary condensing section that is located outwardly beyond the reactor confinement and in a secondary heat sink, such as air ambient the containment, that is cooler than the other reactor component. Means such as shrouding normally isolated the secondary condensing section from effective heat transfer with the heat sink, but a sensor responds to overheat conditions of the reactor to open the shrouding, which thereby increases the cooling capacity of the heat pipe. By having many such heat pipes, an emergency passive cooling system is defined that is operative without electrical power.
Burelbach, James P. (Glen Ellyn, IL)
Spring 2014 Heat Transfer -1
Spring 2014 1 Heat Transfer - 1 Consider a cylindrical nuclear fuel rod of length L and diameter df and the tube at a rate m , and the outer surface of the tube is well insulated. Heat generation occurs within. The specific heat of water pc , and the thermal conductivity of the fuel rod fk are constants. The system
11 Stagnation Point Heat Transfer Measurements in Air atR.M. , and Kemp, N.H. , Heat Transfer from High TemperatureProceedings of the 1963 Heat Transfer and Fluid Mechanics
Heperkan, H.
Electrohydrodynamically enhanced condensation heat transfer
In a condenser the thickness of the liquid condensate film covering the cooled surface constitutes a resistance to the heat transfer. By establishing a non uniform electric field in the vicinity of the condensation surface the extraction of liquid...
Wawzyniak, Markus
MODERN DEVELOPMENTS IN MULTIPHASE FLOW & HEAT TRANSFER "ENGINEERING APPLICATIONS OF FRACTAL and multiphase flow & heat transfer will be stressed. This paper will begin by reviewing some important concepts
Lahey, Richard T.
Summary Weusedthreemethodstomeasureboundarylayer conductance to heat transfer (gbH) and water vapor transfer
Summary Weusedthreemethodstomeasureboundarylayer conductance to heat transfer (gbH) and water vapor of transpiration). The boundary layer conductance to heat transfer is small enough that leaf temperature can become diffusion, the boundary layer around a leaf also provides resistance to the transfer of heat between a leaf
Martin, Timothy
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.
Examination of Liquid Fluoride Salt Heat Transfer
The need for high efficiency power conversion and energy transport systems is increasing as world energy use continues to increase, petroleum supplies decrease, and global warming concerns become more prevalent. There are few heat transport fluids capable of operating above about 600oC that do not require operation at extremely high pressures. Liquid fluoride salts are an exception to that limitation. Fluoride salts have very high boiling points, can operate at high temperatures and low pressures and have very good heat transfer properties. They have been proposed as coolants for next generation fission reactor systems, as coolants for fusion reactor blankets, and as thermal storage media for solar power systems. In each case, these salts are used to either extract or deliver heat through heat exchange equipment, and in order to design this equipment, liquid salt heat transfer must be predicted. This paper discusses the heat transfer characteristics of liquid fluoride salts. Historically, heat transfer in fluoride salts has been assumed to be consistent with that of conventional fluids (air, water, etc.), and correlations used for predicting heat transfer performance of all fluoride salts have been the same or similar to those used for water conventional fluids an, water, etc). A review of existing liquid salt heat transfer data is presented, summarized, and evaluated on a consistent basis. Less than 10 experimental data sets have been found in the literature, with varying degrees of experimental detail and measured parameters provided. The data has been digitized and a limited database has been assembled and compared to existing heat transfer correlations. Results vary as well, with some data sets following traditional correlations; in others the comparisons are less conclusive. This is especially the case for less common salt/materials combinations, and suggests that additional heat transfer data may be needed when using specific salt eutectics in heat transfer equipment designs. All of the data discussed above were taken under forced convective conditions (both laminar and turbulent). Some recent data taken at ORNL under free convection conditions are also presented and results discussed. This data was taken using a simple crucible experiment with an instrumented nickel heater inserted in the salt to induce natural circulation within the crucible. The data was taken over a temperature range of 550oC to 650oC in FLiNaK salt. This data covers both laminar and turbulent natural convection conditions, and is compared to existing forms of natural circulation correlations.
Yoder Jr, Graydon L [ORNL] [ORNL
Enhanced heat transfer using nanofluids
This invention is directed to a method of and apparatus for enhancing heat transfer in fluids such as deionized water. ethylene glycol, or oil by dispersing nanocrystalline particles of substances such as copper, copper oxide, aluminum oxide, or the like in the fluids. Nanocrystalline particles are produced and dispersed in the fluid by heating the substance to be dispersed in a vacuum while passing a thin film of the fluid near the heated substance. The fluid is cooled to control its vapor pressure.
Choi, Stephen U. S. (Lisle, IL); Eastman, Jeffrey A. (Naperville, IL)
Heat transfer assembly for a fluorescent lamp and fixture
In a lighting fixture including a lamp and a housing, a heat transfer structure is disclosed for reducing the minimum lamp wall temperature of a fluorescent light bulb. The heat transfer structure, constructed of thermally conductive material, extends from inside the housing to outside the housing, transferring heat energy generated from a fluorescent light bulb to outside the housing where the heat energy is dissipated to the ambient air outside the housing. Also disclosed is a method for reducing minimum lamp wall temperatures. Further disclosed is an improved lighting fixture including a lamp, a housing and the aforementioned heat transfer structure.
Siminovitch, Michael J. (Richmond, CA); Rubenstein, Francis M. (Berkeley, CA); Whitman, Richard E. (Richmond, CA)
In a lighting fixture including a lamp and a housing, a heat transfer structure is disclosed for reducing the minimum lamp wall temperature of a fluorescent light bulb. The heat transfer structure, constructed of thermally conductive material, extends from inside the housing to outside the housing, transferring heat energy generated from a fluorescent light bulb to outside the housing where the heat energy is dissipated to the ambient air outside the housing. Also disclosed is a method for reducing minimum lamp wall temperatures. Further disclosed is an improved lighting fixture including a lamp, a housing and the aforementioned heat transfer structure. 11 figs.
Siminovitch, M.J.; Rubenstein, F.M.; Whitman, R.E.
An Evaluation of the Impact of Surface Coatings on the Heat Transfer in High Temperature Ceramic Recuperators
COATINGS Engineering ceramics, particular ly SiC, are being investigated for use as high temperature heat exchanger materials. ORNL has conducted exposure test in real and simulated high tempera ture corrosive flue gases and these have... indicated that SiC ceramics are sucepti ble to flue gases containing sodium and potassium, compounds such as sulfates, carbonates and halides. ORNL is current ly investigating whether commercially available ceramic coatings could be from 1500 0...
Guerrero, P. S.; Rebello, W. J.; Federer, J. I.
Nanoscale heat transfer - from computation to experiment
Heat transfer can differ distinctly at the nanoscale from that at the macroscale. Recent advancement in
Luo, Tengfei
Thermal-Hydraulic Analyses of Heat Transfer Fluid Requirements and Characteristics for Coupling A Hydrogen Production Plant to a High-Temperature Nuclear Reactor
The Department of Energy is investigating the use of high-temperature nuclear reactors to produce hydrogen using either thermochemical cycles or high-temperature electrolysis. Although the hydrogen production processes are in an early stage of development, coupling either of these processes to the hightemperature reactor requires both efficient heat transfer and adequate separation of the facilities to assure that off-normal events in the production facility do not impact the nuclear power plant. An intermediate heat transport loop will be required to separate the operations and safety functions of the nuclear and hydrogen plants. A next generation high-temperature reactor could be envisioned as a single-purpose facility that produces hydrogen or a dual-purpose facility that produces hydrogen and electricity. Early plants, such as the proposed Next Generation Nuclear Plant, may be dual-purpose facilities that demonstrate both hydrogen and efficient electrical generation. Later plants could be single-purpose facilities. At this stage of development, both single- and dual-purpose facilities need to be understood. Seven possible configurations for a system that transfers heat between the nuclear reactor and the hydrogen and/or electrical generation plants were identified. These configurations included both direct and indirect cycles for the production of electricity. Both helium and liquid salts were considered as the working fluid in the intermediate heat transport loop. Methods were developed to perform thermalhydraulic and cycle-efficiency evaluations of the different configurations and coolants. The thermalhydraulic evaluations estimated the sizes of various components in the intermediate heat transport loop for the different configurations. The relative sizes of components provide a relative indication of the capital cost associated with the various configurations. Estimates of the overall cycle efficiency of the various configurations were also determined. The evaluations determined which configurations and coolants are the most promising from thermal-hydraulic and efficiency points of view. These evaluations also determined which configurations and options do not appear to be feasible at the current time.
C. B. Davis; C. H. Oh; R. B. Barner; D. F. Wilson
Radiative Heat Transfer between Neighboring Particles
The near-field interaction between two neighboring particles is known to produce enhanced radiative heat transfer. We advance in the understanding of this phenomenon by including the full electromagnetic particle response, heat exchange with the environment, and important radiative corrections both in the distance dependence of the fields and in the particle absorption coefficients. We find that crossed terms of electric and magnetic interactions dominate the transfer rate between gold and SiC particles, whereas radiative corrections reduce it by several orders of magnitude even at small separations. Radiation away from the dimer can be strongly suppressed or enhanced at low and high temperatures, respectively. These effects must be taken into account for an accurate description of radiative heat transfer in nanostructured environments.
Alejandro Manjavacas; F. Javier Garcia de Abajo
Molten Salt Heat Transfer Fluid (HTF)
Energy Innovation Portal (Marketing Summaries) [EERE]
Sandia has developed a heat transfer fluid (HTF) for use at elevated temperatures that has a lower freezing point than any molten salt mixture available commercially. This allows the HTF to be used in applications in which the expensive parasitic energy costs necessary for freeze protection can be significantly reduced. The higher operating temperature limit significantly increases power cycle efficiency and overall power plan sun-to-net electric efficiency....
Heat transfer analysis in Stirling engine heat input system
One of the major factor in commercialization of Stirling engine is mass productivity, and the heat input system including tubular heater is one of the obstacles to mass production because of its complexity in shape and difficulty in manufacturing, which resulted from using oxidation-resistant, low-creep alloys which are not easy to machine and weld. Therefore a heater heat exchanger which is very simple in shape and easy to make has been devised, and a burner system appropriate to this heater also has been developed. In this paper specially devised heat input system which includes a heater shell shaped like U-cup and a flame tube located in the heater shell is analyzed in point of heat transfer processes to find optimum heat transfer. To enhance the heat transfer from the flame tube to the heater shell wall, it is required that the flame tube diameter be enlarged as close to the heater shell diameter as possible, and the flame tube temperature be raised as high as possible. But the enlargement of the flame tube diameter should be restricted by the state of combustion affected by hydraulic resistance of combustion gas, and the boost of the flame tube temperature should be considered carefully in the aspects of the flame tube`s service life.
Chung, W.; Kim, S. [LG Electronics Inc., Seoul (Korea, Republic of). Living System Lab.
Heat Transfer in Complex Fluids
Amongst the most important constitutive relations in Mechanics, when characterizing the behavior of complex materials, one can identify the stress tensor T, the heat flux vector q (related to heat conduction) and the radiant heating (related to the radiation term in the energy equation). Of course, the expression 'complex materials' is not new. In fact, at least since the publication of the paper by Rivlin & Ericksen (1955), who discussed fluids of complexity (Truesdell & Noll, 1992), to the recently published books (Deshpande et al., 2010), the term complex fluids refers in general to fluid-like materials whose response, namely the stress tensor, is 'non-linear' in some fashion. This non-linearity can manifest itself in variety of forms such as memory effects, yield stress, creep or relaxation, normal-stress differences, etc. The emphasis in this chapter, while focusing on the constitutive modeling of complex fluids, is on granular materials (such as coal) and non-linear fluids (such as coal-slurries). One of the main areas of interest in energy related processes, such as power plants, atomization, alternative fuels, etc., is the use of slurries, specifically coal-water or coal-oil slurries, as the primary fuel. Some studies indicate that the viscosity of coal-water mixtures depends not only on the volume fraction of solids, and the mean size and the size distribution of the coal, but also on the shear rate, since the slurry behaves as shear-rate dependent fluid. There are also studies which indicate that preheating the fuel results in better performance, and as a result of such heating, the viscosity changes. Constitutive modeling of these non-linear fluids, commonly referred to as non-Newtonian fluids, has received much attention. Most of the naturally occurring and synthetic fluids are non-linear fluids, for example, polymer melts, suspensions, blood, coal-water slurries, drilling fluids, mud, etc. It should be noted that sometimes these fluids show Newtonian (linear) behavior for a given range of parameters or geometries; there are many empirical or semi-empirical constitutive equations suggested for these fluids. There have also been many non-linear constitutive relations which have been derived based on the techniques of continuum mechanics. The non-linearities oftentimes appear due to higher gradient terms or time derivatives. When thermal and or chemical effects are also important, the (coupled) momentum and energy equations can give rise to a variety of interesting problems, such as instability, for example the phenomenon of double-diffusive convection in a fluid layer. In Conclusion, we have studied the flow of a compressible (density gradient type) non-linear fluid down an inclined plane, subject to radiation boundary condition. The heat transfer is also considered where a source term, similar to the Arrhenius type reaction, is included. The non-dimensional forms of the equations are solved numerically and the competing effects of conduction, dissipation, heat generation and radiation are discussed. It is observed that the velocity increases rapidly in the region near the inclined surface and is slower in the region near the free surface. Since R{sub 7} is a measure of the heat generation due to chemical reaction, when the reaction is frozen (R{sub 7}=0.0) the temperature distributions would depend only on R{sub 1}, and R{sub 2}, representing the effects of the pressure force developed in the material due to the distribution, R{sub 3} and R{sub 4} viscous dissipation, R{sub 5} the normal stress coefficient, R{sub 6} the measure of the emissivity of the particles to the thermal conductivity, etc. When the flow is not frozen (RP{sub 7} > 0) the temperature inside the flow domain is much higher than those at the inclined and free surfaces. As a result, heat is transferred away from the flow toward both the inclined surface and the free surface with a rate that increases as R{sub 7} increases. For a given temperature, an increase in {zeta} implies that the activation energy is smaller and thus, the reaction ra
Mehrdad Massoudi
Heat Transfer Technology
,(C) 122 (5OJ 140 (6OJ 158 (70 DRY TOWER 6< F, (K) (15)18 (10) 36 (20 ~ATER "OUT" F, (C) 27 104 (40) 113 (45) 122 (50 ApPROACH F, (C) (15)18 (10) 36 (20 DRY BULB F, (D 27 (30)86 (30) 86(3086 Wn SFrTlo. WATER "IN" F, (() 104 (40) 113 (45) 122... (50 IIET TOWER 6t F, (K) 18 (10) 0 WATER "OlIT" F, (D S 86 (30) 104 (40) ApPROACH F, (K) ~~ (~l 27 (15)3 (5) ~ET BULB F, (C) 77 (25) 77 (25) 77 (25 VARIATiON OF TEMPERATURES AS A FUNCTION OF THE MODE OF OPERATION. To decrease...
Lefevre, M. R.
Journal of Heat Transfer1999 JHT Heat Transfer Gallery Department of Mechanical 8. Aerospace Engineering
Journal of Heat Transfer1999 JHT Heat Transfer Gallery S. M. You Department of Mechanical 8 Transfer Visualization Committee organized two photo gallery sessions in 1998. The International Heat Transfer Photo Gallery was held at the l la' International Heat Transfer Conference (IHTC) in Kyongju
Kihm, IconKenneth David
Kethcum District Heating District Heating Low Temperature Geothermal...
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Philip District Heating District Heating Low Temperature Geothermal...
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Low-melting point heat transfer fluid
A low-melting point, heat transfer fluid made of a mixture of five inorganic salts including about 29.1-33.5 mol % LiNO.sub.3, 0-3.9 mol % NaNO.sub.3, 2.4-8.2 mol % KNO.sub.3, 18.6-19.9 mol % NaNO.sub.2, and 40-45.6 mol % KNO.sub.2. These compositions can have liquidus temperatures below 80.degree. C. for some compositions.
Cordaro, Joseph Gabriel (Oakland, CA); Bradshaw, Robert W. (Livermore, CA)
ME 519: THEORY OF HEAT TRANSFER Instructor
ME 519: THEORY OF HEAT TRANSFER Fall 2014 Instructor: Class time: Classroom: Office Hours: Prof Tuesday 45pm or by appointment Class description This course will cover the fundamentals of heat transfer. An introductory course in heat transfer (ME 419 or equivalent) is pre-requisite. Grading 20% Homework 25% Exam 1
Lin, Xi
Heat transfer via dropwise condensation on hydrophobic microstructured surfaces
Dropwise condensation has the potential to greatly increase heat transfer rates. Heat transfer coefficients by dropwise condensation and film condensation on microstructured silicon chips were compared. Heat transfer ...
Ruleman, Karlen E. (Karlen Elizabeth)
Radiative Heat Transfer in Enhanced Hydrogen Outgassing of Glass
Kaviany and B.P. Singh, �Radiative heat transfer in porousmedia�, Advances in Heat Transfer, vol. 23, no. 23, pp. 133�Thermal radiation heat transfer, Hemisphere Publishing Co. ,
Kitamura, Rei; Pilon, Laurent
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
Heat Transfer Research, 2010, Vol. 41, No. 6 Turbine Aero-Heat Transfer Studies
AU TH O R PR O O F Heat Transfer Research, 2010, Vol. 41, No. 6 Turbine Aero-Heat Transfer Studies in Rotating Research Facilities CENGIZ CAMCI Turbomachinery Aero-Heat Transfer Laboratory, Department The present paper deals with the experimental aero-heat transfer studies performed in rotating turbine
Heat exchanger device and method for heat removal or transfer
Systems and methods for a forced-convection heat exchanger are provided. In one embodiment, heat is transferred to or from a thermal load in thermal contact with a heat conducting structure, across a narrow air gap, to a rotating heat transfer structure immersed in a surrounding medium such as air.
Koplow, Jeffrey P. (San Ramon, CA)
Koplow, Jeffrey P
Heat-Traced Fluid Transfer Lines
HEAT-TRACED FLUID TRANSFER LINES Robert E. Schilling, P.E. Eaton Corporation Aurora, Ohio This paper discusses basic considerations in designing a heat tracing system using either steam or electrical tracing. Four basic reasons to heat...
Schilling, R. E.
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
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
Jaehne, Bernd
Nuclear reactor safety heat transfer
Reviewed is a book which has 5 parts: Overview, Fundamental Concepts, Design Basis Accident-Light Water Reactors (LWRs), Design Basis Accident-Liquid-Metal Fast Breeder Reactors (LMFBRs), and Special Topics. It combines a historical overview, textbook material, handbook information, and the editor's personal philosophy on safety of nuclear power plants. Topics include thermal-hydraulic considerations; transient response of LWRs and LMFBRs following initiating events; various accident scenarios; single- and two-phase flow; single- and two-phase heat transfer; nuclear systems safety modeling; startup and shutdown; transient response during normal and upset conditions; vapor explosions, natural convection cooling; blockages in LMFBR subassemblies; sodium boiling; and Three Mile Island.
Jones, O.C.
Mpemba effect, Newton cooling law and heat transfer equation
In this work we suggest a simple theoretical solution of the Mpemba effect in full agreement with known experimental data. This solution follows simply as an especial approximation (linearization) of the usual heat (transfer) equation, precisely linearization of the second derivation of the space part of the temperature function (as it is well-known Newton cooling law can be considered as the effective approximation of the heat (transfer) equation for constant space part of the temperature function).
Vladan Pankovic; Darko V. Kapor
Pagosa Springs District Heating District Heating Low Temperature...
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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...
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)
Fourier analysis of conductive heat transfer for glazed roofing materials
For low-rise buildings, roof is the most exposed surface to solar radiation. The main mode of heat transfer from outdoor via the roof is conduction. The rate of heat transfer and the thermal impact is dependent on the thermophysical properties of roofing materials. Thus, it is important to analyze the heat distribution for the various types of roofing materials. The objectives of this paper are to obtain the Fourier series for the conductive heat transfer for two types of glazed roofing materials, namely polycarbonate and polyfilled, and also to determine the relationship between the ambient temperature and the conductive heat transfer for these materials. Ambient and surface temperature data were collected from an empirical field investigation in the campus of Universiti Teknologi MARA Shah Alam. The roofing materials were installed on free-standing structures in natural ventilation. Since the temperature data are generally periodic, Fourier series and numerical harmonic analysis are applied. Based on the 24-point harmonic analysis, the eleventh order harmonics is found to generate an adequate Fourier series expansion for both glazed roofing materials. In addition, there exists a linear relationship between the ambient temperature and the conductive heat transfer for both glazed roofing materials. Based on the gradient of the graphs, lower heat transfer is indicated through polyfilled. Thus polyfilled would have a lower thermal impact compared to polycarbonate.
Roslan, Nurhana Lyana; Bahaman, Nurfaradila; Almanan, Raja Noorliyana Raja; Ismail, Razidah [Faculty of Computer and Mathematical Sciences, Universiti Teknologi MARA, 40450 Shah Alam, Selangor (Malaysia); Zakaria, Nor Zaini [Faculty of Applied Sciences, Universiti Teknologi MARA, 40450 Shah Alam, Selangor (Malaysia)
FLOW AND HEAT TRANSFER IN MICROFLUIDIC DEVICES WITH APPLICATION TO OPTOTHERMAL ANALYTE transfer in microfluidic devices with applica- tion to optothermal analyte preconcentration and manipula the local fluid temperature in microfluidics. Thermal characteristics of the heating system have been
A simplistic model of cyclic heat transfer phenomena in closed spaces
Cyclic heat transfer inside closed spaces is investigated analytically using a simple heat transfer model. The model consists of a gas layer exchanging heat with two bounding parallel walls that pulsate against each other in the transverse direction. Correlations for the magnitude and the phase lag of the heat transfer are obtained. Also, an expression for the power loss due to the cyclic heat transfer is presented. It is shown that the loss approaches zero as the heat transfer process approaches either isothermal or adiabatic conditions. The power loss is shown to be a strong function of the phase angle between the bulk gas temperature and the heat transfer.
Lee, K.
Halide and Oxy-Halide Eutectic Systems for High-Performance, High-Temperature Heat Transfer Fluids (Fact Sheet)
The University of Arizona, Arizona Statue University (ASU), and Georgia Institute of Technology is one of the 2012 SunShot CSP R&D awardees for their Multidisciplinary University Research Initiative (MURI): High Operating Temperature (HOT) Fluids. This fact sheet explains the motivation, description, and impact of the project.
Rod Bundle Heat Transfer: Steady-State Steam Cooling Experiments
Through the joint efforts of the Pennsylvania State University and the United States Nuclear Regulatory Commission, an experimental rod bundle heat transfer (RBHT) facility was designed and built. The rod bundle consists of a 7 x 7 square pitch array with spacer grids and geometry similar to that found in a modern pressurized water reactor. From this facility, a series of steady-state steam cooling experiments were performed. The bundle inlet Reynolds number was varied from 1 400 to 30 000 over a pressure range from 1.36 to 4 bars (20 to 60 psia). The bundle inlet steam temperature was controlled to be at saturation for the specified pressure and the fluid exit temperature exceeded 550 deg. C in the highest power tests. One important quantity of interest is the local convective heat transfer coefficient defined in terms of the local bulk mean temperature of the flow, local wall temperature, and heat flux. Steam temperatures were measured at the center of selected subchannels along the length of the bundle by traversing miniaturized thermocouples. Using an analogy between momentum and energy transport, a method was developed for relating the local subchannel centerline temperature measurement to the local bulk mean temperature. Wall temperatures were measured using internal thermocouples strategically placed along the length of each rod and the local wall heat flux was obtained from an inverse conduction program. The local heat transfer coefficient was calculated from the data at each rod thermocouple location. The local heat transfer coefficients calculated for locations where the flow was fully developed were compared against several published correlations. The Weisman and El-Genk correlations were found to agree best with the RBHT steam cooling data, especially over the range of turbulent Reynolds numbers. The effect of spacer grids on the heat transfer enhancement was also determined from instrumentation placed downstream of the spacer grid locations. The local heat transfer was found to be greatest at locations immediately downstream of the grid, and as the flow moved further downstream from the grid it became more developed, thus causing the heat transfer to diminish. The amount of heat transfer enhancement was found to depend not only on the spacer grid design, but also on the local Reynolds number. It was seen that decreasing Reynolds number leads to greater heat transfer enhancement. (authors)
Spring, J.P.; McLaughlin, D.M. [The Pennsylvania State University, 201 Shields Building University Park, PA 16802 (United States)
Development of a Heat Transfer Model for the Integrated Facade Heating
the heat transfer process of facade heating (mullion radiators) in a pilot research project in Pittsburgh, PA. The heat transfer model for facade heating is developed and verified by measured data. The comparison shows that the heat transfer model predicts...
Gong, X.; Archer, D. H.; Claridge, D. E.
Radiative heat transfer between dielectric bodies
The recent development of a scanning thermal microscope (SThM) has led to measurements of radiative heat transfer between a heated sensor and a cooled sample down to the nanometer range. This allows for comparision of the known theoretical description of radiative heat transfer, which is based on fluctuating electrodynamics, with experiment. The theory itself is a macroscopic theory, which can be expected to break down at distances much smaller than 10-8m. Against this background it seems to be reasonable to revisit the known macroscopic theory of fluctuating electrodynamics and of radiative heat transfer.
Svend-Age Biehs
Design details of a compact heat exchanger and supporting hardware for heat recuperation in a high-temperature electrolysis application are presented. The recuperative heat exchanger uses a vacuum-brazed plate-fin design and operates between 300 and 800�C. It includes corrugated inserts for enhancement of heat transfer coefficients and extended heat transfer surface area. Two recuperative heat exchangers are required per each four-stack electrolysis module. The heat exchangers are mated to a base manifold unit that distributes the inlet and outlet flows to and from the four electrolysis stacks. Results of heat exchanger design calculations and assembly details are also presented.
G. K. Housley; J.E. O'Brien; G.L. Hawkes
"Nanotechnology Enabled Advanced Industrial Heat Transfer Fluids"
ABSTRACT Nanotechnology Enabled Advanced industrial Heat Transfer Fluids� Improving the efficiency of Industrial Heat Exchangers offers a great opportunity to improve overall process efficiencies in diverse industries such as pharmaceutical, materials manufacturing and food processing. The higher efficiencies can come in part from improved heat transfer during both cooling and heating of the material being processed. Additionally, there is great interest in enhancing the performance and reducing the weight of heat exchangers used in automotives in order to increase fuel efficiency. The goal of the Phase I program was to develop nanoparticle containing heat transfer fluids (e.g., antifreeze, water, silicone and hydrocarbon-based oils) that are used in transportation and in the chemical industry for heating, cooling and recovering waste heat. Much work has been done to date at investigating the potential use of nanoparticle-enhanced thermal fluids to improve heat transfer in heat exchangers. In most cases the effect in a commercial heat transfer fluid has been marginal at best. In the Phase I work, we demonstrated that the thermal conductivity, and hence heat transfer, of a fluid containing nanoparticles can be dramatically increased when subjected to an external influence. The increase in thermal conductivity was significantly larger than what is predicted by commonly used thermal models for two-phase materials. Additionally, the surface of the nanoparticles was engineered so as to have a minimal influence on the viscosity of the fluid. As a result, a nanoparticle-laden fluid was successfully developed that can lead to enhanced heat transfer in both industrial and automotive heat exchangers
Dr. Ganesh Skandan; Dr. Amit Singhal; Mr. Kenneth Eberts; Mr. Damian Sobrevilla; Prof. Jerry Shan; Stephen Tse; Toby Rossmann
Self supporting heat transfer element
The present invention provides an improved internal heat exchange element arranged so as to traverse the inside diameter of a container vessel such that it makes good mechanical contact with the interior wall of that vessel. The mechanical element is fabricated from a material having a coefficient of thermal conductivity above about 0.8 W cm.sup.-1.degree. K.sup.-1 and is designed to function as a simple spring member when that member has been cooled to reduce its diameter to just below that of a cylindrical container or vessel into which it is placed and then allowed to warm to room temperature. A particularly important application of this invention is directed to a providing a simple compartmented storage container for accommodating a hydrogen absorbing alloy.
Story, Grosvenor Cook (Livermore, CA); Baldonado, Ray Orico (Livermore, CA)
temperature heat pumps applied to
Very high- temperature heat pumps applied to energy efficiency in industry Application June 21th 2012 Energy efficiency : A contribution to environmental protection Kyoto Copenhage Emission, plastics Partnership : EDF R&D Bil
Oak Ridge National Laboratory
Heat and mass transfer considerations in advanced heat pump systems
Advanced heat-pump cycles are being investigated for various applications. However, the working media and associated thermal design aspects require new concepts for maintaining high thermal effectiveness and phase equilibrium for achieving maximum possible thermodynamic advantages. In the present study, the heat- and mass-transfer processes in two heat-pump systems -- those based on absorption processes, and those using refrigerant mixtures -- are analyzed. The major technical barriers for achieving the ideal performance predicted by thermodynamic analysis are identified. The analysis provides general guidelines for the development of heat- and mass-transfer equipment for advanced heat-pump systems.
Panchal, C.B.; Bell, K.J.
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
Scaling of Heat Transfer Coefficients Along Louvered Fins A. C. Lyman1
1 Scaling of Heat Transfer Coefficients Along Louvered Fins A. C. Lyman1 , R. A. Stephan2 , and K 23681-2199 #12;2 Abstract Louvered fins provide a method for improving the heat transfer performance for evaluating the spatially-resolved louver heat transfer coefficients using various reference temperatures
Thole, Karen A.
Heat-transfer coefficients in agitated vessels. Sensible heat models
Transient models for sensible heat were developed to assess the thermal performance of agitated vessels with coils and jackets. Performance is quantified with the computation of heat-transfer coefficients by introducing vessel heating and cooling data into model equations. Of the two model categories studied, differential and macroscopic, the latter is preferred due to mathematical simplicity and lower sensitivity to experimental data variability.
Kumpinsky, E. [Ashland Chemical Co., Columbus, OH (United States). Research and Development Dept.
High Temperature Heat Exchanger Project
The UNLV Research Foundation assembled a research consortium for high temperature heat exchanger design and materials compatibility and performance comprised of university and private industry partners under the auspices of the US DOE-NE Nuclear Hydrogen Initiative in October 2003. The objectives of the consortium were to conduct investigations of candidate materials for high temperature heat exchanger componets in hydrogen production processes and design and perform prototypical testing of heat exchangers. The initial research of the consortium focused on the intermediate heat exchanger (located between the nuclear reactor and hydrogen production plan) and the components for the hydrogen iodine decomposition process and sulfuric acid decomposition process. These heat exchanger components were deemed the most challenging from a materials performance and compatibility perspective
Anthony E. Hechanova, Ph.D.
Dynamics of heat transfer between nano systems
We develop a dynamical theory of heat transfer between two nano systems. In particular, we consider the resonant heat transfer between two nanoparticles due to the coupling of localized surface modes having a finite spectral width. We model the coupled nanosystem by two coupled quantum mechanical oscillators, each interacting with its own heat bath, and obtain a master equation for the dynamics of heat transfer. The damping rates in the master equation are related to the lifetimes of localized plasmons in the nanoparticles. We study the dynamics towards the steady state and establish connection with the standard theory of heat transfer in steady state. For strongly coupled nano particles we predict Rabi oscillations in the mean occupation number of surface plasmons in each nano particle.
Svend-Age Biehs; Girish S. Agarwal
Heat transfer pathways in underfloor air distribution (UFAD) systems
permission. QC-06-053 Heat Transfer Pathways in Underfloorchange the dynamics of heat transfer within a room as wellchange the dynamics of heat transfer within a room as well
Bauman, F.; Jin, H.; Webster, T.
Optimization of Phase Change Heat Transfer in Biporous Media
in Compressed Open- Celled Foams�. Numerical Heat Transfer,open the need to effectively estimate the heat transfer inopen porosities for different packed bed of spheres arrangements. The scaled heat transfer
Reilly, Sean
Litchfield Correctional Center District Heating Low Temperature...
Correctional Center District Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Litchfield Correctional Center District Heating Low Temperature Geothermal...
A low-melting point, heat transfer fluid comprising a mixture of LiNO.sub.3, NaNO.sub.3, KNO.sub.3, NaNO.sub.2 and KNO.sub.2 salts where the Li, Na and K cations are present in amounts of about 20-33.5 mol % Li, about 18.6-40 mol % Na, and about 40-50.3 mol % K and where the nitrate and nitrite anions are present in amounts of about 36-50 mol % NO.sub.3, and about 50-62.5 mol % NO.sub.2. These compositions can have liquidus temperatures between 70.degree. C. and 80.degree. C. for some compositions.
Cordaro, Joseph G. (Oakland, CA); Bradshaw, Robert W. (Livermore, CA)
Clean Boiler Waterside Heat Transfer Surfaces
This revised ITP tip sheet on cleaning boiler water-side heat transfer surfaces provides how-to advice for improving industrial steam systems using low-cost, proven practices and technologies.
Analysis of Heat Transfer in Metal Hydride Based Hydrogen Separation
This thesis presents a transient heat transfer analysis to model the heat transfer in the Pd/k packed column, and the impact of adding metallic foam.
Fleming, W.H. Jr.
ME 339 Heat Transfer ABET EC2000 syllabus
ME 339 Heat Transfer Page 1 ABET EC2000 syllabus ME 339 Heat Transfer Spring 2010 Required convection; radiation; introduction to phase change heat transfer and to heat exchangers. Prerequisite(s): ME, Fundamentals of Heat and Mass Transfer, 6th ed., Wiley Other Required Material: NA Course Objectives
Ben-Yakar, Adela
Heat transfer coefficients in three phase fluidized beds
In order to obtain a semitheoretical correlation for the heat transfer coefficients in three phase fluidized beds, Deckwer's semitheoretical correlation for the heat transfer coefficients in the bubble column, which was derived from Higbie's surface renewal theory of interphase mass transfer with the concept of isotropic turbulence, has been extended to three phase fluidized beds with the modification of the energy dissipation rate. One of the desirable characteristics of three phase fluidized beds is the uniformity of temperature in the bed. The intense longitudinal and transverse turbulent mixing in a fluidized bed may induce the uniform fields of temperature and solids concentration. For highly exothermic reactions, the uniform temperature in the bed is essential to avoid the local hot spots. In order to control the uniform temperature of three phase fluidized beds, the addition or removal of heat in the bed is required and the information on heat transfer surface and the bed is essential to designing the heat exchanger. Recently, Chiu and Ziegler (1983) determined wall-to-bed heat transfer coefficients in three phase fluidized bed (5.08 cm ID) of glass beads and cylindrical gamma alumina particles which were fluidized by cocurrent flow of air and water. Their data were correlated in terms of the modified Colburn j factor. Kato et al. (1981) measured wall-to-bed heat transfer coefficients in three phase fluidized beds of 5.2 and 12.0 cm internal diameter. Four different sizes of glass beads (0.42-2.2 mm) were fluidized by air and aqueous carboxymethyl cellulose solutions. The coefficients increased with decrease in liquid viscosity and with increase in gas and liquid velocity.
Suh, I.S.; Jin, G.T.; Kim, S.D.
Nanoparticle enhanced ionic liquid heat transfer fluids
A heat transfer fluid created from nanoparticles that are dispersed into an ionic liquid is provided. Small volumes of nanoparticles are created from e.g., metals or metal oxides and/or alloys of such materials are dispersed into ionic liquids to create a heat transfer fluid. The nanoparticles can be dispersed directly into the ionic liquid during nanoparticle formation or the nanoparticles can be formed and then, in a subsequent step, dispersed into the ionic liquid using e.g., agitation.
Fox, Elise B.; Visser, Ann E.; Bridges, Nicholas J.; Gray, Joshua R.; Garcia-Diaz, Brenda L.
Heat Transfer Characteristics of a Generalized Divided Flow Heat Exchanger
The concept of a "Divided-flow" heat exchanger is generalized by locating the shell inlet (or outlet) nozzle off-center such that the two shell sub-streams are unequal and traverse unequal flow paths. The governing equations for heat transfer...
Singh, K. P.
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...
MHD Effects on Heat Transfer in a Molten Salt Blanket
Heat transfer in closed channel flows of molten salts (MS)s, such as FLiBe or FLiNaBe, has been considered under specific reactor conditions. MHD effects have been accessed for two blanket concepts: self-cooled MS blanket, and dual-coolant MS blanket. The effect of heat transfer degradation due to turbulence reduction by a magnetic field in the First Wall channels of the self-cooled blanket was analyzed with the K-{epsilon} model of turbulence. In the dual-coolant blanket, the MS flow is laminar. A 2-D MHD code was used to calculate the laminar velocity profile first. Then, the temperature field was calculated using a 3-D temperature code. Reasonable interface temperatures below the material limit of 550 deg. C, and low heat escape from the breeder zone have been demonstrated. Model limitations and the ways of their improvement are also discussed.
Smolentsev, Sergey; Miraghaie, Reza; Abdou, Mohamed [University of California (United States)
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
Enhanced heat transfer using wire-coil inserts for high-heat-load applications.
Enhanced heat-transfer techniques, used to significantly reduce temperatures and thermally induced stresses on beam-strike surfaces, are routinely used at the APS in all critical high-heat-load components. A new heat-transfer enhancement technique being evaluated at the APS involving the use of wire-coil inserts proves to be superior to previously employed techniques. Wire coils, similar in appearance to a common spring, are fabricated from solid wire to precise tolerances to mechanically fit inside standard 0.375-in-diameter cooling channels. In this study, a matrix of wire coils, fabricated with a series of different pitches from several different wire diameters, has been tested for heat-transfer performance and resulting pressure loss. This paper reviews the experimental data and the analytical calculations, compares the data with existing correlations, and interprets the results for APS front-end high-heat-load components.
Collins, J. T.; Conley, C. M.; Attig, J. N.; Baehl, M. M.
Numerical methods in heat transfer
This book contains nine papers. Some of the titles are: Numerical calculation of bubble growth in nucleate boiling from inception through departure; An evaluation of a translator for finite element data to resistor/capacitor data for the heat diffusion; Thermophoretic deposition due to jet impingement on an inclined plane; and A three-dimensional boundary-fitted coordinate system.
Emery, A.F.; Douglass, R.W.
Enhanced convective and film boiling heat transfer by surface gas injection
Heat transfer measurements were made for stable film boiling of water over a horizontal, flat stainless steel plate from the minimum film boiling point temperature, T{sub SURFACE} {approximately}500K, to T{sub SURFACE} {approximately}950K. The pressure at the plate was approximately 1 atmosphere and the temperature of the water pool was maintained at saturation. The data were compared to the Berenson film-boiling model, which was developed for minimum film-boiling-point conditions. The model accurately represented the data near the minimum film-boiling point and at the highest temperatures measured, as long it was corrected for the heat transferred by radiation. On the average, the experimental data lay within {plus_minus}7% of the model. Measurements of heat transfer were made without film boiling for nitrogen jetting into an overlying pool of water from nine 1-mm- diameter holes, drilled in the heat transfer plate. The heat flux was maintained constant at approximately 26.4 kW/m{sup 2}. For water-pool heights of less than 6cm the heat transfer coefficient deceased linearly with a decrease in heights. Above 6cm the heat transfer coefficient was unaffected. For the entire range of gas velocities measured [0 to 8.5 cm/s], the magnitude of the magnitude of the heat transfer coefficient only changed by approximately 20%. The heat transfer data bound the Konsetov model for turbulent pool heat transfer which was developed for vertical heat transfer surfaces. This agreement suggests that surface orientation may not be important when the gas jets do not locally affect the surface heat transfer. Finally, a database was developed for heat transfer from the plate with both film boiling and gas jetting occurring simultaneously, in a pool of water maintained at its saturation temperature. The effect of passing nitrogen through established film boiling is to increase the heat transfer from that surface. 60 refs.
Duignan, M.R.; Greene, G.A. [Brookhaven National Lab., Upton, NY (United States); Irvine, T.F., Jr. [State Univ. of New York, Stony Brook, NY (United States). Dept. of Mechanical Engineering
Heat transfer measurements were made for stable film boiling of water over a horizontal, flat stainless steel plate from the minimum film boiling point temperature, T{sub SURFACE} {approximately}500K, to T{sub SURFACE} {approximately}950K. The pressure at the plate was approximately 1 atmosphere and the temperature of the water pool was maintained at saturation. The data were compared to the Berenson film-boiling model, which was developed for minimum film-boiling-point conditions. The model accurately represented the data near the minimum film-boiling point and at the highest temperatures measured, as long it was corrected for the heat transferred by radiation. On the average, the experimental data lay within {plus minus}7% of the model. Measurements of heat transfer were made without film boiling for nitrogen jetting into an overlying pool of water from nine 1-mm- diameter holes, drilled in the heat transfer plate. The heat flux was maintained constant at approximately 26.4 kW/m{sup 2}. For water-pool heights of less than 6cm the heat transfer coefficient deceased linearly with a decrease in heights. Above 6cm the heat transfer coefficient was unaffected. For the entire range of gas velocities measured (0 to 8.5 cm/s), the magnitude of the magnitude of the heat transfer coefficient only changed by approximately 20%. The heat transfer data bound the Konsetov model for turbulent pool heat transfer which was developed for vertical heat transfer surfaces. This agreement suggests that surface orientation may not be important when the gas jets do not locally affect the surface heat transfer. Finally, a database was developed for heat transfer from the plate with both film boiling and gas jetting occurring simultaneously, in a pool of water maintained at its saturation temperature. The effect of passing nitrogen through established film boiling is to increase the heat transfer from that surface. 60 refs.
Duignan, M.R.; Greene, G.A. (Brookhaven National Lab., Upton, NY (United States)); Irvine, T.F., Jr. (State Univ. of New York, Stony Brook, NY (United States). Dept. of Mechanical Engineering)
Analysis of heat transfer in unlooped and looped pulsating
Analysis of heat transfer in unlooped and looped pulsating heat pipes M.B. Sha®i and A. Faghri of Mechnical Engineering, New Mexico State University, Las Cruces, USA Keywords Heat transfer, Condensation, Tubing Abstract An advanced heat transfer model for both unlooped and looped Pulsating Heat Pipes (PHPs
Zhang, Yuwen
Heat Transfer Enhancement for Finned-tube Heat Exchangers with Winglets
This paper presents the results of an experimental study of forced convection heat transfer in a narrow rectangular duct fitted with a circular tube and/or a delta-winglet pair. The duct was designed to simulate a single passage in a fin-tube heat exchanger. Heat transfer measurements were obtained using a transient technique in which a heated airflow is suddenly introduced to the test section. High-resolution local fin-surface temperature distributions were obtained at several times after initiation of the transient using an imaging infrared camera. Corresponding local fin-surface heat transfer coefficient distributions were then calculated from a locally applied one-dimensional semi-infinite inverse heat conduction model. Heat transfer results were obtained over an airflow rate ranging from 1.51 x 10-3 to 14.0 x 10-3 kg/s. These flow rates correspond to a duct-height Reynolds number range of 670 � 6300 with a duct height of 1.106 cm and a duct width-toheight ratio, W/H, of 11.25. The test cylinder was sized such that the diameter-to-duct height ratio, D/H is 5. Results presented in this paper reveal visual and quantitative details of local fin-surface heat transfer distributions in the vicinity of a circular tube, a delta-winglet pair, and a combination of a circular tube and a delta-winglet pair. Comparisons of local and average heat transfer distributions for the circular tube with and without winglets are provided. Overall mean finsurface Nusselt-number results indicate a significant level of heat transfer enhancement associated with the deployment of the winglets with the circular cylinder. At the lowest Reynolds numbers (which correspond to the laminar operating conditions of existing geothermal air-cooled condensers), the enhancement level is nearly a factor of two. At higher Reynolds numbers, the enhancement level is close to 50%.
O'Brien, James Edward; Sohal, Manohar Singh
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))
Thermodynamics of enhanced heat transfer: a model study
Situations where a spontaneous process of energy or matter transfer is enhanced by an external device are widespread in nature (human sweating system, enzyme catalysis, facilitated diffusion across bio-membranes, industrial heat exchangers). The thermodynamics of such processes remains however open. Here we study enhanced heat transfer by a model junction immersed between two thermal baths at different temperatures $T_h$ and $T_c$ ($T_h>T_c$). The transferred heat power is enhanced via controlling the junction by means of external time-dependent fields. Provided that the spontaneous heat flow process is optimized over the junction Hamiltonian, any enhancement of this spontaneous process does demand consumption and subsequent dissipation of work. The efficiency of enhancement is defined via the increment in the heat power divided over the amount of consumed work. We show that this efficiency is bounded from above by $T_c/(T_h-T_c)$. Formally this is identical to the Carnot bound for the efficiency of ordinary refrigerators which transfer heat from cold to hot. It also shares some (but not all) physical features of the Carnot bound.
Karen Hovhannisyan; Armen E. Allahverdyan
Trace formulae for non-equilibrium Casimir interactions, heat radiation and heat transfer for arbitrary objects
We present a detailed derivation of heat radiation, heat transfer and (Casimir) interactions for N arbitrary objects in the framework of fluctuational electrodynamics in thermal non-equilibrium. The results can be expressed as basis-independent trace formulae in terms of the scattering operators of the individual objects. We prove that heat radiation of a single object is positive, and that heat transfer (for two arbitrary passive objects) is from the hotter to a colder body. The heat transferred is also symmetric, exactly reversed if the two temperatures are exchanged. Introducing partial wave-expansions, we transform the results for radiation, transfer and forces into traces of matrices that can be evaluated in any basis, analogous to the equilibrium Casimir force. The method is illustrated by (re)deriving the heat radiation of a plate, a sphere and a cylinder. We analyze the radiation of a sphere for different materials, emphasizing that a simplification often employed for metallic nano-spheres is typically invalid. We derive asymptotic formulae for heat transfer and non-equilibrium interactions for the cases of a sphere in front a plate and for two spheres, extending previous results. As an example, we show that a hot nano-sphere can levitate above a plate with the repulsive non-equilibrium force overcoming gravity -- an effect that is not due to radiation pressure.
Matthias Kr�ger; Giuseppe Bimonte; Thorsten Emig; Mehran Kardar
Cooperative heat transfer and ground coupled storage system
A cooperative heat transfer and ground coupled storage system wherein collected solar heat energy is ground stored and permitted to radiate into the adjacent ground for storage therein over an extended period of time when such heat energy is seasonally maximally available. Thereafter, when said heat energy is seasonally minimally available and has propagated through the adjacent ground a substantial distance, the stored heat energy may be retrieved by a circumferentially arranged heat transfer means having a high rate of heat transfer.
Metz, Philip D. (Rocky Point, NY)
Convective heat transfer in rotating, circular channels
Nusselt number values for flow in a rotating reference frame are obtained through computational fluid dynamic (CFD) analysis for Rossby numbers Ro ~1-4 and Reynolds numbers Re ~1,000-2,000. The heat-transfer model is first ...
Hogan, Brenna Elizabeth
Transient Heat Transfer in TCAP Coils
The Thermal Cycling Absorption Process (TCAP) is used to separate isotopes of hydrogen. TCAP involves passing a stream of mixed hydrogen isotopes through palladium deposited on kieselguhr (Pd/k) while cycling the temperature of the Pd/k. Kieselguhr is a silica mineral also called diatomite. To aid in the design of a full scale facility, the Thermal Fluids Laboratory was used by the Chemical and Hydrogen Technology Section to compare the heat transfer properties of three different configurations of stainless steel coils containing kieselguhr and helium. Testing of coils containing Pd/k and hydrogen isotopes would have been more prototypical but would have been too expensive. Three stainless steel coils filled with kieselguhr were tested; one made from 2.0 inch diameter tubing, one made from 2.0 inch diameter tubing with foam copper embedded in the kieselguhr and one made from 1.25 inch diameter tubing. It was known prior to testing that increasing the tubing diameter from 1.25 inch to 2.0 inch would slow the rate of temperature change. The primary purpose of the testing was to measure to what extent the presence of copper foam in a 2.0" tubing coil would compensate for the effect of larger diameter. Each coil was connected to a pressure gage and the coil was evacuated and backfilled with helium gas. Helium was used instead of a mixture of hydrogen isotopes for reasons of safety. Each coil was quickly immersed in a stirred bath of ethylene glycol at a temperature of approximately 100 degrees Celsius. The coil pressure increased, reflecting the increase in average temperature of its contents. The pressure transient was recored as a function of time after immersion. Because of the actual process will use Pd/k instead of kieselguhr, additional tests were run to determine the differences in thermal properties between the two materials. The method was to position a thermocouple at the center of a hollow sphere and pack the sphere with Pd/k. The sphere was sealed, quickly submerged in a bath of boiling water and the temperature transient was recorded. There sphere was then opened, the Pd/k was replaced with kieselguhr and the transient was repeated. The response was a factor of 1.4 faster for Pd/k than for kieselguhr, implying a thermal diffusivity approximately 40 percent higher than for kieselguhr. Another implication is that the transient tests with the coils would have proceeded faster if the coils had been filled with Pd/k rather than kieselguhr.
Steimke, J.L.
Heat Transfer between Graphene and Amorphous SiO2
We study the heat transfer between graphene and amorphous SiO2. We include both the heat transfer from the area of real contact, and between the surfaces in the non-contact region. We consider the radiative heat transfer associated with the evanescent electromagnetic waves which exist outside of all bodies, and the heat transfer by the gas in the non-contact region. We find that the dominant contribution to the heat transfer result from the area of real contact, and the calculated value of the heat transfer coefficient is in good agreement with the value deduced from experimental data.
B. N. J. Persson; H. Ueba
The influence of a magnetic field on turbulent heat transfer of a high Prandtl number fluid
The influence of a transverse magnetic field on the local and average heat transfer of an electrically conducting, turbulent fluid flow with high Prandtl number was studied experimentally. The mechanism of heat transfer modification due to magnetic field is considered with aid of available numerical simulation data for turbulent flow field. The influence of the transverse magnetic field on the heat transfer was to suppress the temperature fluctuation and to steepen the mean temperature gradient in near-wall region in the direction parallel to the magnetic field. The mean temperature gradient is not influenced compared to the temperature fluctuation in the direction vertical to the magnetic field. (author)
Nakaharai, H. [Department of Advanced Energy Engineering Science, Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, Kasuga-kouen 6-1, Kasuga, Fukuoka 816-8580 (Japan); Takeuchi, J.; Morley, N.B.; Abdou, M.A. [Mechanical and Aerospace Engineering Department, University of California, Los Angeles, CA 90095-1597 (United States); Yokomine, T. [Faculty of Energy Engineering Science, Kyushu University, Kasuga-kouen 6-1, Kasuga, Fukuoka 816-8580 (Japan); Kunugi, T. [Department of Nuclear Engineering, Kyoto University, Yoshida, Sakyo, Kyoto 606-8501 (Japan); Satake, S. [Department of Applied Electronics, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510 (Japan)
Heat Transfer Boundary Conditions in the RELAP5-3D Code
The heat transfer boundary conditions used in the RELAP5-3D computer program have evolved over the years. Currently, RELAP5-3D has the following options for the heat transfer boundary conditions: (a) heat transfer correlation package option, (b) non-convective option (from radiation/conduction enclosure model or symmetry/insulated conditions), and (c) other options (setting the surface temperature to a volume fraction averaged fluid temperature of the boundary volume, obtaining the surface temperature from a control variable, obtaining the surface temperature from a time-dependent general table, obtaining the heat flux from a time-dependent general table, or obtaining heat transfer coefficients from either a time- or temperature-dependent general table). These options will be discussed, including the more recent ones.
Richard A. Riemke; Cliff B. Davis; Richard R. Schultz
Castor-1C spent fuel storage cask decay heat, heat transfer, and shielding analyses
This report documents the decay heat, heat transfer, and shielding analyses of the Gesellschaft fuer Nuklear Services (GNS) CASTOR-1C cask used in a spent fuel storage demonstration performed at Preussen Elektra's Wurgassen nuclear power plant. The demonstration was performed between March 1982 and January 1984, and resulted in cask and fuel temperature data and cask exterior surface gamma-ray and neutron radiation dose rate measurements. The purpose of the analyses reported here was to evaluate decay heat, heat transfer, and shielding computer codes. The analyses consisted of (1) performing pre-look predictions (predictions performed before the analysts were provided the test data), (2) comparing ORIGEN2 (decay heat), COBRA-SFS and HYDRA (heat transfer), and QAD and DOT (shielding) results to data, and (3) performing post-test analyses if appropriate. Even though two heat transfer codes were used to predict CASTOR-1C cask test data, no attempt was made to compare the two codes. The codes are being evaluated with other test data (single-assembly data and other cask data), and to compare the codes based on one set of data may be premature and lead to erroneous conclusions.
Rector, D.R.; McCann, R.A.; Jenquin, U.P.; Heeb, C.M.; Creer, J.M.; Wheeler, C.L.
CORRELATING EVAPORATION HEAT TRANSFER COEFFICIENT OF REFRIGERANT R-134a IN A PLATE HEAT EXCHANGER
1 CORRELATING EVAPORATION HEAT TRANSFER COEFFICIENT OF REFRIGERANT R-134a IN A PLATE HEAT EXCHANGER for evaporation heat transfer coefficient of refrigerant R-134a flowing in a plate heat exchanger. Correlation schemes proposed by Yan and Lin (1999b) for modeling the heat transfer coefficient in both a single- phase
Boiling heat transfer in a hydrofoil-based micro pin fin heat sink
Boiling heat transfer in a hydrofoil-based micro pin fin heat sink Ali Kos�?ar, Yoav Peles-based micro pin fin heat sink was investigated. Average two-phase heat transfer coefficients were obtained intermittent and spray-annular flows. Heat transfer coefficient trends and flow morphologies were used to infer
Peles, Yoav
INVESTIGATING THE EFFECT OF HEATING METHOD ON POOL BOILING HEAT TRANSFER Satish G. Kandlikar surfaces in laboratories to obtain the heat transfer coefficient data. In many process applications however, a fluid stream is employed as the heating medium. The heat transfer data generated with the electrically
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...
Nanofluid heat transfer enhancement for nuclear reactor applications
Colloidal dispersions of nanoparticles are known as `nanofluids'. Such engineered fluids offer the potential for enhancing heat transfer, particularly boiling heat transfer, while avoiding the drawbacks (i.e., erosion, ...
Hydrodynamics, heat transfer and flow boiling instabilities in microchannels�
Boiling in microchannels is a very efficient mode of heat transfer with high heat and mass transfer coefficients achieved. Less pumping power is required for two-phase flows than for single-phase liquid flows to achieve ...
Barber, Jacqueline Claire
Thermal Storage and Advanced Heat Transfer Fluids (Fact Sheet)
Fact sheet describing NREL CSP Program capabilities in the area of thermal storage and advanced heat transfer fluids: measuring thermophysical properties, measuring fluid flow and heat transfer, and simulating flow of thermal energy and fluid.
Experimental evaluation of heat transfer characteristics of silica nanofluid
The laminar convective heat transfer characteristics were investigated for silica nanofluid. An experimental loop was built to obtain heat transfer coefficients for single-phase nanofluids in a circular conduit in laminar ...
Zhang, Zihao, S.B. Massachusetts Institute of Technology
Deep Eutectic Salt Formulations Suitable as Advanced Heat Transfer Fluids
Concentrating solar power (CSP) facilities are comprised of many miles of fluid-filled pipes arranged in large grids with reflective mirrors used to capture radiation from the sun. Solar radiation heats the fluid which is used to produce steam necessary to power large electricity generation turbines. Currently, organic, oil-based fluid in the pipes has a maximum temperature threshold of 400 �C, allowing for the production of electricity at approximately 15 cents per kilowatt hour. The DOE hopes to foster the development of an advanced heat transfer fluid that can operate within higher temperature ranges. The new heat transfer fluid, when used with other advanced technologies, could significantly decrease solar electricity cost. Lower costs would make solar thermal electricity competitive with gas and coal and would offer a clean, renewable source of energy. Molten salts exhibit many desirable heat transfer qualities within the range of the project objectives. Halotechnics developed advanced heat transfer fluids (HTFs) for application in solar thermal power generation. This project focused on complex mixtures of inorganic salts that exhibited a high thermal stability, a low melting point, and other favorable characteristics. A high-throughput combinatorial research and development program was conducted in order to achieve the project objective. Over 19,000 candidate formulations were screened. The workflow developed to screen various chemical systems to discover salt formulations led to mixtures suitable for use as HTFs in both parabolic trough and heliostat CSP plants. Furthermore, salt mixtures which will not interfere with fertilizer based nitrates were discovered. In addition for use in CSP, the discovered salt mixtures can be applied to electricity storage, heat treatment of alloys and other industrial processes.
Raade, Justin; Roark, Thomas; Vaughn, John; Bradshaw, Robert
TOPAZ3D. 3-D Finite Element Heat Transfer
TOPAZ3D is a three-dimensional implicit finite element computer code for heat transfer analysis. TOPAZ3D can be used to solve for the steady-state or transient temperature field on three-dimensional geometries. Material properties may be temperature-dependent and either isotropic or orthotropic. A variety of time-dependent and temperature-dependent boundary conditions can be specified including temperature, flux, convection, and radiation. By implementing the user subroutine feature, users can model chemical reaction kinetics and allow for any type of functional representation of boundary conditions and internal heat generation. TOPAZ3D can solve problems of diffuse and specular band radiation in an enclosure coupled with conduction in the material surrounding the enclosure. Additional features include thermal contact resistance across an interface, bulk fluids, phase change, and energy balances.
Shapiro, A.B. [Lawrence Livermore National Lab., CA (United States)
Secondary Heat Exchanger Design and Comparison for Advanced High Temperature Reactor
The goals of next generation nuclear reactors, such as the high temperature gas-cooled reactor and advance high temperature reactor (AHTR), are to increase energy efficiency in the production of electricity and provide high temperature heat for industrial processes. The efficient transfer of energy for industrial applications depends on the ability to incorporate effective heat exchangers between the nuclear heat transport system and the industrial process heat transport system. The need for efficiency, compactness, and safety challenge the boundaries of existing heat exchanger technology, giving rise to the following study. Various studies have been performed in attempts to update the secondary heat exchanger that is downstream of the primary heat exchanger, mostly because its performance is strongly tied to the ability to employ more efficient conversion cycles, such as the Rankine super critical and subcritical cycles. This study considers two different types of heat exchangers�helical coiled heat exchanger and printed circuit heat exchanger�as possible options for the AHTR secondary heat exchangers with the following three different options: (1) A single heat exchanger transfers all the heat (3,400 MW(t)) from the intermediate heat transfer loop to the power conversion system or process plants; (2) Two heat exchangers share heat to transfer total heat of 3,400 MW(t) from the intermediate heat transfer loop to the power conversion system or process plants, each exchanger transfers 1,700 MW(t) with a parallel configuration; and (3) Three heat exchangers share heat to transfer total heat of 3,400 MW(t) from the intermediate heat transfer loop to the power conversion system or process plants. Each heat exchanger transfers 1,130 MW(t) with a parallel configuration. A preliminary cost comparison will be provided for all different cases along with challenges and recommendations.
Piyush Sabharwall; Ali Siahpush; Michael McKellar; Michael Patterson; Eung Soo Kim
Situations where a spontaneous process of energy or matter transfer is enhanced by an external device are widespread in nature (human sweating system, enzyme catalysis, facilitated diffusion across bio-membranes, industrial heat exchangers). The thermodynamics of such processes remains however open. Here we study enhanced heat transfer by a model junction immersed between two thermal baths at different temperatures $T_h$ and $T_c$ ($T_h>T_c$). The transferred heat power is enhanced via controlling the junction by means of external time-dependent fields. Provided that the spontaneous heat flow process is optimized over the junction Hamiltonian, any enhancement of this spontaneous process does demand consumption and subsequent dissipation of work. The efficiency of enhancement is defined via the increment in the heat power divided over the amount of consumed work. We show that this efficiency is bounded from above by $T_c/(T_h-T_c)$. Formally this is identical to the Carnot bound for the efficiency of ordinary ...
Hovhannisyan, Karen; 10.1088/1742-5468/2010/06/P06010
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)
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
Proceeding of the 1st International Forum on Heat Transfer
Proceeding of the 1st International Forum on Heat Transfer November 24-26, 2004, Kyoto, Japan Paper No. HEAT TRANSFER PROBLEMS RELATED WITH CARBON NANOTUBES BY MOLECULAR DYNAMICS-BASED SIMULATIONS Dynamics Simulation, Thermal Conductance ABSTRACT Several heat transfer problems related to single
Maruyama, Shigeo
Heat transfer from nanoparticles: a corresponding state analysis
Heat transfer from nanoparticles: a corresponding state analysis Samy Merabia , Sergei Shenogin that inhibits the formation of an insulating vapor film. heat transfer | nanoparticles | liquids | phase transitions Introduction Sub-micron scale heat transfer is attracting a growing inter- est, motivated by both
Chapter V STEADY STATE LIQUID CRYSTAL THERMOGRAPHY AND HEAT TRANSFER MEASUREMENTS ON SURFACES Composite Heat Transfer Surface Liquid Crystal Image Processing Technique V . 4 Experimental Results and Discussion Test Conditions and Data Analysis Application to Endwall Heat Transfer Problem Further Application
16 Heat Transfer and Air Flow in a Domestic Refrigerator
445 16 Heat Transfer and Air Flow in a Domestic Refrigerator Onrawee Laguerre UMR Génie Industriel........................................................................447 16.2.2 Heat Transfer and Airflow Near a Vertical Plate..................................................448 16.2.3 Heat Transfer and Airflow in Empty Closed Cavity
RADIATIVE HEAT TRANSFER WITH QUASI-MONTE CARLO METHODS A. Kersch1 W. Moroko2 A. Schuster1 1Siemens of Quasi-Monte Carlo to this problem. 1.1 Radiative Heat Transfer Reactors In the manufacturing of the problems which can be solved by such a simulation is high accuracy modeling of the radiative heat transfer
Dt2boool2> Nora Heat Transfer Correlations
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Proceedings of NHTC'00: 34 th National Heat Transfer Conference
Proceedings of NHTC'00: 34 th National Heat Transfer Conference Pittsburgh, Pennsylvania, August 20 ON SINGLE- AND TWO-PHASE HEAT TRANSFER CHARACTERISTICS IN A MICROCHANNEL Michael S June Graduate Student study investigates the heat transfer characteristics of single and two-phase flows in a 200 m wide
Proceedings of HT2009 2009 ASME Summer Heat Transfer Conference
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Guo, Zhixiong "James"
innovati nAdvanced Heat Transfer Technologies Increase Vehicle
innovati nAdvanced Heat Transfer Technologies Increase Vehicle Performance and Reliability Keeping with industry to develop and demonstrate advanced heat transfer technologies such as jet impingement cooling for thermal grease and significantly enhances direct heat transfer from the electronics. A series of nozzles
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
Molten salt as a heat transfer fluid for heating a subsurface formation
A heating system for a subsurface formation includes a conduit located in an opening in the subsurface formation. An insulated conductor is located in the conduit. A material is in the conduit between a portion of the insulated conductor and a portion of the conduit. The material may be a salt. The material is a fluid at operating temperature of the heating system. Heat transfers from the insulated conductor to the fluid, from the fluid to the conduit, and from the conduit to the subsurface formation.
Nguyen, Scott Vinh (Houston, TX); Vinegar, Harold J. (Bellaire, TX)
Forced Convection Heat Transfer in Curved RectangularInfluence of Curvature on Heat Transfer to IncompressibleT. , "Forced Convective Heat Transfer in a Curved Channel
Yee, G.
Heat Transfer Operators Associated with Quantum Operations
Any quantum operation applied on a physical system is performed as a unitary transformation on a larger extended system. If the extension used is a heat bath in thermal equilibrium, the concomitant change in the state of the bath necessarily implies a heat exchange with it. The dependence of the average heat transferred to the bath on the initial state of the system can then be found from the expectation value of a hermitian operator, which is named as the heat transfer operator (HTO). The purpose of this article is the investigation of the relation between the HTOs and the associated quantum operations. Since, any given quantum operation on a system can be realized by different baths and unitaries, many different HTOs are possible for each quantum operation. On the other hand, there are also strong restrictions on the HTOs which arise from the unitarity of the transformations. The most important of these is the Landauer erasure principle. This article is concerned with the question of finding a complete set of restrictions on the HTOs that are associated with a given quantum operation. An answer to this question has been found only for a subset of quantum operations. For erasure operations, these characterizations are equivalent to the generalized Landauer erasure principle. For the case of generic quantum operations however, it appears that the HTOs obey further restrictions which cannot be obtained from the entropic restrictions of the generalized Landauer erasure principle.
�. Aksak; S. Turgut
Modeling of Heat and Mass Transfer in Fusion Welding
In fusion welding, parts are joined together by melting and subsequent solidification. Although this principle is simple, complex transport phenomena take place during fusion welding, and they determine the final weld quality and performance. The heat and mass transfer in the weld pool directly affect the size and shape of the pool, the solidification microstructure, the formation of weld defects such as porosity and humping, and the temperature distribution in the fusion zone and heat-affected zone (HAZ). Furthermore, the temperature evolution affects the kinetics and extent of various solid-state phase transformations, which in turn determine the final weld microstructure and mechanical properties. The formation of residual stresses and distortion originates from the thermal expansion and contraction during welding heating and cooling, respectively.
Zhang, Wei [ORNL
Local Heat Transfer for Finned-Tube Heat Exchangers using Oval Tubes
This paper presents the results of an experimental study of forced convection heat transfer in a narrow rectangular duct fitted with either a circular tube or an elliptical tube in crossflow. The duct was designed to simulate a single passage in a fin-tube heat exchanger. Heat transfer measurements were obtained using a transient technique in which a heated airflow is suddenly introduced to the test section. High-resolution local fin-surface temperature distributions were obtained at several times after initiation of the transient using an imaging infrared camera. Corresponding local fin-surface heat transfer coefficient distributions were then calculated from a locally applied one-dimensional semi-infinite inverse heat conduction model. Heat transfer results were obtained over an airflow rate ranging from 1.56 x 10-3 to 15.6 x 10-3 kg/s. These flow rates correspond to a duct-height Reynolds number range of 630 � 6300 with a duct height of 1.106 cm and a duct width-toheight ratio, W/H, of 11.25. The test cylinder was sized such that the diameter-to-duct height ratio, D/H is 5. The elliptical tube had an aspect ratio of 3:1 and a/H equal to 4.33. Results presented in this paper reveal visual and quantitative details of local fin-surface heat transfer distributions in the vicinity of circular and oval tubes and their relationship to the complex horseshoe vortex system that forms in the flow stagnation region. Fin surface stagnation-region Nusselt numbers are shown to be proportional to the square-root of Reynolds number.
Numerical study of high heat ux pool boiling heat transfer Ying He a,*, Masahiro Shoji b
Numerical study of high heat ¯ux pool boiling heat transfer Ying He a,*, Masahiro Shoji b , Shigeo simulation model of boiling heat transfer is proposed based on a numerical macrolayer model [S. Maruyama, M. Shoji, S. Shimizu, A numerical simulation of transition boiling heat transfer, in: Proceedings
Effects of winglets to augment tube wall heat transfer in louvered fin heat exchangers
Effects of winglets to augment tube wall heat transfer in louvered fin heat exchangers Paul A transfer along the tube wall of the compact heat exchanger through the use of winglets placed of attack, aspect ratio, direction, and shape, were all evaluated based on heat transfer augmentation
Journal of Enhanced Heat Transfer, 19 (5): 457476 (2012) EXPERIMENTAL INVESTIGATION OF HEAT
Journal of Enhanced Heat Transfer, 19 (5): 457476 (2012) EXPERIMENTAL INVESTIGATION OF HEAT microfin tubes, most of the heat transfer and friction factor studies were focused on the turbulent region. However, there is a lack of information about the heat transfer and friction factor behavior of microfin
Ghajar, Afshin J.
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
Residential Slab-On-Grade Heat Transfer in Hot Humid Climates
Heat transfer through an uninsulated slab on grade is calculated using a simple method developed by Kusuda. The seasonal and annual slab loads are graphed as a function of annual average soil temperature, Tm, for a variety of floor system...
Clark, E.; Ascolese, M.; Collins, W.
ASME 2008 Summer Heat transfer Conference August 10-14, 2008, Jacksonville, FL., USA
ASME 2008 Summer Heat transfer Conference August 10-14, 2008, Jacksonville, FL., USA HT2008, University of Victoria Victoria, BC , V8W 2Y2, Canada ABSTRACT Accurate information on the temperature eld
Thermal conductivity and heat transfer in superlattices
Understanding the thermal conductivity and heat transfer processes in superlattice structures is critical for the development of thermoelectric materials and devices based on quantum structures. This work reports progress on the modeling of thermal conductivity of superlattice structures. Results from the models established based on the Boltzmann transport equation could explain existing experimental results on the thermal conductivity of semiconductor superlattices in both in plane and cross-plane directions. These results suggest the possibility of engineering the interfaces to further reduce thermal conductivity of superlattice structures.
Chen, G.; Neagu, M.; Borca-Tasciuc, T.
Heat Transfer Laboratory | Argonne National Laboratory
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
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 FlickrGuidedCH2M HILL SecretaryHazmat work opensHeat Transfer
Outside heat transfer coefficients for atmospheric coolers
for the same conditions of operation is given by Robinson ()i. 9). TABLE I Comparison of various authors' values of outside heat transfer coefficients Btugour x square foot x F ~ ) Adams (1 ) 1001 1041 915 74, 6 1021 981 910 Clarke 945 997 841... ozeventing any recycling of the wet air. "M~4~ 1 f jc, : 1 C. X L, w 38 Cooled water fro~ the tower is centrifugally pmnoed through a 2 inch pipe to a rotameter and a I and operated control valve, Figure 8, before entering a 1 1/g inch by 5 foot...
George, David Mark
Exploring the Limits of Boiling and Evaporative Heat Transfer Using Micro/Nano Structures
using boiling heat transfer, it opens up a new direction forusing boiling heat transfer. This opens up a new direction
Lu, Ming-Chang
Developing Low-Conductance Window Frames: Capabilities and Limitations of Current Window Heat Transfer Design Tools
Goss. (1998). �Local heat transfer in open frame cavities ofthe local heat transfer in cavities open to the exterior
Gustavsen, Arild
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.
= heat, f = LO-mode, g = LO, h = LA-mode, i = negligible, j = remote heat sink 7/ 70 #12;Heat conductionFLUID MECHANICS AND HEAT TRANSFER OF ELECTRON FLOW IN SEMICONDUCTORS Mihir Sen Department · Shallow water analogy · Vorticity dynamics · Linear stability analysis · Numerical simulations of heat
Sen, Mihir
RADIATIVE HEAT TRANSFER WITH QUASIMONTE CARLO METHODS \\Lambda
RADIATIVE HEAT TRANSFER WITH QUASIMONTE CARLO METHODS \\Lambda A. Kersch 1 W. Morokoff 2 A accuracy modeling of the radiative heat transfer from the heater to the wafer. Figure 1 shows the draft Carlo simulation is often used to solve radiative transfer problems where complex physical phenomena
CONDUCTION HEAT TRANSFER Dr. Ruhul Amin Fall 2011
ME 525 CONDUCTION HEAT TRANSFER Dr. Ruhul Amin Fall 2011 Office: 201C Roberts Hall Lecture Room of conduction heat transfer. Important results which are useful for engineering application will also: 121 Roberts Hall Phone: 994-6295 Lecture Periods: 12:45- 2:00, TR TEXT: Heat Conduction, M. N. Ozisik
Dyer, Bill
Proceedings of NHTC'00 34th National Heat Transfer Conference
Proceedings of NHTC'00 34th National Heat Transfer Conference Pittsburgh, Pennsylvania, August 2022, 2000 NHTC2000-12151 HEAT TRANSFER IN A FUEL CELL ENGINE J. Musser and C.Y. Wang Department-4848 E-mail: email@example.com KEYWORDS: PEM, Fuel Cell Engine, Heat Generation, Current Density, System
Wang, Chao-Yang
Natural convection heat transfer for a staggered array of heated, horizontal cylinders within a rectangular enclosure
This thesis presents the results of an experimental investigation of natural convection heat transfer in a staggered array of heated cylinders, oriented horizontally within a rectangular enclosure. The main purpose of this research was to extend the knowledge of heat transfer within enclosed bundles of spent nuclear fuel rods sealed within a shipping or storage container. This research extends Canaan`s investigation of an aligned array of heated cylinders that thermally simulated a boiling water reactor (BWR) spent fuel assembly sealed within a shipping or storage cask. The results are presented in terms of piecewise Nusselt-Rayleigh number correlations of the form Nu = C(Ra){sup n}, where C and n are constants. Correlations are presented both for individual rods within the array and for the array as a whole. The correlations are based only on the convective component of the heat transfer. The radiative component was calculated with a finite-element code that used measured surface temperatures, rod array geometry, and measured surface emissivities as inputs. The correlation results are compared to Canaan`s aligned array results and to other studies of natural convection in horizontal tube arrays.
Triplett, C.E.
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.
Situ soil sampling probe system with heated transfer line
The present invention is directed both to an improved in situ penetrometer probe and to a heated, flexible transfer line. The line and probe may be implemented together in a penetrometer system in which the transfer line is used to connect the probe to a collector/analyzer at the surface. The probe comprises a heater that controls a temperature of a geologic medium surrounding the probe. At least one carrier gas port and vapor collection port are located on an external side wall of the probe. The carrier gas port provides a carrier gas into the geologic medium, and the collection port captures vapors from the geologic medium for analysis. In the transfer line, a flexible collection line that conveys a collected fluid, i.e., vapor, sample to a collector/analyzer. A flexible carrier gas line conveys a carrier gas to facilitate the collection of the sample. A system heating the collection line is also provided. Preferably the collection line is electrically conductive so that an electrical power source can generate a current through it so that the internal resistance generates heat.
Robbat, Jr., Albert (Andover, MA)
1M . B a h r a m i ENSC 388 Experiment 1 a: Fundamentals of Temperature Measurements ENSC 388: Engineering Thermodynamics and Heat Transfer
of temperature measuring devices including: bimetallic thermometer, several electrical temperature sensors, liquid thermometer, and gas thermometers, see Fig. 1. Three temperature sensors are fitted to the unit thermometer: In a glass thermometer, the relative expansion of a liquid compared to the contents of the bulb
Exact microscopic theory of electromagnetic heat transfer between a dielectric sphere and plate
Near-field electromagnetic heat transfer holds great potential for the advancement of nanotechnology. Whereas far-field electromagnetic heat transfer is constrained by Planck's blackbody limit, the increased density of states in the near-field enhances heat transfer rates by orders of magnitude relative to the conventional limit. Such enhancement opens new possibilities in numerous applications, including thermal-photo-voltaics, nano-patterning, and imaging. The advancement in this area, however, has been hampered by the lack of rigorous theoretical treatment, especially for geometries that are of direct experimental relevance. Here we introduce an efficient computational strategy, and present the first rigorous calculation of electromagnetic heat transfer in a sphere-plate geometry, the only geometry where transfer rate beyond blackbody limit has been quantitatively probed at room temperature. Our approach results in a definitive picture unifying various approximations previously used to treat this problem, and provides new physical insights for designing experiments aiming to explore enhanced thermal transfer.
Clayton Otey; Shanhui Fan
Predicting temperatures of stacked heat sinks with a shroud
Air cooling of enclosed electrical and electronic equipment is a common application for natural convection heat sinks. Space restrictions lead to stacking of the sinks into vertical arrays. A need for mechanical and electrical isolation leads to placement of a shroud over the array. The result is a complicated heat transfer situation. This paper reports on the first step toward development of analytical design procedures for stacked heat sink arrays with a shroud. It explores the use of a one-dimensional model based on available semi-empirical free convection correlations. These correlations do not yield air temperatures within the sink array.
Petrie, T.W.; Bajabir, A.A. (Marquette Univ., Milwaukee, WI (USA)); Petrie, D.J. (Eaton Corporation, Milwaukee, WI (USA))
Sensitivity Analysis of the Gap Heat Transfer Model in BISON.
This report summarizes the result of a NEAMS project focused on sensitivity analysis of the heat transfer model in the gap between the fuel rod and the cladding used in the BISON fuel performance code of Idaho National Laboratory. Using the gap heat transfer models in BISON, the sensitivity of the modeling parameters and the associated responses is investigated. The study results in a quantitative assessment of the role of various parameters in the analysis of gap heat transfer in nuclear fuel.
Swiler, Laura Painton; Schmidt, Rodney C.; Williamson, Richard (INL); Perez, Danielle (INL)
IntroductiontoProcessEngineering(PTG) 5. Heat transfer
#5/6 IntroductiontoProcessEngineering(PTG) VST rz13 1/114 5. Heat transfer Ron Zevenhoven �?boProcessEngineering(PTG) VST rz13 Three heat transfer mechanisms Conduction Convection Radiation 2/114 Pic: B�?88 #12;#5/6 IntroductiontoProcessEngineering(PTG) VST rz13 3/114 5.1 Conductive heat transfer #5/6 Introductionto
Effects of solar photovoltaic panels on roof heat transfer
the�energy�performance�of� photovoltaic�roofs,�ASHRAE�Trans�A�thermal�model�for�photovoltaic�systems,�Solar�Energy,�Effects�of�Solar�Photovoltaic�Panels�on�Roof�Heat�Transfer�
Dominguez, Anthony; Kleissl, Jan; Luvall, Jeffrey C
Heat Transfer Interface for Thermo-Solar Energy - Energy Innovation...
Energy Efficiency Building Energy Efficiency Find More Like This Return to Search Heat Transfer Interface for Thermo-Solar Energy Lawrence Berkeley National Laboratory...
Characterization and Development of Advanced Heat Transfer Technologies (Presentation)
This presentation gives an overview of the status and FY09 accomplishments for the NREL thermal management research project 'Characterization and Development of Advanced Heat Transfer Technologies'.
Kelly, K.
Submersible pumping system with heat transfer mechanism
A submersible pumping system for downhole use in extracting fluids containing hydrocarbons from a well. In one embodiment, the pumping system comprises a rotary induction motor, a motor casing, one or more pump stages, and a cooling system. The rotary induction motor rotates a shaft about a longitudinal axis of rotation. The motor casing houses the rotary induction motor such that the rotary induction motor is held in fluid isolation from the fluid being extracted. The pump stages are attached to the shaft outside of the motor casing, and are configured to impart fluid being extracted from the well with an increased pressure. The cooling system is disposed at least partially within the motor casing, and transfers heat generated by operation of the rotary induction motor out of the motor casing.
Hunt, Daniel Francis Alan; Prenger, F. Coyne; Hill, Dallas D; Jankowski, Todd Andrew
Heat transfer and pressure drop in tape generated swirl flow
The heat transfer and pressure drop characteristics of water in tape generated swirl flow were investigated. The test sections were electrically heated small diameter nickel tubes with tight fitting full length Inconel ...
Lopina, Robert F.
2.51 Intermediate Heat and Mass Transfer, Fall 2001
Analysis, modeling, and design of heat and mass transfer processes with application to common technologies. Unsteady heat conduction in one or more dimensions, steady conduction in multidimensional configurations, numerical ...
Lienhard, John H., 1961-
NGNP/HTE full-power operation at reduced high-temperature heat exchanger temperatures.
Operation of the Next Generation Nuclear Plant (NGNP) with reduced reactor outlet temperature at full power was investigated for the High Temperature Electrolysis (HTE) hydrogen-production application. The foremost challenge for operation at design temperature is achieving an acceptably long service life for heat exchangers. In both the Intermediate Heat Exchanger (IHX) and the Process Heat Exchanger (PHX) (referred to collectively as high temperature heat exchangers) a pressure differential of several MPa exists with temperatures at or above 850 C. Thermal creep of the heat exchanger channel wall may severely limit heat exchanger life depending on the alloy selected. This report investigates plant performance with IHX temperatures reduced by lowering reactor outlet temperature. The objective is to lower the temperature in heat transfer channels to the point where existing materials can meet the 40 year lifetime needed for this component. A conservative estimate for this temperature is believed to be about 700 C. The reactor outlet temperature was reduced from 850 C to 700 C while maintaining reactor power at 600 MWt and high pressure compressor outlet at 7 MPa. We included a previously reported design option for reducing temperature at the PHX. Heat exchanger lengths were adjusted to reflect the change in performance resulting from coolant property changes and from resizing related to operating-point change. Turbomachine parameters were also optimized for the new operating condition. An integrated optimization of the complete system including heat transfer equipment was not performed. It is estimated, however, that by performing a pinch analysis the combined plant efficiency can be increased from 35.5 percent obtained in this report to a value between 38.5 and 40.1 percent. Then after normalizing for a more than three percent decrease in commodities inventory compared to the reference plant, the commodities-normalized efficiency lies between 40.0 and 41.3. This compares with a value of 43.9 for the reference plant. This latter plant has a reactor outlet temperature of 850 C and the two high temperature heat exchangers. The reduction in reactor outlet temperature from 850 C to 700 C reduces the tritium permeability rate in the IHX metal by a factor of three and thermal creep by five orders of magnitude. The design option for reducing PHX temperature from 800 C to 200 C reduces the permeability there by three orders of magnitude. In that design option this heat exchanger is the single 'choke-point' for tritium migration from the nuclear to the chemical plant.
VIlim, R.; Nuclear Engineering Division
Proceedings of HT'03 2003 Summer Heat Transfer Conference
Proceedings of HT'03 2003 Summer Heat Transfer Conference July 2123, 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
Neutron behavior, reactor control, and reactor heat transfer. Volume four
Volume four covers neutron behavior (neutron absorption, how big are nuclei, neutron slowing down, neutron losses, the self-sustaining reactor), reactor control (what is controlled in a reactor, controlling neutron population, is it easy to control a reactor, range of reactor control, what happens when the fuel burns up, controlling a PWR, controlling a BWR, inherent safety of reactors), and reactor heat transfer (heat generation in a nuclear reactor, how is heat removed from a reactor core, heat transfer rate, heat transfer properties of the reactor coolant).
E-Print Network 3.0 - advanced heat transfer Sample Search Results
Performance Evaluations Alternate... and Diagnostic Center (EADC) Ground Coupled Heat Pumps Heat and Mass Transfer in Attic Systems Industrial... and Heat Transfer...
Generator-absorber-heat exchange heat transfer apparatus and method and use thereof in a heat pump
Numerous embodiments and related methods for generator-absorber heat exchange (GAX) are disclosed, particularly for absorption heat pump systems. Such embodiments and related methods use the working solution of the absorption system for the heat transfer medium. A combination of weak and rich liquor working solution is used as the heat transfer medium.
Phillips, Benjamin A. (Benton Harbor, MI); Zawacki, Thomas S. (St. Joseph, MI)
Internal Heat Transfer Coefficient Determination in a Packed Bed From the Transient Response Due to Solid Phase Induction Heating
the Hydraulic Drag and Heat Transfer Coefficients in PorousT. E. W. , 1929, �Heat Transfer: A Liquid Flowing Through a5] Locke, G. L. , 1950, �Heat Transfer and Flow Friction
Geb, David; Zhou, Feng; Catton, Ivan
Numerous embodiments and related methods for generator-absorber heat exchange (GAX) are disclosed, particularly for absorption heat pump systems. Such embodiments and related methods use the working solution of the absorption system for the heat transfer medium.
Phillips, Benjamin A. (Benton Harbor, MI); Zawacki, Thomas S. (St. Joseph, MI); Marsala, Joseph (Glen Ellyn, IL)
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: email@example.com; Butkovskii, A. V., E-mail: email@example.com [Zhukovski Central Aerohydrodynamics Institute (Russian Federation)
Hydrodynamics and heat transfer during flow boiling instabilities in a single microchannel
Hydrodynamics and heat transfer during flow boiling instabilities in a single microchannel July 2008 Keywords: Boiling Microchannels Visualisation Flow boiling instabilities Heat transfer a b intensification heat removal. Flow boiling heat transfer in microchannel geometry and the associated flow
Aussillous, Pascale
860. Batchelor, G.K. 1954. Heat transfer by free convectionfree convection. In: Heat Transfer and Turbulent BuoyantHEAT2, A PC-program for heat transfer in two dimensions.
Industrial Low Temperature Waste Heat Utilization
In this paper, some common and emerging techniques to better utilize energy in the chemical process industries are discussed. Temperature levels of waste heat available are pointed out. Emerging practices for further economical utilization of waste...
Altin, M.
Near-field electromagnetic heat transfer holds great potential for the advancement of nanotechnology. Whereas far-field electromagnetic heat transfer is constrained by Planck's blackbody limit, the increased density of states in the near-field enhances heat transfer rates by orders of magnitude relative to the conventional limit. Such enhancement opens new possibilities in numerous applications, including thermal-photo-voltaics, nano-patterning, and imaging. The advancement in this area, however, has been hampered by the lack of rigorous theoretical treatment, especially for geometries that are of direct experimental relevance. Here we introduce an efficient computational strategy, and present the first rigorous calculation of electromagnetic heat transfer in a sphere-plate geometry, the only geometry where transfer rate beyond blackbody limit has been quantitatively probed at room temperature. Our approach results in a definitive picture unifying various approximations previously used to treat this problem, ...
Otey, Clayton
Measurement and analysis of gas turbine blade endwall heat transfer
the aerodynamic flow and external heat transfer distribution around the airfoils and end-wall surfaces. A stationary 5 vane linear cascade is designed and developed to investigate gas turbine blade endwall heat transfer and flow. The test cascade is instrumented...
Lee, Joon Ho
Enhanced surfaces lead to increased heat transfer and power density.
Enhanced surfaces lead to increased heat transfer and power density. Inverters are used in hybrid researchers are using the coating to improve heat transfer in automotive power electron- ics devices. Photo electric vehicles (HEVs) and electric vehicles (EVs) to con- vert DC battery power into a form that can
Heat transfer in proteinwater interfaces Anders Lervik,ab
Heat transfer in proteinwater interfaces Anders Lervik,ab Fernando Bresme,*ac Signe Kjelstrup of the heat diffusion equation we compute the thermal conductivity and thermal diffusivity of the proteins by about 4 nm.4 It is expected that the energy transfer between these sites may involve the concerted
Kjelstrup, Signe
Enhanced radiative heat transfer between nanostructured gold plates
We compute the radiative heat transfer between nanostructured gold plates in the framework of the scattering theory. We predict an enhancement of the heat transfer as we increase the depth of the corrugations while keeping the distance of closest approach fixed. We interpret this effect in terms of the evolution of plasmonic and guided modes as a function of the grating's geometry.
R. Gu�rout; J. Lussange; F. S. S. Rosa; J. -P. Hugonin; D. A. R. Dalvit; J. -J. Greffet; A. Lambrecht; S. Reynaud
Augmentation of condensation heat transfer with electrohydrodynamics on vertical enhanced tubes
for various heat loads . 48 . 49 . 58 NOMENCLATURE cr D ha k Nu qual Re V area, m', or current, A specific heat at constant pressure, J/kgK diameter, m electric field strength, V/m gravity, (9. 81 m/s') heat transfer coefficient, W... fluorocarbon or a hydrocarbon, the temperature of heat addition from the primary fluid to the secondary working fluid tends to be lower, thereby increasing the amount of heat rejected. In many cases the waste heat can be rejected through a condensation...
Motte, Edouard
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
Dependency of Heat Transfer Rate on the Brinkman Number in Microchannels
Heat generation from electronics increases with the advent of high-density integrated circuit technology. To come up with the heat generation, microscale cooling has been thought as a promising technology. Prediction of heat transfer rate is crucial in design of microscale cooling device but is not clearly understood yet. This work proposes a new correlation between heat transfer rate and Brinkman number which is nondimensional number of viscosity, flow velocity and temperature. It is expected that the equation proposed by this work can be useful to design microchannel cooling device.
H. S. Park
Phase change based cooling for high burst mode heat loads with temperature regulation above the phase change temperature
An apparatus and method for transferring thermal energy from a heat load is disclosed. In particular, use of a phase change material and specific flow designs enables cooling with temperature regulation well above the fusion temperature of the phase change material for medium and high heat loads from devices operated intermittently (in burst mode). Exemplary heat loads include burst mode lasers and laser diodes, flight avionics, and high power space instruments. Thermal energy is transferred from the heat load to liquid phase change material from a phase change material reservoir. The liquid phase change material is split into two flows. Thermal energy is transferred from the first flow via a phase change material heat sink. The second flow bypasses the phase change material heat sink and joins with liquid phase change material exiting from the phase change material heat sink. The combined liquid phase change material is returned to the liquid phase change material reservoir. The ratio of bypass flow to flow into the phase change material heat sink can be varied to adjust the temperature of the liquid phase change material returned to the liquid phase change material reservoir. Varying the flowrate and temperature of the liquid phase change material presented to the heat load determines the magnitude of thermal energy transferred from the heat load.
The United States of America as represented by the United States Department of Energy (Washington, DC)
Heat transfer between elastic solids with randomly rough surfaces
We study the heat transfer between elastic solids with randomly rough surfaces. We include both the heat transfer from the area of real contact, and the heat transfer between the surfaces in the noncontact regions. We apply a recently developed contact mechanics theory, which accounts for the hierarchical nature of the contact between solids with roughness on many different length scales. For elastic contact, at the highest (atomic) resolution the area of real contact typically consists of atomic (nanometer) sized regions, and we discuss the implications of this for the heat transfer. For solids with very smooth surfaces, as is typical in many modern engineering applications, the interfacial separation in the non-contact regions will be very small, and for this case we show the importance of the radiative heat transfer associated with the evanescent electromagnetic waves which exist outside of all bodies.
B. N. J. Persson; B. Lorenz; A. I. Volokitin
Calculation of unsteady-state heat and mass transfer in steam injection wells
and mass transfer computation. Results obtained from this study were compared to field data and re- sults obtained from a semi-unsteady-state heat transfer and steady-state mass transfer model. As actual downhole steam quality measurements were...- hole pressure, temperature, and quality data from steam injection wells is virtually nonexistent in the literature. One limitation is that no downhole tool has been developed to reliably measure steam quality. Be- cause of the lack of field data from...
Ruddy, Kenneth Edward
Dual circuit embossed sheet heat transfer panel
A heat transfer panel provides redundant cooling for fusion reactors or the like environment requiring low-mass construction. Redundant cooling is provided by two independent cooling circuits, each circuit consisting of a series of channels joined to inlet and outlet headers. The panel comprises a welded joinder of two full-size and two much smaller partial-size sheets. The first full-size sheet is embossed to form first portions of channels for the first and second circuits, as well as a header for the first circuit. The second full-sized sheet is then laid over and welded to the first full-size sheet. The first and second partial-size sheets are then overlaid on separate portions of the second full-sized sheet, and are welded thereto. The first and second partial-sized sheets are embossed to form inlet and outlet headers, which communicate with channels of the second circuit through apertures formed in the second full-sized sheet. 6 figs.
Morgan, G.D.
The Advantages of Sealless Pumps in Heat Transfer Fluid Services
THE ADV ANTAGES OF SEALLESS PUMPS IN HEAT TRANSFER FLUID SERVICES Michael D. Smith Engineering Manager Sundstrand Fluid Handling Arvada, CO ABSTRACT The expectations for heat transfer fluid (HTF) system safety and reliability... of the issues which challenge mechanical seals. In addition, one type of sealless pump, the canned motor pump, raises the thermal efficiency of HTF systems. Waste heat from the drive motors of m'ost pumps is dissipated to the air. A shaft driven fan wastes...
Smith, M. D.
Modesto Memorial Hospital Space Heating Low Temperature Geothermal...
Memorial Hospital Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Modesto Memorial Hospital Space Heating Low Temperature Geothermal Facility...
Jackson Hot Springs Lodge Space Heating Low Temperature Geothermal...
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Walley's Hot Springs Resort Space Heating Low Temperature Geothermal...
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Senior Citizens' Center Space Heating Low Temperature Geothermal...
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Steamboat Villa Hot Springs Spa Space Heating Low Temperature...
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Warm Springs State Hospital Space Heating Low Temperature Geothermal...
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Agua Calientes Trailer Park Space Heating Low Temperature Geothermal...
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Pagosa Springs Private Wells Space Heating Low Temperature Geothermal...
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Glenwood Hot Springs Lodge Space Heating Low Temperature Geothermal...
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Hot Springs National Park Space Heating Low Temperature Geothermal...
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Broadwater Athletic Club & Hot Springs Space Heating Low Temperature...
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Klamath Apartment Buildings (13) Space Heating Low Temperature...
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Merle West Medical Center Space Heating Low Temperature Geothermal...
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Maywood Industries of Oregon Space Heating Low Temperature Geothermal...
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Elko County School District District Heating Low Temperature...
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Cedarville Elementary & High School Space Heating Low Temperature...
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Fort Boise Veteran's Hospital District Heating Low Temperature...
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Osmotic Heat Engine for Energy Production from Low Temperature...
Osmotic Heat Engine for Energy Production from Low Temperature Geothermal Resources Osmotic Heat Engine for Energy Production from Low Temperature Geothermal Resources Project...
New Mexico State University District Heating Low Temperature...
Heating Low Temperature Geothermal Facility Jump to: navigation, search Name New Mexico State University District Heating Low Temperature Geothermal Facility Facility New...
Enhanced two phase flow in heat transfer systems
A family of structures and designs for use in devices such as heat exchangers so as to allow for enhanced performance in heat exchangers smaller and lighter weight than other existing devices. These structures provide flow paths for liquid and vapor and are generally open. In some embodiments of the invention, these structures can also provide secondary heat transfer as well. In an evaporate heat exchanger, the inclusion of these structures and devices enhance the heat transfer coefficient of the evaporation phase change process with comparable or lower pressure drop.
Tegrotenhuis, Ward E; Humble, Paul H; Lavender, Curt A; Caldwell, Dustin D
Natural convection heat transfer within horizontal spent nuclear fuel assemblies
Natural convection heat transfer is experimentally investigated in an enclosed horizontal rod bundle, which characterizes a spent nuclear fuel assembly during dry storage and/or transport conditions. The basic test section consists of a square array of sixty-four stainless steel tubular heaters enclosed within a water-cooled rectangular copper heat exchanger. The heaters are supplied with a uniform power generation per unit length while the surrounding enclosure is maintained at a uniform temperature. The test section resides within a vacuum/pressure chamber in order to subject the assembly to a range of pressure statepoints and various backfill gases. The objective of this experimental study is to obtain convection correlations which can be used in order to easily incorporate convective effects into analytical models of horizontal spent fuel systems, and also to investigate the physical nature of natural convection in enclosed horizontal rod bundles in general. The resulting data consist of: (1) measured temperatures within the assembly as a function of power, pressure, and backfill gas; (2) the relative radiative contribution for the range of observed temperatures; (3) correlations of convective Nusselt number and Rayleigh number for the rod bundle as a whole; and (4) correlations of convective Nusselt number as a function of Rayleigh number for individual rods within the array.
Canaan, R.E.
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
Heat Transfer of a Multiple Helical Coil Heat Exchanger Using a Microencapsulated Phase Change Material Slurry
The present study has focused on the use of coil heat exchangers (CHEs) with microencapsulated phase change material (MPCM) slurries to understand if CHEs can yield greater rates of heat transfer. An experimental study was conducted using a...
Gaskill, Travis
TEMP: A finite line heat transfer code for geologic repositories for nuclear waste
TEMP is a FORTRAN computer code for calculating temperatures in a geologic repository for nuclear waste. It will calculate the incremental temperature contributed by a single heat source, by an infinite array of heat sources, or by heat sources geometrically arranged in a finite array. In the finite array geometry, different types of heat sources can be placed in different regions at different times to more closely approximate the emplacement of waste in a repository. TEMP uses a semi-analytical technique for solving the equation for a heat producing finite length line source in an infinite and isotropic medium. Temperature contributions from individual heat sources are superimposed to determine the temperature at a specific location and time in a repository of multiple heat sources. Thermal conductivity of the geologic medium can be a function of temperature, and, when it is, an approximation is made for the temperature dependence of thermal diffusivity. This report derives the equations solved by TEMP and documents its accuracy by comparing its results to known analytical solutions and to the finite-difference and finite-element heat transfer codes HEATING5, HEATING6, THAC-SIP-3D, SPECTROM-41, and STEALTH-2D. The temperature results from TEMP are shown to be very accurate when compared to the analytical solutions and to the results from the finite-difference and finite-element codes. 8 refs., 97 figs., 39 tabs.
Wurm, K.J.; Bloom, S.G.; Atterbury, W.G.; Hetteberg, J.R.
Joule heating and heat transfer in poly(dimethylsiloxane) microfluidic systems
Joule heating and heat transfer in poly(dimethylsiloxane) microfluidic systems David Erickson microfluidic/biochip systems must have the ability to rapidly reject this heat to the surroundings. Generally it is the ability to dissipate this heat that limits the strength of the applied electric field and thus the maximum
Erickson, David
Low Temperature Heat Recovery for Boiler Systems
be economically heated to within 50 0 F of the entering flue gas temperature. Other less common, but practical, uses for energy include driving a low-temperature electric turbine cycle or an absorption chilling cycle. An improvement in boiler efficiency of 3...% to 8% can normally be realized by cooling boiler flue gasses down to llO o F_200 0 F. This recovers a large quantity of the available sensible heat in most boiler flue gas streams. Efficiency can be improv ed by up to 10% if flue gas is cooled down...
Shook, J. R.; Luttenberger, D. B.
Performance Optimization of an Irreversible Heat Pump with Variable-temperature Heat Reservoirs
An irreversible cycle model of a heat pump operating between two variable-temperature heat reservoirs is established and used to analyze the performance of the heat pump affected by heat resistances, heat leakage and internal dissipation...
Huang, Y.; Sun, D.
AndreiG.Fedorov Title: George W. Woodruff Professorship in Heat Transfer, Combustion and
AndreiG.Fedorov Title: George W. Woodruff Professorship in Heat Transfer, Combustion and Energy Research Areas of Interest Heat Transfer, combustion, and energy systems Bioengineering, lab ionization and imaging for bioanalytical mass spectrometry Thermal radiation heat transfer Thermal
Garmestani, Hamid
Rheology and Convective Heat Transfer of Colloidal Gas Aphrons in Horizontal Minichannels
Single-phase convective heat transfer in microchannels: aand Newell, M. E. , 1967. Heat transfer in fully developed3 /s at 130 W. Water CGA Heat Transfer Coefficient, h (W/m 2
Tseng, H.; Pilon, L.; Warrier, G.
Downflow heat transfer in a heated ribbed vertical annulus with a cosine power profile
Experiments designed to investigate downflow heat transfer in a heated, ribbed annulus test section simulating one of the annular coolant channels of a Savannah River Plant production reactor Mark 22 fuel assembly have been conducted at the Idaho National Engineering Laboratory. The inner surface of the annulus was constructed of aluminum and was electrically heated to provide an axial cosine power profile and a flat azimuthal power shape. Data presented in this report are from the ECS-2c series, which was a follow on series to the ECS-2b series, conducted specifically to provide additional data on the effect of different powers at the same test conditions, for use in evaluation of possible power effects on the aluminum temperature measurements. Electrical powers at 90%, 100%, and 110% of the power required to result in the maximum aluminum temperature at fluid saturation temperature were used at each set of test conditions previously used in the ECS-2b series. The ECS-2b series was conducted in the same test rig as the previous ECS-2b series. Data and experimental description for the ECS-2b series is provided in a previous report. 18 refs., 25 figs., 3 tabs.
Anderson, J.L.; Condie, K.G.; Larson, T.K.
Experimental and numerical study of pressure drop and heat transfer in a single-phase micro-channel heat sink
Experimental and numerical study of pressure drop and heat transfer in a single-phase micro Received 6 July 2001; received in revised form 26 October 2001 Abstract The pressure drop and heat transfer-dimensional heat transfer characteristics of the heat sink were analyzed numerically by solving the conjugate heat
Qu, Weilin
Vibration damping and heat transfer using material phase changes
A method and apparatus wherein phase changes in a material can dampen vibrational energy, dampen noise and facilitate heat transfer. One embodiment includes a method for damping vibrational energy in a body. The method comprises attaching a material to the body, wherein the material comprises a substrate, a shape memory alloy layer, and a plurality of temperature change elements. The method further comprises sensing vibrations in the body. In addition, the method comprises indicating to at least a portion of the temperature change elements to provide a temperature change in the shape memory alloy layer, wherein the temperature change is sufficient to provide a phase change in at least a portion of the shape memory alloy layer, and further wherein the phase change consumes a sufficient amount of kinetic energy to dampen at least a portion of the vibrational energy in the body. In other embodiments, the shape memory alloy layer is a thin film. Additional embodiments include a sensor connected to the material.
Kloucek, Petr (Houston, TX); Reynolds, Daniel R. (Oakland, CA)
An experimental investigation was completed on nanoparticle enhanced ionic liquid heat transfer fluids as an alternative to conventional organic based heat transfer fluids (HTFs). These nanoparticle-based HTFs have the potential to deliver higher thermal conductivity than the base fluid without a significant increase in viscosity at elevated temperatures. The effect of nanoparticle morphology and chemistry on thermophysical properties was examined. Whisker shaped nanomaterials were found to have the largest thermal conductivity temperature dependence and were also less likely to agglomerate in the base fluid than spherical shaped nanomaterials.
Fox, E.
Heat transfer during film condensation of a liquid metal vapor
The object of this investigation is to resolve the discrepancy between theory and experiment for the case of heat transfer durirnfilm condensation of liquid metal vapors. Experiments by previous investigators have yielded ...
Sukhatme, S. P.
Survey and evaluation of techniques to augment convective heat transfer
This report presents a survey and evaluation of the numerous techniques which have been shown to augment convective heat transfer. These techniques are: surface promoters, including roughness and treatment; displaced ...
Bergles A. E.
Effects of operating conditions on a heat transfer fluid aerosol
of heat transfer fluid aerosols from process leaks. To simulate industrial leaks, aerosol formation from a plain orifice into ambient air is studied by measuring liquid drop sizes and size distributions at various distances from an orifice. Measurements...
Sukmarg, Passaporn
Using Solid Particles as Heat Transfer Fluid for use in Concentrating...
Broader source: Energy.gov (indexed) [DOE]
Using Solid Particles as Heat Transfer Fluid for use in Concentrating Solar Power (CSP) Plants Using Solid Particles as Heat Transfer Fluid for use in Concentrating Solar Power...
Heat transfer between anisotropic nanopartricles: Enhancement and switching
We theoretically study heat transfer between two anisotropic nanoparticles in vacuum, and derive closed expressions in terms of the anisotropic dipole polarizabilities. We show that transfer between two small spheroids can be many times as large as the one for two spheres of same volumes. Such increase with anisotropy is also found for the heat emission of an isolated small spheroid. Furthermore, we observe a strong dependence of transfer on the relative orientation, yielding the interpretation as a heat transfer switch. The switch quality, given as the ratio of transfer in the ``on'' and ``off'' positions, is observed to be as large as $10^3$ in the near field and even larger in the far field.
Roberta Incardone; Thorsten Emig; Matthias Kr�ger
Heat transfer characteristics of a two-pass trapezoidal channel and a novel heat pipe
large variation of the local heat (mass) transfer distribution in the turn and downstream of the turn. The local heat (mass) transfer was high near the end wall and the downstream outer wall in the turn and was relatively low in two regions near...
Lee, Sang Won
Heat Transfer Research 44(1), 130 (2013) ENTROPY GENERATION ANALYSIS
Heat Transfer Research 44(1), 130 (2013) ENTROPY GENERATION ANALYSIS FOR A PULSATING HEATvapor phase 2 Kim, Zhang, & Choi Heat Transfer Research NOMENCLATURE A area, m2 Qin,s,l sensible heat transfer into cp specific heat at constant liquid slug, W pressure, Qout,s,l sensible heat transfer out cv specific
Heat transfer enhancement resulting from induction electrohydrodynamic pumping
HEAT TRANSFER ENHANCEMENT RESULTING FROM INDUCTION ELECTROHYDRODYNAMIC PUMPING A Thesis by BRYAN DAVID MARGO 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 December 1992 Major Subject: Mechanical Engineering HEAT TRANSFER ENHANCEMENT RESULTING FROM INDUCTION ELECTROHYDRODYNAMIC PUMPING A Thesis by BRYAN DAVID MARGO Approved as to style and content by: Jamal Seyed- Yagoobi (Chair...
Margo, Bryan David
Literature survey of heat transfer enhancement techniques in refrigeration applications
A survey has been performed of the technical and patent literature on enhanced heat transfer of refrigerants in pool boiling, forced convection evaporation, and condensation. Extensive bibliographies of the technical literature and patents are given. Many passive and active techniques were examined for pure refrigerants, refrigerant-oil mixtures, and refrigerant mixtures. The citations were categorized according to enhancement technique, heat transfer mode, and tube or shell side focus. The effects of the enhancement techniques relative to smooth and/or pure refrigerants were illustrated through the discussion of selected papers. Patented enhancement techniques also are discussed. Enhanced heat transfer has demonstrated significant improvements in performance in many refrigerant applications. However, refrigerant mixtures and refrigerant-oil mixtures have not been studied extensively; no research has been performed with enhanced refrigerant mixtures with oil. Most studies have been of the parametric type; there has been inadequate examination of the fundamental processes governing enhanced refrigerant heat transfer, but some modeling is being done and correlations developed. It is clear that an enhancement technique must be optimized for the refrigerant and operating condition. Fundamental processes governing the heat transfer must be examined if models for enhancement techniques are to be developed; these models could provide the method to optimize a surface. Refrigerant mixtures, with and without oil present, must be studied with enhancement devices; there is too little known to be able to estimate the effects of mixtures (particularly NARMs) with enhanced heat transfer. Other conclusions and recommendations are offered.
Jensen, M.K.; Shome, B. [Rensselaer Polytechnic Inst., Troy, NY (United States). Dept. of Mechanical Engineering, Aeronautical Engineering and Mechanics
Technical Note Theoretical analysis of film condensation heat transfer
transfer coefficient of steam condensing inside an equilateral triangular channel is found. They divided the condensation area on the micro-fin surface into the flooded and the unflooded areasTechnical Note Theoretical analysis of film condensation heat transfer inside vertical mini
Zhao, Tianshou
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.
Heating tar sands formations to visbreaking temperatures
Methods for treating a tar sands formation are described herein. Methods may include heating at least a section of a hydrocarbon layer in the formation from a plurality of heaters located in the formation. The heat may be controlled so that at least a majority of the section reaches an average temperature of between 200.degree. C. and 240.degree. C., which results in visbreaking of at least some hydrocarbons in the section. At least some visbroken hydrocarbon fluids may be produced from the formation.
Karanikas, John Michael (Houston, TX); Colmenares, Tulio Rafael (Houston, TX); Zhang, Etuan (Houston, TX); Marino, Marian (Houston, TX); Roes, Augustinus Wilhelmus Maria (Houston, TX); Ryan, Robert Charles (Houston, TX); Beer, Gary Lee (Houston, TX); Dombrowski, Robert James (Houston, TX); Jaiswal, Namit (Houston, TX)
Modeling of Heat Transfer in Geothermal Heat Exchangers
, University of Lund, Sweden, [7] Fang, Z., Diao, N., and Cui, P., Discontinuous operation of geothermal heat exchangers [J], Tsinghua Science and Technology. , 2002, 7 194?197. [8] Hellstrom, G., Ground heat storage -- Thermal analysis of duct storage... systems [D], Department of Mathem Sweden, 1991. [9] Mei, V. C. and Baxter, V. D., Performance of a ground-coupled heat pump with multiple dissimilar U-tu Transactions, 1986, 92 Part 2, 22-25. [10] Yavuzturk, C., Spitler, J. D. and Rees, S. J., A...
Cui, P.; Man, Y.; Fang, Z.
Heat transfer in the plate heat exchanger of an ammonia-synthesis column
The planning and construction of high-capacity synthetic ammonia plants requires the development and fabrication of unique, high unit-power equipment with high technical and economic characteristics. In foreign and domestic practice, tubular heat exchangers with relatively low heat-transfer coefficients are used. Plate heat exchangers are a promising alternative. They are compact and have a high heat energy efficiency and a relatively small metal content. To make an experimental check of the operating capability of a plate heat exchanger under ammonia production conditions, a welded plate heat exchanger was designed for an ammonia synthesis column 800mm in diameter. On prolonged testing (four years), the device provided an autothermal operating mode in the column and the heat transfer coefficient was practically constant for fixed space velocities. Consequently, the heat exchange surface was not contaminated significantly with catalyst dust, confirmed by visual observation of the heat exchanger after disassembly.
Obolentsev, Y.G.; Chus', M.S.; Norobchanskii, O.A.; Teplitshi, Y.S.; Tovazhnyanskii, L.L.
Method of measuring heat influx of a cryogenic transfer system. [Patent application
A method is provided for measuring the heat influx of a cryogenic transfer system. A gaseous phase of the cryogen used during normal operation of the system is passed through the system. The gaseous cryogen at the inlet to the system is tempered to duplicate the normal operating temperature of the system inlet. The temperature and mass flow rate of the gaseous cryogen is measured at the outlet of the system, and the heat capacity of the cryogen is determined. The heat influx of the system is then determined from known thermodynamic relationships.
Niemann, R.C.; Zelipsky, S.A.; Rezmer, R.R.; Smelser, P.
Thermal Analysis of the Divertor Primary Heat Transfer System Piping During the Gas Baking Process
A preliminary analysis has been performed examining the temperature distribution in the Divertor Primary Heat Transfer System (PHTS) piping and the divertor itself during the gas baking process. During gas baking, it is required that the divertor reach a temperature of 350 C. Thermal losses in the piping and from the divertor itself require that the gas supply temperature be maintained above that temperature in order to ensure that all of the divertor components reach the required temperature. The analysis described in this report was conducted in order to estimate the required supply temperature from the gas heater.
Yoder Jr, Graydon L [ORNL; Harvey, Karen [ORNL; Ferrada, Juan J [ORNL
Error Analysis of Heat Transfer for Finned-Tube Heat-Exchanger Text-Board
In order to reduce the measurement error of heat transfer in water and air side for finned-tube heat-exchanger as little as possible, and design a heat-exchanger test-board measurement system economically, based on the principle of test-board system...
Chen, Y.; Zhang, J.
Active heat transfer enhancement in integrated fan heat sinks
Modern computer processors require significant cooling to achieve their full performance. The "efficiency" of heat sinks is also becoming more important: cooling of electronics consumes 1% of worldwide electricity use by ...
Staats, Wayne Lawrence
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 ...
Kim, Sung Joong, Ph. D. Massachusetts Institute of Technology
Heat transfer in a thermoelectric generator for diesel engines
This paper discusses the design and test results obtained for a 1kW thermoelectric generator used to convert the waste thermal energy in the exhaust of a Diesel engine directly to electric energy. The paper focuses on the heat transfer within the generator and shows what had to be done to overcome the heat transfer problems encountered in the initial generator testing to achieve the output goal of 1kW electrical. The 1kW generator uses Bismuth-Telluride thermoelectric modules for the energy conversion process. These modules are also being evaluated for other waste heat applications. Some of these applications are briefly addressed.
Bass, J.C. [Hi-Z Technology, Inc., San Diego, CA (United States)
Heat Transfer Enhancement for Finned-Tube Heat Exchangers with Vortex Generators: Experimental and Numerical Results
A combined experimental and numerical investigation is under way to investigate heat transfer enhancement techniques that may be applicable to large-scale air-cooled condensers such as those used in geothermal power applications. The research is focused on whether air-side heat transfer can be improved through the use of finsurface vortex generators (winglets,) while maintaining low heat exchanger pressure drop. A transient heat transfer visualization and measurement technique has been employed in order to obtain detailed distributions of local heat transfer coefficients on model fin surfaces. Pressure drop measurements have also been acquired in a separate multiple-tube row apparatus. In addition, numerical modeling techniques have been developed to allow prediction of local and average heat transfer for these low-Reynolds-number flows with and without winglets. Representative experimental and numerical results presented in this paper reveal quantitative details of local fin-surface heat transfer in the vicinity of a circular tube with a single delta winglet pair downstream of the cylinder. The winglets were triangular (delta) with a 1:2 height/length aspect ratio and a height equal to 90% of the channel height. Overall mean fin-surface Nusselt-number results indicate a significant level of heat transfer enhancement (average enhancement ratio 35%) associated with the deployment of the winglets with oval tubes. Pressure drop measurements have also been obtained for a variety of tube and winglet configurations using a single-channel flow apparatus that includes four tube rows in a staggered array. Comparisons of heat transfer and pressure drop results for the elliptical tube versus a circular tube with and without winglets are provided. Heat transfer and pressure-drop results have been obtained for flow Reynolds numbers based on channel height and mean flow velocity ranging from 700 to 6500.
O'Brien, James Edward; Sohal, Manohar Singh; Huff, George Albert
Simultaneous heat and mass transfer in absorption of gases in laminar liquid films
A theoretical analysis of the combined heat and mass transfer process taking place in the absorption of a gas or vapor into a laminar liquid film is described. This type of process, which occurs in many gas-liquid systems, often releases only a small amount of heat, making the process almost isothermal. In some cases, however, the heat of absorption is significant and temperature variations cannot be ignored. One example, from which the present study originated, is in absorption heat pumps where mass transfer is produced specifically to generate a temperature change. The model analyzed describes a liquid film that flows over an inclined plane and has its free surface in contact with stagnant vapor. The absorption process at the surface creates nonuniform temperature and concentration profiles in the film, which develop until equilibrium between the liquid and vapor is achieved. The energy and diffusion equations are solved simultaneously to give the temperature and concentration variations at the interface and the wall. Two cases of interest are considered: constant-temperature and adiabatic walls. The Nusselt and Sherwood numbers are expressed in terms of the operating parameters, from which heat and mass transfer coefficients can be determined. The Nusselt and Sherwood numbers are found to depend on the Peclet and Lewis numbers as well as on the equilibrium characteristics of the working materials.
Grossman, G
Measurements and Predictions of the Heat Transfer at the Tube-Fin Junction for Louvered Fin Heat Exchangers
Measurements and Predictions of the Heat Transfer at the Tube-Fin Junction for Louvered Fin Heat Transfer at the Tube-Fin Junction for Louvered Fin Heat Exchangers Abstract The dominant thermal resistance used to increase heat transfer by initiating new boundary layer growth and increasing surface area
Heat transfer augmentation along the tube wall of a louvered fin heat exchanger using practical delta winglets
Heat transfer augmentation along the tube wall of a louvered fin heat exchanger using practical the formation of streamwise vortices and increase heat transfer between a working fluid and the surface on which the winglets are placed. This study investigates the use of delta winglets to augment heat transfer on the tube
Fairmont Hot Springs Resort Space Heating Low Temperature Geothermal...
Oregon Institute of Technology's Geo-Heat Center1 Fairmont Hot Springs Resort is a Space Heating low temperature direct use geothermal facility in Fairmont, Montana. This...
Salida Hot Springs (Poncha Spring) Space Heating Low Temperature...
Salida Hot Springs (Poncha Spring) Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Salida Hot Springs (Poncha Spring) Space Heating Low...
Numerical model of mixed convection heat transfer between a series of vertical parallel plates with planar heat sources
Heat transfer between a series of vertical parallel plates with planar heat sources has been studied numerically. The series of plates formed a series of channels, or cooling passages, in which fluid could flow. Heat dissipation from the heat...
Watson, James Christopher
A Study of Heat Transfer in a Composite Wall Collector System with Porous Absorber
In this paper, heat transfer and flow in a composite solar wall with porous absorber has been studied. The unsteady numerical simulation is employed to analyze the performance of the flow and temperature field in the composite solar wall. The excess...
Chen, W.
MEASUREMENT OF HEAT TRANSFER DURING DROP-WISE CONDENSATION OF WATER ON POLYETHYLENE Gagan Deep distribution of temperature during drop-wise condensation over a polyethylene substrate was measured using on the substrate was simultaneously visualized. Static contact angles of water on polyethylene are measured
Khandekar, Sameer
Mechanical Properties of Granite, Stripa, Sweden," TR 77-92,Properties of Stripa Granite from Temperature MeasurementsPermeability Test o~ the Granite in the Stripa Mine and
Chan, T.
Heat Flow, Heat Transfer And Lithosphere Rheology In Geothermal...
of geothermal energy. As a consequence of anomalously high temperature, the mechanical lithosphere is thin and its total strength can be reduced by almost one order of...
ME 544 Advanced Heat Transfer Spring 2013 Time: 2pm-3pm MWF
1 ME 544 Advanced Heat Transfer Spring 2013 Time: 2pm-3pm MWF Location: B4 Instructor: Dr. Allan and engineering applications of heat transfer including conduction, convection, and radiation. Course Learning, convection, and radiation heat transfer modes. 2. Determine the dominant modes of heat transfer, and apply
Heat Transfer Measurements for a Horizontal Micro-Tube Using Liquid Crystal Thermography
62 TC02-007 Heat Transfer Measurements for a Horizontal Micro-Tube Using Liquid Crystal-tube and 1000m micro-tube. In the single-phase heat transfer experiments, the fully-developed flow heat transfer were also measured using thermocouples (TC). The results showed that the heat transfer coefficient
Numerous embodiments and related methods for generator-absorber heat exchange (GAX) are disclosed, particularly for absorption heat pump systems. Such embodiments and related methods use, as the heat transfer medium, the working fluid of the absorption system taken from the generator at a location where the working fluid has a rich liquor concentration. 5 figs.
Phillips, B.A.; Zawacki, T.S.
Numerous embodiments and related methods for generator-absorber heat exchange (GAX) are disclosed, particularly for absorption heat pump systems. Such embodiments and related methods use, as the heat transfer medium, the working fluid of the absorption system taken from the generator at a location where the working fluid has a rich liquor concentration.
Research on Convective Heat Transfer and Mass Transfer of the Evaporator in Micro/Mini-Channel
on the reviewers on the present household air conditioners, the potential requirements for new heat transfer enhancement used for household air conditioners are discussed. Investigations on condensation and boiling of refrigerants in mini/micro channels have...
Su, J.; Li, J.
"Developing novel heat transfer diagnostics for nanosystems."
and development of electronic devices, power generation modules, and waste energy harvesting techniques alloys. Thermal conductivity of bismuth-doped III-V alloys Thermoelectric power generation (TPG) has become an increasingly popular technology for waste heat recovery in the last few years. The efficiency
Acton, Scott
Modeling studies of heat transfer and phase distribution in two-phase geothermal reservoirs
Phase distribution as well as mass flow and heat transfer behavior in two-phase geothermal systems have been studied by numerical modeling. A two-dimensional porous-slab model was used with a non-uniform heat flux boundary conditions at the bottom. Steady-state solutions are obtained for the phase distribution and heat transfer behavior for cases with different mass of fluid (gas saturation) in place, permeabilities, and capillary pressures. The results obtained show very efficient heat transfer in the vapor-dominated zone due to the development of heat pipes and near-uniform saturations. The phase distribution below the vapor-dominated zone depends on permeability. For relatively high-permeability systems, single-phase liquid zones prevail, with convection providing the energy throughput. For lower permeability systems, a two-phase liquid-dominated zone develops, because single-phase liquid convection is not sufficient to dissipate heat released from the source. These results are consistent with observations from the field, where most high-temperature liquid-dominated two-phase systems have relatively low permeabilities e.g. Krafla, Iceland; Kenya; Baca, New Mexico. The numerical results obtained also show that for high heat flow a high-temperature single-phase vapor zone can develop below a typical (240 C) vapor-dominated zone, as has recently been found at the Geysers, California, and Larderello, Italy.
Lai, C.H.; Bodvarsson, G.S.; Truesdell, A.H. (Lawrence Berkeley Lab., CA (United States). Earth Sciences Div.)
This paper presents an experimental study of natural convection heat transfer for an Ionic Liquid. The experiments were performed for 1-butyl-2, 3-dimethylimidazolium bis(trifluoromethylsulfonyl)imide, ([C{sub 4}mmim][NTf{sub 2}]) at a Raleigh number range of 1.26 x 10{sup 7} to 8.3 x 10{sup 7}. In addition to determining the convective heat transfer coefficients, this study also included experimental determination of thermophysical properties of [C{sub 4}mmim][NTf{sub 2}] such as, density, viscosity, heat capacity, and thermal conductivity. The results show that the density of [C{sub 4}mmim][NTf{sub 2}] varies from 1.437-1.396 g/cm{sup 3} within the temperature range of 10-50 C, the thermal conductivity varies from 0.105-0.116 W/m.K between a temperature of 10 to 60 C, the heat capacity varies from 1.015 J/g.K - 1.760 J/g.K within temperature range of 25-340 C and the viscosity varies from 18cp-243cp within temperature range 10-75 C. The results for density, thermal conductivity, heat capacity, and viscosity were in close agreement with the values in the literature. Measured dimensionless Nusselt number was observed to be higher for the ionic liquid than that of DI water. This is expected as Nusselt number is the ratio of heat transfer by convection to conduction and the ionic liquid has lower thermal conductivity (approximately 18%) than DI water.
Fox, E.; Visser, A.; Bridges, N.
heat transfer | OpenEI Community
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 Office of InspectorConcentrating SolarElectric Coop,SaveWhiskey Flats GeothermalElectricsecretaryguidanceheat transfer
Heat transfer and fluid flow characteristics in various micro devices for the development of micro absorption heat pump systems.
??This thesis presents a series of studies on heat transfer and fluid flow characteristics in various micro devices for the development of micro absorption heat� (more)
Hu, Jinshan
A vectorized heat transfer model for solid reactor cores
The new generation of nuclear reactors includes designs that are significantly different from light water reactors. Among these new reactor designs is the Modular High-Temperature Gas-Cooled Reactor (MHTGR). In addition, nuclear thermal rockets share a number of similarities with terrestrial HTGRs and would be amenable to similar types of analyses. In these reactors, the heat transfer in the solid core mass is of primary interest in design and safety assessment. One significant safety feature of these reactors is the capability to withstand a loss of pressure and forced cooling in the primary system and still maintain peak fuel temperatures below the safe threshold for retaining the fission products. To accurately assess the performance of gas-cooled reactors during these types of transients, a Helium/Hydrogen Cooled Reactor Analysis (HERA) computer code has been developed. HERA has the ability to model arbitrary geometries in three dimensions, which allows the user to easily analyze reactor cores constructed of prismatic graphite elements. The code accounts for heat generation in the fuel, control rods and other structures; conduction and radiation across gaps; convection to the coolant; and a variety of boundary conditions. The numerical solution scheme has been optimized for vector computers, making long transient analyses economical. Time integration is either explicit or implicit, which allows the use of the model to accurately calculate both short- or long-term transients with an efficient use of computer time. Both the basic spatial and temporal integration schemes have been benchmarked against analytical solutions. Also, HERA has been used to analyze a depressurized loss of forced cooling transient in a HTGR with a very detailed three-dimensional input model. The results compare favorably with other means of analysis and provide further validation of the models and methods. 18 refs., 11 figs.
Rider, W.J.; Cappiello, M.W.; Liles, D.R.
Convective heat transfer inside passive solar buildings
Natural convection between spaces in a building can play a major role in energy transfer. Two situations are investigated: convection through a single doorway into a remote room, and a convective loop in a two-story house with a south sunspace where a north stairway serves as the return path. A doorway-sizing equation is given for the single-door case. Detailed data are given from the monitoring of airflow in one two-story house and summary data are given for five others. Observations on the nature of the airflow and design guidelines are presented.
Jones, R.W.; Balcomb, J.D.; Yamaguchi, K.
Natural convection between spaces in a building which play a major role in energy transfer are discussed. Two situations are investigated: Convection through a single doorway into a remote room, and a convective loop in a two story house with a south sunspace where a north stairway serves as the return path. A doorway sizing equation is given for the single door case. Data from airflow monitoring in one two-story house and summary data for five others are presented. The nature of the airflow and design guidelines are presented.
Heat transfer education : Keeping it relevant and vibrant.
The motivation for a fresh look at heat transfer education, both in content and in methodology, is generated by a number of trends in engineering practice. These include the increasing demand for engineers with interdisciplinary skills, rapid integration of technology, emergence of computerized and interactive problem-solving tools, shortening time of concept-to-market, availability of new technologies, and an increasing number of new or redesigned products and processes in which heat transfer plays a part. Examination of heat transfer education in this context can be aided by considering the changes, both qualitatively and quantitatively, in the student, educator, and researcher populations, employment opportunities, in the needs of corporations, government, industry, and universities, and in the relevant technical problems and issues of the day. Such an overview provides the necessary background for charting a response to the difficult question of how to maintain excellence and continuity in heat transfer education in the face of rapid, widespread, and complex changes. The present paper addresses how to make heat transfer education more relevant and stimulating. This paper represents a written summary of a 1996 panel discussion at the 1996 International Mechanical Engineering Conference and Exhibition (IMECE) of the American Society of Mechanical Engineers (ASME) in Atlanta, Georgia, on ''Heat Transfer Education: Keeping it Relevant and Vibrant,'' with significant expansion and amplification by the authors and the panelists in the 1997-98 period. The consensus of the participants is that the steps necessary to ensure the desired outcome in heat transfer education should include: (1) a better understanding of the interaction between the student, course content, and market needs; (2) an appreciation of the need in multidisciplinary industrial environments for engineers trained with a broad background: (3) a revision of the introductory heat transfer course to incorporate illustrative and insightful industrial examples and case studies reducible to order-of-magnitude analyses; (4) a reinforcement of real-world problem-solving abilities in students by introducing them to examples that emphasize multidisciplinary issues in modern thermal management problems and finally (5) industrial collaboration that would provide the educator with meaningful thermal management case studies (and possible funding), the student with an appreciation of industrial practices, and the industrial sponsor with access to academia for assistance in problem solving. Also suggested is an effective regular review program to provide assessment, feedback, and suggestions for quality control to interested institutions on their teaching methodology and materials.
Khounsary, A. M.
Radiative heat transfer in 2D Dirac materials
We compute the radiative heat transfer between two sheets of 2D Dirac materials, including topological Chern insulators and graphene, within the framework of the local approximation for the optical response of these materials. In this approximation, which neglects spatial dispersion, we derive both numerically and analytically the short-distance asymptotic of the near-field heat transfer in these systems, and show that it scales as the inverse of the distance between the two sheets. Finally, we discuss the limitations to the validity of this scaling law imposed by spatial dispersion in 2D Dirac materials.
Pablo Rodriguez-Lopez; Wang-Kong Tse; Diego A. R. Dalvit
Heat Flow, Heat Transfer And Lithosphere Rheology In Geothermal Areas-
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 Home5b9fcbce19 No revision hasInformation Earth's Heat Jump to:Photon Place:NetHealth Division |Hays,Community CollegeFeatures
Combined heat and mass transfer device for improving separation process
A two-phase small channel heat exchange matrix simultaneously provides for heat transfer and mass transfer between the liquid and vapor phases of a multi-component mixture at a single, predetermined location within a separation column, significantly improving the thermodynamic efficiency of the separation process. The small channel heat exchange matrix is composed of a series of channels having a hydraulic diameter no greater than 5.0 millimeters for conducting a two-phase coolant. In operation, the matrix provides the liquid-vapor contacting surfaces within the separation column, such that heat and mass are transferred simultaneously between the liquid and vapor phases. The two-phase coolant allows for a uniform heat transfer coefficient to be maintained along the length of the channels and across the surface of the matrix. Preferably, a perforated, concave sheet connects each channel to an adjacent channel to facilitate the flow of the liquid and vapor phases within the column and to increase the liquid-vapor contacting surface area.
Tran, Thanh Nhon (Flossmoor, IL)
A two-phase small channel heat exchange matrix simultaneously provides for heat transfer and mass transfer between the liquid and vapor phases of a multi-component mixture at a single, predetermined location within a separation column, significantly improving the thermodynamic efficiency of the separation process. The small channel heat exchange matrix is composed of a series of channels having a hydraulic diameter no greater than 5.0 millimeters for conducting a two-phase coolant. In operation, the matrix provides the liquid-vapor contacting surfaces within the separation column, such that heat and mass are transferred simultaneously between the liquid and vapor phases. The two-phase coolant allows for a uniform heat transfer coefficient to be maintained along the length of the channels and across the surface of the matrix. Preferably, a perforated, concave sheet connects each channel to an adjacent channel to facilitate the flow of the liquid and vapor phases within the column and to increase the liquid-vapor contacting surface area. 12 figs.
Tran, T.N.
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.
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.
Heat transfer in theory of relativity
The traditional Fourier equation just allows us to study the evolution of temperature in an "undeformable" bar. The search for its relativistic variant is a task which is expected to fail because in relativity there are no undeformable bars. Rigid bodies, in the sense of "as rigid as possible", are deformables. In this work we show how to write in relativity the system of equations necessary to study simultaneously deformation and temperature evolution along a rigid deformable bar. The solutions of the two simultaneous equations is discussed assuming convenient constitutive relations for the material. An application is presented.
A. Brotas; J. C. Fernandes
Heat transfer and film cooling with steam injection
for both coolants was determined for similar blowing rates and was used as a basis for comparisons. Heat transfer coefficients were calcula- ted from the experimental data using a transient analysis. DEDICATION To my wife and family. ACKNOWLEDGEMENTS... LIST OF TABLES PAGE TABLE 1 Variation in the Blowing Rate ------------ 55 TABLE 2 TABLE 3 Typical Air Film Cooling Effectiveness Data Typical Steam Film Cooling Effectiveness Data 62 62 1X LIST OF FIGURES PAGE Figure 1 Comparison of Heat...
Conklin, Gary Eugene
Open-cycle magnetohydrodynamic power plant based upon direct-contact closed-loop high-temperature heat exchanger
A magnetohydrodynamic (MHD) power generating system in which ionized combustion gases with slag and seed are discharged from an MHD combustor and pressurized high temperature inlet air is introduced into the combustor for supporting fuel combustion at high temperatures necessary to ionize the combustion gases, and including a heat exchanger in the form of a continuous loop with a circulating heat transfer liquid such as copper oxide. The heat exchanger has an upper horizontal channel for providing direct contact between the heat transfer liquid and the combustion gases to cool the gases and condense the slag which thereupon floats on the heat transfer liquid and can be removed from the channel, and a lower horizontal channel for providing direct contact between the heat transfer liquid and pressurized air for preheating the inlet air. The system further includes a seed separator downstream of the heat exchanger.
Berry, Gregory F. (Naperville, IL); Minkov, Vladimir (Skokie, IL); Petrick, Michael (Joliet, IL)
A magnetohydrodynamic (MHD) power generating system is described in which ionized combustion gases with slag and seed are discharged from an MHD combustor and pressurized high temperature inlet air is introduced into the combustor for supporting fuel combustion at high temperatures necessary to ionize the combustion gases, and including a heat exchanger in the form of a continuous loop with a circulating heat transfer liquid such as copper oxide. The heat exchanger has an upper horizontal channel for providing direct contact between the heat transfer liquid and the combustion gases to cool the gases and condense the slag which thereupon floats on the heat transfer liquid and can be removed from the channel, and a lower horizontal channel for providing direct contact between the heat transfer liquid and pressurized air for preheating the inlet air. The system further includes a seed separator downstream of the heat exchanger.
Berry, G.F.; Minkov, V.; Petrick, M.
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 Transfer Applications for the Stimulated Reservoir Volume
from oil shale. Thermal decomposition of kerogen to oil and gas requires heating the oil shale to 700 degrees F. High quality saturated steam generated using a small scale nuclear plant was used for heating the formation to the necessary temperature...
Thoram, Srikanth
Enhanced heat transfer surface for cast-in-bump-covered cooling surfaces and methods of enhancing heat transfer
An annular turbine shroud separates a hot gas path from a cooling plenum containing a cooling medium. Bumps are cast in the surface on the cooling side of the shroud. A surface coating overlies the cooling side surface of the shroud, including the bumps, and contains cooling enhancement material. The surface area ratio of the cooling side of the shroud with the bumps and coating is in excess of a surface area ratio of the cooling side surface with bumps without the coating to afford increased heat transfer across the element relative to the heat transfer across the element without the coating.
Chiu, Rong-Shi Paul (Glenmont, NY); Hasz, Wayne Charles (Pownal, VT); Johnson, Robert Alan (Simpsonville, SC); Lee, Ching-Pang (Cincinnati, OH); Abuaf, Nesim (Lincoln City, OR)
RELAP5-3D Modeling of Heat Transfer Components (Intermediate Heat Exchanger and Helical-Coil Steam Generator) for NGNP Application
The Next Generation Nuclear Plant project is aimed at the research and development of a helium-cooled high-temperature gas reactor that could generate both electricity and process heat for the production of hydrogen. The heat from the high-temperature primary loop must be transferred via an intermediate heat exchanger to a secondary loop. Using RELAP5-3D, a model was developed for two of the heat exchanger options a printed-circuit heat exchanger and a helical-coil steam generator. The RELAP5-3D models were used to simulate an exponential decrease in pressure over a 20 second period. The results of this loss of coolant analysis indicate that heat is initially transferred from the primary loop to the secondary loop, but after the decrease in pressure in the primary loop the heat is transferred from the secondary loop to the primary loop. A high-temperature gas reactor model should be developed and connected to the heat transfer component to simulate other transients.
N. A. Anderson; P. Sabharwall
Passive heat-transfer means for nuclear reactors. [LMFBR
An improved passive cooling arrangement is disclosed for maintaining adjacent or related components of a nuclear reactor within specified temperature differences. Specifically, heat pipes are operatively interposed between the components, with the vaporizing section of the heat pipe proximate the hot component operable to cool it and the primary condensing section of the heat pipe proximate the other and cooler component operable to heat it. Each heat pipe further has a secondary condensing section that is located outwardly beyond the reactor confinement and in a secondary heat sink, such as air ambient the containment, that is cooler than the other reactor component. By having many such heat pipes, an emergency passive cooling system is defined that is operative without electrical power.
Burelbach, J.P.
and conventional packed-bed lab reactors (m-PBR's). Strong evidence has suggested that the reverse water-gas transport limitations of conventional lab reactors [3,4,5,6]: the fast surface chemistry of the exothermic1 EFFECT OF REACTOR HEAT TRANSFER LIMITATIONS ON CO PREFERENTIAL OXIDATION X. Ouyang, R.S. Besser
Besser, Ronald S.
Heat transfer through a water spray curtain under the effect of a strong radiative source
Heat transfer through a water spray curtain under the effect of a strong radiative source P. Boulet - mail firstname.lastname@example.com Keywords : heat transfer, radiative transfer, vaporization, convection, water spray Abstract Heat transfer inside a participating medium, made of droplets flowing in gas
Heat Transfer from Condensate Droplets Falling through an Immiscible Layer of Tributyl Phosphate
As part of a safety analysis of reactions in two-layer mixtures of nitric acid and tributyl phosphate (TBP), an experiment was conducted to study how steam condensate mixes with the TBP layer when steam passes over a TBP-nitric acid mixture. The experiments showed that the condensate does not form a separate layer on top of the TBP but instead percolates as droplets through the TBP layer. The temperature at the top surface of the TBP layer undergoes a step change increase when the initial condensate droplets reach the surface. Temperatures at the surface and within the TBP and aqueous layers subsequently approach a steady state distribution governed by laminar convection and radiation heat transfer from the vapor space above the two-layer mixture. The rate of temperature increase and the steady state temperature gradient are determined by a characteristic propagation velocity and a streamwise dispersion coefficient for heat transfer. The propagation velocity is the geometric mean of the thermal convection velocities for the organic and aqueous phases, and the dispersion coefficient equals 0.494 times the product of the superficial condensate droplet velocity and the diameter of the test vessel. The value of the dispersion coefficient agrees with the Joshi (1980) correlation for liquid phase backmixing in bubble columns. Transient perturbations occur in the TBP layer temperatures. A Fourier analysis shows that the dominant frequency of these perturbations equals the natural frequency given by the transient heat transfer solution.
Laurinat, James E.
Radiative heat transfer in a hydrous mantle transition zone Sylvia-Monique Thomas a,n
Radiative heat transfer in a hydrous mantle transition zone Sylvia-Monique Thomas a,n , Craig R contribute significantly to heat transfer in the mantle and demonstrate the importance of radiative heat, radiative heat transfer was considered relatively unimportant in the mantle. Earlier experimental work
Jacobsen, Steven D.
Flow and heat transfer of a third grade fluid past an exponentially stretching sheet with
Flow and heat transfer of a third grade fluid past an exponentially stretching sheet with partial-Newtonian boundary layer flow and heat transfer over an exponentially stretch- ing sheet with partial slip boundary. The heat transfer analysis has been carried out for two heating processes, namely (i) with prescribed sur
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.
Molten Glass for Thermal Storage: Advanced Molten Glass for Heat Transfer and Thermal Energy Storage
HEATS Project: Halotechnics is developing a high-temperature thermal energy storage system using a new thermal-storage and heat-transfer material: earth-abundant and low-melting-point molten glass. 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 is 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. Halotechnics new thermal storage material targets a price that is potentially cheaper than the molten salt used in most commercial solar thermal storage systems today. It is also extremely stable at temperatures up to 1200�C�hundreds of degrees hotter than the highest temperature molten salt can handle. Being able to function at high temperatures will significantly increase the efficiency of turning heat into electricity. Halotechnics is developing a scalable system to pump, heat, store, and discharge the molten glass. The company is leveraging technology used in the modern glass industry, which has decades of experience handling molten glass.
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
Determination of temperature-dependent heat conductivity and thermal diffusivity of waste glass melter feed
The cold cap is a layer of reacting glass batch floating on the surface of melt in an all-electric continuous glass melter. The heat needed for the conversion of the melter feed to molten glass must be transferred to and through the cold cap. Since the heat flux into the cold cap determines the rate of melting, the heat conductivity is a key property of the reacting feed. We designed an experimental setup consisting of a large cylindrical crucible with an assembly of thermocouples that monitors the evolution of the temperature field while the crucible is heated at a constant rate. Then we used two methods to calculate the heat conductivity and thermal diffusivity of the reacting feed: the approximation of the temperature field by polynomial functions and the finite-volume method coupled with least-squares analysis. Up to 680�C, the heat conductivity of the reacting melter feed was represented by a linear function of temperature.
Pokorny, Richard; Rice, Jarrett A.; Schweiger, Michael J.; Hrma, Pavel R.
Intraparticle heat and mass transfer characteristics of silica-gel/water vapor adsorption
Recently, highly efficient energy utilization systems which extensively employ adsorption phenomena such as pressure swing adsorption, heat storage, adsorption heat pump, etc. are being regarded as one of the countermeasures for environmental issues such as green house effect and ozone layer destruction. An Adsorption Heat Pump (AHP) has been investigated as one of the important techniques via which cold heat energy is obtained from waste thermal energy below 373K without using electricity and CFCs. An AHP normally consists of an adsorber and an evaporator/condenser and cold heat energy is generated by latent heat of evaporation during adsorption process. For realizing the AHP technology, it has been pointed out that the development of an adsorber with optimum heat and mass transfer characteristics is essentially important. In this study, experimental studies were carried out which was based on the data of temperature inside the adsorbent particle and adsorptivity profiles at the adsorption/desorption process by volumetric method. To clarify adsorption mechanism relatively large silica-gel particle (7 mm f) was used. Temperature distribution in the particle is determined at the center, at one half radius in the radial direction and at the surface by using very thin (30 mm f) thermocouples. The temperatures at these points simultaneously increase/decrease as soon as the adsorption/desorption started, reached their respective maximum/minimum values and then return to initial temperature. The temperature profiles for the adsorption process show that the temperature at the surface is initially slightly higher than the other two points. All three points reached their respective maximum temperature at the same time with the temperature at the center point the highest and at the surface the lowest. The temperature profiles during the desorptive process are almost exactly the opposite to that of the adsorption process. This shows that the adsorption phenomena can take place not only at the surface but inside the adsorbent particle, implying that intraparticle vapor diffusion has a great influence on adsorptivity.
Yamamoto, Eri; Watanabe, Fujio; Hasatani, Masanobu
Heat transfer performance of an external receiver pipe under unilateral concentrated solar radiation
The heat transfer and absorption characteristics of an external receiver pipe under unilateral concentrated solar radiation are theoretically investigated. Since the heat loss ratio of the infrared radiation has maximum at moderate energy flux, the heat absorption efficiency will first increase and then decrease with the incident energy flux. The local absorption efficiency will increase with the flow velocity, while the wall temperature drops quickly. Because of the unilateral concentrated solar radiation and different incident angle, the heat transfer is uneven along the circumference. Near the perpendicularly incident region, the wall temperature and absorption efficiency slowly approaches to the maximum, while the absorption efficiency sharply drops near the parallelly incident region. The calculation results show that the heat transfer parameters calculated from the average incident energy flux have a good agreement with the average values of the circumference under different boundary conditions. For the whole pipe with coating of Pyromark, the absorption efficiency of the main region is above 85%, and only the absorption efficiency near the parallelly incident region is below 80%. In general, the absorption efficiency of the whole pipe increases with flow velocity rising and pipe length decreasing, and it approaches to the maximum at optimal concentrated solar flux. (author)
Jianfeng, Lu; Jing, Ding [School of Engineering, Sun Yat-Sen University, Guangzhou 510006 (China); Jianping, Yang [Key Laboratory of Enhanced Heat Transfer and Energy Conservation of the Ministry of Education, South China University of Technology, Guangzhou 510640 (China)
Convective heating analysis of an IFE target in a high temperature, low Reynolds number xenon environment
E. M. Sparrow. "Heat Transfer From an Open- or Closed-Boreat differences in heat transfer of open- and closed-bore
Holdener, Dain Steffen
Predictive control of supply temperature in district heating systems
Predictive control of supply temperature in district heating systems Torben Skov Nielsen Henrik This report considers a new concept for controlling the supply temperature in district heating systems using stochastic modelling, prediction and control. A district heating systems is a di#30;cult system to control
CONTROL OF SUPPLY TEMPERATURE IN DISTRICT HEATING SYSTEMS T.S. Nielsen, H. Madsen Informatics the supply temperature in district heating systems using stochastic modelling, prediction and control at Roskilde Varmeforsyning. The results obtained for the Roskilde district heating utility are evaluated
E-Print Network 3.0 - accurate heat transfer Sample Search Results
Pennsylvania State University Collection: Engineering 11 Boiling heat transfer in a hydrofoil-based micro pin fin heat sink Summary: in large scatter and were not able to...
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.
Conjugate heat transfer and particle transport in outside vapor deposition process
A numerical study of conjugate heat transfer and particle transport has been carried out for the outside vapor deposition process. A buoyant jet flow impinging on a two-layered cylinder has been analyzed including heat conduction occurring through the two-layered cylinder, which consists of the original target rod and the deposited porous layers. Temperature and flow fields have been obtained by an iterative method, and thermophoretic particle deposition has been studied. Of particular interest are the effects of the thickness of deposited layers, the torch speed, the rotation speed of the cylinder, and the distance between the torch and the cylinder on the heat transfer and particle deposition. Effects of variable properties and tube rotation are also included.
Choi, M.; Song, Y.; Kang, S.H. [Seoul National Univ., Seoul (Korea, Republic of). Dept. of Mechanical Engineering
In the United States, commercial spent nuclear fuel is typically moved from spent fuel pools to outdoor dry storage pads within a transfer cask system that provides radiation shielding to protect personnel and the surrounding environment. The transfer casks are cylindrical steel enclosures with integral gamma and neutron radiation shields. Since the transfer cask system must be passively cooled, decay heat removal from spent nuclear fuel canister is limited by the rate of heat transfer through the cask components, and natural convection from the transfer cask surface. The primary mode of heat transfer within the transfer cask system is conduction, but some cask designs incorporate a liquid neutron shield tank surrounding the transfer cask structural shell. In these systems, accurate prediction of natural convection within the neutron shield tank is an important part of assessing the overall thermal performance of the transfer cask system. The large-scale geometry of the neutron shield tank, which is typically an annulus approximately 2 meters in diameter but only 10-15 cm in thickness, and the relatively small scale velocities (typically less than 5 cm/s) represent a wide range of spatial and temporal scales that contribute to making this a challenging problem for computational fluid dynamics (CFD) modeling. Relevant experimental data at these scales are not available in the literature, but some recent modeling studies offer insights into numerical issues and solutions; however, the geometries in these studies, and for the experimental data in the literature at smaller scales, all have large annular gaps that are not prototypic of the transfer cask neutron shield. This paper proposes that there may be reliable CFD approaches to the transfer cask problem, specifically coupled steady-state solvers or unsteady simulations; however, both of these solutions take significant computational effort. Segregated (uncoupled) steady state solvers that were tested did not accurately capture the flow field and heat transfer distribution in this application. Mesh resolution, turbulence modeling, and the tradeoff between steady state and transient solutions are addressed. Because of the critical nature of this application, the need for new experiments at representative scales is clearly demonstrated.
Fort, James A.; Cuta, Judith M.; Bajwa, C.; Baglietto, E.
A visualization comparison of convective flow boiling heat transfer augmentation devices
The qualitative effects of inset-table heat transfer phics. augmentation devices on vertical in-tube convective flow boiling flow regimes, transition mechanisms, and heat transfer are presented in this study. Three twisted tapes with twist ratios...
Lundy, Brian Franklin
Heat transfer rates for filmwise, dropwise, and superhydrophobic condensation on silicon substrates
Condensation, a two-phase heat transfer processes, is commonly utilized in industrial systems. Condensation heat transfer can be optimized by using surfaces in which dropwise condensation (DWC) occurs, and even further ...
Hery, Travis M
FALL 2011 EMEC 326 DR. RUHUL AMIN HEAT TRANSFER 201 C Roberts Hall
FALL 2011 EMEC 326 DR. RUHUL AMIN HEAT TRANSFER 201 C Roberts Hall Phone: 994-6295 POLICY STATEMENT, convection, and radiation formulations. Introduction to heat transfer equipment. Course credit: 4
Modeling of fuel-to-steel heat transfer in core disruptive accidents
A mathematical model for direct-contact boiling heat transfer between immiscible fluids was developed and tested experimentally. The model describes heat transfer from a hot fluid bath to an ensemble of droplets of a cooler ...
Smith, Russell Charles
Heat transfer during film condensation of potassium vapor on a horizontal plate
The object of the investigation is to analyze the following two features of heat transfer during condensation of potassium vapor: a. Heat transfer during film condensation of a pure saturated potassium vapor on a horizontal ...
Meyrial, Paul M.
Remote administration and user experience evaluation of the iLab Heat Transfer Project site
The iLab Heat Transfer Project provides a means for students to remotely execute, via a web interface, experiments related to the topic of heat transfer. The website associated with this project provides instructors with ...
Graham, Rodney K
A numerical model of convective heat transfer in a three dimensional channel with baffles
to minimize the effects of the temperature. Chandrupatla and Sastri (1977) used a finite difference method to study laminar heat transfer and fluid flow for Non-Newtonian fluids. In the limiting case of Newtonian fluids their results showed good agreement... and Sastri (1977) for developing laminar flow in a rectangular smooth channel. Figure 4. 1 shows the numerically predicted centerline axial velocity compared with the experimental data of Goldstein and Kreid (1967). The agreement between the numerical...
Lopez Buso, Jorge Ricardo
An experimental investigation of turbine blade heat transfer and turbine blade trailing edge cooling
studies have investigated the fluid flow and heat transfer behavior in high Reynolds number flows. Blair [7,8] investigated the effect of grid generated turbulence on flat plate heat transfer. He showed that turbulent heat transfer coefficient in flow... AN EXPERIMENTAL INVESTIGATION OF TURBINE BLADE HEAT TRANSFER AND TURBINE BLADE TRAILING EDGE COOLING A Dissertation by JUNGHO CHOI Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment...
Choi, Jungho
Heat transfer enhancement in a channel with porous baffles
with staggered positioned porous baffles. A numerical procedure was implemented, in conjunction with a commercially available Navier-Stokes solver, to model the turbulent flow in porous media. The Brinkman-Forchheimer-Extended Darcy model was used for modeling... fluid flow through the porous baffles. Conventional, one- equation, and two-equation models were used for heat transfer modeling. The accuracy and characteristics of each model were investigated and discussed. The results were compared...
Ko, Kang-Hoon
Shape-independent limits to near-field radiative heat transfer
We derive shape-independent limits to the spectral radiative heat-transfer rate between two closely spaced bodies, generalizing the concept of a black body to the case of near-field energy transfer. By conservation of energy, we show that each body of susceptibility $\\chi$ can emit and absorb radiation at enhanced rates bounded by $|\\chi|^2 / \\operatorname{Im} \\chi$, optimally mediated by near-field photon transfer proportional to $1/d^2$ across a separation distance $d$. Dipole--dipole and dipole--plate structures approach restricted versions of the limit, but common large-area structures do not exhibit the material enhancement factor and thus fall short of the general limit. By contrast, we find that particle arrays interacting in an idealized Born approximation exhibit both enhancement factors, suggesting the possibility of orders-of-magnitude improvement beyond previous designs and the potential for radiative heat transfer to be comparable to conductive heat transfer through air at room temperature, and s...
Miller, Owen D; Rodriguez, Alejandro W
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
Experimental investigation on heat transfer and frictional characteristics of vertical upward rifled tube in supercritical CFB boiler
Water wall design is a key issue for supercritical Circulating Fluidized Bed (CFB) boiler. On account of the good heat transfer performance, rifled tube is applied in the water wall design of a 600 MW supercritical CFB boiler in China. In order to investigate the heat transfer and frictional characteristics of the rifled tube with vertical upward flow, an in-depth experiment was conducted in the range of pressure from 12 to 30 MPa, mass flux from 230 to 1200 kg/(m{sup 2} s), and inner wall heat flux from 130 to 720 kW/m{sup 2}. The wall temperature distribution and pressure drop in the rifled tube were obtained in the experiment. The normal, enhanced and deteriorated heat transfer characteristics were also captured. In this paper, the effects of pressure, inner wall heat flux and mass flux on heat transfer characteristics are analyzed, the heat transfer mechanism and the frictional resistance performance are discussed, and the corresponding empirical correlations are presented. The experimental results show that the rifled tube can effectively prevent the occurrence of departure from nucleate boiling (DNB) and keep the tube wall temperature in a permissible range under the operating condition of supercritical CFB boiler. (author)
Yang, Dong; Pan, Jie; Zhu, Xiaojing; Bi, Qincheng; Chen, Tingkuan [State Key Laboratory of Multiphase Flow in Power Engineering, Xi'an Jiaotong University, Xi'an 710049 (China); Zhou, Chenn Q. [Department of Mechanical Engineering, Purdue University Calumet, Hammond, IN 46323 (United States)
Heat transfer and pollutant formation mechanisms in insulated combustion chambers
The authors have studied the quenching situation as it can be found in constant volume combustion chambers for a methane flame over a range of wall temperatures between 300 K and 600 K using Direct Numerical Simulation. To do this, the authors solved the fully compressible, one-dimensional Navier-Stokes equations with detailed mechanisms for kinetics and diffusion. This approach allows to compare various reaction schemes, to identify the most important species and reaction paths, and to investigate the influence of different modeling assumptions. The computational results show that the dimensional wall heat flux increases with wall temperature over the whole range of wall temperatures studied; this agrees well with the most recent measurements in a strongly improved experimental setup. It is found that the wall can be modeled as chemically inert and thermal diffusion processes are negligible for low wall temperatures between 300 K and 400 K. However, at higher temperatures, due to a dramatically increasing radical concentration (H, Oh, OH) at the wall, both become increasingly important leading to large heat release rates directly at the metallic wall surface of the combustion chamber, and can thus not be neglected in the modeling of the quenching process. Furthermore, these high radical concentrations adjacent to the wall indicate that the uncertainties in wall heat flux measurements at high wall temperatures could be underestimated by the experimentalists. The UHC concentration at a wall temperature of 600 K is about 20 times smaller than for 300 K after quenching. 37 refs., 12 figs., 1 tab.
Popp, P.; Baum, M.
A high temperature gas reactor, HTGR, can produce industrial process steam, high-temperature heat-transfer gases, and/or electricity. In conventional industrial processes, these products are generated by the combustion of fossil fuels such as coal and natural gas, resulting in significant emissions of greenhouse gases such as carbon dioxide. Heat or electricity produced in an HTGR could be used to supply process heat or electricity to conventional processes without generating any greenhouse gases. Process heat from a reactor needs to be transported by a gas to the industrial process. Two such gases were considered in this study: helium and steam. For this analysis, it was assumed that steam was delivered at 17 MPa and 540 C and helium was delivered at 7 MPa and at a variety of temperatures. The temperature of the gas returning from the industrial process and going to the HTGR must be within certain temperature ranges to maintain the correct reactor inlet temperature for a particular reactor outlet temperature. The returning gas may be below the reactor inlet temperature, ROT, but not above. The optimal return temperature produces the maximum process heat gas flow rate. For steam, the delivered pressure sets an optimal reactor outlet temperature based on the condensation temperature of the steam. ROTs greater than 769.7 C produce no additional advantage for the production of steam.
Michael G. McKellar
Hypersonic Heat Transfer and Anisotropic Visualization with a Higher Order Discontinuous Galerkin Finite Element Method
Hypersonic Heat Transfer and Anisotropic Visualization with a Higher Order Discontinuous Galerkin;Hypersonic Heat Transfer and Anisotropic Visualization with a Higher Order Discontinuous Galerkin Finite used to predict heat transfer to a cylinder in a hypersonic flow. The strong shock is captured
Peraire, Jaime
Heat Transfer on a Hypersonic Sphere with Gas Injection Vladimir V. Riabov
Heat Transfer on a Hypersonic Sphere with Gas Injection Vladimir V. Riabov Department be considered as an effective way of the reduction of heat transfer to the surface in this area [1 the viscous layer is blown completely off the surface, and heat transfer is zero. The effect of injecting
Riabov, Vladimir V.
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 the dynamical effects from the heat transfer process. The fluid flow in an enclosed disk system with axial with heat transfer along the stator, which corresponds to the experiment of Djaoui et al. [2]. Our results
Boyer, Edmond
Numerical computation of 3D heat transfer in complex parallel convective exchangers using generalized Graetz modes
Numerical computation of 3D heat transfer in complex parallel convective exchangers using insights into the most con- tributing structure to exchanges and transfers. Several examples of heat, whilst many other can be found in a recent review [12]. As quoted in [12] conjugate heat transfer
Heat Transfer Engineering, 29(9):793804, 2008 Copyright C Taylor and Francis Group, LLC
Heat Transfer Engineering, 29(9):793804, 2008 Copyright C Taylor and Francis Group, LLC ISSN: 0145 for Laminar and Turbulent Flow Convection Heat Transfer in a Horizontal Tube Using Artificial Neural Network was used to develop empirical correlations for laminar and turbulent heat transfer in a horizontal tube
Surface-Phonon Polariton Contribution to Nanoscale Radiative Heat Transfer. Emmanuel Rousseau
Surface-Phonon Polariton Contribution to Nanoscale Radiative Heat Transfer. Emmanuel Rousseau-sud Campus Polytechnique RD 128 91127 Palaiseau cedex, France Heat transfer between two plates of polar far-field value. In this article, we show that nanoscale heat transfer is dominated by the coupling
SINGLE-PHASE LIQUID HEAT TRANSFER IN PLAIN AND ENHANCED MICROCHANNELS Mark E. Steinke
SINGLE-PHASE LIQUID HEAT TRANSFER IN PLAIN AND ENHANCED MICROCHANNELS Mark E. Steinke Systems upon the understanding of the fundamental heat transfer processes that occur in these systems. There have been great advancements in our understanding of the heat transfer and fluid flow mechanisms
A Scaleless Snake: Tests of the Role of Reptilian Scales in Water Loss and Heat Transfer
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Bennett, Albert F.
Numeric Simulation of Heat Transfer and Electrokinetic Flow in an Electroosmosis-Based
Numeric Simulation of Heat Transfer and Electrokinetic Flow in an Electroosmosis-Based Continuous is dedicated to under- standing the fluid flow and heat transfer mechanisms occurring in continuous flow PCR are discussed in detail. The importance of each heat transfer mechanism for different situations is also
Le Roy, Robert J.
Assignment 6: Heat Transfer Page 1 of 8 600.112: Introduction to Programming
Assignment 6: Heat Transfer Page 1 of 8 600.112: Introduction to Programming for Scientists and Engineers Assignment 6: Heat Transfer Peter H. Fr¨ohlich firstname.lastname@example.com Joanne Selinski joanne to Programming for Scientists and Engineers is all about heat transfer and how to simulate it. There are three
Fröhlich, Peter
Heat transfer in soft nanoscale interfaces: the influence of interface curvature
Heat transfer in soft nanoscale interfaces: the influence of interface curvature Anders Lervik transient non-equilibrium molecular-dynamics simulations, heat-transfer through nanometer-scale interfaces processes. We show that the modeling of heat transfer across a nanodroplet/fluid interface requires
Convective heat transfer as a function of wavelength: Implications for the cooling of the Earth
Convective heat transfer as a function of wavelength: Implications for the cooling of the Earth C, in particular, on its variation with the wavelength of convection. The heat transfer strongly depends in Earth's mantle can significantly reduce the efficiency of heat transfer. The likely variations
Proceedings of HT2007 2007 ASME-JSME Thermal Engineering Summer Heat Transfer Conference
Proceedings of HT2007 2007 ASME-JSME Thermal Engineering Summer Heat Transfer Conference July 8-12, 2007, Vancouver, British Columbia, CANADA HT2007-32219 VALIDATION OF A GENERAL HEAT TRANSFER, Stillwater, OK 74078, USA E-mail: email@example.com ABSTRACT A general heat transfer correlation
MHD EFFECTS ON HEAT TRANSFER IN A MOLTEN SALT BLANKET Sergey Smolentsev, Reza Miraghaie, Mohamed Abdou
MHD EFFECTS ON HEAT TRANSFER IN A MOLTEN SALT BLANKET Sergey Smolentsev, Reza Miraghaie, Mohamed-mail (Sergey Smolentsev): firstname.lastname@example.com Heat transfer in closed channel flows of molten salts (MS of the concept is that the flows in the FW channels are turbulent to provide a high heat transfer coefficient
Abdou, Mohamed
Finite element solutions of heat transfer in molten polymer flow in tubes with viscous dissipation
Finite element solutions of heat transfer in molten polymer flow in tubes with viscous dissipation the results of finite element analysis of a heat transfer problem of flowing polymer melts in a tubeNusselt problem 1. Introduction Heat transfer to incompressible viscous non-Newto- nian fluids is a problem
Wei, Dongming
FliHy experimental facilities for studying open channel turbulent flows and heat transfer
FliHy experimental facilities for studying open channel turbulent flows and heat transfer B. Freeze) facility was constructed at UCLA to study open channel turbulent flow and heat transfer of low supercritical flow regimes (Fr /1), in which the surface waves are amplified and heat transfer is enhanced due
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
Convective heat transfer characteristics of China RP-3 aviation kerosene at supercritical pressure
Convective heat transfer characteristics of China RP-3 aviation kerosene at supercritical pressure Keywords: Supercritical pressure Aviation kerosene Convective heat transfer Numerical study a b s t r a c convective in kerosene pipe flow is complicated. Here the convective heat transfer characteristics of China
Heat Transfer Engineering, 27(5):2338, 2006 Copyright C Taylor and Francis Group, LLC
Heat Transfer Engineering, 27(5):2338, 2006 Copyright C Taylor and Francis Group, LLC ISSN: 0145-7632 print / 1521-0537 online DOI: 10.1080/01457630600559538 Transitional Heat Transfer in Plain Horizontal, Oklahoma, USA In this study, the heat transfer behavior in the transition region for plain horizontal tubes
Friction and Heat Transfer Characteristics of Silica and CNT Nanofluids in a Tube Flow
Friction and Heat Transfer Characteristics of Silica and CNT Nanofluids in a Tube Flow MILIVOJE email@example.com * www.kostic.niu.edu Abstract: - An apparatus for exploring friction and heat transfer characteristics flow. Initial turbulent friction and heat transfer measurements for silica and carbon nanotube (CNT
Kostic, Milivoje M.
Heat Transfer Engineering, 28(6):525540, 2007 Copyright C Taylor and Francis Group, LLC
Heat Transfer Engineering, 28(6):525540, 2007 Copyright C Taylor and Francis Group, LLC ISSN: 0145-7632 print / 1521-0537 online DOI: 10.1080/01457630701193906 Heat Transfer Measurements, Flow Pattern Maps, Stillwater, Oklahoma, USA Local heat transfer coefficients and flow parameters were measured for air
1 FLIHY EXPERIMENTAL FACILITIES FOR STUDYING OPEN CHANNEL TURBULENT FLOWS AND HEAT TRANSFER B was constructed at UCLA to study open channel turbulent flow and heat transfer of low-thermal and low supercritical flow regimes (Fr>1), in which the surface waves are amplified and heat transfer is enhanced due
California at Los Angeles, University of
On the Effect of Porous Layers on Melting Heat Transfer in an Enclosure
On the Effect of Porous Layers on Melting Heat Transfer in an Enclosure E. A. Ellinger* and C. To enhance heat transfer, the porous layers are located in regions where the melting rates for a pure the porous layer and the pure fluid layer cause strong variations in heat transfer, melt convection
Beckermann, Christoph
Flow Boiling Heat Transfer Coefficient In Minichannels Correlation and Trends Satish G. Kandlikar
Flow Boiling Heat Transfer Coefficient In Minichannels Correlation and Trends Satish G. Kandlikar York 14623, USA The flow boiling heat transfer in small diameter passages is being applied in many boiling heat transfer coefficient with the correlations developed for conventional channels. It is found
Nanoscale Heat Transfer at Contact Between a Hot Tip and a Substrate Stphane Lefvre
Nanoscale Heat Transfer at Contact Between a Hot Tip and a Substrate Stéphane Lefèvre Laboratoire d three heat transfer modes with experimental data and modeling. We conclude that the three modes in "International Journal of Heat and Mass Transfer 49, 1-2 (2006) 251-258" DOI : 10.1016/j.ijheatmasstransfer.2005
Heat transfer from multiple row arrays of low aspect ratio pin fins Seth A. Lawson a,
Heat transfer from multiple row arrays of low aspect ratio pin fins Seth A. Lawson a, , Alan A 18 March 2011 Available online 5 May 2011 Keywords: Pin fins Heat transfer augmentation Array to enhance heat transfer. In modern gas turbines, for exam- ple, airfoils are designed with sophisticated
The Influence of Heat Transfer Irreversibilities on the Optimal Performance of Diabatic
The Influence of Heat Transfer Irreversibilities on the Optimal Performance of Diabatic is only slightly dependent on the heat transfer law considered. In the limit of an infinite number of trays even this column with resistance to transfer of heat becomes reversible. 1 #12;Keywords Diabatic
Salamon, Peter
Accepted Manuscript A wall heat transfer correlation for the baffled-rotary kilns with secondary air
Accepted Manuscript A wall heat transfer correlation for the baffled-rotary kilns with secondary;1 A wall heat transfer correlation for the baffled- rotary kilns with secondary air flow and recycled industrial applications suggests examining the heat transfer phenomena in order to improve the multi
HEAT TRANSFER ON A HYPERSONIC SPHERE WITH DIFFUSE RAREFIED-GAS INJECTION Vladimir V. Riabov* Rivier numbers Re0,R.3-7 Mass injection can be considered as an effective way of the reduction of heat transfer in the case of small Reynolds numbers. Moss12 found that mass injection dramatically reduces heat transfer
1 HEAT TRANSFERS IN A DOUBLE SKIN ROOF VENTILATED BY NATURAL CONVECTION IN SUMMER TIME P. H or in tropical and arid countries. In this work, radiation, convection and conduction heat transfers-dimensional numerical simulation of the heat transfers through the double skin reveals the most important parameters
Numerical simulations of heat transfer in plane channel flow Najla EL GHARBI 1, 3, a
Numerical simulations of heat transfer in plane channel flow Najla EL GHARBI 1, 3, a , Rafik ABSI 2 email@example.com Keywords: turbulent flows, heat transfer, forced convection, low Reynolds number model data for Re = 150. Introduction Turbulent flow with heat transfer mechanism is of great importance from
Heat transfer and friction characteristics of air flow in microtubes Chien-Yuh Yang a,
Heat transfer and friction characteristics of air flow in microtubes Chien-Yuh Yang a, , Chia September 2011 Keywords: Microtube Heat transfer Liquid Crystal Thermography a b s t r a c t Several researches dealing with the single-phase forced convection heat transfer inside microchannels have been
Two-Dimensional Computational Fluid Dynamics and Conduction Simulations of Heat Transfer in Window Frames
1 Two-Dimensional Computational Fluid Dynamics and Conduction Simulations of Heat Transfer Arasteh and Dragan Curcija ABSTRACT Accurately analyzing heat transfer in window frame cavities radiation heat-transfer effects.) We examine three representative complex cavity cross-section profiles
Int. Symp. on Heat Transfer in Gas Turbine Systems 9 14 August, 2009, Antalya, Turkey
Int. Symp. on Heat Transfer in Gas Turbine Systems 9 14 August, 2009, Antalya, Turkey EXPERIMENTAL TURBINE AERO-HEAT TRANSFER STUDIES IN ROTATING RESEARCH FACILITIES Cengiz Camci Turbomachinery Aero-Heat Transfer Laboratory Department of Aerospace Engineering The Pennsylvania State University 233
Global weak solutions to magnetic fluid flows with nonlinear Maxwell-Cattaneo heat transfer law
Global weak solutions to magnetic fluid flows with nonlinear Maxwell-Cattaneo heat transfer law F transfer in a magnetic fluid flow under the action of an applied magnetic field. Instead of the usual heat-Cattaneo law, heat transfer, magnetic field, magnetization AMS subject classifications: 76N10, 35Q35. 1
Radiative heat transfer at nanoscale mediated by surface plasmons for highly doped Emmanuel Rousseau
Radiative heat transfer at nanoscale mediated by surface plasmons for highly doped silicon the role of surface plasmons for nanoscale radiative heat transfer between doped silicon surfaces. We derive a new accurate and closed-form expression of the radiative near- field heat transfer. We also
Calculating Radiative Heat Transfer in an Axisymmetric Closed Chamber: An Application
Calculating Radiative Heat Transfer in an Axisymmetric Closed Chamber: An Application to Crystal University of New York at Stony Brook Stony Brook N.Y. 11794 ABSTRACT Radiative heat transfer plays simulating radiative heat transfer in the crystal and in the region above the melt containing gas under
New York at Stoney Brook, State University of
The effects of topology upon fluid-flow and heat-transfer within cellular copper structures
and packed beds, but also a function of orientation (open area ratio). The overall heat transfer dependsThe effects of topology upon fluid-flow and heat-transfer within cellular copper structures J. Tian February 2004 Available online 20 March 2004 Abstract The fluid-flow and heat-transfer features of cellular
Wadley, Haydn
A FAST MULTILEVEL ALGORITHM FOR THE SOLUTION OF NONLINEAR SYSTEMS OF CONDUCTIVERADIATIVE HEAT TRANSFER EQUATIONS \\Lambda
differential equations that model steadystate combined conductiveradiative heat transfer. This system of equationsBrakhage algorithm. Key words. conductiveradiative heat transfer, multilevel algorithm, compact fixed point problems integrodifferential equations that model steadystate combined conductiveradiative heat transfer
Pool boiling heat transfer enhancement over cylindrical tubes with water at atmospheric pressure, Part I: Experimental results
Pool boiling heat transfer enhancement over cylindrical tubes with water at atmospheric pressure online 4 May 2013 Keywords: Pool boiling Heat transfer enhancement Open microchannels Cylindrical tube boiling heat transfer over enhanced cylindrical microchannel test surfaces with water at atmospheric
Convective heat transfer on leeward building walls in an urban environment: Measurements in an outdoor scale model
surface, Proc. 5 th Int. Heat Transfer Conf. 3 (1974) 129-a vertical plate, J. Heat Transfer 109(1) [13] K. Patel,Experimental study of heat transfer in turbulent flows over
Nottrott, A.; Onomura, S.; Inagaki, A.; Kanda, M.; Kleissl, J.
Indirect Heat Transfer Technology For Waste Heat Recovery Can Save You Money
-drllt fIn lb. FI~-to_heot-roccvery .ylt8m Stoek gl' ..---::-----'1 _._.__.@_.; -+ Farcod?drall fan le. Air-prohe8ting syotem UBing I ....Hransfer ayltem Three typical arrangements for recovering waste heat from furnace flue gas Fig. 1 *Trademark... heat transfer fluid and thence to selected heat "user" sites (Figure 1C). This basic method often offers an attractive investment return, particu larly in applications where stack gas exit tempera tures exceed 316?C (600?F) and the furnace duty...
Beyrau, J. A.; Bogel, N. G.; Seifert, W. F.; Wuelpern, L. E.
Thermo-mechanical simulations in double-sided heat transfer power assemblies.
Thermo-mechanical simulations in double-sided heat transfer power assemblies. E. Woirgard; I. Favre In power assemblies, heat transfer due to the die self- heating is one of the most important point on time life assemblies. Heat has to be evacuated toward the base- plate not to weaken the solder joint under
The primary objective of the present work is to perform a heat balance study for type-I waste tank to assess the impact of using submersible mixer pumps during waste removal. The temperature results calculated by the model will be used to evaluate the temperatures of the slurry waste under various tank operating conditions. A parametric approach was taken to develop a transient model for the heat balance study for type-I waste tanks such as Tank 11, during waste removal by SMP. The tank domain used in the present model consists of two SMP?s for sludge mixing, one STP for the waste removal, cooling coil system with 36 coils, and purge gas system. The sludge waste contained in Tank 11 also has a decay heat load of about 43 W/m{sup 3} mainly due to the emission of radioactive gamma rays. All governing equations were established by an overall energy balance for the tank domain, and they were numerically solved. A transient heat balance model used single waste temperature model, which represents one temperature for the entire waste liquid domain contained in the tank at each transient time.
Lee, S.
The convergence of an explicit finite difference solution for transient heat transfer in solids with radiation at one boundary
at the Interior Point 'n ' 17 8 ? 01 Temperature Resp C 2'( C 1, Wi Constant Tempera x = L, and Havin Transfer to a He Degree Absolute Calculated With Modulus as Per S at x/L = 0. 0 onse th a ture g Ra at S Temp a Mr tabi of Hea at dian ink.... The Fourier equation for one? dimensional heat conduction in solids with constant physical properties is BT K 0 T Qe gC Q~x (3 ? 01) The net radiant heat transfer rate between two gray bodies A and B at absolute temperature T and T will be B according...
Patel, Bhagubhai Desaibhai
Barr and Showman: Heat Transfer in Europa's Icy Shell 405 Heat Transfer in Europa's Icy Shell
Europa's ice shell controls the thermal evolution of its interior and provides a source of energy surface features with steady-state thermal convection is challeng- ing, even with tidal heating, because convects, can the ocean be thermodynamically stable? What role might compositional heterogeneity play
Boise City Geothermal District Heating District Heating Low Temperatur...
66.20x109 Btuyr 19.40 GWhyr Delat T 53.00 F Load Factor 0.07 Contact Kent Johnson; 208-384-3926 References Oregon Institute of Technology's Geo-Heat Center1 Boise...
Prediction of heat transfer for a supercritical water test with a four pin fuel bundle
As a next step to validate prediction methods for core design of a Supercritical Water Cooled Reactor, a small, electrically heated fuel bundle with 4 pins is planned to be tested. This paper summarizes first heat transfer predictions for such a test, which were performed based on supercritical and subcritical sub-channel analyses. For heat transfer under supercritical pressure conditions, the sub-channel code STAFAS has been applied, which had been tested successfully already for a supercritical water reactor design. Design studies with different assembly box sizes at a given pin diameter and pitch have been performed to optimize the coolant temperature distribution. With a fuel pin outer diameter of 10 mm and a pitch to diameter ratio of 1.15, an optimum inner width of the assembly box was determined to be 24 mm. Coolant and cladding surface temperatures to be expected at subcritical pressure conditions have been predicted with the sub-channel code MATRA. As, different from typical PWR or BWR conditions, a dryout has been foreseen for the tests, this code had to be extended to include suitable dryout criteria as well as post dryout heat transfer correlations at higher enthalpies and pressures. Different from PWR or BWR design, the cladding surface temperature of fuel pins in supercritical water reactors can vary significantly around the circumference of each pin, causing bending towards its hotter side which, in turn, can cause additional sub-channel heat-up and thus additional thermal bending of the pin. To avoid a thermal instability by this effect, a sensitivity study with respect to thermal bending of fuel pins has been performed, which determines the minimum number of grid spacers needed for this test. (authors)
Behnke, L. [RWE Power AG, Essen (Germany); Himmel, S.; Waata, C.; Schulenberg, T. [Forschungszentrum Karlsruhe GmbH, Institute for Nuclear and Energy Technologies, PO Box 3640, D-76021 Karlsruhe (Germany); Laurien, E. [University of Stuttgart (Germany)
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
An analysis of a reversed absorption heat pump for low temperature waste heat utilization
AN ANALYSIS OF A REVERSED ABSORPTION HEAT PUMP FOR LOW TEMPERATURE WASTE HEAT UTILIZATION A Thesis by GLENN WILLIAM WADE Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement for the degree... of MASTER OF SCIENCE May 1979 Major Subject: Mechanical Engineering AN ANALYSIS OF A REVERSED ABSORPTION HEAT PUMP FOR LOW TEMPERATURE WASTE HEAT UTILIZATION A Thesis by GLENN WILLIAM WADE Approved as to style and content by: Chai n of Committee...
Wade, Glenn William
Low exhaust temperature electrically heated particulate matter filter system
A system includes a particulate matter (PM) filter, a sensor, a heating element, and a control module. The PM filter includes with an upstream end that receives exhaust gas, a downstream end and multiple zones. The sensor detects a temperature of the exhaust gas. The control module controls current to the heating element to convection heat one of the zones and initiate a regeneration process. The control module selectively increases current to the heating element relative to a reference regeneration current level when the temperature is less than a predetermined temperature.
Gonze, Eugene V. (Pinckney, MI); Paratore, Jr., Michael J. (Howell, MI); Bhatia, Garima (Bangalore, IN)
Heat Transfer -2 A long copper wire is used to carry an electric current and has an electrical resistance of 0.4 ohm
Heat Transfer - 2 A long copper wire is used to carry an electric current and has an electrical the electrical heat generation per length of wire (W/m) when current is 170 A. c) (10 pts) Find the steady state temperature of the wire for b). d) (10 pts) Find the electrical heat generation per length of wire (W/m) when
Low GWP Working Fluid for High Temperature Heat Pumps
Low GWP Working Fluid for High Temperature Heat Pumps: DR-2 Chemical Stability at High Temperatures Temp Heat Pumps: DR-2 Very Low GWP AND Non-Flammable HFC-245fa DR-2 Chemical Formula CF3CH2CHF2 HFO 171.3 Pcr [MPa] 3.65 2.9 Kontomaris-DuPont; European Heat Pump Summit, Nuremberg, October 15th, 2013
Heat pump augmented radiator for low-temperature space applications
Closed-cycle, space-based heat rejection systems depend solely on radiation to achieve their heat dissipation function. Since the payload heat rejection temperature is typically 50 K above that of the radiation sink in near earth orbit, the size and mass of these systems can be appreciable. Size (and potentially mass) reductions are achievable by increasing the rejection temperature via a heat pump. Two heat pump concept were examined to determine if radiator area reductions could be realized without increasing the mass of the heat rejection system. The first was a conventional, electrically-driven vapor compression system. The second is an innovative concept using a solid-vapor adsorption system driven by reject heat from the prime power system. The mass and radiator area of the heat pumpradiator systems were compared to that of a radiator only system to determine the merit of the heat pump concepts. Results for the compressor system indicated that the mass minimum occured at a temperature lift of about 50 K and radiator area reductions of 35% were realized. With a radiator specific mass of 10 kgm/sup 2/, the heat pump system is 15% higher than the radiator only baseline system. The complex compound chemisorption systems showed more promising results. Using water vapor as the working fluid in a single stage heat amplifier resulted in optimal temperature lifts exceeding 150 K. This resulted in a radiator area reduction of 83% with a mass reduction of 64%. 7 refs., 9 figs.
Olszewski, M.; Rockenfeller, U.
Flexible profile approach to the conjugate heat transfer problem
The flexible profile approach proposed earlier to create CTM (compact or reduced order thermal models) is extended to cover the area of conjugate heat transfer. The flexible profile approach is a methodology that allows building a highly boundary conditions independent CTM, with any desired degree of accuracy, that may adequately replace detailed 3D models for the whole spectrum of applications in which the modeled object may be used. The extension to conjugate problems radically solves the problem of interfacing two different domains. Each domain, fluid or solid, can be "compacted" independently creating two CTM that can be joined together to produce reliable results for any arbitrary set of external boundary conditions.
M. -N. Sabry
Grid-independent Issue in Numerical Heat Transfer
Grid independent is associated with the accuracy or even rationality of numerical results. This paper takes two-dimensional steady heat transfer for example to reveal the effect of grid resolution on numerical results. The law of grid dependence is obtained and a simple mathematical formula is presented. The production acquired here can be used as the guidance in choosing grid density in numerical simulation and get exact grid independent value without using infinite fine grid. Through analyzing grid independent, we can find the minimum number of grid cells that is needed to get grid-independent results. Such strategy can save computational resource while ensure a rational computational result.
Yao Wei; Wang Jian; Liao Guangxuan
Heat Transfer in GE Jet Engines | GE Global Research
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 MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsingFun with Bigfront.jpgcommunity200cellHeat Transfer in GE Jet Engines Click to
Effects of slitted fins on the heat transfer and pressure drop characteristics of a compact heat exchanger
A compact heat exchanger which consists of air-cooled aluminum fins and copper tubes circulating refrigerant has been used in a cooling system for a long time. There are two key parameters to be seriously considered for a design of the heat exchanger and its performance improvement. These are the heat transfer rate and pressure drop coefficient which varies with the change of the tube size, its arrangement and the fin configuration. In here, a numerical study was carried to understand the effect of the fin configuration on the heat transfer and pressure drop of the heat exchanger. The diameter and the arrangement of tubes were fixed but three different types of the fin configuration were used to see its effect on the heat transfer capacity and the static pressure drop. The calculation results were compared with that of a flat plate fin. From the comparison, it was found that the slitted fins have higher pressure drop; however, they have higher heat transfer rate. It means that the simpler of the fin configuration, the lower pressure drop and heat transfer coefficients are obtained. It is mainly due to the discretisation of the thermal boundary layer on the fin surface to maximize the heat transfer to air. The slitted sides of fins act like obstacles in the airflow path. From the experimental result, it was found that the same trend in the variation of the heat transfer rate and the pressure drop with the change of the fin configuration was obtained.
Kim, C.H.; Yun, J.Y. [LG Electronics Living System Research Lab., Seoul (Korea, Republic of)
Experimental and numerical study of laminar forced convection heat transfer for a dimpled heat sink
characteristics in a laminar and a turbulent airflow condition. A relative dimple depth in the range of 0.06 to 0.24 and a SIMPLEC (Semi-Implicit Method for Pressure-Linked Equations) method with multiblock grids were used to evaluate the flow change and heat....3) 4.3 Computation Procedure The computations of the fluid flow field and heat transfer were performed using CFD by Fluent software, version Fluent 6.2.16. Gambit 2.2.30 was used for the development of the computational grid. 4.3.1 Computational...
Park, Do Seo
Study of natural convection heat transfer above a horizontal heated plate using a laser specklegram technique
flow from the horizontal isothermal plate. 15. Study of the effect of aspect ratio (AR) of the heated surface on the global Nusselt number for Ra = 104 50 NOMENCLATURE a distance between the test section and the second parabolic mirror (mm) b... plane of a CCD-camera (mm) h heat transfer coefficient. K Gladstone ? Dale constant for air ( m'/kg) . K, thermal conductivity of air ((tj)/m-'C) L Length of the test section measured along the optical axis m magnification of the second (parabolic...
Cheeti, Satish K.R.
Heat transfer to a fluid flowing in an annulus
. ii I ~ DIMENSIONS AND SYMBOLS o ~ ~ ~ . ~ ~ ~ ~ I II e INTRODUCTION AND THEORY ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ 3 IXI e APPARATUS AND PROCEDURES ~ ~ e ~ ~ ~ ~ ~ ~ ~ ~ 7 XV o RESULTS ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ e ~ ~ ~ ~ 17 V, DXSCUSSION OF RESULTS... of times 0 Prandtl nnnber~ e~& dimensionless initial temperature oi' surfaoe and fluids% D equivalent diameter& Di g~ L Q - volume flow rate~ L3/T V~ mass velooity, FT/L3 6 mass floe rate~ FT/L IMTRODUCTIOR AND THEORY This thesis comprises heat tz...
Logan, Earl
TOPAZ2D heat transfer code users manual and thermal property data base
TOPAZ2D is a two dimensional implicit finite element computer code for heat transfer analysis. This user's manual provides information on the structure of a TOPAZ2D input file. Also included is a material thermal property data base. This manual is supplemented with The TOPAZ2D Theoretical Manual and the TOPAZ2D Verification Manual. TOPAZ2D has been implemented on the CRAY, SUN, and VAX computers. TOPAZ2D can be used to solve for the steady state or transient temperature field on two dimensional planar or axisymmetric geometries. Material properties may be temperature dependent and either isotropic or orthotropic. A variety of time and temperature dependent boundary conditions can be specified including temperature, flux, convection, and radiation. Time or temperature dependent internal heat generation can be defined locally be element or globally by material. TOPAZ2D can solve problems of diffuse and specular band radiation in an enclosure coupled with conduction in material surrounding the enclosure. Additional features include thermally controlled reactive chemical mixtures, thermal contact resistance across an interface, bulk fluid flow, phase change, and energy balances. Thermal stresses can be calculated using the solid mechanics code NIKE2D which reads the temperature state data calculated by TOPAZ2D. A three dimensional version of the code, TOPAZ3D is available. The material thermal property data base, Chapter 4, included in this manual was originally published in 1969 by Art Edwards for use with his TRUMP finite difference heat transfer code. The format of the data has been altered to be compatible with TOPAZ2D. Bob Bailey is responsible for adding the high explosive thermal property data.
Shapiro, A.B.; Edwards, A.L.
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
JOURNAL OF THERMOPHYSICS AND HEAT TRANSFER Vol. 14, No. 4, OctoberDecember 2000
JOURNAL OF THERMOPHYSICS AND HEAT TRANSFER Vol. 14, No. 4, OctoberDecember 2000 Multidimensional are optical tomographyof tissue, remote sensing of oceansand atmospheres, laser material processing radiative heat transfer in participat- ing media in recent years. However, the analysis of radiative heat
Characterization of the effect of Froude number on surface waves and heat transfer in inclined turbulent
describes wave/heat transfer phenomena in inclined turbulent open surface water flows. The experiments wereCharacterization of the effect of Froude number on surface waves and heat transfer in inclined Abstract Interfacial heat transport in open channel turbulent flows is strongly dependent on surface waves
Heat Transfer in Buildings: Application to Solar Air Collector and Trombe Wall Design
11 Heat Transfer in Buildings: Application to Solar Air Collector and Trombe Wall Design H. Boyer focuses on the modeling of Trombe solar walls. In each case, detailed modeling of heat transfer allows with same thermal behaviour). For heat conduction in walls, it results from electrical analogy
2.13 HEAT TRANSFER & FLUID FLOW IN MICROCHANNELS 2.13.7-1 Molecular dynamics methods in
2.13 HEAT TRANSFER & FLUID FLOW IN MICROCHANNELS 2.13.7-1 2.13.7 Molecular dynamics methods in microscale heat transfer Shigeo Maruyama A. Introduction In normal heat transfer and fluid flow calculations of molecules. This situation is approached in microscale heat transfer and fluid flow. Molecular level
Evaporation heat transfer and friction characteristics of R-134a flowing downward in a vertical corrugated tube
Differently from most previous studies, the heat transfer and friction characteristics of the pure refrigerant HFC-134a during evaporation inside a vertical corrugated tube are experimentally investigated. The double tube test sections are 0.5 m long with refrigerant flowing in the inner tube and heating water flowing in the annulus. The inner tubes are one smooth tube and two corrugated tubes, which are constructed from smooth copper tube of 8.7 mm inner diameter. The test runs are performed at evaporating temperatures of 10, 15, and 20 C, heat fluxes of 20, 25, and 30 kW/m{sup 2}, and mass fluxes of 200, 300, and 400 kg/m{sup 2} s. The quality of the refrigerant in the test section is calculated using the temperature and pressure obtained from the experiment. The pressure drop across the test section is measured directly by a differential pressure transducer. The effects of heat flux, mass flux, and evaporation temperature on the heat transfer coefficient and two-phase friction factor are also discussed. It is found that the percentage increases of the heat transfer coefficient and the two-phase friction factor of the corrugated tubes compared with those of the smooth tube are approximately 0-10% and 70-140%, respectively. (author)
Aroonrat, Kanit; Wongwises, Somchai [Fluid Mechanics, Thermal Engineering and Multiphase Flow Research Lab. (FUTURE), Department of Mechanical Engineering, King Mongkut's University of Technology Thonburi, Bangmod, Bangkok 10140 (Thailand)
Heat energy Q: -energy exchanged between systems if they have a different temperature
About heat Heat energy Q: - energy exchanged between systems if they have a different temperature - heat flows from higher to lower temperature - without temperature difference, no heat is exchanged If a system is receiving or releasing heat, then this heat is called a) Sensible heat, if the system changes
Boyd, Sylke
A comparison of two heat transfer models for estimating thermal drawdown in Hot Dry Rock reservoirs
Estimates of thermal drawdown in Hot Dry Rock geothermal systems have been made with two different models of heat transfer from hydraulically fractured reservoir rock blocks to water circulated through the fracture permeability. One model is based on deconvolution of experimental tracer response curves into a network of flowpaths connected in parallel with heat transfer calculated individually in each flowpath. The second model is based on one-dimensional flow through the rock with a block size distribution described as a group of equivalent-radius spheres for which the heat transfer equations can be solved analytically. The two models were applied to the planned Phase II long-term thermal drawdown experiment at Fenton Hill, NM. The results show good agreement between the two models, with estimates of temperature cooldown from 240�C to 150�C in a few years depending on selected operation parameters, but with somewhat differing cooldown curve characteristic shapes. Data from the long-term experiment will be helpful in improving the two models.
Robinson, Bruce A.; Kruger, Paul
Temperature initiated passive cooling system
A passive cooling system for cooling an enclosure only when the enclosure temperature exceeds a maximum standby temperature comprises a passive heat transfer loop containing heat transfer fluid having a particular thermodynamic critical point temperature just above the maximum standby temperature. An upper portion of the heat transfer loop is insulated to prevent two phase operation below the maximum standby temperature.
Forsberg, Charles W. (Oak Ridge, TN)
A passive cooling system for cooling an enclosure only when the enclosure temperature exceeds a maximum standby temperature comprises a passive heat transfer loop containing heat transfer fluid having a particular thermodynamic critical point temperature just above the maximum standby temperature. An upper portion of the heat transfer loop is insulated to prevent two phase operation below the maximum standby temperature. 1 fig.
Forsberg, C.W.
Taylor bubble-train flows and heat transfer in the context of Pulsating Balkrishna Mehta, Sameer Khandekar
Taylor bubble-train flows and heat transfer in the context of Pulsating Heat Pipes Balkrishna Mehta Nusselt number Heat transfer enhancement a b s t r a c t Understanding the performance of Pulsating Heat Pipes (PHPs) requires spatio-temporally coupled, flow and heat transfer information during the self
Turbulent heat transfer in parallel flow boundary layers with streamwise step changes in surface conditions
This paper examines the convective heat/mass transfer behavior of a turbulent boundary layer with parallel streamlines. The most notable example of such flow is an atmospheric boundary layer with a steady mean wind in the absence of topography. The classic, two-dimensional problem involves the surface boundary condition of a finite-length step change in temperature/concentration in the streamwise direction of an atmospheric flow. In the literature on geophysical evapotranspiration, this problem is known as Sutton's problem (cf. Sutton, 1934, and Brutsaert, 1984). This flow situation is equally applicable to heat/mass transfer in solar ponds, ground solar collectors, and heated roadways, as examples. The present note revisits the Sutton problem, with the can Driest eddy diffusivity model, and expands the types of boundary conditions that are examined to include surface changes in temperature/concentration and fluxes. The parallel streamline condition allows for Graetz-type solutions, with boundary conditions at the surface and in the far flow field. The predicted results are presented as a series of power law correlations of the relevant nondimensional parameters.
Lindberg, W.R.; Lee, R.C.; Smathers, L.B. (Univ. of Wyoming, Laramie (United States))
Natural convection heat transfer from a plate in a semicircular enclosure
The present paper is about characterizing the two-dimensional convective transfer across the air-filled region between a flat plate and a semicircular cylindrical enclosure. In the subject geometry, a long thin plate at uniform temperature is contained coaxially and symmetrically in a long semicircular trough closed at the top and having a uniform but different temperature. Heat flows across the air-filled region between the two by both natural convection and gaseous conduction. The problem of characterizing the free convective component of this heat transfer - that is, the component caused by bulk fluid motion - is treated experimentally by using a heat balance technique, with the measurements being repeated at different pressures, in order to cover a wide Rayleigh number range, from Ra {approximately} 10 to Ra {approximately} 10{sup 8}. Nusselt number versus Rayleigh number plots are presented for each of several combinations of plate-to-trough spacing and tilt angle, and the plots are correlated by equations. The problem of characterizing the conductive component is treated by numerically solving the steady diffusion equation in the air-filled region, and the results are correlated as a function of the spacing and the plate thickness.
Moore, G.A.; Hollands, K.G.T. (Univ. of Waterloo, Ontario (Canada))
Infrared Thermography applied to measurement of Heat transfer coefficient of water in a pipe heated by Joule effect
)" #12;1. Introduction Brazed aluminium heat exchangers are composed of flat tubes on the refrigerant exchangers with round tube, such as charge reduction and higher heat transfer coefficient. But, according are thus not suitable to small-channel heat exchangers. As a consequence, the refrigerant distribution
Project Profile: High Operating Temperature Liquid Metal Heat...
A freezing point below 100C Stable at temperatures greater than 800C Low corrosion of stainless steel and high-nickel content alloys A heat capacity greater than 2...
Temperatures, heat flow, and water chemistry from drill holes...
Temperatures, heat flow, and water chemistry from drill holes in the Raft River geothermal system, Cassia County, Idaho Jump to: navigation, search OpenEI Reference LibraryAdd to...
Phenylnaphthalene Derivatives as Heat Transfer Fluids for Concentrating Solar Power: Loop Experiments and Final Report
ORNL and subcontractor Cool Energy completed an investigation of higher-temperature, organic thermal fluids for solar thermal applications. Although static thermal tests showed promising results for 1-phenylnaphthalene, loop testing at temperatures to 450 C showed that the material isomerized at a slow rate. In a loop with a temperature high enough to drive the isomerization, the higher melting point byproducts tended to condense onto cooler surfaces. So, as experienced in loop operation, eventually the internal channels of cooler components such as the waste heat rejection exchanger may become coated or clogged and loop performance will decrease. Thus, pure 1-phenylnaphthalene does not appear to be a fluid that would have a sufficiently long lifetime (years to decades) to be used in a loop at the increased temperatures of interest. Hence a decision was made not to test the ORNL fluid in the loop at Cool Energy Inc. Instead, Cool Energy tested and modeled power conversion from a moderate-temperature solar loop using coupled Stirling engines. Cool Energy analyzed data collected on third and fourth generation SolarHeart Stirling engines operating on a rooftop solar field with a lower temperature (Marlotherm) heat transfer fluid. The operating efficiencies of the Stirling engines were determined at multiple, typical solar conditions, based on data from actual cycle operation. Results highlighted the advantages of inherent thermal energy storage in the power conversion system.
McFarlane, Joanna [ORNL; Bell, Jason R [ORNL; Felde, David K [ORNL; Joseph III, Robert Anthony [ORNL; Qualls, A L [ORNL; Weaver, Samuel P [ORNL
A method of correlating heat transfer data for surface boiling of liquids
A method based an a logical uxplanation of the meani of beat transfer associated with the boiling process is presented for correlating heat transfer data for nucleate boiling of liquids for the case of pool boiling. Tbe ...
Rohsenow, Warren M.
High temperature thermographic measurements of laser heated silica
In situ spatial and temporal surface temperature profiles of CO{sub 2} laser-heated silica were obtained using a long wave infrared (LWIR) HgCdTe camera. Solutions to the linear diffusion equation with volumetric and surface heating are shown to describe the temperature evolution for a range of beam powers, over which the peak surface temperature scales linearly with power. These solutions were used with on-axis steady state and transient experimental temperatures to extract thermal diffusivity and conductivity for a variety of materials, including silica, spinel, sapphire, and lithium fluoride. Experimentally-derived thermal properties agreed well with reported values and, for silica, thermal conductivity and diffusivity are shown to be approximately independent of temperature between 300 and 2800K. While for silica our analysis based on a temperature independent thermal conductivity is shown to be accurate, for other materials studied this treatment yields effective thermal properties that represent reasonable approximations for laser heating. Implementation of a single-wavelength radiation measurement in the semi-transparent regime is generally discussed, and estimates of the apparent temperature deviation from the actual outer surface temperature are also presented. The experimental approach and the simple analysis presented yield surface temperature measurements that can be used to validate more complex physical models, help discriminate dominant heat transport mechanisms, and to predict temperature distribution and evolution during laser-based material processing.
Elhadj, S; Yang, S T; Matthews, M J; Cooke, D J; Bude, J D; Johnson, M; Feit, M; Draggoo, V; Bisson, S E
Design of a high temperature hot water central heating system
The paper reviews the conceptual design of a central heating system at Los Alamos Scientific Laboratory. The resource considered for this heating system design was hot dry rock geothermal energy. Design criteria were developed to ensure reliability of energy supply, to provide flexibility for adaptation to multiple energy resources, to make optimum use of existing equipment and to minimize reinvestment cost. A variable temperature peaking high temperature water system was selected for this purpose.
Beaumont, E.L.; Johnson, R.C.; Weaver, J.M.
Constructal multi-scale package of vertical channels with natural convection and maximal heat transfer density. CONSTRUCTAL DESIGN: THE GENERATION OF MULTI-SCALE HEAT
transfer density. CONSTRUCTAL DESIGN: THE GENERATION OF MULTI-SCALE HEAT AND FLUID FLOW STRUCTURES-scale structures in natural convection with the objective of maximizing the heat transfer density, or the heat transfer rate per unit of volume§ . The flow volume is filled with vertical equidistant heated blades
A Comparative Heat Transfer Examination of Structural Insulated Panels (SIPs) With and Without Phase Change Materials (PCMs) Using a Dynamic Wall Simulator
transferring approximately the same amount of heat regardless of the fact that one panel was outfitted with PCM. Equivalent Thermal Resistance Thermal resistance is the resistance to heat flow through a material caused by a temperature difference across.... Therefore, the "q T & ? values at any point in time during heating up or cooling down processes were referred to as equivalent thermal resistance, R e Figure 14 shows the equivalent thermal resistances estimated during the heating up and cooling...
Medina, M.; Zhu, D.
Jet impingement heat transfer in two-pass rotating rectangular channels
temperature of the blade material. Since the turbine blades are the next component downstream of the combustor, they must be cooled effectively to keep from burning out. The coolant for these blades is mostly air extracted &om the compressor of the engine...(Outward Flow) Coolant Supply(Inward Flow) Figure 3 Cross sectional view of jet impingement cooling in two-pass rotating channel However, the spent jets in rotation make the channel arrangement favor channel heat transfer &om the suction and pressure surfaces...
Zhang, Yuming
On numerical simulation of flow, heat transfer and combustion processes in tangentially-fired furnace
In this work, an Eulerian/Lagrangian approach has been employed to investigate numerically flow characteristics, heat transfer and combustion processes inside corner-fired power plant boiler furnace. To avoid pseudo-diffusion that is significant in modeling tangentially-fired furnaces, some attempts have been made at improving the finite-difference scheme. Comparisons have been made between standard {kappa}-{epsilon} model and RNG {kappa}-{epsilon} model. Some new developments on turbulent diffusion of particles are taken into account in an attempt to improve computational accuracy. Finally, temperature deviation is studied numerically so as to gain deeper insight into tangentially fired furnace.
Sun, P.; Fan, J.; Cen, K.
Local Measurement of Fuel Energy Deposition and Heat Transfer Environment During Fuel Lifetime Using Controlled Calorimetry
A comprehensive description of the accomplishments of the DOE grant titled, ''Local Measurement of Fuel Energy Deposition and Heat Transfer Environment During Fuel Lifetime using Controlled Calorimetry''.
Don W. Miller; Andrew Kauffmann; Eric Kreidler; Dongxu Li; Hanying Liu; Daniel Mills; Thomas D. Radcliff; Joseph Talnagi
Application Of A Spherical-Radial Heat Transfer Model To Calculate...
Spherical-Radial Heat Transfer Model To Calculate Geothermal Gradients From Measurements In Deep Boreholes Jump to: navigation, search OpenEI Reference LibraryAdd to library...
A phase-field method for 3D simulation of two-phase heat transfer
stationary grids, different modes of heat transfer (e.g. convection/conduction), as well as its ... flow systems with sharp-interface models, moving-grid methods.
X. Zheng
E-Print Network 3.0 - accident heat transfer Sample Search Results
accident situations involving hundreds of kilograms... of the expansion, heat transfer is small and therefore fuel-coolant mixing and hydro- dynamics must be considered... from the...
This report describes the RELAP5 model that has been developed for the divertor primary heat transfer system (PHTS). The model is intended to be used to examine the transient performance of the divertor PHTS and evaluate control schemes necessary to maintain parameters within acceptable limits during transients. Some preliminary results are presented to show the maturity of the model and examine general divertor PHTS transient behavior. The model can be used as a starting point for developing transient modeling capability, including control system modeling, safety evaluations, etc., and is not intended to represent the final divertor PHTS design. Preliminary calculations using the models indicate that during normal pulsed operation, present pressurizer controls may not be sufficient to keep system pressures within their desired range. Additional divertor PHTS and control system design efforts may be required to ensure system pressure fluctuation during normal operation remains within specified limits.
Popov, Emilian L [ORNL; Yoder Jr, Graydon L [ORNL; Kim, Seokho H [ORNL
Extensions and enhancements to the iLab heat transfer project site
The iLab Heat Transfer Project website started four years ago to enable web access to experiments related to movement of heat through transport processes. This thesis details improvements made to the site which extend and ...
Saylor, David P. (David Patrick)
A cut-cell method for adaptive high-order discretizations of conjugate heat transfer problems
Heat transfer between a conductive solid and an adjacent convective fluid is prevalent in many aerospace systems. The ability to achieve accurate predictions of the coupled heat interaction is critical in advancing ...
Ojeda, Steven Matthew
Low temperature barriers with heat interceptor wells for in situ processes
A system for reducing heat load applied to a frozen barrier by a heated formation is described. The system includes heat interceptor wells positioned between the heated formation and the frozen barrier. Fluid is positioned in the heat interceptor wells. Heat transfers from the formation to the fluid to reduce the heat load applied to the frozen barrier.
McKinzie, II, Billy John (Houston, TX)
Determination of the controlling process in coupled heat and mass transfer
The influence of non-condensable gases on condensation is well known going back to Nusselt. The non-condensables tend to form a blanket around the cooled surface which can significantly slow condensation rates by introducing a controlling mass transfer resistance. The coupled heat and mass transfer process that results has a significant impact on the optimum design of compact condenser bundles. One of the questions that arises in analyzing such a coupled process is which of the two processes is controlling the overall transfer process? One way to quantify a solution to this problem is to take a thermodynamic perspective and to compute the entropy generation associated with each of the individual processes. Then, the process that contributes the largest entropy generation is viewed as the controlling process. The result of such a determination provides insight as to how to augment the overall transfer process. The approach taken in this study is to use available CFD (computational fluid dynamics) codes to formulate and solve the condenser problem to gain insight into the coupled process. The resulting temperature, velocity and concentration data can then be analyzed to determine the entropy generation associated with each of the processes. Results are presented for a series of simplified geometries that define the magnitude of the effects contributed by each of the transfer processes.
Bell, B.; Kakavas, T.; Herold, K.E. [Univ. of Maryland, College Park, MD (United States). Center for Environmental Energy Engineering
Thermoacoustic sensor for nuclear fuel temperaturemonitoring and heat transfer enhancement
A new acoustical sensing system for the nuclear power industry has been developed at The Pennsylvania State University in collaboration with Idaho National Laboratories. This sensor uses the high temperatures of nuclear fuel to convert a nuclear fuel rod into a standing-wave thermoacoustic engine. When a standing wave is generated, the sound wave within the fuel rod will be propagated, by acoustic radiation, through the cooling fluid within the reactor or spent fuel pool and can be monitored a remote location external to the reactor. The frequency of the sound can be correlated to an effective temperature of either the fuel or the surrounding coolant. We will present results for a thermoacoustic resonator built into a Nitonic-60 (stainless steel) fuel rod that requires only one passive component and no heat exchangers.
James A. Smith; Dale K. Kotter; Randall A. Alli; Steven L. Garrett
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.
Determination of heat conductivity and thermal diffusivity of waste glass melter feed: Extension to high temperatures
The heat conductivity ({lambda}) and the thermal diffusivity (a) of reacting glass batch, or melter feed, control the heat flux into and within the cold cap, a layer of reacting material floating on the pool of molten glass in an all-electric continuous waste glass melter. After previously estimating {lambda} of melter feed at temperatures up to 680 deg C, we focus in this work on the {lambda}(T) function at T > 680 deg C, at which the feed material becomes foamy. We used a customized experimental setup consisting of a large cylindrical crucible with an assembly of thermocouples, which monitored the evolution of the temperature field while the crucible with feed was heated at a constant rate from room temperature up to 1100�C. Approximating measured temperature profiles by polynomial functions, we used the heat transfer equation to estimate the {lambda}(T) approximation function, which we subsequently optimized using the finite-volume method combined with least-squares analysis. The heat conductivity increased as the temperature increased until the feed began to expand into foam, at which point the conductivity dropped. It began to increase again as the foam turned into a bubble-free glass melt. We discuss the implications of this behavior for the mathematical modeling of the cold cap.
Rice, Jarrett A.; Pokorny, Richard; Schweiger, Michael J.; Hrma, Pavel R.
BWR spent fuel storage cask performance test. Volume 2. Pre- and post-test decay heat, heat transfer, and shielding analyses
This report describes the decay heat, heat transfer, and shielding analyses conducted in support of performance testing of a Ridhihalgh, Eggers and Associates REA 2033 boiling water reactor (BWR) spent fuel storage cask. The cask testing program was conducted for the US Department of Energy (DOE) Commercial Spent Fuel Management Program by the Pacific Northwest Laboratory (PNL) and by General Electric at the latters' Morris Operation (GE-MO) as reported in Volume I. The analyses effort consisted of performing pretest calculations to (1) select spent fuel for the test; (2) symmetrically load the spent fuel assemblies in the cask to ensure lateral symmetry of decay heat generation rates; (3) optimally locate temperature and dose rate instrumentation in the cask and spent fuel assemblies; and (4) evaluate the ORIGEN2 (decay heat), HYDRA and COBRA-SFS (heat transfer), and QAD and DOT (shielding) computer codes. The emphasis of this second volume is on the comparison of code predictions to experimental test data in support of the code evaluation process. Code evaluations were accomplished by comparing pretest (actually pre-look, since some predictions were not completed until testing was in progress) predictions with experimental cask testing data reported in Volume I. No attempt was made in this study to compare the two heat transfer codes because results of other evaluations have not been completed, and a comparison based on one data set may lead to erroneous conclusions.
Wiles, L.E.; Lombardo, N.J.; Heeb, C.M.; Jenquin, U.P.; Michener, T.E.; Wheeler, C.L.; Creer, J.M.; McCann, R.A.
USING LIGA BASED MICROFABRICATION TO IMPROVE OVERALL HEAT TRANSFER EFFICIENCY OF PRESSURIZED WATER REACTOR: I. Effects of Different Micro Pattern on Overall Heat Transfer.
The Pressurized Water Reactors (PWRs in Figure 1) were originally developed for naval propulsion purposes, and then adapted to land-based applications. It has three parts: the reactor coolant system, the steam generator and the condenser. The Steam generator (a yellow area in Figure 1) is a shell and tube heat exchanger with high-pressure primary water passing through the tube side and lower pressure secondary feed water as well as steam passing through the shell side. Therefore, a key issue in increasing the efficiency of heat exchanger is to improve the design of steam generator, which is directly translated into economic benefits. The past research works show that the presence of a pin-fin array in a channel enhances the heat transfer significantly. Hence, using microfabrication techniques, such as LIGA, micro-molding or electroplating, some special microstructures can be fabricated around the tubes in the heat exchanger to increase the heat-exchanging efficiency and reduce the overall size of the heat-exchanger for the given heat transfer rates. In this paper, micro-pin fins of different densities made of SU-8 photoresist are fabricated and studied to evaluate overall heat transfer efficiency. The results show that there is an optimized micro pin-fin configuration that has the best overall heat transfer effects.
Zhang, M.; Ibekwe, S.; Li, G.; Pang, S.S.; and Lian, K.
Design, Feasibility, and Testing of Instrumented Rod Bundles to Improve Heat Transfer Knowledge in PWR Fuel Assemblies
Two 5 x 5 test rod bundles mimicking the PWR fuel assembly have been adapted into two suitable test loop facilities, respectively, to carry out sufficiently detailed hydraulic and thermal measurements in identical geometric configuration. The objective is to investigate heat transfer phenomena in single-phase as well as with onset of nucleate boiling (ONB). The accuracy and reproducibility of the temperature measurements using the sliding-traversing thermocouple device under typical PWR conditions has been demonstrated in the thermal test facility. In the hydraulic loop, a Laser Doppler Velocimetry (LDV) system to precisely scan the local axial velocity component in each sub-channel has been implemented. The approach is to utilize mean sub-channel axial velocity distributions and pressure drop data from the hydraulic loop and the global boundary conditions (Pressure, Temperature, flow rate) from the thermal loop to simulate sub-channels in appropriate T/H codes. This permits computation of sub-channel averaged fluid temperatures (as well as mass velocity) in various subchannels within the test bundle. Subsequently, in conjunction with the wall temperatures and applied heat flux values from the thermal loop, it is possible to develop a complete map of heat transfer coefficients along the 9 instrumented central heater rods. Locations downstream of spacer grids would be of special interest. Depending on pressure, mass velocity and heat flux conditions of a given test, the inlet temperature will be a parameter to be varied so that the ONB boundary can be observed within the bundle. Detailed designs of the test section, required loop modifications, and adaptation of specialized instrumentation and data acquisition systems have been accomplished in both test loops. Further we have established that based on such detailed rod surface temperature and sub-channel axial velocity measurements, it is possible to achieve sufficient accuracy in the temperature measurements to meet the objective of improving the heat transfer correlations applicable to PWR cores. (authors)
Bergeron, A. [CEA, Saclay (France); Chataing, T.; Garnier, J. [CEA, Genoble (France); Decossin, E.; Peturaud, P. [EDF/R and D, Chatou (France); Yagnik, S.K. [Electric Power Research Institute - EPRI (United States)
Heat-transfer calculations for a potted (solid matrix embedded) subassembly
Standard Liquid Metal Fast Breeder Reactor (LMFBR) subassemblies used in the Experimental Breeder Reactor II (EBR-II) have been investigated for fuel-bundle distortion using a destructive examination method known as potting. The potting technique embeds and permanently fixes the fuel elements in a solid matrix that can be sectioned and polished to reveal details in the internal structure of the elements or subassembly. Thus, an advantage of the potting technique is that it permits investigation of the internal structure of the subassembly in situ, as this structure would be lost or significantly altered during subassembly disassembly. However, since the elements in the subassembly are radioactive, the potting material must efficiently conduct radioactive decay heat to the environment so that the melting or softening temperatures of the potting material are not exceeded. The purpose of this paper is to present the heat transfer calculations for a potted subassembly and to recommend a simplified method for solving similar problems.
Betten, P.R.
A study of heat transfer and particle motion relative to the modified chemical vapor deposition process
Heat transfer and particle motion relative to the modified chemical vapor deposition process have been studied for general values of the torch speed. Three-dimensional temperature fields have been obtained over the entire cross section of the tube and the effects of tube rotation and localized torch heating in the axial and circumferential directions have been studied. The particle trajectories have been calculated from a formulation that includes the contributions from forced flow, i.e., Poiseuille flow in the axial direction, rigid body rotation about the tube axis, and thermophoretic contributions in the axial, radial, and angular directions. The particle trajectories are helices and are shown to be strongly dependent on the tube rotation.
Choi, M.; Greif, R. (Univ. of California, Berkeley (United States)); Baum, H.R. (National Inst. of Standards and Technology, Gaithersburg, MD (United States))
Abstract--The use of structured porous media is a proposed technique to achieve higher heat transfer coefficients by
transfer coefficients by increasing the specific surface area for heat transfer while aiming to maintain pressure drop for a given heat transfer performance. A comprehensive thermo-fluid model called MERLOT [1] was used to assess the use of porous heat transfer media for fusion plasma facing component applications
Pulsifer, John
Abstract. Tailored porous media is a proposed method of achieving higher heat transfer coefficients while seeking to
Abstract. Tailored porous media is a proposed method of achieving higher heat transfer coefficients general porous flow model (MERLOT [1]). The Model of Energy- transfer Rate for fLow in Open transfer performance. The low heat capacities and low heat transfer coefficients, h, of gas coolants
BOILING CRISIS:THEORY,SIMULATION,AND EXPERIMENTSBOILING CRISIS: THEORY, SIMULATION, AND EXPERIMENTS Boiling is a very efficient way to transfer heat from a heater to the liquid heat carrier. We discuss the
that separates the liquid from the heater. Film boiling can be also observed in the kitchen by sprinkling water onto a hot frying pan. In spite of the large temperature of the heater (the pan) the water drops Boiling is a very efficient way to transfer heat from a heater to the liquid heat carrier. We discuss
Nikolayev, Vadim S.
Transient heat transfer in helium II due to a sudden vacuum break
To ensure future cryogenic devices meet safety and operational specifications, significant value is gained from a developed understanding of the transient heat fluxes that result from failure of an insulating vacuum jacket around a helium II (He II)-cooled device. A novel, one-dimensional experiment is successfully performed examining the phenomena immediately following a vacuum rupture onto a cryosurface. In the experiment, a fast-opening (?10 ms) valve isolates a rigid container of ultra high purity nitrogen (N{sub 2}) gas kept at room temperature and adjustable pressure from a vertically oriented, highly evacuated (?10{sup ?3} Pa) tube roughly 1 m in length. The bottom of the evacuated tube is sealed via a 2.54 mm thick copper disk, whose bottom surface is in intimate contact with an open column of He II (?1.8 K). The evacuated tube, disk, and He II column share a diameter of 24 mm. Opening the valve results in a vacuum rupture. N{sub 2} gas is immediately drawn into the evacuated space and cryopumped onto the disk as a growing layer of solid cryodeposit. Various coupled transient heat transfer processes proceed as the internal energy of the warm gas is transferred through the growing layer of solid N{sub 2}, through the copper disk, and into the He II column. This work examines the qualitative nature of these transient phenomena and the magnitude of the heat fluxes present through each of the series of thermal resistances.
Bosque, Ernesto S.; Dhuley, Ram C.; Van Sciver, Steven W. [National High Magnetic Field Laboratory, Tallahassee, FL 32310, USA and FAMU-FSU College of Engineering, Tallahassee, FL 32310 (United States)
Airfoil Heat Transfer Characteristics in Syngas and Hydrogen Turbines
Hydrogen or coal-derivative syngas turbines promise increased efficiency with exceptionally low NOx emissions compared to the natural gas based turbines. To reach this goal, turbine inlet temperature (TIT) will need to be elevated to a level exceeding 1700�C [1, 2]. The thermal load induced by such a temperature increase alone will lead to immense challenges in maintaining material integrity of turbine components. In addition, as working fluid in the gas path will primarily be steam, possibly mixed with carbon oxides, the aero-thermal characteristic in a hydrogen turbine is expected to be far different from that of air/nitrogen enriched gas stream in a gas turbine. For instance, steam has distinctly higher density and specific heat in comparison to a mixture of air and combustion gases as they are expanded in a conventional gas turbine. Even if the temperature limits remain about the same, the expansion in a hydrogen turbine will have to proceed with a greater enthalpy drop and therefore requires a larger number of stages. This also implies that the flow areas may need to be expanded and blade span to be enlarged. Meanwhile, a greater number of stages and hot surfaces need to be protected. This also suggests that current cooling technology available for modern day gas turbines has to be significantly improved. The ultimate goal of the present study is to systematically investigate critical issues concerning cooling technology as it is applicable to oxy-fuel and hydrogen turbine systems, and the main scope is to develop viable means to estimate the thermal load on the turbine �gas side�, that is eventually to be removed from the �coolant side�, and to comparatively quantify the implication of external heat load and potential thermal barrier coating (TBC) degradation on the component durability and lifing. The analysis is based on two well-tested commercial codes, FLUENT and ANSYS.
Mazzotta, D.W. (Univ. of Pittsburgh); Chyu, M.K. (Univ. of Pittsburgh); Alvin, M.A.
RADIATION HEAT TRANSFER IN TISSUE WELDING AND SOLDERING WITH ULTRAFAST LASERS Kyunghan Kim to incorporate transient radiation heat transfer in tissue welding and soldering with use of ultrafast lasers are performed between laser welding and laser soldering. The use of solder is found to substantially enhance
Experimental Study of Heat Transfer and Flow Characteristics for a New Type of Air Heater
. It is found that the integrated characteristics of heat transfer and flow friction increase with the hole's diameter at the same hole density (which is equal to the ratio of the hole's total area to the baffle's area), and the heat transfer rate increases...
Zheng, H.; Fan, X.; Li, A.
Rectification of evanescent heat transfer between dielectric-coated and uncoated silicon carbide plates
Rectification of evanescent heat transfer between dielectric-coated and uncoated silicon carbide://jap.aip.org/authors #12;Rectification of evanescent heat transfer between dielectric-coated and uncoated silicon carbide-infinite bodies of the dielectric-coated silicon carbide and uncoated silicon carbide. The permittivity
Fan, Shanhui
Bibliography of US patents on augmentation of convective heat and mass transfer-II
Patents are an important source of information on the potential commercialization of augmented heat transfer technology. This report presents a bibliography of US patents pertinent to that technology. The total number of patents cited is 454. They are presented in three separate lists: by patent number, alphabetically by first inventor, and by augmentation technique (with secondary arrangement according to mode of heat transfer).
Webb, R.L.; Bergles, A.E.; Junkhan, G.H.
1 Copyright 2012 by ASME Proceedings of the ASME 2012 Summer Heat Transfer Conference
1 Copyright � 2012 by ASME Proceedings of the ASME 2012 Summer Heat Transfer Conference HT2012 July. INTRODUCTION Passive cooling is a widely preferred method for electronic and power electronic devices since, #12;2 Copyright � 2012 by ASME is convective heat transfer coefficient and is thermal conductivity
Adaptive higher order numerical simulation of heat and mass transfer in fluidized beds
Adaptive higher order numerical simulation of heat and mass transfer in fluidized beds Ch. Nagaiah1 adaptive numerical results of heat and mass transfer in fluidized beds using higher order time stepping injection. The numerical results are tested with different time stepping methods for different spatial grid
Magdeburg, Universität
Radiative Heat Transfer Analysis of Fibrous Insulation Materials Using the ZonalGEF Method
Radiative Heat Transfer Analysis of Fibrous Insulation Materials Using the Zonal�GEF Method Walter to analyze radiative heat transfer in high porosity insulation materials which have a large scattering for LI900, a material used in the insulation tile for the space shuttle. Comparisons are presented
Yuen, Walter W.
MODELING OF HEAT TRANSFER IN ROOMS IN THE MODELICA "BUILDINGS" LIBRARY Michael Wetter, Wangda Zuo describes the implementation of the room heat transfer model in the free open-source Modelica "Buildings National Lab- oratory started the development of the free open- source Modelica "Buildings" library
Effect of surface conditions on boiling heat transfer of refrigerants in shell-and-tube evaporators
Experimental results are presented for the boiling heat transfer performance of R 22 and R 717 on surfaces with porous metallized coatings. A calculational-theoretical model is given for predicting the heat transfer of refrigerants boiling on a bundle of finned tubes.
Danilova, G.N.; Dyundin, V.A.; Borishanskaya, A.V.; Soloviyov, A.G.; Vol'nykh, Y.A.; Kozyrev, A.A.
JOURNAL OF THERMOPHYSICS AND HEAT TRANSFER Vol. 19, No. 1, JanuaryMarch 2005
developed turbulent nonrotating tube flow Dh, D = hydraulic diameter, m h = heat transfer coefficient, W/m2 Program, Department of Civil Engineer- ing. Senior Member AIAA. Professor, Turbine Heat Transfer thermal efficiency, gas-turbine stages are being de- signed to operate at increasingly high inlet
Al-Qahtani, Mohammad
Glass foams: formation, transport properties, and heat, mass, and radiation transfer
Glass foams: formation, transport properties, and heat, mass, and radiation transfer Andrei G depend, to a large extent, on foams formed on the surface of the molten glass and of the batch due models for thermophysical and transport properties and heat, mass, and radiation transfer in glass foams
Pilon, Laurent
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.
Heat transfer in the trailing edge cooling channels of turbine blades
Foundation and from the funded research contract (RF5810) through Dr. Han. NOMENCLATURE A area of heat transfer in the pin fin channel AI, area of heat transfer in the long ejection segments Az cross-sectional area, of trailing edge ejection holes A..., ?minimum flow cross-sectional area in the pin fin channel C'~ discharge coefficient Cp specific heat of air 1 diameter of trailing edge ejection holes D diameter of pins f overall friction factor h?heat transfer coefficient in the n th segment...
Kumaran, T. K.
Development of a UF{sub 6} cylinder transient heat transfer/stress analysis model
A heat transfer/stress analysis model is being developed to simulate the heating to a point of rupture of a cylinder containing UF{sub 6} when it is exposed to a fire. The assumptions underlying the heat transfer portion of the model, which has been the focus of work to date, will be discussed. A key aspect of this model is a lumped parameter approach to modeling heat transfer. Preliminary results and future efforts to develop an integrated thermal/stress model will be outlined.
Williams, W.R. [Martin Marietta Energy Systems, Inc., Oak Ridge, TN (United States)
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
The Temperature of Interstellar Clouds from Turbulent Heating
To evaluate the effect of turbulent heating in the thermal balance of interstellar clouds, we develop an extension of the log-Poisson intermittency model to supersonic turbulence. The model depends on a parameter, d, interpreted as the dimension of the most dissipative structures. By comparing the model with the probability distribution of the turbulent dissipation rate in a simulation of supersonic and super-Alfvenic turbulence, we find a best-fit value of d=1.64. We apply this intermittency model to the computation of the mass-weighted probability distribution of the gas temperature of molecular clouds, high-mass star-forming cores, and cold diffuse HI clouds. Our main results are: i) The mean gas temperature in molecular clouds can be explained as the effect of turbulent heating alone, while cosmic ray heating may dominate only in regions where the turbulent heating is low; ii) The mean gas temperature in high-mass star-forming cores with typical FWHM of ~6 km/s (corresponding to a 1D rms velocity of 2.5 km/s) may be completely controlled by turbulent heating, which predicts a mean value of approximately 36 K, two to three times larger than the mean gas temperature in the absence of turbulent heating; iii) The intermittency of the turbulent heating can generate enough hot regions in cold diffuse HI clouds to explain the observed CH+ abundance, if the rms velocity on a scale of 1 pc is at least 3 km/s, in agreement with previous results based on incompressible turbulence. Because of its importance in the thermal balance of molecular clouds and high-mass star-forming cores, the process of turbulent heating may be central in setting the characteristic stellar mass and in regulating molecular chemical reactions.
Liubin Pan; Paolo Padoan
Temperature and thermal stress distributions for the HFIR permanent reflector generated by nuclear heating
The beryllium permanent reflector of the High Flux Isotope Reactor has the main functions for slowing down and reflecting the neutrons and housing the experimental facilities. The reflector is heated as a result of the nuclear reaction. Heat is removed mainly by the cooling water passing through the densely distributed coolant holes along the vertical or axial direction of the reflector. The reflector neutronic distribution and its heating rate are calculated by J.C. Gehin of the Oak Ridge National Laboratory by applying the Monte Carlo Code MCNP. The heat transfer boundary conditions along several reflector interfaces are estimated to remove additional heat from the reflector. The present paper is to report the calculation results of the temperature and the thermal stress distributions of the permanent reflector by applying the computer aided design code I-DEAS and the finite element code ABAQUS. The present calculation is to estimate the high stress areas as a result of the new beam tube cutouts along the horizontal mid-plane of the reflector of the recent reactor upgrade project. These high stresses were not able to be calculated in the preliminary design analysis in earlier 60`s. The heat transfer boundary conditions are used in this redesigned calculation. The material constants and the acceptance criteria for the allowable stresses are mainly based on that assumed in the preliminary design report.
Chang, S.J.
Numerical method for fluid flow and heat transfer in magnetohydrodynamic flow
A new numerical algorithm was developed to provide a fully detailed flow field in liquid metal MHD flow with a relatively large Hartmann number and interaction parameter. The algorithm includes the effects of advection and diffusion, and is capable of predicting momentum and heat transfer in MHD flows. Using this algorithm, an incompressible, viscous, three-dimensional MHD flow in a square duct is investigated at a low magnetic Reynolds number by means of the finite volume method. The velocity and temperature profiles are obtained in the developing region for constant wall temperature. The result shows that large velocities are obtained near the insulating walls parallel to the magnetic field. Also, near the perfectly conducting walls perpendicular to the field, a velocity profile like a Hartmann layer is obtained. In association with the velocity profiles, Nusselt number at the insulating walls (with side layer) is seen to be larger than that at the perfectly conducting walls (with Hartmann layer).
Kim, C.N.; Abdou, M.A.
by a heating lamp emitting in the visible and near infraredwith heating in a furnace at 400 o C. The infrared lamp was
Dual-circuit embossed-sheet heat-transfer panel
A heat transfer panel provides redundant cooling for fusion reactors or the like environment requiring low-mass construction. Redundant cooling is provided by two independent cooling circuits, each circuit consisting of a series of channels joined to inlet and outlet headers. The panel comprises a welded joinder of two full-size and two much smaller partial-size sheets. The first full-size sheet is embossed for form first portions of channels for the first and second circuits, as well as a header for the first circuit. The second full-sized sheet is then laid over and welded to the first full-size sheet. The first and second partial-size sheets are then overlaid on separate portions of the second full-sized sheet, and are welded thereto. The first and second partial-sized sheets are embossed to form inlet and outlet headers, which communicate with channels of the second circuit through apertures formed in the second full-sized sheet.
Determination of heat transfer and friction characteristics of an adapted inclined louvered fin
An experimental study of a fin-and-tube heat exchanger was performed. To this end a test rig was constructed to measure the heat transfer rate on the air and waterside of the heat exchanger. A wide range of Reynolds numbers on the airside was investigated. The resulting data was used to determine the convective heat transfer correlation (expressed using the Colburn factor) and the friction factor on the airside. The fin type used in the heat exchanger of this research is an adaptation of the standard inclined louvered type. A thorough error analysis was performed, to validate the results. (author)
T'Joen, C.; Steeman, H.-J.; Willockx, A.; De Paepe, M. [Department of Flow, Heat and Combustion Mechanics, Ghent University-UGent, Sint-Pietersnieuwstraat 41, 9000 Gent (Belgium)
Condensation heat transfer in square, triangular, and semi-circular mini-channels Melanie Derby a
, and Nuclear Engineering, Rensselaer Polytechnic Institute, Troy, NY 12180, United States b Department was the coolant. The heat transfer rate was obtained through a coolant-side energy balance. To obtain condensation. An energy balance on the fluid-to-fluid heat exchanger measured heat duty while sensors in two obstructed
Numerical simulation of the heat transfer in amorphous silicon nitride membrane-based microcalorimeters
Numerical simulation of the heat transfer in amorphous silicon nitride membrane July 2003 Numerical simulations of the two-dimensional 2D heat flow in a membrane-based microcalorimeter have been performed. The steady-state isotherms and time-dependent heat flow have been calculated
Hellman, Frances
Generator-Absorber heat exchange transfer apparatus and method using an intermediate liquor
Numerous embodiments and related methods for generator-absorber heat exchange (GAX) are disclosed, particularly for absorption heat pump systems. Such embodiments and related methods use the working solution of the absorption system for the heat transfer medium where the working solution has an intermediate liquor concentration.
air flow measurement. A water source heat pump provided chilled water to a fan-coil unit which in turn on volumetric air flow measurement and an overall room heat balance. Analysis was directed at results fromA FULL SCALE ROOM FOR THE EXPERIMENTAL STUDY OF INTERIOR BUILDING CONVECTIVE HEAT TRANSFER: DESIGN
The influence of convective heat transfer on flow stability in rotating disk chemical vapor deposition reactors
Flow and heat transfer of NH{sub 3} and He were studied in a rotating disk system with applications to chemical vapor deposition reactors. Flow field and disk heat flux were obtained over a range of operating conditions. Comparisons of disk convective heat transfer were made to infinite rotating disk results to appraise uniformity of transport to the disk. Important operating variables include disk spin rate, disk and enclosure temperatures, flow rate, composition, pressure, and gas mixture temperature at the reactor inlet. These variables were studied over ranges of the spin Reynolds number, Re{omega}; disk mixed convection parameter, MCP{sub w}; and wall mixed convection parameter, MCP{sub w}. Results obtained for NH{sub 3} show that increasing Re{omega} from 314.5 to 3145 increases the uniformity of rotating disk heat flux and results in thinner thermal boundary layers at the disk surface. At Re{omega}=314.5, increasing MCP{sub d} to 15 leads to significant departure from the infinite disk result with nonuniform disk heat fluxes and recirculating flow patterns; flow becomes increasingly complex at larger values of MCP{sub d}. At Re{omega} of 3145, results are closer to the infinite disk for MCP{sub d} up to 15. For large negative (hot walls) and positive (cold walls) values of MCP{sub w}, flow recirculates and there is significant deviation from the infinite disk result; nonuniformities occur at both values of Re{omega}. The influence of MCP{sub w} on flow stability is increased at larger MCP{sub d} and lower Re{omega}. To determine the influence of viscosity and thermal conductivity variation with temperature, calculations were made with He and NH{sub 3}; He transport property variation is low relative to NH{sub 3}. Results show that the flow of NH{sub 3} is less stable than that of He as MCP{sub d} is increased for MCP{sub w}=0 and Re{omega}=314.5. 16 refs., 15 figs., 1 tab.
Winters, W.S.; Evans, G.H. [Sandia National Labs., Livermore, CA (United States); Grief, R. [Univ. of California, Berkeley, CA (United States). Mechanical Engineering Dept.
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.
Design and Experiments of a Solar Low-temperature Hot Water Floor Radiant Heating System
The solar low-temperature hot water floor radiant heating system combines solar energy heating with floor radiant heating. This kind of environmental heating way not only saves fossil resources and reduces pollution, but also makes people feel more...
Wu, Z.; Li, D.
Eurotherm Seminar N81 Reactive Heat Transfer in Porous Media, Ecole des Mines d'Albi, France June 4-6, 2007 ET81-1 HEAT TRANSFER BY SIMULTANEOUS RADIATION-CONDUCTION
Eurotherm Seminar N°81 Reactive Heat Transfer in Porous Media, Ecole des Mines d'Albi, France June 4-6, 2007 ET81- 1 HEAT TRANSFER BY SIMULTANEOUS RADIATION-CONDUCTION AND CONVECTION IN A HIGH for the packed bed. The comparison between the radiative heat transfer and the exchanges by conduction and forced
The design, construction, and instrumentation of a chamber to study heat, mass, and momentum transfer from humid air to metal under conditions of frosting and free convection
THE DESIGN? CONSTRUCTION? AND INSTRUMENTATION OF A CEAMSER TO STUDY HEAT, MASS? AND MOSNTUM TRANSFER FROM HUMID AIR TO METAL UNDER CONDITIONS OF FROSTING AND FREE CONVECTION A Thesis By James P. Hutchison Submitted to the Graduate School... temperatures a cryogenic pump wss necessary. The sire of the pump was computed on the basis of maintaining a one degree Fahrenheit drop of the coolant temperature through the supply systms. The greatest heat load on the supply system being 3718 BTU per hour...
Hutchison, James P
Flow-Induced Deformation of a Flexible Thin Structure as Manifestation of Heat Transfer Enhancement
Flow-induced deformation of thin structures coupled with convective heat transfer has potential applications in energy harvesting and is important for understanding functioning of several biological systems. We numerically demonstrate large-scale flow-induced deformation as an effective passive heat transfer enhancement technique. An in-house, strongly-coupled fluid-structure interaction (FSI) solver is employed in which flow and structure solvers are based on sharp-interface immersed boundary and finite element method, respectively. In the present work, we validate convective heat transfer module of the in-house FSI solver against several benchmark examples of conduction and convective heat transfer including moving structure boundaries. The thermal augmentation is investigated as well as quantified for the flow-induced deformation of an elastic thin plate attached to lee side of a rigid cylinder in a heated channel laminar flow. We show that the wake vortices past the plate sweep higher sources of vorticity...
Soti, Atul Kumar; Sheridan, John
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)
.Heat Generation Patterns and Temperature Profiles in_ Electroslag Welding
l .Heat Generation Patterns and Temperature Profiles in_ Electroslag Welding ) · T. DEBROY, J in the slag and metal phases for an electroslag welding system. It is shown that the current is significantly larger for the electroslag welding process than that of the electroslao refinino process operating
Eagar, Thomas W.
Grid-region heat transfer in a gas solid fluidized bed
The grid region heat transfer to a horizontal tube in a gas-solid fluidized bed was studied experimentally and theoretically. A preliminary experimental study was first conducted to investigate semi-quantitatively the heat transfer characteristics in the grid region as well as in the bubbling region of the gas-solid fluidized bed using a simple hot water circulation system. Experimental parameters included particle size, static bed height, superficial gas velocity, distributor open area, distributor hole sizes, distributor hole numbers, and vertical locations of the heating tube. An additional experimental study was then carried out to study quantitatively the heat transfer coefficient in each grid region phase, i.e., jet phase, emulsion phase and dead phase using an artificial jet and an electrically heated tube. The observed heat transfer coefficients for each phase were correlated as a function of experimental parameters. The observed results are also compared with results estimated from a heat transfer model, which is based on plausible heat transfer mechanisms in the grid region of a gas-solid fluidized bed.
Wang, R.C.
Chemistry control and corrosion mitigation of heat transfer salts for the fluoride salt reactor (FHR)
The Molten Salt Reactor Experiment (MSRE) was a prototype nuclear reactor which operated from 1965 to 1969 at Oak Ridge National Laboratory. The MSRE used liquid fluoride salts as a heat transfer fluid and solvent for fluoride based {sup 235}U and {sup 233}U fuel. Extensive research was performed in order to optimize the removal of oxide and metal impurities from the reactor's heat transfer salt, 2LiF-BeF{sub 2} (FLiBe). This was done by sparging a mixture of anhydrous hydrofluoric acid and hydrogen gas through the FLiBe at elevated temperatures. The hydrofluoric acid reacted with oxides and hydroxides, fluorinating them while simultaneously releasing water vapor. Metal impurities such as iron and chromium were reduced by hydrogen gas and filtered out of the salt. By removing these impurities, the corrosion of reactor components was minimized. The Univ. of Wisconsin - Madison is currently researching a new chemical purification process for fluoride salts that make use of a less dangerous cleaning gas, nitrogen trifluoride. Nitrogen trifluoride has been predicted as a superior fluorinating agent for fluoride salts. These purified salts will subsequently be used for static and loop corrosion tests on a variety of reactor materials to ensure materials compatibility for the new FHR designs. Demonstration of chemistry control methodologies along with potential reduction in corrosion is essential for the use of a fluoride salts in a next generator nuclear reactor system. (authors)
Kelleher, B. C.; Sellers, S. R.; Anderson, M. H.; Sridharan, K.; Scheele, R. D. [Dept. of Engineering Physics, Univ.of Wisconsin - Madison, 1500 Engineering Drive, Madison, WI 53706 (United States)
A Validation Study of Pin Heat Transfer for MOX Fuel Based on the IFA-597 Experiments
Abstract The IFA-597 (Integrated Fuel Assessment) experiments from the International Fuel Performance Experiments (IFPE) database were designed to study the thermal behavior of mixed oxide (MOX) fuel and the effects of an annulus on fission gas release in light-water-reactor fuel. An evaluation of nuclear fuel pin heat transfer in the FRAPCON-3.4 and Exnihilo codes for MOX fuel systems was performed, with a focus on the first 20 time steps ( 6 GWd/MT(iHM)) for explicit comparison between the codes. In addition, sensitivity studies were performed to evaluate the effect of the radial power shape and approximations to the geometry to account for the thermocouple hole, dish, and chamfer. The analysis demonstrated relative agreement for both solid (rod 1) and annular (rod 2) fuel in the experiment, demonstrating the accuracy of the codes and their underlying material models for MOX fuel, while also revealing a small energy loss artifact in how gap conductance is currently handled in Exnihilo for chamfered fuel pellets. The within-pellet power shape was shown to significantly impact the predicted centerline temperatures. This has provided an initial benchmarking of the pin heat transfer capability of Exnihilo for MOX fuel with respect to a well-validated nuclear fuel performance code.
Phillippe, Aaron M [ORNL; Clarno, Kevin T [ORNL; Banfield, James E [ORNL; Ott, Larry J [ORNL; Philip, Bobby [ORNL; Berrill, Mark A [ORNL; Sampath, Rahul S [ORNL; Allu, Srikanth [ORNL; Hamilton, Steven P [ORNL
The effects of airflow modulation and multi-stage defrost on the performance of an air source heat pump
. This transfer of heat energy from a low temperature ambient to the high temperature conditioned space is accomplished by the input of electrical energy to the compressor. During the heating season, the heat pump transfers heat energy from the low temperature... pump refrigeration circuit includes a compressor, an indoor heat exchanger, an outdoor heat exchanger, an expansion device, and fans to transfer heat energy from a low temperature heat energy source to a higher temperature heat energy sink...
Payne, William Vance
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.
Heat transfer coefficients in two-dimensional Yukawa systems (numerical simulations)
New data on heat transfer in two-dimensional Yukawa systems have been obtained. The results of a numerical study of the thermal conductivity for equilibrium systems with parameters close to the conditions of laboratory experiments in dusty plasma are presented. The Green-Kubo relations are used to calculate the heat transfer coefficients. The influence of dissipation (internal friction) on the heat transfer processes in nonideal systems is studied. New approximations are proposed for the thermal conductivity and diffusivity for nonideal dissipative systems. The results obtained are compared with the existing experimental and numerical data.
Khrustalyov, Yu. V., E-mail: firstname.lastname@example.com; Vaulina, O. S. [Russian Academy of Sciences, Joint Institute for High Temperatures (Russian Federation)
Temperature measurements using multicolor pyrometry in thermal radiation heating environments
Temperature measurements are important for thermal-structural experiments in the thermal radiation heating environments such as used for thermal-structural stress analyses. This paper describes the use of multicolor pyrometry for the measurements of diffuse surfaces in thermal radiation environments that eliminates the effects of background radiation reflections and unknown emissivities based on a least-squares algorithm. The near-infrared multicolor pyrometer had a spectral range of 1100�2400 nm, spectrum resolution of 6 nm, maximum sampling frequency of 2 kHz, working distance of 0.6 m to infinity, temperature range of 700�1700 K. The pyrometer wavelength response, nonlinear intensity response, and spectral response were all calibrated. The temperature of a graphite sample irradiated by quartz lamps was then measured during heating and cooling using the least-squares algorithm based on the calibrated irradiation data. The experiments show that higher temperatures and longer wavelengths are more suitable for the thermal measurements in the quartz lamp radiation heating system. This analysis provides a valuable method for temperature measurements of diffuse surfaces in thermal radiation environments.
Fu, Tairan, E-mail: firstname.lastname@example.com [Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Department of Thermal Engineering, Tsinghua University, Beijing 100084 (China) [Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Department of Thermal Engineering, Tsinghua University, Beijing 100084 (China); Beijing Key Laboratory of CO2 Utilization and Reduction Technology, Beijing 100084 (China); Liu, Jiangfan; Duan, Minghao; Zong, Anzhou [Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Department of Thermal Engineering, Tsinghua University, Beijing 100084 (China)] [Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Department of Thermal Engineering, Tsinghua University, Beijing 100084 (China)
International Conference on Heat Transfer, Fluid Mechanics, and Thermodynamics 8-10 April 2002, Kruger Park, South Africa
HEFAT2002 1st International Conference on Heat Transfer, Fluid Mechanics, and Thermodynamics 8 topic in heat transfer. The power dissipation of the computer chips is rapidly increasing. The thermal management of these high power systems provides a complex challenge. Unfortunately, the heat transfer area
Molecular Dynamics Simulation of Heat Transfer Issues of Nanotubes. > Yasuhiro Igarashi, Yuki Taniguchi, Yasushi Shibuta and Shigeo Maruyama
Molecular Dynamics Simulation of Heat Transfer Issues of Nanotubes. ·> Yasuhiro Igarashi, Yuki 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan Heat transfer between single-walled carbon nanotubes, which was 0.105 µm. In other words, when the length of SWNT is 0.105 µm, the radial heat transfer
Fusion Engineering and Design 81 (2006) 549553 Numerical analysis of MHD flow and heat transfer in a
Fusion Engineering and Design 81 (2006) 549553 Numerical analysis of MHD flow and heat transfer January 2006 Abstract MHD flow and heat transfer have been analyzed for a front poloidal channel blanket; Magnetohydrodynamics; Heat transfer 1. Introduction Using flow channel inserts (FCIs) made
EUROTHERM Seminar 74 Proceedings Heat transfer in unsteady and transitional flows March 23-26, 2003 Eindhoven (The Netherlands)
EUROTHERM Seminar 74 Proceedings Heat transfer in unsteady and transitional flows March 23-26, 2003 to be governed by heat transfer and time microscales of turbulence through the inner sublayer. Physical interpreta- tions are given to relate the observed heat transfer correlation and these turbulence transition
PIV flow measurements for heat transfer characterization in two-pass square channels with smooth and 90 ribbed walls
PIV flow measurements for heat transfer characterization in two-pass square channels with smooth the correlation between the high- Reynolds number turbulent flow and wall heat transfer characteristics in a two number (Re) of 30,000. The PIV measurement results were compared with the heat transfer experimental data
Boiling heat transfer in a vertical microchannel: Local estimation during flow boiling with a non intrusive method
Boiling heat transfer in a vertical microchannel: Local estimation during flow boiling with a non the results of experimental and numerical studies concerning boiling heat transfer inside vertical in minichannels for several gravity levels (µg, 1g, 2g). To fully understand the high heat transfer potential
Effect of radiative heat transfer on the coagulation dynamics of combustion-generated particles
We examine the influences of radiation heat transfer on the size and number density evolution of small coagulating particles. On a microscopic level, radiative emission and/or absorption by the particle will perturb the gas temperature field adjacent to each particle. As a result of thermophoretic particle transport, the nonequilibrium condition can alter the collision rates with neighboring particles. A simplified analysis of the thermophoretic coagulation mechanism suggests that net radiative cooling of the particles can lead to an accelerated growth of [mu]m-sized particles, whereas net radiative heating can act to essentially freeze coagulation rates. On the macroscopic level, the addition or removal of heat in the gas through radiative absorption emission by the particle cloud can also significantly alter, through thermophoretic transport, the local particle number density. Under certain cases these effects can augment the accelerated coagulation rates that occur under radiative cooling conditions. We also examine the particular situation of equilibrium between particle cloud radiative absorption and emission - which results in no net macroscopic effect on the gas. 30 refs., 9 figs.
Mackowski, D.W. (Auburn Univ., AL (United States)); Tassopoulos, M.; Rosner, D.E. (Yale Univ., New Haven, CT (United States))
A study of temperature distributions due to conduction reservoir heating
of thermal conductivity with temperature. He showed this effect could be very important in considering a material such as oil shale, where the conductivity of the raw shale may be five times as great as that of the spent shale. Neglecting this variation... conduction model to investigate the in place heating of oil shale by hot gases forced through a fracture. The heat injection rate he considered is much less than would normally be employed for steam injection into permeable reservoirs and is only about...
Connaughton, Charles Richard
Design of a continuous fiber ceramic composite heat exchanger for high-temperature, high-pressure applications
A conceptual design of a continuous fiber ceramic composite (CFCC) heat exchanger for high-temperature, high-pressure applications is presented. The CFCC materials under consideration are SiC reinforced with SiC fibers manufactured using the continuous vapor infiltration process and alumina reinforced with SiC or alumina fibers manufactured using the directed metal oxidation process. These composite materials are highly resistant to high-temperature corrosive environment and possess a greater creep strength than metallic materials. Heat exchangers constructed of CFCC material may be utilized for high-temperature, high-pressure applications such as air/gas heaters in advanced energy systems and high-temperature energy recovery systems. This paper presents a design of a gas-to-air CFCC heat exchanger for the high temperature advanced furnace (HITAF) in the high-performance power system (HIPPS). The 1.38 MPa (200 psia) air is heated from 760 C (1,400 F) to 982 C (1,800 F) using the combustion products at 1,650 C (3,000 F). The heat exchanger is of a cross-parallel/counter flow type in which the tube-side air flow makes a combined parallel and counter flow arrangement with a cross-flowing combustion gas in such a way that the maximum CFCC tube temperature will not exceed a 1,260 C (2,300 F) design limit. The main heat transfer mechanism from the external hot gas to the tube-side air is that of gaseous radiation for the first few rows of the tubes, followed by convective heat transfer across the remainder of the tube bundle. The design characteristics of this high-temperature, high-pressure CFCC heat exchanger with supporting thermal, flow, structural, and vibrational analyses are presented in detail in the paper.
Cho, S.M.; Seltzer, A.H.; Narayanan, T.V. [Foster Wheeler Development Corp., Livingston, NJ (United States); Shah, A.C.; Weddell, J.K. [DuPont Lanxide Composites Inc., Newark, DE (United States)
Heat transfer from combustion gases to a single row of closely spaced tubes in a swirl crossflow Stirling engine heater
This paper describes an experimental program to determine the heat-transfer characteristics of a combustor and heat-exchange system in a hybrid solar receiver which utilizes a Stirling engine. The system consists of a swirl conbustor with a crossflow heat exchanger composed of a single row of 48 closely spaced curved tubes. In the present study, heat-transfer characteristics of the combustor/heat-exchanger system without a Stirling engine have been studied over a range of operating conditions and output levels using water as the working fluid. Non-dimensional heat-transfer coefficients based on total heat transfer have been obtained and are compared with available literature data. The results show significantly enhanced heat transfer for the present geometry and test conditions. Also, heat transfer along the length of the tubes is found to vary, the effect depending upon test condition.
Bankston, C.P.; Back, L.H.
Investigation of boiling heat transfer at a surface with a system of cylindrical cavities under conditions of free motion
The authors propose a mathematical model for the intensification of boiling heat transfer and the subsequent increase in thermal efficiency of the cylindrical heat transfer surfaces in an evaporative cooling system. The boiling curves for water, ethanol, and freon 113 are calculated for a surface with artificial nucleation sites. The model incorporates such coolant properties as surface tension, specific heat, and vaporization heat.
Danilova, G.N.; Reznikov, V.I.
The Hypothetical Accident Conditions (HAC) sequential test of radioactive materials packages includes a thermal test to confirm the ability of the package to withstand a transportation fire event. The test specified by the regulations (10 CFR 71) consists of a 30 minute, all engulfing, hydrocarbon fuel fire, with an average flame temperature of at least 800 C. The requirements specify an average emissivity for the fire of at least 0.9, which implies an essentially black radiation environment. Alternate test which provide equivalent total heat input at the 800 C time averaged environmental temperature may also be employed. When alternate tests methods are employed, such as furnace or gaseous fuel fires, the equivalence of the radiation environment may require justification. The effects of furnace and open confinement fire environments are compared with the regulatory fire environment, including the effects of gases resulting from decomposition of package overpack materials. The results indicate that furnace tests can produce the required radiation heat transfer environment, i.e., equivalent to the postulated pool fire. An open enclosure, with transparent (low emissivity) fire does not produce an equivalent radiation environment.
Smith, A
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