question
stringlengths 19
6.88k
| answer
stringlengths 38
33.3k
|
|---|---|
Problem Statement: The flare tip outlet pressure that I am seeing on the flare tip Summary tab does not correspond to the atmospheric pressure that I specified in the Calculation Options Editor. Why is this so, and how can I fix this? | Solution: It is possible that a different system back pressure for a particular scenario has been set on the General tab of the Scenario Editor (under Build | Scenarios). This would normally be atmospheric pressure, but it is sometimes used to represent system design conditions at the exit point. If a system back pressure is not specified for a scenario, the value on the General tab of the Calculation Options Editor (under Calculations | Options) will be used. Therefore to ensure that the atmospheric pressure that you have specified in Calculation Options Editor will be used, simply delete the value specified in the System Back Pressure field in the Scenario Editor.
Keywords: backpressure
References: None |
Problem Statement: How to directly import Aspen HYSYS Depressuring Utility peak flow results into sources | Solution: The composition, temperature, pressure and mass flow results of the depressuring utility peak flow can be imported directly as the data for the sources in the flare system networks built in Aspen Flare System Analyzer.
1. Make sure your Aspen HYSYS depressuring utility solved.
2. Go to Aspen One button in Aspen Flare System Analyzer and go to Import Sources-> HYSYS Sources.
3. Instead of using option Stream, choose Options: Dynamic Depressuring Utilities
4. After you import the case, you should get all depressuring utilities from your HYSYS case.
Keywords: Depressuring Utility, Import and export, HYSYS source.
References: None |
Problem Statement: What is the difference between the flow regime by Beggs & Brill on the pipe window and the one on Results | Flow map? | Solution: The Flow regime presented under Results | Flow map is calculated accordingly to Mandhane flow map.
On the other hand the flow regime calculated by Beggs & Brill is calculated based on the flow regimes that are part of the Beggs & Brill correlations, e.g.
The Beggs & Brill method was primarily developed as a unified correlation capable of handling all pipe geometry (horizontal/vertical/inclined). However there are some things that need to be taken into account regarding its applicability:
1. Beggs & Brill tends to overpredict pressure drop for larger diameter pipes.
2. An over predicted pressure drop is obtained with increasing gas liquid ratio (GLR). The errors become especially large for GLR above 5000.
3. The accuracy of the pressure profile predictions is generally good up to about 10% water-cut.
Keywords: Beggs & Brill, Flow map, Flow regime, Pressure drop
References: None |
Problem Statement: Can I add my own fitting to the fittings database? | Solution: Yes, it is possible to modify the fittings database used in Aspen FLARENET to include a user-defined fitting. The fitting can be added to the database interactively, i.e. while Aspen FLARENET is running. While the program is running go to the Database menu and select Pipe Fittings from the list of available options. A Fittings Database Editor will then pop up displaying all of the currently available fittings along with their corresponding fittings loss coefficients.
To add a fitting simply click on the Add button at the bottom of the Fittings Database Editor view, supply a name and the appropriate fittings loss coefficients. Once finished, click the OK button and the fitting will now available for use in any pipe segment.
The fittings loss K value for all fittings is calculated according to the following formula : K = A + B*Ft , where Ft = turbulent friction factor.
Note also that user defined pipe schedules can be added to the Pipe Schedule database in much the same manner.
Keywords: customize
References: None |
Problem Statement: Can I edit multiple pipe segments simultaneously? | Solution: Yes, it is possible to edit multiple pipes simultaneously by following the steps below:
1. Select Pipes from the Build menu and select multiple pipes by holding down the <Ctrl> key and picking the desired pipes from the list.
2. Click on the Edit button to display the Pipe Editor view.
3. Make the appropriate changes; when a given field is not edited it will contain an asterisk (*) to indicate that the corresponding value will not be changed in any of the pipe segments.
4. Click on the OK button to make the changes in the appropriate pipe segments.
Note that not all variables are available when editing multiple pipe segments simultaneously.
Keywords: edit, multiple, pipe segment
References: None |
Problem Statement: What parameters define the flare tip curve: mass flow versus total pressure drop or rated flow versus total pressure drop or flow versus static pressure drop? | Solution: The flare tip curve allows the user to input mass flowrate versus static pressure drop at different molecular weights.
The mass flowrate is used because it does not depend on temperature and pressure unlike volume.
Many flare tip vendors provide the curve data in terms of total pressure drop. Currently, Aspen Flare System analyzer doesn't have option to enter the flare tip curve using total pressure drop.
However, the static pressure drop can be calculated using the equation provided in Knowledge BaseSolution 109475.
Keywords: flare tip curve, mass flowrate, rated flowrate, total pressure drop, static pressure drop
References: None |
Problem Statement: Where are the \Samples, \Database and \Help folders located in the Aspen FLARENET 2004 installation? | Solution: In Aspen FLARENET 2004, by default the \Samples, \Database and \Help folders are installed to:-
C:\Documents and Settings\All Users\Application Data\AspenTech\Aspen FLARENET 2004\
This location is based on Microsoft's recommendation for User application data and is used to avoid problems with Administrators preventing the installation of data folders in C:\Program Files\AspenTech\Aspen FLARENET 2004\ .
Note that users may specify the location for these files during the installation procedure by choosing the location for the Working Files (see attached screenshot).
Keywords: Samples, Database, Help, locations, installation
References: None |
Problem Statement: What does the Rated Flow for Tailpipes option on the Calculations\Options\General tab mean? | Solution: When modelling tailpipes, FlareNet can base the pressure drop calculations on either the design (nominal) mass flows or the rated mass flows from upstream Relief Valve sources (see alsoSolution # 109493 for details of the rated flow calculation in Relief Valves http://support.aspentech.com/webteamcgi/SolutionDisplay_view.cgi?key=109493 ).
When the Rated Flow for Tailpipes option (which is located on the Calculations\Options\General tab) is checked, FlareNet will use the rated mass flow for the pressure drop calculations in tailpipes in accordance with API 521, for all run modes (Rating, Design or Debottleneck). This means that the overall mass and energy balances are based upon the design (nominal) flows for Relief Valve sources but the pressure drops are calculated based on a separate rated flow mass balance (which is actually hidden from the user).
Rated flows are only used for pipes marked as tailpipes
Keywords: tailpipe, rated flow, tail pipe
References: None |
Problem Statement: Can Aspen FLARENET be used for continuous flare/vent systems? | Solution: Aspen FLARENET is a steady state modeling tool that will calculate the pressures and flows throughout the network based on specified boundary conditions (flows at the relief sources and pressures at the flare tips). For convergent (non-looped) systems it can also be used to size pipes so that back pressure, Mach number, noise, etc. constraints are met.
Since Aspen FLARENET is a steady state tool (rather than a full dynamic solver), when modeling emergency flare/vent systems Aspen FLARENET solves assuming that the emergency relief load is a continuous flow through the system. Hence Aspen FLARENET can be used to simulate continuous flare / vent systems.
Keywords: Continuous Flare / Vent, Emergency Relief, Steady State solver
References: None |
Problem Statement: How can I make Aspen FLARENET calculate the outlet temperature of a PSV / BDV? It is asking me to input it. | Solution: To have Aspen FLARENET calculate a PSV/BDV outlet temperature, first ensure that you have selected a two phase VLE and enthalpy method (i.e. Peng-Robinson with Lee Kesler enthalpies). This can be done via the Calculations | Options | Methods menu item. You can then get the outlet temperature by clicking on the Set button (beside the Outlet temperature field) on the Conditions tab of the PSV/BDV property view.
Keywords: outlet, temperature, calculate, PSV, input, BDV
References: None |
Problem Statement: What does the option Calculate Ignored Sources with Zero Flow mean? | Solution: The MAWP constraint is ignored by sizing calculation when a source si ignored.
If the user selects the option Calculate Ignored Sources with Zero Flow (located under Calculations | Options), then the sources that have been ignored will be treated as if they have zero flow.
This will result in the back pressure being calculated and the limit checked against the source MABP even if the source has been ignored. Therefore the effect of these sources can be observed on the back pressure.
Keywords: Back pressure, MABP, Ignored sources
References: None |
Problem Statement: How can a multi-stage flare tip pressure drop curve be entered in Aspen Flare System Analyzer? | Solution: For detailed information about entering regular curves on flare tips, please reviewSolution 109487.
The best available way to enter this kind of data is to enter it as a single curve. The only challenge while handling these types of curves is if there are two different pressure drop values for the same mass flow (i.e. where one curve ends at the top point & the next one begins at the bottom).
To avoid these problems, it is necessary to introduce some spacing between the mass flow values (i.e. if one curve ends at 10000 lb/hr, the next one should begin at 10000.01 lb/hr).
Note that the spaced area (i.e. between 10000 lb/hr and 10000.01 lb/hr) might not be handled accurately. The user must verify after solving the case that the mass flow through the flare tip does not land in this area. Although uncommon, if this were the case, reduce the spacing until the actual mass flow value lands out of this space.
Lastly, all the extrapolation checkboxes need to be turned off as extrapolation will not work with these types of non-monotonous curves.
Once these conditions have been set, Aspen Flare System Analyzer will be able to correctly handle the information from the multi-stage curve.
Keywords: Multi Stage, Flare Tip, Curves
References: None |
Problem Statement: When you are using the Exchanger Design and Rating (EDR) functionality embedded inside of Aspen HYSYS and you try to print the datasheet of a heat exchanger, the printed document has several pages.
The problem is that after the first page, you have a page feed for each item. The issue occurs only when you are inside of HYSYS. | Solution: The workarounds are:
Export the *.edr file, then run in the standalone version 7.3 to print.
To print in EDR V7.3 follow the steps below:
1. Go to the File Menu > Print
2. Check the box against the Calculation details
3. Select Print
Upgrade to V8. This is a defect that has been fixed in V8.0 and higher.
To print in Aspen HYSYS V8 follow the steps below:
1. Right click on the heat exchanger
2. Select print datasheet
3. Select between the available datablocks
4. Select print
Keywords: EDR, Print, Heat Exchanger, Datasheet
References: None |
Problem Statement: How can I predict laboratory data of oil and gas mixtures accurately using an Equation of State (EoS)? | Solution: Cubic equations of state (EoS) usually do not predict laboratory data of oil/gas mixtures accurately without tuning of the EoS parameters. DBR PVT Pro provides a wizard to guide the user through the tuning process. Model tuning is achieved in Aspen HYSYS by using a multi-variable regression package to fit one or more of the following experimental data:
1. Saturation Pressures
2. PVT Tests
3. Saturation Pressures and PVT Tests
4. Viscosities
It is recommended that model tuning be performed right after the system is defined, but before any calculation functions are executed. Otherwise, you may need to update the calculation results that were generated prior to model tuning. Note that Aspen HYSYS Upstream License is required to access the features and functionality of the PVT environment
Keywords: Tuning, Laboratory Data EOS
References: None |
Problem Statement: How can I specify a fixed pressure drop across a Flare Tip? | Solution: You can force FlareNet to use a fixed pressure drop across a Flare Tip by specify a Pressure Drop Curve with a single data point of zero flow and the required pressure drop. Ensure also that no reference temperature is specified to prevent FlareNet from performing a pressure drop temperature correction.
See alsoSolution ID 109487 How can I make the pressure drop calculation across the flare tip dependent on flowrate?Solution ID 112825 How is the pressure drop across a Flare Tip calculated using Pressure Drop Curves?
Keywords: flare tip, pressure drop
References: None |
Problem Statement: In Aspen Flare System Analyzer, users can specify back pressure and relieving pressure. What is the maximum pressure value set in Aspen Flare System Analyzer? | Solution: The allowable back pressure upper limit set in Aspen Flare System Analyzer is 600 bar while the back pressure upper limit is 1000 bar. This is usually reached when the model is not converging.
The relieving pressure upper limit set in Aspen Flare System Analyzer is 600 barg.
Keywords: limit, back pressure, relieving pressure
References: None |
Problem Statement: Why doesn't the utility design load match the sum of each exchanger load in Aspen Energy Analyzer? | Solution: This utility load discrepancy is due to an inappropriate splitter ratio for this utility.
In Aspen Energy Analyzer (AEA), one utility stream can be split into branches in order to satisfy the Heat Exchanger Network (HEN) design requirement. As the split ratio for the utility cannot be determined automatically by the program, the user must input the correct split ratio. The calculated outlet temperature should be the same as the utility outlet temperature provided.
The split ratio page is shown as below:
To get rid of the load discrepancy, the user needs to modify the split ratio to set the calculated and specified outlet temperature the same, as shown in the screenshot above.
Currently, AEA calculates the Design Load for a utility with branches as below:
Design Load = MCp,calc* Delta T, spec
Delta T,spec = |Tout,spec - Tin, spec|
MCp,calc = total loads of this utility exchangers / (Tout, calc - Tin,spec)
where
Delta T,spec - utility in/out temperature difference specified by user
MCp,calc - calculated flow for this utility under current HEN design
Tin, spec - utility inlet temperature specified by user
Tout, spec - utility outlet temperature specified by user
Tout, calc - utility outlet temperature calculated by mixing all the branches under current HEN design
Keywords: Utility, Design Load
References: None |
Problem Statement: The pipe segment block inside a Hydraulics subflowsheet gives the user the option to Estimate the heat transfer coefficients to calculate the heat losses to the environment. What are the methods used for estimating those values? | Solution: There are a few different methods available:
· For the inner convection heat transfer coefficient, the calculation in Hydraulics is done with the HTFS method. This method is further described in the HTFS Handbook.
· For the outer convection HTC, the method used is described by J.P. Holman in Heat Transfer (1989).
· For the wall and insulation conduction, the conductivity and thickness is specified.
· Finally overall HTC is calculated by combining the resistance of each section to obtain an overall heat transfer coefficient.
Keywords: HTFS estimation film
References: None |
Problem Statement: I have multiple scenarios in my case - how can I tell which scenario is active? | Solution: At the far right-hand side of the row of icons below the main menu is a drop-down list containing the names of all the scenarios in the case. The scenario name which is displayed is the active scenario. To switch active scenarios, select the drop-down arrow on the right-hand side of the list and choose the desired scenario.
Keywords: scenario, active
References: None |
Problem Statement: What is the best way to model a pure steam system in Aspen Flare System Analyzer? | Solution: In order to model pure steam correctly, you need to do the following:
1. Make sure your inlet is steam. If you only specify the relieving pressure and inlet temperature at bubble point, Aspen Flare System Analyzer may treat as inlet. You may want to use superheat option and give a small number for superheat value such as 0.001. Make sure that you have steam inlet. As you know, for pure component, any small different for temperature specification will be either vapor or liquid.
2. VLE methods should be EOS such as PR. You also can try to use API Vapor Pressure. Sometime it works better for pure water system.
3. If you model a steam system through a turbo and valve, it means that its energy balance will be between equal enthalpy and equal entropy. So in Aspen Flare System Analyzer, you will need to use isentropic flash and efficiency to tune in reaching your outlet vapor fraction (or temperature).
Keywords: Pure steam, superheat, turbo
References: None |
Problem Statement: How to model splitter? | Solution: Reverse the TEE to make it splitter. For example, make one outlet as inlet and inlet as two outlet (inlet and branch) TEE can handle negative flow.
Note: Red dot is normally an inlet and blue dot is an outlet. If you connect outlet at red dot and inlet at blue dot, Flarenet solver will represent it as negative flow. The solver will converge appropriately on pressure and flow calculation.
Keywords: Tee, mixer, Splitter
References: None |
Problem Statement: How are two-phase sonic velocities calculated in FlareNet? | Solution: FlareNet uses a homogeneous model assuming no-slip between phases for the calculation of two phase sonic velocities (in general the assumption of a homogeneous two-phase mixture is reasonable given the flow velocities usually experienced in flare systems). The sonic velocity is defined as:
c^2 = dP/d(rho) @ constant entropy [1]
where
c two-phase sonic velocity
rho homogeneous fluid density
P static pressure
(see, for example, Perry's Chemical Engineers' Handbook)
The equation of state methods in FlareNet are used to calculate the density and entropy at the pipe conditions and then a small pressure pertubation is used to obtain the density and pressure gradients
Sonic velocities are known to be very low in the two-phase region and can be as low as 30-40 m/s.
The calculated sonic velocities in FlareNet can be cross-checked in HYSYS using the method outlined below:
In HYSYS define a stream to be at the same conditions (temperature, composition and pressure) as those of the FlareNet pipe of interest.
To make a constant entropy pressure pertubation in HYSYS connect the stream defined in step 1 to an Expander unit operation with a specified efficiency of 100%. Connect an outlet stream to this expander and set the pressure of the outlet stream to 0.1 kPa less than the pressure of the inlet stream. This defines a 0.1 kPa pressure pertubation at constant entropy.
Add a Spreadsheet unit operation and import the pressures and mass densities from the streams defined in steps 1 and 2. Use the spreadsheet to calculate the sonic velocity from equation [1] above.
The attached HYSYS 3.1 file demonstrates this calculation to cross-check the downstream sonic velocity of pipe Header 3 in FlareNet sample case Sample-S1.fnw (located in the \Samples\Convergent folder of the FlareNet installation).
Keywords: sonic velocity, mach number, choke, choked, critical flow
References: None |
Problem Statement: Can I specify only the molecular weight of a stream without inputting a composition? | Solution: Yes you can, however you still need to specify a component slate. Once you have selected the components, you can then specify the molecular weight of the stream. Flarenet will then look at the molecular weights of the components that straddle the specified molecular weight and propagate the corresponding composition.
Keywords: molecular weight, composition, components
References: None |
Problem Statement: What does the colour of the status bar in FLARENET mean? | Solution: The FLARENET status bar is activated via the Show Status Bar option under the File\Preferences menu. When activated, the colour of the status bar has the following meanings:
RED - no scenarios calculated
YELLOW - some scenarios calculated
GREEN - all scenarios calculated
Keywords: status bar colour color
References: None |
Problem Statement: OLE Automation Example, Produce a table of which sources are active/ignored for all scenarios in the model | Solution: Attached is an Excel spreadsheet that uses OLE Automation code to produce a table of which sources are active / ignored for all scenarios in the model. Simply press the button to produce the table for the current Flarenet case.
When linking Excel to Flarenet, the Flarenet type library must be correctly referenced to allow VBA to access Flarenet. If you are using a version of Flarenet other than 3.5.1a or you receive any unexpected errors then you should re-reference the Flarenet type library. The procedure to do this is as follows:
Close Flarenet and Excel
Open the version of Flarenet that is to be used
Open the spreadsheet in Excel
Go to the VBA editor. (Tools ... Macro ... Visual Basic Editor menu option, or press Alt + F11)
In the VBA editor go to Tools ...
Keywords: OLE Automation, Sources, Scenarios, Ignored, Active
References: s
If Flarenet #.# (where #.# is the version of Flarenet being used) is checked, uncheck it and press OK, then go to Tools ... References again
Find Flarenet #.# in the list, check it, press OK and close the VBA editor. |
Problem Statement: What is the difference between a convergent, divergent and looped system? | Solution: A convergent system is a network that has a single exit point, e.g.
A divergent system terminates in multiple exit points:
In the case of looped systems, this applies when there are multiple flow path options:
Keywords: System
Network
Looped
Convergent
Divergent
References: None |
Problem Statement: How do I export data from Aspen Flare System Analyzer to MS Excel? | Solution: The attached excel files will provide a way to extract data from Aspen Flare System Analyzer. You will be able to select different scenarios and export the data to MS Excel. In order to do it, you have to open the Flarenet and the attached MS Excel at same time. If option Save Phase Properties (File->Preferences->General) is not checked, please check it and run it again.
Attached files will work for V2004.1, V2006, V2006.5, V7.1 and V7.2.
If you get the error messages when you click the button Connect Flarenet Case, it means that you could have the different patches with the sample. You need change the library reference in Marco if you have different Patches (build #) for the version. To check the build #, go to Help->About Aspen Flare System Analyzer, for example, V7.1 (23.0.1.756) means that you have one patch in your Flarenet.
Go to the VBA editor. (Tools ... Macro ... Visual Basic Editor menu option, or press Alt + F11)
In the VBA editor go to Tools ...
Keywords: Automation, Excel, Macro.
References: s
If Flarenet #.# (where #.# is the version of Aspen Flarenet being used - see note below) is checked, uncheck it and press OK.
Then go to Tools ... References again
Click Browse, and Find flarenet.exe in folder C:\Program Files\AspenTech\Aspen Flare System Analyzer V7.1 (changing File of type in order to find exe file), open it, press OK and close the VBA editor.
Note
This Automation application has been created by AspenTech as an example of what can be achieved through the object architecture of Aspen Flare System Analyzer. This application is provided for academic purposes only and as such is not subject to the quality and support procedures of officially released AspenTech products. Users are strongly encouraged to check performance and results carefully and, by downloading and using, agree to assume all risk related to the use of this example. We invite any feedback through the normal support channel at [email protected]. |
Problem Statement: How to solve the error Design Calculations Not Available For Looped/Split Systems | Solution: Aspen Flare System Analyzer (AFSA) has three calculation modes available, there are described inSolution ID 119537
In Design or Debottlenecking run modes, AFSA first evaluates the amount of flow that goes through each pipe to then determine the conditions of this, then calculates the Mach number on each pipe and allows the program to adjust the diameter of every pipe to the smallest dimension that presents no choking problems.
This however cannot be performed on Split or Looped systems, because Aspen Flare System Analyzer does not know at first instance the amount of flow that will be divided through each split, making it unable to determine the choke conditions on all the pipes.
Split systems:
Looped Systems:
Design mode is intended to be used in networks with no split to allow the resize of the pipes on the network and avoid choking problems. If the purpose of the simulation is an evaluation of the performance of the network, make sure to run on Rating mode rather than Design or Debottlenecking.
Keywords: Design, Looped, Split, Error, Debottlenecking
References: None |
Problem Statement: What is the Number Of Valves option for on the Relief Valve Editor \ Conditions page and how is the value used? | Solution: In Flarenet a single relief valve source can be used to model several relief valves connected to a common tailpipe. This is done by setting the Number Of Valves field on the Relief Valve Editor \ Conditions page to the appropriate value.
The value for the specified Number Of Valves is used as follows:
The specified Mass Flow is divided equally between the specified Number Of Valves, to give the mass flow per valve.
The total Rated Flow is calculated as the product of the rated flow for a single valve (seeSolution ID # 109493) and the specified Number Of Valves.
The total flange area used in the swage calculation (between the source and the downstream piping) is taken as the flange area calculated from the specified Flange Diameter multiplied by the specified Number Of Valves.
The attached Flarenet 2004 case demonstrates the above by comparing two separate flare systems:
Flare Line A contains a single Relief Valve source (PSV01) with the Number Of Valves set to 2.
Flare Line B contains two individual Relief Valve Sources (PSV01a and PSV01b) with the Number Of Valves for each source set to 1.
It can be seen that identical results for the two lines are obtained only when using twice the mass flow and half the flange area (**see note 2 below) for source PSV01 in Flare Line A, as compared with the flows/areas in sources PSV01a and PSV01b in Flare Line B.
Note 1, small differences will be observed in the results between the two cases in this example if the Include Kinetic Energy option is selected on the Calculations\Options\General page under the Energy Balance options. This is due to the fact that kinetic energy is a function of the flow velocity squared and, with a single source (as in Flare Line A), the flow velocity used in the energy balance across the swage from the source to the downstream piping is twice that of an equivalent swage fed from two individual sources (as in Flare Line B).
Note 2, there was a bug in Flarenet version 3.51 and earlier where half the flange diameters (instead of the flange areas) where used in the calculation. This was fixed for Flarenet 2004.
Keywords: Number Of Valves, Relief Valve, PSV, Source, Valve
References: None |
Problem Statement: How do I change the atmospheric pressure in Aspen Flare System Analyzer? | Solution: If you use Aspen Flare System Analyzer V7.2 or previous versions, you can go to Calculation->options->general tab:
Calculation:
Options Editor:
If you use version V7.3, you will need click Options in RUN group as following:
Options:
Options Editor:
Keywords: Atmospheric pressure, calculation, options.
References: None |
Problem Statement: The relief valve in Aspen Flare System Analyzer is sized based on static pressure at the outlet of the relief valve. What is the basis for sizing pipes, flanges and fittings? Total pressure or Static pressure? | Solution: Normally, the design aspect of the tailpipe and header piping is a sizing exercise (i.e. selection of appropriate diameter) such that one or all of the Mach number, velocity, Rho V2 and noise constraints are satisfied.
The pipe walls or fittings feels the static pressure, not dynamic pressure. Therefore sizing is based on static pressure.
As for the flare tip, one can specify the pressure drop based on either static or total pressures. Aspen Flare System Analyzer offers an option to display the total pressure or static pressure by checking/unchecking a check box in the 'File>>Preferences>>General' menu.
Keywords: Static pressure, Total pressure
References: None |
Problem Statement: How can I change the number of decimal points for a variable that is shown in the output results of a .pdf? | Solution: Yes, User can change default settings by following below procedure
Go to File || Preferences || Formatting tab || Click on Edit Variables Format tab
In next window under Objects please select Results then select required property to be changed under variable list then click on Format tab then change decimal digit from default to required decimal number and click on OK tab
Keywords: decimal point, Results on PFD etc;
References: None |
Problem Statement: Can I protect my simulation with a password so no one else can modify it? | Solution: This option is not available in Aspen Flare System Analyzer.
However the databases can be protected so they cannot be modified, i.e. no one would be able to change the pipe fitting, schedule and components).
To do so, click on the AspenONE button on the upper left corner of the application window. Choose the option Set Password .
The Password Editor window will now be open
If you have already set your password, you first need to enter the existing password before supplying the new one.
1. Enter your existing password in Old Password.
2. Enter your new password in both New Password and Confirm New Password and then click OK, or Cancel to abort the procedure.
Keywords: Password, protect, databases
References: None |
Problem Statement: End users are getting a Aspen HYSYS Upstream licensing error after the installation of the new license file received from Aspentech and created after January 1st 2010. | Solution: From the SLM perspective the newer license files issued as of 1 January 2010 will only support the versions of Aspen HYSYS Upstream V7.1 and above and in the case of Aspen HYSYS Upstream V7.1 it has the following additional requirements:
? Aspen HYSYS V7.1 should be upgraded with the CP2
The hotfix available from Aspentech KBSolution #127848 must be applied
Aspen Engineering V7.1 Aspen HYSYS Upstream Patch January 2010
The older versions of Aspen HYSYS 2006.5 and V7.0 are NOT supported by the new licenses.
It should also be noted that existing customers of Aspen HYSYS Upstream have the right to continue to use the
older embedded (version 3.3) Multiflash Technology within Aspen HYSYS Upstream versions V7.1.
Data from Multiflash 3.8. can also be imported to Aspen HYSYS V7.1 after the upgrade outlined above.
Please refer to Infochem Computer Services Ltd. for more detailed information about Multiflash 3.8 licensing and installation.
Computer Services Ltd.
http://www.infochemuk.com
+44 (0) 20 7357 0800
Keywords: SLM, HYSYS Upstream Licensing error, Token System
References: None |
Problem Statement: The temperature results do not match each other when switching between steady state model and dynamic model in the hydraulic subflowsheet. | Solution: One of reasons is not including dissipation effects in the energy balance during dynamics. By default, this is turned off (on the dynamics tab, solver control box, Dissipation during Heat Transfer). When the mass flow is pretty high, viscous dissipation can have an impact on the temperature profile. If you turn it on, then the outlet temperature is closer to the steady-state value.
It seems that turning this on also requires more cells to really converge. If you increase the cells, then the outlet temperature decreases a little more towards the steady-stateSolution. But as you increase the number of cells, you will also have to decrease the time-step to see a stableSolution. So there is a trade-off here.
Keywords: Hydraulic subflowsheet, pressure, temperature
References: None |
Problem Statement: How can I import a PVTSim text file into HYSYS? | Solution: The user can add PVTSim .txt file into the Fluid Basis using the PVT Environment inside HYSYS. It does not require a separate PVTSim reader, but to access this feature the user will need the HYSYS Upstream license.
1. First enter the Simulation Basis Environment and select Enter PVT Environment.
2. From the PVT Environment select Add Package.
3. From list of Selected Engine select PVTSim Database Text File Import.
4. Now click Launch Engine...
5. Browse for the PVTsim file name in .txt file format.
Note that the PVTsim fluid package cannot be viewed or edited from HYSYS.
Keywords: PVTsim database
References: None |
Problem Statement: How does Hydraulic subflowsheet calculates the pressure drop for single phase flow when I set up the pipe with two-phase flow correlation? | Solution: In a single phase flow in steady-state, Hydraulics uses the darcy equation. In a single phase flow in dynamics, one momentum and one energy equation are solved. The interfacial terms are zero and a single friction factor is calculated for the single phase.
Keywords: Single phase, two phase flow, HTFS, pressure drop
References: None |
Problem Statement: In HYSYS Dynamics, the pipe segment can model heat transfer using a cylindrical co-ordinate system when selecting the 'Radial Losses' option. What does this mean? | Solution: In HYSYS dynamics the Radial Losses option inside the pipe segment is shown below:
Heat conduction in solids can be reduced to theSolution of a single differential equation. The equation can be derived by making a thermal energy balance on a differential volume element in the solid. For the case of conduction in a linear direction, the heat balance is as follows:
(rate of thermal energy in) – (rate of thermal energy out) + (net rate of thermal energy generation) = (rate of accumulation of thermal energy)
The generation term can be ignored as is only applicable for material which generates heat due to an electric current or by the decay of a radioactive material. Given that the pipe material has a constant density and heat capacity the following equation can easily be derived charactering heat loss through a solid material. This equation just constitutes the heat conduction loss in the x direction.
(1)
Where T is temperature, t is time, x is linear distance, k is thermal conductivity, is density, c is heat capacity and q is heat.
Cylindrical Co-ordinates have the following vector system:
The derivation of the heat loss in the radial direction results in the following equation:
(2)
Due to vector system that represents the circular nature of the pipe, solving equation 2 results with improved accuracy for modeling the heat loss through the pipe wall.
Keywords: Pipe Wall, Radial Losses, Cylindrical Co-ordinates
References: s
Evans, L.C. (1998), Partial Differential Equations, American Mathematical Society |
Problem Statement: In Aspen HYSYS what stream input variable should I use to represent Sm3/h? | Solution: The unit of measurement Sm3/h refers to Standard Cubic Meter per Hour which means the flow rate per hour at standard conditions.
In Aspen HYSYS, the stream variable input for Sm3/h will be the Liq Vol Flow @ Std Cond. Refer to Knowledge Base article 110700.
Standard condition varies from industry to industry.
In Aspen HYSYS. the standard condition reference for pressure is always 1 atm and reference for temperature depends on the unit of measurement used.
For Field units 60F and for SI units 15C.
The user can change the reference standard conditions in Aspen HYSYS. Refer to Knowledge Base article 108976
Keywords: Sm3/h, Standard Cubic Meter per Hour, Liquid Vol Flow @ Std Conditions.
References: None |
Problem Statement: How do you set the Stock Tank Density property in a stream? | Solution: This property is only available when you use the Oil and Gas Feed page to define your stream. The Oil and Gas Feed page it is used to define stream composition as a mixture of oil and gas. You can define the feed makeup as an oil and gas feed using bulk properties or one using information from an imported petroleum oil assay.
Double click on your stream. Go to Worksheet | Oil & Gas Feed. You have two options here:
1. If you defined the feed makeup as an oil and gas feed using bulk properties, you can set the Stock Tank Density directly on the GOR Specifications or in the Oil Properties as Std Liq Density.
2. If you are using information from an imported petroleum oil assay, you must define the Stock Tank Density directly in the GOR Specifications.
Keywords: Stock Tank Density, Oil & Gas feed, Bulk oil properties, Oil assay
References: None |
Problem Statement: How to fix dbupdate error: Failed to execute, file sharing lock exceeded. | Solution: This error is caused when the conversion process failed to modify a Table (Example CRDCUTX Table as shown in the screenshot). It is a common error message that is issued when the specific Table contains too many records (CRDCUTX, in this case). This problem can be resolved by increasing MaxLocksPerFile. Please click HERE to refer to the procedure to increase MaxLocksPerFile given in Microsoft website. The content in the URL is also attached as a word document to this article
Keywords: Dbupdate error
File sharing lock count exceeded
MaxLock per file registry entry
References: None |
Problem Statement: What is the definition of the Compressible Transition value located in the Aspen Hydraulics Orifice? | Solution: The Compressible Transition defines the pressure drop as a fraction of the inlet pressure at which compressible flow pressure drop calculations will be used. For fractional pressure drops larger than the specified value, compressible calculations will be used. Enter zero to always use compressible calculations or one to always use incompressible calculations.
Keywords: Compressible Transition, Orifice, Aspen Hydraulics, Pressure Drop
References: None |
Problem Statement: In Aspen Refinery Multiblend Optimizer, you cannot see the Beginning Inventories data input screen enabled, after creating a new Event Screen, Why? | Solution: Every Event Screen for Aspen Refinery Multiblend Optimizer, requirs at least one Product be defined. If any of the screens does not have a Product defined, then the Beginning Inventory data input Screen is disabled, for that particular Event Screen.
To enable this Option, you need to define at least one of the product for this Event Screen
After enabling the product for the new Event Screen, you can see that Beginning Inventory data input screen is enabled.
Keywords: Beginning Inventories
Disabled
Data Input Screen
References: None |
Problem Statement: How do I report results in both volume and weight for Aspen Multi-Blend Optimizer? | Solution: 1) Turn on memory cache and then run the optimizer
2) Click on report wizard
3) Click on new template
4) Click on Get Started
5) Select volume and weight and push it to the right hand side by clicking on the arrow
6) Click next, give a name in the next dialog and then click finish
7) Now click on Preview Report
Values will be reported in both weight and volume.
Keywords: Volume- weight MBO
MBO results
MBO results in weigh and volume
References: None |
Problem Statement: You may notice that if you attempt to lump pure non-petrochemical components (hydrogen, for example) to hypothetical components – you will get some unrealistic property predictions as shown in the following image. | Solution: The lumper and de-lumper are unit operations intended to help manage converting component sets to different bases.
The Lumper converts a large number of pure and hypothetical components to a smaller reduced slate of components required by other applications, to improve performance or match known stream characteristics.
The Delumper converts a small set of lumped components back to a complete list of components when increased fidelity is required, or when an allocation back to an individual source or well flow composition is required.
The Lumper and Delumper should not be used to lump pure components with hypotheticals, specially if the properties are very different between them; you should use lumping to help with converting to and from different slates of hypotheticals only.
Components which are similar should be lumped together. Attempts to lump components which have vastly different chemical makeups or underlying chemical behavior may generate unrealistic property results.
Keywords: Lumper, Delumper, hypotheticals, Upstream, Aspen HYSYS
References: None |
Problem Statement: The value for ‘Regime’ in the Profiles page in the Performance tab of a Pipe Segment inside an Aspen Hydraulics subflowsheet is displayed as: Unknown. | Solution: The prediction of the flow regime is performed using the calculation method specified in the Data page of the Design page of this unit. If the default option (HTFS) is selected, no flow regime prediction occurs. The same applies to the following methods: Lockhart and Martinelli, Hagedorn and Brown, and Dukler. Selection of another method is recommended (see the entry in the Help files for Aspen HYSYS Hydraulics).
Keywords: Flow regime, Pipe Segment, Hydraulics, HTFS, Slug, Segregated, Annular, Unknown
References: None |
Problem Statement: I am unable to specify the maximum return of investment when I add a heat exchanger in Retrofit mode? | Solution: Inside the base case in retrofit mode it is possible to conduct a retrofit design such as ‘Add Area’ to optimize the heat exchanger network (HEN) design. This feature to add area to optimize the HEN diagram is shown below:
Select the ‘Add Area’ to optimize the HEN
The user selects the base design inside retrofit design
The user will not be able enter the maximum investment when add area is selected for when the EO Solver is checked. If the user would like to add area and enter the maximum investment, they will need to uncheck the EO solver option from the ‘options tab’ and then do a retrofit design. A screenshot showing where the EO solver option can be unselected is shown below:
Keywords: Energy Analyser, HEN, Retrofit
References: None |
Problem Statement: From the 'Model Settings' window, do we need to configure 'MBO ODBC Data Source Name (DSN)' when we choose to use MBO Microsoft Access Database File? If not, why does it show a DSN name? | Solution: The 'MBO ODBC Data Source Name (DSN)' field reads the User DSN and System DSN of the ODBC data source in the machine automatically. In the above screen, it shows 'AspenScop11g' which is the first DSN data source which is shown on this field by default.
In the above model configuration, it reads recipe source from 'MBO Microsoft Access Database File'. Therefore, BCI will not read the ?MBO ODBC Data Source Name (DSN)? field as the MBO model. This field only works when 'Microsoft Access Database File' and 'Microsoft ODBC File DSN' are empty.
Keywords: BCI
Blend Controller Interface
Recipe
ODBC
MBO
Data Source Name
RECIPE.BPC
Honeywell BPC
References: None |
Problem Statement: What could cause Aspen Petroleum Scheduler (APS) or Aspen Refinery Multi-Blend Optimizer (MBO) to crash when launched? | Solution: There are multiple causes that can lead the application to crash. Please follow the next steps to find the root cause of the problem.
1. Check the version of the APS/MBO on the machine. The application folder is located by default in the next path: C:\Program Files (x86)\AspenTech
           Make sure that the latest patch is installed. You can find the latest patches in the next webpage:
http://support.aspentech.com/webteamasp/AllServicePacks_list.asp?at2_division=&at2_product_id=2970
2. Check the version of Mircosoft Office and ensure it is installed properly, e.g. launch Excel separately and make sure it works well.
3. Check the OS and make sure the version of APS/MBO is supported on that OS and Office. You can find the supported versions by looking at the Installation Guide
4. Check the system has enough RAM, a large model can easily consume up to 2+ GB of RAM. Make sure the system has 6 or more GB of RAM for optimal performance. Moreover, the installation guide offers you the recommended settings.
5. Check the version of ABML and make sure it is consistent with the version of APS/MBO.
6. Check the version of UBML and make sure they don’t have multiple versions on their machines and the system is looking for the right version.
7. Make sure the system has the right path for UBML and units.xls file. Since V8.7 (CP4) you can change the default path of your UBML file (application folder) by going to the user settings dialog box:
If the application is still crashing up to this point, please try to use Aspentech's UBML file, located on the next path:
C:\Program Files (x86)\AspenTech\Aspen Petroleum Scheduler\bak
And try to load the demo.mdb model:
C:\Users\Public\Documents\AspenTech\Aspen Petroleum Scheduler\Demo\Access
8. Make sure the user has right privileges to the working folder.
9. Make sure the user has permissions to read / write to the APS/MBO database.
10. Ensure the macro security settings are set to medium so APS can update the units.xls file.
11. Make sure the APS model database has been properly updated to the current version of the APS application. If not, APS will launch an error message asking for updating the model. Please follow KB 119374 to guide you through the process.
Keywords: Crash, Aspen Petroleum Scheduler, Aspen Refinery Multi Blend Optimizer, UBML, RAM, version, security
References: None |
Problem Statement: How can discretization of pipe segments cause dynamic run issues? | Solution: The spatial discretization plays an important role on the time step on dynamic Integrator. When arranging different length pipe segments in Hydraulics sub flowsheet, please make sure number of cells selected will result into uniform length/cell. In the screen shot, pipes are of different length while number of cells is 5 for each. Hence Length/cell ranges from 20 to 1400 m/cell. The Integrator will follow the time step set by smallest discretization (20 m/cell), which can cause the dynamic run significantly slow or fail.
So to avoid dynamic run issues, please assign different cells numbers for different length pipes, so length/cell is almost uniform.
Key Words
Hydraulics, Cells, Segment, Integrator
Keywords: None
References: None |
Problem Statement: What is net cross pinch duty? | Solution: Net cross pinch duty is the sum of all cross pinch duties in a heat exchanger network (HEN).
Keywords: Net cross pinch duty
References: None |
Problem Statement: Does modifying the pour point, wax content or paraffin number using an Assay Manipulator affect the feed characterization properties of a Hydrocracker? | Solution: Using a manipulator to modify these properties does not affect the feed characterization in the Hydrocracker. This behavior is normal since by default these parameters are not considered directly as part of the calibration for the feed properties.
The hydrocracker uses the specific gravity, the 9 distillation points, sulfur (S), nitrogen (N) and basic nitrogen (BN) to map the assay basis to the hydrocracker lumps. Pour point and wax content do not have an effect on the feed.
Normally, the feed objective function tries to match the S, N, BN, distillate, gasoil and residue content of the feed as well as the aromatic carbon fraction (Ca) and naphthenic carbon fraction (Cn). The Ca is estimated from the Total carbon correlation and the Cn is estimated from the NDM (refractive index, density, and molecular weight) correlation; consequently, the Paraffinic, Naphthenic and Aromatic breakdown (PNA) is the variable calculated in order to match the rest of the values.
However, although the paraffin content is not typically used for the assay basis, it can be included in the objective function.
If you go into the hydrocracker environment and then to the Feed Data> Properties page you can select a feed and go into the Advanced options to define the new objective function weights.
By default, the weighting for Paraffins, Naphthenes and Aromatics are zero. You can change these weights in order to take into consideration the alkane content during the feed characterization. Please consider that you should change the Ca and Cn weights to 0 in order to allow the solver to have more freedom to match the PNA, otherwise the match will probably be poor.
This approach would be the best way to indirectly allow the Hydrocracker feed characterization to be affected by changes in properties related to alkane content.
Keywords: Hydrocracker, feed properties, Wax Content, Paraffin content, Pour Point, Refining, Lumps, Assay
References: None |
Problem Statement: I would like MBO to always give inventory infeasibilities over quality infeasibilities. This way MBO will allow component tanks to go infeasible in order to make on spec blends if necessary. | Solution: In order to accomplish this you can increase the Specs Infeasibility Breaker Factor. For example, the next blend was optimized with a Specs Infeasibility Breaker Factor equal to 1:
Notice that we are not complying with specs DON and T160 and we don't have enough inventory of HCL and ALK.
If we change the value of the Specs Infeasibility Breaker Factor to 10, the optimized blend will be:
In this case all properties are within specification, but now the optimizer tell us that we will require different quantities of components HCL and ALK.
Keywords: specs infeasibility breaker factor, optimizer, qualities, inventory
References: None |
Problem Statement: What is Improved in Aspen HYSYS Upstream V7.3 - Aspen Hydraulics and HYSYS Pipe segment | Solution: Aspen Hydraulics is a subflowsheet available with Aspen HYSYS Upstream for the rigorous modeling of pipeline and hydraulic networks. In V7.3, both its flexibility and functionality has been improved, which are summarized below and in the attached presentation.
Substantial Improvement inSolution Speed for Steady-State Flow Networks
The speed of the V7.3 steady-state hydraulic flow network solver has been improved significantly. In some more complicated flow networks, Aspen Hydraulics V7.3 can be up to 10 times faster than V7.2.
Support of Flexible Boundary Conditions for Steady-State Flow Networks
Three variables characterize flow through a pipe - inlet pressure, outlet pressure and the mass flow. Specifying two of these variables (e.g., inlet and outlet pressures) will allow the third variable (e.g., mass flow) to be calculated. The table below shows the different solving scenarios.
Scenario
Inlet Pressure
Outlet Pressure
Mass Flow
1
Calculated
Specified
Specified
2
Specified
Calculated
Specified
3
Specified
Specified
Calculated
Prior to V7.3, Aspen Hydraulics required the specification of outlet pressure and mass flow (Scenario #1). In V7.3, all three scenarios are supported, allowing more flexibility in defining and solving complicated flow networks.
Flexibility to Model Shut-in Branches / Sections of a Flow Network
Individual unit operations (e.g., pipe, tee, valves) can now be ignored in an Aspen Hydraulics subflowsheet, allowing faster development of scenarios where flow through a particular branch or section of the flow network is shut-in.
New Heat Transfer Options
There are two new options for specifying the heat transfer of a pipe segment unit operation in Aspen Hydraulics: (1) specifying the total rate of heat transfer into or out of the pipe segment and (2) specifying the outlet temperature of the fluid leaving the pipe segment.
Check for Choked Flow
Within an Aspen Hydraulics subflowsheet, you can now control whether or not choking calculations are performed across the flow network. If the choking calculations are included, then the fluid velocity at each unit operation is constrained to the local speed of sound. Conversely, without the choking calculation, there are no constraints on the fluid velocity.
Kinetic Energy Treatment
You can now ignore the kinetic energy contribution to the energy balance for all unit operations in an Aspen Hydraulics flow network.
Static Head Treatment
For a pipe unit operation or a pipe segment within a complex pipe, the contribution from the static head to the pressure drop can be controlled. You can choose to include this contribution, always ignore the contribution, or only ignore the contribution for downward flows.
Internal Fittings
The Aspen Hydraulics pipe segment operation now supports internal fittings. Each pipe segment has a Fittings section where you can specify a list of fittings with given loss factors or define overall fitting loss factors for the entire pipe. In addition, you can define a length multiplier for the pipe. When these types of fittings are included, an equivalent pipe length is calculated and reported.
Acceleration Pressure Drop
For a pipe unit operation or a pipe segment within a complex pipe, the contribution from the acceleration to the pressure drop can be controlled. You can choose to include this contribution using the method defined by the flow correlation, always ignore the contribution, or to calculate the acceleration pressure drop based on a homogeneous flow model.
Attached Power Point presentation gives an overview of improvements made to HYSYS Pipe Segment and Aspen Hydraulics Sub-Flowsheet.
Keywords: Aspen Hydraulics, HYSYS Upstream, Upstream, Pipe, Pipe segment.
References: None |
Problem Statement: What could prevent the actual volume flow calculated by the stream from matching the user-supplied oil flow target? | Solution: The oil flow target supplied by the user in the material stream (Worksheet tab/Oil & Gas Feed page), is assumed by Aspen HYSYS to be at stock tank conditions and relatively free ofSolution gas. Therefore, the input value may not be the same as the actual liquid flow, or actual volume flow - liquid phase, which is calculated by the stream and reported in Worksheet tab/Properties page. The oil flow target provided is used to calculate the stream molar flow while the actual liquid flow is a multiplication of the stream molar flow and molar density.
To get the actual liquid flow to match the oil target flow, the mixture must go through oil-gas separation processes to bring the final liquid to stock tank conditions at 60 F and 1 atm. The temperature and pressure conditions of the oil mixture will determine how muchSolution gas is flashed off, as the pressure drops and consequently the actual liquid flow.
Keywords: Oil flow target,
References: None |
Problem Statement: I'm in the process of making additions and deletions to our component tanks in MBO. Nevertheless, when I add a new component in Model/Components, I cannot see it in the Model/Component Rundowns section. | Solution: In order to the component to appear in the Component Rundowns section, the component must be used in a product blend. For example if I add the component CMP1 in the component section:
I will not be able to see it in the Component rundown section:
Until I have specified it to a blend in Model/Products (remember to save the model):
Keywords: New component, component rundown, product blend
References: None |
Problem Statement: Tray sizing Warning: Weir loading is too high | Solution: This is a warning to inform users that the calculated weir load by Aspen HYSYS has exceeded the user specified Max Weir Loading or the default value of 120 USGPM/ft If not specified by user.
The weir loading is a measure of the liquid loading on the weirs. Aspen HYSYS calculates the average weir loading for all weirs and reports it on the Performance | Results | Hydraulic Results | Max Weir Load.
This value is then checked against the specified Max Weir Loading on the Design | Tray Internals. A warning is issued if the calculated value exceeds specified value.
The options to resolve this warning are
1. Increasing the number of flow paths
2. Install a relief weir which may reduce weir loading. Refer to Knowledge Base article 117861 for information on installing a relief weir.
3. Increase the user specified value for Max Weir Loading via Design | Tray Internals page
Keywords: Weir loading, Max Weir Loading
References: None |
Problem Statement: What are the definitions of Oil & Gas Feed (Black Oil) properties in Aspen HYSYS Upstream? | Solution: Oil Formation Volume Factor (FVF) - The Oil FVF is equal to the ratio of the volume of oil andSolution gas at the given process conditions to the volume of dead oil at stock tank conditions.
Solution Gas Oil Ratio (GOR) - TheSolution GOR is a measure of the amount of gas dissolved in the oil at current process conditions. It is calculated as the standard volume of gas (such as the volume of gas at standard conditions) contained in one volume of oil (for example, SCF/bbl or STDm3/m3). At high pressures, where all of the gas is dissolved in the oil, this ratio will be nearly equal to the Produced GOR; at low pressures, theSolution GOR will be near zero.
WOR - A ratio of the water volumetric flow to the oil volumetric flow.
Keywords: Black oil properties, GOR, WOR etc;
References: None |
Problem Statement: I know the inlet stream pressure and the outlet stream pressure as well as the temperature of each, the composition, the heat loss, and the length and diameter of my pipe. Will HYSYS be able to calculate the flow rate of my stream given those conditions? | Solution: This is achievable with the Hydraulics Sub-Flowsheet in HYSYS.
To calculate the flow through the pipe given stream and pipe conditions/dimensions you must do the following:
1. Add the stream in question, and give it Temperature, pressure and composition specifications:
2. Add the Hydraulics subflowsheet from the Upstream tab of the palette.
3. In the connections tab of the Hydraulics sub-flowsheet specify as external stream the stream you added. The properties specified from the original stream will be transferred to the stream in the subflowsheet without the need for you to do it again.
4. Enter the subflowsheet and add a pipe segment. In Design | connections, input the necessary streams, with the feed as the stream you had originally.
5. In data enter the Design | Dimensions of your pipe and in Design | Heat Transfer the heat loss suffered.
6. Open the outlet stream and in Worksheet | Conditions specify the outlet pressure.
7. Lastly move to the
Keywords: Pipe, Flow Calculation, Hydraulics
References: Tab and enter a temperature estimate of the exiting stream.
Once done this, the pipe will automatically solve, calculating the stream flow. |
Problem Statement: How can I model restriction orifice in a pipe line? | Solution: You can enter the orifice diameter or upstream diameter ratio or downstream diameter ratio.
Note: Orifice can be used to divert the flow from one direction to other direction in the network. For example if flow is moving in direction A and direction B (user have two flare tip). And capacity to handle large flow is in the direction A. Then user would like to divert more flow to direction A, instead of increasing the pipe size in direction B. In that case user would like to put an orifice in the flow direction B, so that more flow go to direction A.
Keywords: Orifice
References: None |
Problem Statement: Aspen HYSYS Automation including ASW no longer works after installing a new version: “Error dll not found� | Solution: Certain object type interfaces have changed in newer releases of Aspen HYSYS, so tlbs of different versions are slightly incompatible. Windows will always go to the newest version of the type library when finding interfaces, even if the interfaces were registered with an older version of the type library. That is why this error may arise if you are using code developed for an older version.
The former version of the type library can be explicitly used while the new type is still present. The new type library needs to be unregistered, and the old type library re-registered before using automation.
To unregister the new type library:
1. Open a command prompt as administrator. This can be done by searching for cmd in the Start Menu, right clicking the cmd.exe, and selecting Run as Administrator)
2. Navigate to the HYSYS Vx.x installation directory: cd C:\Program Files (x86)\AspenTech\Aspen HYSYS Vx.x.
3. Run the command: aspenhysys /unregserver. There should be a pop-up saying the OLE registration has been removed.
To re-register the old type library you can either:
1. Open the Start Menu and go to All Programs > AspenTech > Process Modeling Vx.x > Aspen HYSYS
2. Right click on Restore File Associations and select Run as Administrator. There should be a pop-up that the OLE registration was successful.
OR
1. Open a command prompt as administrator
2. Navigate to the HYSYS installation directory
3. Run the command: hysys /regserver (only for v7.3; for 8.0 and above: aspenhysys /regserver). There should be a pop-up that the OLE registration was successful.
To use automation again with the newer version, you will need to re-register the type library as shown above.
In order to confirm that the new type library was successfully unregistered and the old type library was successfully re-registered, you can go to the type library's key in the registry (HKEY_CLASSES_ROOT\TypeLib\{DFC1C58B-AE9F-11CF-8EB2-0020AF119B90}), and check that the subkey for the old version is the only one present (“2.3� will correspond to v.8.6 and “1.7� for v7.3)
Keywords: Automation, dll not found, registering COM components.
References: None |
Problem Statement: Optimization in MBO takes too long when using Rundown components. | Solution: The performance is a direct result of the large size of the resulting MIP problem. In order to improve performance the user can follow the next steps.
1.- Open the CONFIG table inside the database:
2.- Add the next line:
3.- Save the database and run the optimization.
This will reduce theSolution time to a third of the current one.
Keywords: Rundown, MBO, slow, optimization, MIP
References: None |
Problem Statement: I have a software crash when using Aspen HYSYS. How do I view the Event View Log to analyse the source of the crash? | Solution: To help Customer Support solve the issue surrounding the crash we might require the Event View Log. The steps below detail how one can retrieve the Event View Log for the associated crash in Aspen HYSYS.
1. Open the Event Viewer by searching through Windows Search Function.
2. Select Application once you have opened the Event Viewer.
3. Find the Error associated with the application. Scroll to the time and date for when the simulation crashed. Alternatively you can search via the ‘Find…’ function.
4. Copy the Error message Log into a Word Document or Notepad and send this through to [email protected].
5. In addition to the Error Message log please also send through a screenshot showing the Error in the Event Viewer.
If you are struggling with this application please contact Customer Support and Training and we will examine the issue further.
Keywords: Event Log
References: None |
Problem Statement: When a stream line is broken and when it's not? | Solution: A solid stream's line means the enthalpy change (duty) of the stream is completely used by exchangers.If there is a gap in it, then that portion is shown by broken line.
Keywords: Broken, stream, solid
References: None |
Problem Statement: What is the Logic behind tanks included in beginning inventories dialog box? | Solution: The logic is that the component must be a part of a blend product on the screen, for it to show up in the beginning inventories dialog box.
Following is an example using the sample model:
The concerned component is Butane and the component tank is TBUT. Component BUT is part of U87, as defined here:
This will make sure the component comes up in the beginning inventories dialog box:
The criteria is that the component should be part of at least one blend defined on that event screen.
If the user removes the component BUT from ALL the products, the beginning inventories dialog box will not show the name of the component anymore, even if I have its entries in the TNKINV table.
Keywords: Beginning inventories
Blend Component tank
References: None |
Problem Statement: How to locate the time range for a data set that has been imported into APC Builder? | Solution: A user can see (and edit) the time range of the dataset when vector files are initially imported from an external file source into APC Builder.
For the data sets that are already imported into APC Builder, the user will need to look up the properties of the data set in order to view the time range. However, the time range is not displayed in the standard Dataset Properties view. The user would need to follow the steps outlines below in such situations-
a. Move the data set from the Project Tree (left and navigation panel) to the APC Workspace.
b. Right-click on the data set and select Edit Vector Data. This opens a new window.
c. Select one of the vectors from the dropdown menu at the top left corner of the window.
d. Right click on the plot and ensure that the Zoom Out option is greyed out. In case it is not, click the Zoom Out button until the full-width of the data set is visible.
e. This fills in the information for Begin and End time as shown in the screenshot below.
Keywords: APC Builder
Vector Data
Time Range
References: None |
Problem Statement: The user wants to set the same value for a variable in a large number of objects in a flowsheet, and be able to change this value without opening each object and introducing a new specification. For example, we may want to set the same value of temperature or pressure in multiple inlet streams to a pipe network. Then, we may wish to change this value to a different one, and perform a new simulation. | Solution: There are several ways to connect variables in the flowsheet. Assume that we want to specify the same value of a variable (e.g. temperature) to N objects (e.g. N streams). Consider the following options:
1- Using a Set function between two blocks. This involves introducing and specifying N-1 blocks, where the first stream may act as the source object, and all others as the target object. This introduces additional icons and connections in the flowsheet that may be inconvenient (the user may choose to Hide these objects one by one). Also, it requires definition of 2 connections and choice of variable. The relationship between the variables is limited to a linear relation (the default will set the same value in the target object).
2- Exporting the variable value from a Spreadsheet. This requires creating a spreadsheet and defining the value of the desired variable in one cell (say, B1). Then, introduce formulas in N cells of the type “=B1” (or other expression, if desired). Afterwards, the value in each calculated cell needs to be exported to each object. This is done by right-clicking on the cell, choosing ‘Export Formula Result’, and navigating to the desired objects, and associating the same variable.
If a new value is to be introduced to study a different scenario, or when performing a flowsheet analysis (Case Study, Adjust, etc.), only one variable needs to be considered. In this way all objects will have the updated value, and calculations performed accordingly.
3- Using Data Tables. When first specifying each stream, send the value for the desired value to a Data Table (to an existing one or to a newly created one, by right-clicking on the variable field and choosing Send To/Data Tables).
- This will create Data Table ProcData1 if none is created so far. Access this table in the Data Tables folder in the Navigation pane (left side).
- Then, in an application like Excel create a column with the desired value for each variable (this can be done writing the value once and dragging through a number of rows equal to the number of units)
- Copy these values and Paste then into the Data Table for the referred variable. The same value will now be specified into all streams in the Data Table.
Comparing the effort required by these 3 approaches, one can see that while the Set function is adequate for a couple of objects in the flowsheet, if you have more, using the Spreadsheet is more useful. However, the most convenient option is the use of the Data Table, an option usually less explored by users. Ultimately, users will decide which approach is more suitable for their model.
Keywords: Data Table, Input, Flowsheet, Objects, Set, Spreadsheet
References: None |
Problem Statement: Aspen Refinery Multi-Blend Optimizer (MBO) now allows the user to change the prices of components, products and tank increases and decreases in the inventory using new feature called Time varying prices | Solution: Since V7.1 three database tables have been added to support this feature and data entered directly:
- ATORIONMaterialPriceDef : Identifies Material Pricing available to the model
- ATORIONMaterialPriceDetails: Price and time when a material pricing is applicable
- ATORIONMaterialPriceSet: Adds a description to the Price Set
The following records need to be written in capitals :
- SETID, PURCHASEORSALE, OBJ_TYPE,BASIS
In addition, a new dialog box, Price Set has been added where you can select a price set and view price set data. A price set can also be selected from the Model Settings tab of the Settings dialog box
Keywords:
References: None |
Problem Statement: How to troubleshoot, Aspen Process Controller?s Online Servers are not running, after an upgrade? | Solution: After upgrading Aspen Process Controller?s Online Servers are not running.
The following message appears:
?APC Builder
Could not connect to online server `server name?.
Verify that you have permission to access the online system.
Verify that the network is up.
Verify that the Aspen Production Control RTE Service is running on the online server?s host machine and is compatible with this version of AOD.
Verify that you are using the correct ports numbers.
Verify that the online system?s firewall is configured to allow access to the Aspen Production Control RTE Service.?
Check that the Aspen Production Control RTE Service running on the Windows Service Panel points to the right path (in the screenshot the RTEService.exe points to the older version folder).
To fix the path go to the registry HKLM\SYSTEM\CurrentControlSet\services\aspenrtesvc and change the path to the right one.
Stop the service, cross-check that the path is corrected and start the service.
Keywords: Aspen Process Controller, Online Servers, RTE Service
References: None |
Problem Statement: How do I configure cache reads for APC software? Aspen Process Controller exception | Solution: How do I configure cache reads for APC software? Aspen Process Controller exception
In the Aspen Process Controller's Online menu \ Configure This Server
Configuring for IO Source Type: OPC
Uses cached reads
Check box, which if selected, enables retrieving tag values from a tag value cache maintained by the OPC server. If the check box is cleared, then tag values are read on demand from the device.
By default, this check box is cleared.
The use of cached reads has two advantages: it can be significantly faster to read from the OPC server cache than from the underlying device, and use of the tag value cache can reduce the communications load on the underlying DCS or other device. The main disadvantage is that the values in the cache might not reflect the actual current value on the device being served; however, you do have some control over how often the cached tag values are refreshed by setting the Cache Timeout value appropriately. (See next item.)
Tip: You can use multiple IO Sources for an OPC server to help tune the use of cached reads to balance the need of the application for current data against the need for reduced IO loading on the DCS. You can configure one server to use no cache or a fast cache (one with a short cache timeout) for critical tag values, and configure another server with cached reads (with, perhaps, a longer cache timeout) for less critical tag values. Because the use of more than one IO source per OPC server introduces complexity in the online server and online application configurations, you should only attempt this if you anticipate performance problems, or you have other compelling needs that could be addressed by this technique.
Cache Timeout (in seconds)
If a tag value in the OPC server cache was last refreshed more than Cache Timeout seconds before the read, then the OPC server will update that cached value to the actual current device value before fulfilling the read request.
The default value of Cache Timeout is 1 (one) second. This value is used only if the Uses cached reads check box is selected.
For further information please read the Aspen Process Controller Builder Help.
SeeSolution 129885 How do I configure cache reads for APC software? for DMCplus information.
Keywords: Cache, CimIO, OPC, Aspen Process Controller
References: None |
Problem Statement: Regarding the MV definition in the token contract, is it only refer to manipulated variable and doesn't include the Disturbance Variable and Feed Forward Variable?
In other words, the SLM will only charge token by counting the number of manipulated variables but will not count the number of Disturbance Variable and Feed Forward Variable? | Solution: Correct.
From V 7.1 DMCplus started to support token license. And, its software license agreement says token consumption is based on the number of MV(Manipulated Variable). Feedforward/Disturbance variables are not counted for Token consumption. Only MVs is counted for Token consumption.
Keywords: MV
CV
Token
FF
References: None |
Problem Statement: How can I add and display additives in my BCI XML document? | Solution: These are the steps to display a new additive in the XML document:
1. In MBO:
a. Go to Model->Properties: Click on the New button.
b. Created a property and added additive parameters as follows:
c. In Model-> Products: Map this additive dopant to a particular product (U87-CTDR)
d. Also add TEST property as a specification (see the same above screenshot). Click OK.
e. Run the optimizer from Events-> Optimize
f. Exported the blends from Events-> Publish -> Export Blends
g. The AB_ADDITIVES contained the additive details
2. In BCI:
a. Add a new table named AddiMap
b. Map the MBO code (CTDR) to a custom BCI code (TESTED)
c. Submit the recipe and once the XML is generated, we can see the additive details added
Keywords: BCI, Blend Controller Interface, MBO, Additive, AB_ADDITIVES, XML
References: None |
Problem Statement: Is there a way to retrieve the value of a parameter with a selector (MODE) from a unit operating event using automation? | Solution: Operating parameters of events are subitems of the Orion.EventItem and Orion.EventsColl methods. The Tag property will identify the parameter and the Quantity property will bring the value of that parameter.
For example, We have defined the next TEST Unit:
And We have added a new unit operation event with the next information:
The following code will bring the name of the unit (TEST) in cell(1,2) and write the parameter description in column A and the value in column B.
Sub gete()
Dim evnt22 As orion.EventsColl
Set evnt22 = CreateObject(orion.eventscoll)
Dim eventItem As New orion.eventItem
Dim k As Integer
Dim i As Integer
Set eventItem = evnt22.ItemByEventSeq(12476) 'get the event with sequence number 12476
Cells(1, 2) = eventItem.Unit 'write the name of the unit in Cell B1
i = eventItem.count(EVPROP) ' count the number of EVPROP subitems (parameters)
For k = 0 To i - 1
Dim eventsubitemp As orion.EventSubItem 'specify the subitem
Set eventsubitemp = eventItem.Item(EVPROP, k) 'specify that the subitem is a parameter and get the parameter k
Cells(k + 2, 1) = eventsubitemp.Description 'Write the description of parameter k in cell A k+2
Cells(k + 2, 2) = eventsubitemp.Quantity 'write the value of parameter k in cell B k+2
Next k
End Sub
When we run the code, it will bring the next information:
Keywords: parameters, automation, EventsColl, EVPROP, EventItem, subItem, VBA
References: None |
Problem Statement: Depressurization of Liquid filled vessels with Depressuring utility. | Solution: In a liquid filled vessel, the liquid level will be above the nozzle. When the valve opens, it is liquid that will flow out initially until there is sufficient vapour in the top of the vessel. The reason for this is that Aspen HYSYS vessels only allow nozzles to be specified on the side wall of the vessel not on the top of the vessel.
In the case of saturated liquid, there will be initial liquid flow because the nozzle is underneath the liquid level. Vapour will follow immediately as the pressure drop instigates vaporization.
For a sub cooled liquid. There will be initial liquid flow through the valve followed by a mixture of liquid and vapour as the pressure drop continues to the point when the liquid becomes saturated at lower pressure and from then on vapour flow.
Until vapour is generated, the profile will be based on liquid, then liquid + vapour and then finally vapour hence the presence of irregular profile.
Below are a few pointers on modeling the depressurization of a liquid (sub cooled) filled vessel using dynamic depressuring utility. These are general recommendations.
1. Modeling a depressurization of vessel to be 100% full of liquid is not exactly realistic, and it would be better to include some pad gas (like N2 or air) to occupy the vapour space in the tank. This will help with quick vapourization to avoid flash convergence problems which can be caused with using a 100% liquid-filled vessel.
2. Use of small time steps of integration. Since a small change in the vessel holdup of a liquid filled vessel impacts the pressure of the vessel significantly, the first and foremost requirement of modeling the depressuring of a liquid filled vessel is to use a smaller time step(can adjust this on 'operating conditions' time step size e.g. 0.1 secs). In general, a smaller time step helps solving the differential equation in difficult conditions such as sharp changes in the profile. However the model takes longer to run.
3. If a number of flash problems are encountered then try using the Try IO Flash First option on the Stab test page of the Fluid Package. This option is only really applicable for dynamic cases such as this. Even though it is not recommended generally in steady state but it could solve problems with the dynamic depressuring utility.
4. It is a better idea to run the model in Calculate Pressure mode rather than Calculate Area mode (Design | Operating Conditions | Valve Outlet Solving Option). Pressure is calculated in every one step whilst Area in several steps. With the possibility of already existing irregular calculation profile, several step calculations for Area will not very helpful.
5. If depressuring supercritical fluids, check the results very carefully and use your engineering judgment while analyzing the results.
Keywords: 100% Liquid filled, Depressuring utility, Nozzle, Calculate Pressure, Calculate Area, Step size
References: None |
Problem Statement: A value for the pressure drop multiplier is specified in EDR Fired Heater in the Program Options ¦ Pressure Drop menu:
However, when the simulation is run with this parameter, and then for the default value (one), the pressure drop ratio between the two runs does not equal the specified value for the multiplier. For example, if we put 2 as multiplier, the pressure drop calculated does not double. | Solution: The Pressure Drop Multiplier adjusts the stream frictional pressure drop. In order to analyze the effect of this parameter on the outlet stream pressures, the contributions of tube-tube loss and loss after bank in the firebox should be turned off. You can do so by specifying these factors as zero for the respective banks (in this case, stream 3 was associated to Bank 4). User can see the banks/streams information in the geometry of the fired heater.
If a new simulation is run for a pressure drop multiplier m, the ratio between the stream pressure drops of that run and the one with defaults (m=1) is m.
Keywords: EDR, Fired Heater, Pressure Drop, Multiplier, Velocity, Head
References: None |
Problem Statement: How to generate a datasheet (API type or more) in Aspen Fired Heater. | Solution: In Aspen Exchanger Design and Rating (EDR), we have the export to Excel function that can help users generate datasheet. People use this feature most frequently for Aspen Fired Heater because currently the overall summary does not have an API format datasheet.
Please follow the instructions below.
1. Go to File> Export> Excel using specified template.
2. Find the default rout for those template on C:\Program Files (x86)\AspenTech\Aspen Exchanger Design and Rating V8.8\Excel Templates.
3. Select the right template and click open. Users have to match their Exchanger type with the datasheet type very well.
4. Select the location that you want to save the file. You will see the API datasheet generated.
Keywords: API, Datasheet, Export to Excel
References: None |
Problem Statement: Why is my 3-phase separator not solving when using Acid Gas property package? | Solution: The Acid gas package is by default considering only two phases: Vapor and Liquid. To consider Vapor-Liquid-Liquid equilibrium you need to change the Phase Handling in the Properties environment for the package. After doing this, the 3 phase separator should be solved showing the 3 phases.
Keywords: 3 phase separator, Acid Gas, property package, Phase Handling
References: None |
Problem Statement: A new option has been added in Multi-Period Blend Optimization dialog box | Solution: The Fix In-Progress Blends option has been added in v8.4 which allows users to specify the delay time when working with in-progress blends.
This option allows the user to fix the recipe of any blend that starts prior to the start of the campaign, as shown:
The Fix In-Progress Blends Delay, Min option, allows users to specify how in-progress blends are handled:
A.- If (BlendStart-ModelStart+Fix In-Progress Blends Delay) <0, then blends are considered in progress and will be made a fixed recipe blend.
B.- If this value is set to 0, all blends that start at the Model start will not be considered in progress. These blends will not be marked as a Fixed recipe, (as indicated in the Blend Summary report) if the event itself is not originally marked as fixed recipe. Default value is 0.17 minutes.
Keywords: -Multi period Blend Optimization dialog box
-Fixed recipes
References: None |
Problem Statement: Beginning derived properties are not correctly calculated when importing the baseline (bad input data) Eg. DON is not being properly calculated from RON and MON values. Nevertheless, as these properties are derived properties, APS/MBO simulator should correct these values using the correlations defined in Model/Properties. Why are the wrong values are being published at model start date instead? | Solution: APS/MBO assumes that TNKINV values are correct. So, the values published at model start date in _TANKS are TNKINV values. In order to tell APS/MBO to publish simulated values you need to add the PUBLISH_AT_10_SEC keyword in the CONFIG table with a value a of Y. This way, the correct derived properties will be calculated and published in _TANKS results table.
Keywords: bad input data, derived properties, TNKINV, _TANKS, PUBLISH_AT_10_SEC
References: None |
Problem Statement: What is the most suitable HYSYS property package to use with the following components: Water, Air, Ammonia, Carbon dioxide and Urea? Most fluid packages indicate that the Urea is in solid phase, whereas the Urea should be vapor in the stream. | Solution: The recommended property package is NRTL. Please find below a step-by-step procedure to select it.
1. Select Aspen Properties database
2. Add your components
3. Select Aspen Properties fluid packages
4. Select Electrolyte NRTL and click Electrolyte Wizard
5. Deselect Salt formation and tick Water dissociation as your stream consists mostly of water. Then click Get Reactions and OK. This will add the ionic components to your component list.
6. Go to the simulation environment and create a stream with your P, T and mass flows. Observe that urea as well as the other components are vapour.
Keywords: Urea, property package, vapor
References: None |
Problem Statement: When modelling an absorber using the Acid Gas package, the property page of the product streams takes a while to open (15-20 seconds). Why does this page take longer to open than any other page? | Solution: When opening the property view of the product streams for the first time, the program will take some time to calculate Cp/Cv and related parameters. This is because of the the rigorous calculation methods used by the acid gas package. This may not happen in every cases, for example the properties are already populated in which case the update will take less time.
The workaround to open the property view quicker is to remove Cp/Cv and related properties such as Cv, mass Cv, Cp/Cv using the correlation manager.
Keywords: Acid Gas, property view, Cp/Cv
References: None |
Problem Statement: How does Aspen HYSYS calculate Bulk Velocity in the Erosion page of Flow Assurance tool? | Solution: The Bulk Velocity as reported in the Erosion page of Flow Assurance is the superficial velocity calculated at actual flowing condition.
Bulk velocity = Volumetric flow rate of the combined phases at actual condition / cross-sectional area of the pipe
Keywords: Flow Assurance, Erosion, Bulk Velocity
References: None |
Problem Statement: How do I delete and reset my available unit sets to the system default in Aspen HYSYS? | Solution: The available unit sets are viewable in the Unit Sets feature found on the Home ribbon, which opens the Units of Measure menu of the Options window.
In the Load Preference Set button, the user can delete the current .prf file for the version they are using. Once this .prf file is deleted, the unit set will reset to the system default the next time the user opens HYSYS. The system default unit sets are EuroSI, SI and Field Units.
Keywords: Unit Sets, SI, Unit of Measure
References: None |
Problem Statement: How do I save APC controller changes? | Solution: The Aspen Production Control Web Server Manager only shows the Start / Stop button as an active option for the APC controllers.
To save the APC controllers changes you need to go to the APC Builder \ Online Applications (Online menu \ Applications) \ Get Snapshot button.
What’s a Snapshot: “A retrieved application snapshot provides you with everything you need—at your desktop client location—to operate and inspect the application, in the same state in which the application existed on the server when the application was stored or retrieved as a snapshot”.
Additional Information is found in the Help section: Retrieving Application Snapshots from Online (hit the Help button in the Get Application Snapshot window to access it).
Keywords: APC, Aspen Process Controller, PCWS, Save, Snapshot
References: None |
Problem Statement: Is there a lookup table for AW_INDFLG values? | Solution: It may happen that one controller turns due to variable validation failure. In Aspen Watch, it is useful to see the AW_INDFLG to evaluate which failure this variable has.
A lookuptable for all the errors can be found in the message.dat file (under ProgramData\AspenTech\APC\Online\cfg).
For instance, the condition number 11020. points out to the message Antiwindup AWS = 3 -- No movement.
Keywords: AW_INDFLG, table
References: None |
Problem Statement: How to switch Models and Tuning Sets in APC applications? | Solution: Note: In Aspen Process Controller Builder, the feature for switching models / tuning sets is available only for FIR model-based applications.
Engineer permission is required. Go to Aspen Process Controller Builder, Online menu, Manage Model Switching. The related dialog box is displayed.
As prerequisite the associated *.mdl and *.tuningset files are required in the proper path:
Windows Server 2003 :\Documents and Settings\All Users\Application Data\AspenTech\RTE\<Version> \Clouds\Online\app\<AppName>
Windows Server 2008 & 2012 :\Program Data\AspenTech\RTE\<Version>\Clouds\Online \app\<AppName>
The Models and Tuning Sets can be changed manually or by statements in calculations.
Further information is found in the Aspen Process Controller Builder Help \ Application Management \ Switching Models and Tuning Sets in Applications.
Keywords: Aspen Process Controller, APC, Model Switching, Model, Tuning Set, CCF Switcher
References: None |
Problem Statement: How to adjust number of MIP iterations (MAX_MIP_ITER in CONFIG) in MBO? | Solution: In CONFIG setting of Aspen Refinery Multi-Blend Optimizer, MAX_MIP_ITER defines the maximum number of iterations under MIP constraints. The default setting for MAX_MIP_ITER is 100. In most cases, MBO will finish MIP iterations way before 100 so that there is little need to fine tune this parameter.After these MIP iterations, MBO will fix the integer variables and keep on doing optimization based on continuous LP system.
However for MBO rundown blending models, if MAX_MIP_ITER is not set or it is set to 100, MBO will automatically set MAX_MIP_ITER to 5. User may need to fine tune MAX_MIP_ITER in rundown blending cases mainly for speed reason.Smaller MAX_MIP_ITER value will speed up MBO running, butSolution may be less optimal.
Keywords: MAX_MIP_ITER
CONFIG Setting
References: None |
Problem Statement: Where can I find all of the Aspen Process Controller messages? | Solution: In V7.2 and earlier, the ACP online messages are stored in a system event log. You can use the standard Event Viewer utility (available from the Administrative Tools menu) to inspect it. In the Event Viewer you will see a custom event log called AspenRTE. Right click on it and select Save Log As. This will allow you to save it as either a .txt or a .csv file for inspection by any editor or spreadsheet program.
Keywords: APC, log, event viewer, messages
References: None |
Problem Statement: How do I configure the Language support for Aspen Process Controller Builder? | Solution: Added in V7.3.0.2 and V8.0.0.2, language support is now available in Aspen Process Controller Builder.
There are ten (10) supported languages: English, Chinese, French, German, Italian, Japanese, Korean, Spanish, Portuguese and Russian.
When Aspen Process Controller Builder starts, it detects the Regional and Language Options and uses the current Microsoft Windows locale settings to select the language to display.
It can be change from Regional and Language Options (Windows Server 2003) / Region and Language (Windows 7 & Windows Server 2008).
Note: If you change the Windows locale settings, restart the Aspen Process Controller Builder program for the change to take effect.
For example, find below a Spanish Aspen Process Controller Builder screenshot.
Note: Different English standard Date and Time formats can cause issues with some functions. Please seeSolution 136859 What could prevent me from importing a dataset?
Keywords: APC, Language Location
References: None |
Problem Statement: Why does my utility consumption from Retrofit Design go below the Energy Target? | Solution: It is true that the Energy Target is the minimum energy required using Pinch Technology. The utility consumption from user design or retrofit can either equal or higher than the target values. However, user may see the utility calculated from retrofit design goes below the Target, e.g. the screenshot as shown below:
The reason is the minimum temperature approach used in Targeting and Retrofit Design are different. Energy Targeting is using the DTmin user specified as is seen in Flowsheet Option:
While in Retrofit Design, the lowest exchanger minimum temperature approach (EMAT) in the existing networks is used which can be found in Setup | Constraints:
Therefore, if user specified DTmin is too far away from the EMAT in the existing exchangers, there will be discrepancy and it is possible to see utility in retrofit design have lower values compared to the energy target.
It is recommended to check if the DTmin is reasonable before the activated Energy Analysis.
Keywords: DTmin, EMAT, Utility, Energy Target
References: None |
Problem Statement: Can the Post sheet in the Units file be used to add additional constraints in MBO? | Solution: No. The post sheet cannot be used to impose additional constraints in Aspen Refinery Multi-Blend Optimizer. MBO only uses Units worksheet for UserCalcs or automation. If the user doesn't have any UserCalcs/automation in the model, even a blank Units file would work for MBO optimization.
Keywords: Post Sheet
Units.xls
UserCalcs
References: None |
Problem Statement: A new section called Adjust Stop/Start dependent events, has been added to the Model Settings tab associated with the Setting dialog box | Solution: The associated options allow you to truncate seconds from time dependent event Start/Stop times and to select what to automatically adjust, rate or volume, in order to accommodate the time changes.
Adjust Stop/Start dependent events:
These options allow you to specify if seconds will be removed from the Start or Stop times associated with a particular time dependent event. The ability to input Start/Stop seconds through the event dialogs is not allowed and therefore you will not see seconds appear on the event dialog interface. However, the database supports the inclusion of seconds and if seconds are manually entered or imported as part of an event Start/Stop time, these seconds will be used in calculations. Note that inclusion of seconds in the database may also occur when the system makes adjustments to Start/Stop times to meet rate or volume requirements. Though it may not be apparent from the dialog interface, these seconds may exist and will therefore affect calculations unless the Trim seconds for Start/Stop option is selected.
Select Settings | Model Settings from the menu bar or Settings icon to see this option:
A.- Trim seconds for Start/Stop
Select this option to truncate Start and Stop times to exclude seconds. When truncating seconds, Rate or Quantity amounts will be adjusted, if necessary, to accommodate for the difference in time. Selection of this option only applies to new or edited events moving forward. Your selection does not affect existing events. By default, this option is not selected.
B.- Adjust Measure Type
Select what you wish the system to adjust to compensate for the truncation of seconds in your Start and Stop times. You can select Rate or Volume to be adjusted. The default is Quantity.
Scenario 1: Default un-check the Trim settings
1. Open with the MBO demo model
2. Goto the model setting, check the default setting is uncheck for the Trim seconds for start and stop,
3, Add a new Product Recipe event as below
4. G oto the database and check the Stop time is with the seconds time, and the rate/Quantity is with the original value
Run below query on the .mdb
SELECT STOP , RATE , QTY ,X_SEQ FROM ATORIONEVENTS WHERE X_SEQ = 1193
Get below result
Scenario 2: With Trim Seconds, and Rate Type
1. Open the demo Access model on MBO
2. Go to the model setting, check the Trim seconds for start and stop option and set the type with Rate ,
3, Add a new Product Recipe event as below
4. Run below query on the database .mdb
SELECT STOP , RATE , QTY ,X_SEQ FROM ATORIONEVENTS WHERE X_SEQ = 2577
Get below result, The stop seconds time is trimmed and the Rate value is changed accordingly with the value of 150.0163
Scenario 3: With Trim Seconds, and Quantity Type
1. Open the demo Access model on MBO
2. Go to the model setting, check the Trim seconds for start and stop option and set the type with Quantity,
3, Add a new Product Recipe event as below
4. Run below query on the database .mdb
SELECT STOP , RATE , QTY ,X_SEQ FROM ATORIONEVENTS WHERE X_SEQ = 1195
Get below result, The stop seconds time is trimmed and the Quantity value is changed accordingly with the value of 191.9792
Keywords: -Model settings
References: None |
Problem Statement: Why can't I find vertical gridlines in trend thumbnails in v7.3.03? | Solution: After enhancing the vertical gridline features (see the Gantt Options - tab Graphic Features), we eliminated vertical gridlines in thumbnails. Thumbnails do not have tickmarks, but some gridline types cannot be implemented without tickmarks. Besides, it makes drawing faster. All the gridline features are set via the Gantt Option dialog (tab Graphic features). The obsolete menu command Vertical Gridlines was eliminated.
Keywords: thumbnail
tickmarks
gridline
Gantt
References: None |
Problem Statement: Why are the Volume% Yields calculated in a Reformer different from the Volume Fractions reported by the stream properties in HYSYS? | Solution: The calculation of Volume% Yields and Volume Fractions depends on the density used for each component. These differences are caused by two reasons:
1. The density values the Reformer uses for Hydrogen, Methane, Ethane and Ethylene (represented as H2, P1, P2 and OL2 respectively by the Reformer) are not the same than the values HYSYS uses. The Reformer uses FOE (Fuel Oil Equivalent) specific gravities for these components. This is because there's not realistic values for standard liquid densities for light ends, so it's fairly common to use FOE to get volume yields.
2. The yields are calculated on a reduced component slate in the Reformer. For example, the component MBP6 is used on when the Reformer volume yields are calculated. However, this component is mapped as 22-dimethyl butane and 23-dimethyl butane in HYSYS, and the densities of these will be slightly different. So even if the Reformer were using the same densities for the light ends, the results would be very close, but not exactly the same.
If you want to reproduce the volume yields values reported by the Reformer, you need to take the volume flows of the products and divide them by the Standard Volume Flow of the feed stream (do not normalize). The results will be different for the light ends (due to Reason 1), and it might be some differences for the rest of the components (due to Reason 2), but they will be very similar.
If you want, you can modify the FOE specific densities HYSYS uses, you can do this by going to the Reformer Environment | Operation | Advanced, just keep in mind that these modifications will adjust the light ends volume yields, but yields for the rest of the components will stay the same.
Keywords: FOE, Volume yields, Reformer
References: None |
Problem Statement: How HTC is calculated? | Solution: The default velocity and flow area of a stream is given under Physical Properties tab. These two variables along with several physical properties are used to calculate HTC. You need to change the velocity and flow area to have relatively accurate HTC.
The equations used to calculate HTC is provided in page 13 of AspenEnergyAnalRefGuideV7_2.pdf. It's in the same page from V7.0 to the current version. The file is there in the installation folder of Aspen Energy Analyzer Vx.x. The default location is C:\Program Files\AspenTech\Aspen Energy Analyzer Vx.x (for example, V7.2).
The equations are shown below as reported in the above mentioned document.
Keywords: HTC, equation, heat transfer coefficient.
References: None |
Problem Statement: How do I report vapor pressure in Aspen HYSYS? | Solution: There is no direct way to report vapor pressure, however you can add a Property Table for each stream and calculate it.
Go to each stream> Attachments Tab> Utilities> Add> Property Table
Then in the Property Table,
Select the Temperature and the Vapour Fraction as the Independent Variables, and setup the Mode for both as State, and the value for the Temperature has to be the same as the temperature in you material stream and define the Vapour Fraction as 0.
Then define the Pressure as the Dependent Property
Press Calculate, go to Performance and see the Pressure which is going to be the vapour pressure,
Keywords: Vapour Pressure, Vapor Pressure
References: None |
Problem Statement: A new SLM v8.0 hotfix targeted to address high network bandwidth consumption for APC Controllers is available through | Solution: 138502. How does this affect the manner in which the APC software license checkout the licenses?
Solution
With the latest hotfix the APC software itself does not have a timeout on the license check. The message you see every 4 hours is more of a status message than an indication that another checkout attempt is performed. With the latest hotifx, if a license acquisition attempt fails we immediately try again; before the hotfix, the software would wait an hour before trying again.
However, the APC software uses an SLM client component that does have an internal 4 minute timer. Once a license server is contacted, then the SLM client component tries to communicate with the server every 4 minutes. If it fails to get a response back 3 times in a row (or within 12 minutes), then it will assume the server is unreachable. If the communcations delay is longer than 4 minutes, then no connection to the server is established and so no license checkout will ever succeed.
SLM profiler also has a timeout, but it is different as each key gets its own timeout as the data request for each key is independent.
Keywords: APC Builder
SLM
Network Bandwidth
References: None |
Problem Statement: How can I add constraints on the total volume of blends in MBO? | Solution: In MBO, trend limits can be used to add constraints. Trend limits on the tanks are hard constraints and are taken into consideration while optimization of blends. For example, if the user needs to put a constraint on the Sum of all premium blend volumes, a simple workaround is to blend all the premium blends into a virtual tank instead of individual physical tanks and use trend limit for this virtual tank to represent the constraint of the total production. MBO will be able to optimize all the blend events quantity and try to keep the total tank inventory (represented by the amount of premium product) within the specified range.
Keywords: None
References: None |
Problem Statement: How do you calculate the Overall Efficiency and Firebox Efficiency shown under the Fired Heater Summary page? | Solution: Overall Efficiency = (Total heat absorbed by all process streams in heater)/(heat released from fuel combustion + sensible heat from fuel and oxidant)*100
Firebox Efficiency = (Heat absorbed by process stream in firebox)/(heat released from fuel combustion + sensible heat from fuel and oxidant) *100
Heat released from fuel combustion (W) = flowrate of fuel (kg/s) * Lower calorifcic value of fuel (J/kg).
Sensible heat = Flowrate x (Enthalpy (at inlet temp) - Enthalpy(at 25C))
Keywords: calculation, efficiency, firebox, heater, overall
References: None |
Problem Statement: In the the Configuration form for the column operation in Aspen HYSYS, the user needs to specify the number of trays. How many trays should be entered for a packed column? | Solution: In Aspen HYSYS, by default, the user supplies the number of theoretical trays and the pressure profile in the column. In this way it does not really matter whether the column has trays or packing as the internals. This is because, HYSYS uses the concept of equilibrium 'stages'. Stages in HYSYS do not necessarily mean trays. Therefore, if you were to use a packed column, you would have to do the simulation in the exactly same way, i.e. using number of stages.
Tray Sizing Utility in HYSYS can calculate the pressure drop over a column (or section of column) given details about the diameter of the column and the column internals. In fact, this is the only time in HYSYS that the column internals can impact the column calculations. In this utility, the user can either select Packing or Trays for the pressure drop calculations.
When using Packing then depending on the HETP (Height Equivalent to Theoretical Plate/Stage) of the packing the height of the column can be calculated. Based on the packing vendor's specifications for the HETP the packed height is given by HETP * Number of stages.
Keywords: ,
Packed Column, Number of stages, HETP
References: None |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.