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Problem Statement: How can I set a variable equal to the initial value of another variable?
This is needed for example when you want to monitor the conversion in a batch reactor. If we have a simple reaction such as A --> B, the conversion is equal to (CA(t) - CA(0)) / CA(0), where CA(t) is the concentration at time t, and CA(0) the initial concentration.
The problem is to have a variable which contains the value of the concentration at time 0. | Solution: The model below shows how this can be done.
Model Reactor
CA as conc_mole (initial);
CA0 as conc_mole;
r as realvariable (description:reaction rate);
k as realvariable (fixed, 0.123, description:kinetic constant);
// material balance
$CA = -r;
// reaction rate
r = k*CA;
// conversion
conv as realvariable;
conv = (CA0 - CA)/CA0;
// equations to record initial value of A
dCA0a as hidden realvariable;
dCA0b as hidden realvariable;
$CA0 = 0; // freeze CA0
$dCA0a = CA0 - CA;
dCA0a : rateinitial;
$dCA0a : 0; // --> this means that CA0 = CA for the initialization
dCA0b = dCA0a;
dCA0b : initial; // --> this is to complete the initial conditions
End
The mechanism only requires an understanding of the initialization run and initial conditions. As you can guess, the trick is here:
// equations to record initial value of A
dCA0a as hidden realvariable;
dCA0b as hidden realvariable;
$CA0 = 0; // freeze CA0
$dCA0a = CA0 - CA;
dCA0a : rateinitial;
$dCA0a : 0; // --> this means that CA0 = CA for the initialization
dCA0b = dCA0a;
dCA0b : initial; // --> this is to complete the initial conditions
When we say $CA0 = 0, this implies that CA0 is a constant (because its rate of change is zero). So the objective is to set CA0 equal to CA at time zero for the initialization run. If we can get that, then we are done for the rest of the dynamic simulation.
When we say $dCA0a = CA0 - CA, we state that there's a new state variable dCA0a which time derivative is equal to the difference of CA0 and CA. If we specify dCA0a as rateinitial, this means we specify the value of $dCA0a at time 0. If we specify this value to 0, this means CA0 = CA, which is exactly what we want. So we are almost done. The final bit is to have the correct number of initial conditions. We have 3 state variables, so we need 3 initial conditions. CA is an obvious initial condition, $dCA0a is another one. So we're still missing one initial condition. In the ideal world we would like to specify the initial value of dCA0a, but in ACM we can't because it's either rateinitial or initial. So the idea is to declare another variable dCA0b, which is equal to dCA0a, and so we can set our missing initial condition.
Keywords:
References: None |
Problem Statement: A simulation that uses user procedures returning derivatives is running correctly in version 11.1 but fails in version 12.1 with the following error message:
An exception (code 0xc0000005 - access violation) occurred in user procedure pExampleDerivs, loaded from D:\how to return derivatives\example.dll
Why? | Solution: The handling of derivatives from procedures has been changed in version 12.1. The derivative matrix (usually called DERIVS) is allocated memory by ACM only if the derivatives are to be calculated by the procedure (if ICALL is 3 or 4). This means that DERIVS should not be accessed in the other cases.
For example, this code is incorrect:
SUBROUTINE EXAMPLE(x, y, Iflag, Derivs, NOut, NIn, ICall) IMPLICIT NONE
DOUBLE PRECISION x, y
INTEGER Iflag
INTEGER NOut,NIn
DOUBLE PRECISION Derivs(NOut,NIn)
INTEGER ICall
Derivs(1,1) = 0d0 ! this will cause an access violation in version 12.1
C
IF ( ICALL .EQ. 0 .OR. ICALL .EQ. 4) THEN
C Put your code to calculate output value(s) here
Iflag = 1
y = 3*x**2
ENDIF
C
IF ( ICALL .EQ. 3 .OR. ICALL .EQ. 4) THEN
C Put your code to calculate derivative value(s) here
derivs(1,1) = 3*2*x
Iflag = 1
ENDIF
C
RETURN
END
Use Derivs only if ICALL is 3 or 4.
Keywords: fortran
procedure
derivative
References: None |
Problem Statement: Expressions and statements in tasks require values to be specified in base units of measurements (usually Metrics, for example for Aspen Dynamics simulations). This is annoying if you are used to non-metric units. Is there any trick that could make life easier? | Solution: Two approaches can be used:
Create variables (fixed) in Flowsheet constraints, a dummy equation to make them active, with the appropriate variable time. You can then use these variables in the task statements, the unit conversion will be handled in the flowsheet LocalVariables table automatically.
Use a script for doing the conversion. You can invoke a script from a task.
Attached is an example showing both methods. The script (in Flowsheet) ConvertValue is generic and therefore can be used in other simulations.
This limitation is being considered for a future release.
Keywords:
References: None |
Problem Statement: How does the new Vapor Phase Association (VPA) model in AES 10.2 work? | Solution: A new Vapor Phase Association (VPA) model of IK-CAPE (a consortium of German companies which cooperate to define key standard property models and data exchange format for use in Computer-Aided Process Engineering) has been added to Aspen Properties. This VPA model is more general than the existing vapor phase association models, such as the Nothnagel, Hayden-O''Connell, and Hydrogen Fluoride (HF) hexamerization models. The new VPA model can account for the formation of dimers, tetramers, and hexamers.
The enclosed document (vpa.doc, courtesy of IK-CAPE) contains some more information on the new vapor phase association (VPA) model. The basic assumption of the model is that the gas phase non-ideality is caused exclusively by molecular association. Attractive forces between the molecules and the complexes are neglected, and molecular association is modeled by means of chemical theory. The latter accounts for the formation of dimers, tetramers, and hexamers by means of LN(K) = A + B/T, and the coefficients A and B for each species/equilibrium have the following parameter names:
DMER - VPA DIMER EQUILIBRIUM CONSTANT
TMER - VPA TETRAMER EQUILIBRIUM CONSTANT
HMER - VPA HEXAMER EQUILIBRIUM CONSTANT
All of these coeffcients are Pure Component Temperature-dependent correlation parameters where DMER/1 corresponds to A and DMER/2 corresponds to B, for example.
To use the new model, select the model name for PHIVMX and PHIV as ESVPA and ESVPA0 (for mixtures and pure components, respectively) on the Properties / Property Method / Models sheet.
Keywords:
References: None |
Problem Statement: You can use the automation methods and properties to build a flowsheet remotely using, for example, Visual Basic for Applications (VBA) in Excel.
You may wish use automation to:
Automate repetitive changes to flowsheet layout.
Add new blocks from a list of unit names and types already existing in Excel.
Make modifications to very large flowsheets, where response times can be slow.
Optimize flowsheet layout (Aspen Water uses these automation methods and properties to optimize water networks.)
Have fun and use a cool feature to impress your colleagues! | Solution: The attached example shows the basic commands for adding a new block to the flowsheet and connecting it to existing blocks.
The file is an Excel spreadsheet that contains a macro. If you are asked whether you wish to enable macros when you open the .xls file choose to enable. You need to edit the VB code (access the editor with Alt+F11) and change the path to the Aspen Custom Modeler example file fivetank.acmf if you have not done a default installation onto the C: drive. Of course, you can modify the code to suit your own circumstances.
From the spreadsheet, click the button marked GO! Aspen Custom Modeler starts with the fivetank example, runs the simulation as an Initialization and saves a snapshot of the results. Then, the Visual Basic code adds a new tank and a new stream, connects the new entities up to the existing flowsheet, and runs the simulation again.
Check the Aspen Custom Modeler Help for more information and options. Open Help / Help Topics, click on the Index tab and enter automation. Select the page Overview and click on the link for automation methods and properties. From the tree-view, click on Flowsheet. The properties and methods you need are documented under the Flowsheet-Specific Methods and Stream-Specific Methods links.
Keywords:
References: None |
Problem Statement: How do I refer to .NET KB dlls from a different location? | Solution: We refer to .Net DLL KBs in the library set configuration file by specifying the KB directory path using the following definition:
ManagedKBsDirectory= C:\KBS
This definition refers to all KB .dll files in the C:\KBS location.
For one workspace you can only have one KBs dll directory, if you want you can also add location of KBScripts by adding the following lines.
KBScriptDirectory = C:\KBS
KBScripts =
Keywords: .NET KB dll
References: None |
Problem Statement: How do I display Case name in a datasheet or a drawing? | Solution: The GlobalsClassView class view has the attribute CaseName. This can be used to display the case name in a datasheet or drawing.
To display in a datasheet:
You can create a field of type' value' and map this to CaseName attribute under GlobalsClassView
To display in a drawing:
You can create a label with an attribute mapped to CaseName attribute under GlobalsClassView
Keywords: display case name, show case name, show case
References: None |
Problem Statement: If we move Workspaces and Workspace Libraries folder to different server (on different computer on which Aspen Basic Engineering is not installed), then to which account should we give access rights to access these folders and what kind of access should we provide (i.e. read only or read and write)? | Solution: You should provide access rights to ZYQADADMINISTRATOR group and ZYQADUSER group based on this table below.
Workspaces Folder
Workspace Libraries Folder
ZyqadAdministrator Groups
Read and Write access
Read and Write access
ZyqadUsers Groups
Read and Write access
ReadOnly access is possible
Keywords: User access, access rights
References: None |
Problem Statement: What call should be used for the Nelder Mead estimation parameters?
For the NL2Sol parameters there is some examples from the online help which show which calls should be used for this parameter option, but for the Nelder Mead parameters this is not available. | Solution: When you open the Help topic Estimation Solver Properties please look at the OpenNLPEstSolverParameter row in the table and there you can see example of the syntax for calling parameters. To set Nelder-Mead options substitute Nelder-Mead with OpenNLPEstSolverParameters and use the following call syntax:
Application.Simulation.Options.OpenNLPEstSolverParameters.Item(Initial_simplex) = 0.1
Application.Simulation.Options.OpenNLPEstSolverParameters.Item(Maximum_iterations) = 500
Application.Simulation.Options.OpenNLPEstSolverParameters.Item(Number_of_restarts) = 1
Application.Simulation.Options.OpenNLPEstSolverParameters.Item(Optimization_tolerance) = 0.0001
Application.Simulation.Options.OpenNLPEstSolverParameters.Item(Penalty_parameter) = 1
Keywords: Nelder-Mead parameter, calling,
References: None |
Problem Statement: How do I change the scale of the symbol/label in graphic definer? | Solution: You can change the scale of a symbol or label using the 'scale' button from the toolbar:
If you don't see the scale button in the toolbar then you can activate it by right clicking on the gray area and picking 'change' toolbar from the menu as below:
Keywords: GUI, interface, settings, customization
References: None |
Problem Statement: I want to create datasheets on Aspen Basic Engineering (ABE) from Aspen HYSYS simulation data (Figure 1), but I do not want to create PFDs. How I can do that?
Figure 1. Aspen HYSYS library model Natural gas dehydration with TEG. | Solution: This can be accomplished by using the ABE Simulation Importer and ABE Explorer.
Please do the following to create a datasheet from ABE Explorer using imported simulation results.
1. Import your HYSYS model using Simulation Importer.
2. From the Simulation Importer mapping dialog box, click Select/ Options. Make sure the below options are selected, then click OK.
A
3. From the Simulation Importer mapping dialog box,A click Select/ Create. The Equipment dialog box
appears. Select the check box next to the equipment that you want to create. Clear the check box for the equipment that you do not what to create. The Equipment Class column allows the change of equipment class that will be created on workspace. When ready, click OK.
4. Navigate to Material Ports tab and map the equipment ports.A
A
When ready, navigate to Results and then click Transfer.
5. Open ABE Explorer and click on All Major Equipment on Filters column.
6. Right click on E-101 Shell and Tube Heat Exchanger and select Datasheet
7. Select E-101: AZ Shell And Tube Heat Exchanger and click open on Datasheet dialog box New Tab.
8. A Datasheet (Figure 2) populated with data from the HYSYS heat exchanger block E-101 (Figure 3) will be created.
Figure 2. E-101: AZ Shell And Tube Heat Exchanger datasheet.
Figure 3. HYSYS Heat Exchanger E-101 Worksheet.
Keywords: datasheet, simulation importer, ABE Explorer, equipment ports
References: None |
Problem Statement: How do I find the class name of an object using the query editor based on object ID? Or, if we know the object ID then how can we find the class of that object from query editor? | Solution: To find a class of object using Query Editor application you need to open Query Editor from Explorer application by going to View menu.
Once Query Editor is opened you can write below query which assumes Object ID is 1234. You can replace this Object ID number with your specific Object ID.
<%
set objClass = ObjectStore.FindObject(1234)
response.write objClass.class.name
%>
Once above query is written then click on Submit button to see the results.
Keywords: Query, query editor, find, class
References: None |
Problem Statement: Which version of Smartplant Foundation is compatible with Aspen Basic EngineeringV 7.3 | Solution: Aspen Basic Engineering V7.3 is compatible with Smartplant Foundation 4.3
Keywords: Compatibility, SPF, smartplant
References: None |
Problem Statement: How does Aspen Air Cooled Exchanger calculate the total surface area? | Solution: The total surface is calculated from the number of bundles per unit times Ext surface/bundle
In this example, you can see we have a total surface of 351.3 m2 because there is one baysperunit and one bundle per bay
Keywords: Air cooled exchanger, total surface area, bundle, ext surface.
References: None |
Problem Statement: Why are some values from UOStreams not transferred to Aspen Basic Engineering (ABE) Streams when using the Simulation Importer to transfer simulation results? | Solution: Make sure the attributes that you are trying to transfer from UOStream to ABE Stream exists in ObjecMapperFlow Classview and composite view.
If that attribute does not exist then you need to customize ObjectMapperFlow Classview and compositeview to add these attributes.
Once customization is done, then you need to transfer the results again using Simulation Importer.
Keywords: Simulation importer, UO results
References: None |
Problem Statement: When I add the Service.sym label to a PFD and connect it to a piece of equipment, the only way I can input the service is by creating a datasheet for it. Label cannot be edited from Drawing Editor, the label field is all grayed out and looks like it is locked. | Solution: Options can be attached to a field in a label in the same way as for datasheets to give the end user a pick list of options via the PFD at run time. In this case the label field cannot be edited because it was defined as read only. (See Fig. 1)
In order to make label field edible, do the following:
1. Open Graphics Definer,
2. Open the workspace,
3. Open service.sym label.
4. Right click on service field and select properties,
Figure 1. Label Field Properties.
5. Go to Text Properties tab and make sure the Field is read only check box at the bottom is not selected. (See Fig. 1)
6. Click Apply and then OK,
7. Go to Definer on tool bar and then compile label,
8. Save label with the same name Service.ztf to the templates folder under
C:\AspenZyqadServer\Basic Engineering16.2\WorkspaceLibraries\Templates
9. Save label with the same name Service.sym to the label folder under
C:\AspenZyqadServer\Basic Engineering16.2\WorkspaceLibraries\Symbols\Labels\Equipment
10. Close Graphics Definer and Reload workspace via Administration tool
11. Open an existing PFD file using Drawing Editor and add a Service label to any equipment.
12. You should be able to edit field on Service label.
Keywords: Label, drawing Editor, Graphics Definer
References: None |
Problem Statement: Why are the Show line number and Print header and footer options greyed out in the KB Script rule editor? | Solution: If mouse cursor is in the Build, Trace or Run Errors tabs or any one of these three tabs are selected then you will see Show Line Numbers and Print header and Footer option is grayed out.
To enable this option click in KB script area as highlighted below and you will see Show Line Numbers and Print Header and Footer options are enabled.
Keywords: Options, Disabled, grayed out
References: None |
Problem Statement: When detaching a datasheet from the XLDSE (Excel Data Sheet Editor), there are some cells that will show the green warning flag on the upper-left corner of the cell(see screenshot below). How can I remove this type of warning messages from these cells? | Solution: In order to avoid showing these warning messages on the cells, under the XLDSE go to File | Options | Formulas | Error Checking, uncheck the option called ‘Enable background error checking’, as the screenshot below shows:
The cells should now be displayed without the green warning flag as shown below:
Keywords: Green warning flag, Formulas options, XLDSE.
References: None |
Problem Statement: What version of Oracle is supported with ABE 7.3? | Solution: 10g
Keywords:
References: None |
Problem Statement: If one of the property databanks, like Aspen Properties, ComThermo or B-Jac is used to generate the physical property data, then when the program is run, you may get an Input Error 8002 that stops the execution of the program. This | Solution: explains how you can run the program at low temperatures.Solution
Depending upon the stream that is giving problems, go to the Input | Property Data | Tube Stream Properties | Properties tab, where you may notice that the lowest temperature in the Range field has a dark red background, indicating that the input is outside the expected range.
In the form, delete the lowest temperature from the Range and then check the Overwrite properties. Now the case should run.
Keywords: Input Error 8002, Property Data
References: None |
Problem Statement: DMCplus has to read loop status and alarm status of Yokogawa CENTUM as integer value or its calculation cannot handle character strings. | Solution: For CENTUM CS
*** 25-Feb-2008 11:25PM *** Matsuno, Hiroaki ***
Following shows how to read loop status as integer
CS type Use @MODE
Example FC3105.@MODE
MAN 8388608
ROUT 262144
RCAS 524288
AUTO 4194304
CAS 2097152
XL/V type
Sample : FC3105.LS
MAN 9
AUTO 11
CAS 19
SPC 27
Keywords: EXAOPC
Yokogawa CENTUM
References: None |
Problem Statement: Fixing Aspen DMCplus Model Near-Colinearities | Solution: An explanation / overview of the Smart Audit tool is provided in that attached document.
Download document and open.
Keywords: tools, model, dmc, co-linearity
References: None |
Problem Statement: How can we change database location for existing SQL workspace? | Solution: You can change database location, user name and password from workspace.udl file located under that particular Workspace folder.
For example if your workspace name is AZ162 then you can change these information by opening workspace.udl file which is by default located at C:\AspenZyqadServer\Basic Engineering16.2\Workspaces\AZ162.
Here is the screenshot of workspace.udl file
Keywords:
References: None |
Problem Statement: After successfully running an Air Cooled Exchanger case, on Results | Calculation Details | Interval Analysis - Tube Side | Pressure Change tab, users will see there is a column called ''Flow Pattern Data'', containing ''X'' ''Y'' ''Flow pattern'' and ''Regime''.
This | Solution: explains what they mean.
Solution
Users will see ''Flow Pattern Data'' outputs like this:
The column ''Flow pattern'' refers to the tube orientation, which can be seen from the table below together with the empirical flow pattern map used.
Flow Pattern
Empirical Flow Pattern Map
HF
VD
VU
ID
IU
Horizontal Flow
Vertical Downflow
Vertical Upflow
Inclined Downflow
Inclined Upflow
Taitel and Dukler A.I.Ch.E.Journal vol 22 no.1 Jan '76.
Golan and Stenning 1969, ''Two phase vertical flow maps'', Proc. Inst. Mech. Eng., Vol. 184, Pt. 3C, pp. 108-114
Hewitt and Roberts 1969, ''Studies of two phase flow pattern by simultaneous X-ray and flash photography'', AERE - M 2159.
Vertical downflow map is used
Vertical upflow map is used
The X and Y values are coordinates of the above flow pattern maps. Depending on the empirical flow pattern map used, they could be represented by local liquid/vapour ρν2 values, superficial velocities or other parameters. The pair of local X and Y values will determine a point that is in a certain flow regime zone in the map. Users shall be aware that, the boundary curves separating flow pattern regimes are not clear distinct boundaries and will have uncertainties.
For the ''Regimes'', the following codes are used
Regime
Description
ANDSLQ
ANNULR
BUBBLE
BUBSLG
CHURN
DISBUB
INTMIT
OSCLRY
SLGBUB
STRSMO
STRWAV
WSANLR
OUTRNG
SNGLIQ
SNGVAP
ANNULAR DISPERSED LIQUID
ANNULAR
BUBBLE
BUBBLY SLUG
CHURN
DISPERSED BUBBLE
INTERMITTENT
OSCILLATORY
SLUG AND BUBBLE
STRATIFIED SMOOTH
STRATIFIED WAVY
WISPY ANNULAR
COORDINATES OUTSIDE RANGE OF MAP
SINGLE PHASE LIQUID
SINGLE PHASE VAPOUR
Keywords: Flow Pattern Data, Flow Pattern, Regime, X and Y, Interval Analysis - Tube Side
References: None |
Problem Statement: Why can't I find the unmapped simulation objects in the workspace after transferring the results? | Solution: Whether the unmapped simulation objects will stay in the workspace or will be deleted from the workspace depend on the setting under Results=>options. If the option Delete unmapped simulation objects under Results|Options is checked, then the unmapped simulation objects will be deleted from the workspace after the transfer of results is complete:
Keywords:
References: None |
Problem Statement: User experiences frequent crash in modeler based product (ACM, APD etc) with the message: Cannot Open PlotData.CPD to write in his machine. What is reason of this crash and how do I prevent it? | Solution: PlotData.CPD is created in AM_XXXX in ACM based product to save plot related data while running dynamic models. It saves plot related variables history.Model may crash while writing in PlotData.CPD.Following are the reasons and the steps how to prevent this crash:
1. One reason would be interference with any third party software deployed by the company for security purpose. If you have anti-virus installed (e.g; McAfee) and running, Plotdata.CPD could be considered as threat for antivirus and may try to delete this file from the machine. You may try to work with IT to add PlotData.CPD as an exclusion in threat searching. This would prevent interference with antivirus with PlotData.CPD.
2. Another reason of the crash might be related to plotdata.cpd file that max out at 2GB owing to 32 bit addressing limits (signed integer data pointers used). Thus we must look at the ways to reduce the rate of growth of the data file. The 2GB limit is huge. This is unlikely to grow file that much bigger unless you have very large models and running for quite long time.
There would be many other third party tools, user may run for security purpose. Make sure you consider to exclude PlotData.CPD from your threat list.
Keywords: Anti-Virus, PlotData.CPD
References: None |
Problem Statement: Is it possible to report the stream composition in the Air Cooled Exchanger results? | Solution: Starting with Aspen Air Cooled Exchanger Program V7.2, when the tube side stream physical properties are calculated using one of the internal properties packages (B-JAC, COMThermo and Aspen Properties), phase composition information is generated at each of the property points. This information is used to produce new output information, giving the stream compositions at both inlet and outlet as both mass and mole fractions and mass flows of each phase and of each component in each phase.
Note: It reports the components in the order of its entry into physical properties with name Comp1, Comp2, Comp3 respectively instead of their actual names.
To access the Tube side stream composition results, Run the simulation and go to Results | Thermal /Hydraulic Summary | Performance | Tube Side Composition. Please see the picture below.
Keywords: Results, Composition, Phase Compositions, Stream Composition, Tube side Composition
References: None |
Problem Statement: Which classviews are used during import and export operations in Thermal Design Interface? | Solution: The Export To Option uses the following class views, depending on the type of object selected for export:
Export To
Classview Name
Aspen Aircooled
AcolPlusExchangerInput
Aspen Plate
PlatePlusExchangerInput
Aspen Shell&Tube
TascPlusExchangerInput
File | HTRI
HTRIExchangerInput
File | EDR
TascPlusExchangerInput
The Import From Option uses the following class views, depending on the type of object selected for import:
Import From
Classview Name
Aspen Aircooled
AcolPlusExchangerResults
Aspen shell & Tube
TascPlusExchangerResults
HTRI
HTRIExchangerOutput
Aspen Plate
PlatePlusExchangerResults
Keywords: import, export
References: None |
Problem Statement: What versions for Fortran compiler are supported? Which version of developer studio should be used with Aspen Custom Modeler? These are common questions from Aspen Custom Modeler users. | Solution: This table gives the requirements for users intended to develop their own components to run in Aspen Custom Modeler. The selection of Fortran compiler options has been expanded since V7.2.
Fortran
C++
Visual Basic
For procedures
For procedures or exporting model to Aspen Plus or Aspen HYSYS
For custom forms
V7.0
Intel Fortran 9, or 9.1
Microsoft Visual C++ 2008
Microsoft Visual Basic .NET 2008
V7.1
Intel Fortran 9, or 9.1
Microsoft Visual C++ 2008
Microsoft Visual Basic .NET 2008
V7.2
Intel Fortran 9, 9.1, 10, 10.1, 11, or 11.1
Microsoft Visual C++ 2008
Microsoft Visual Basic .NET 2008
V7.3
Intel Fortran 9, 9.1, 10, 10.1, 11, or 11.1
Microsoft Visual C++ 2008
Microsoft Visual Basic .NET 2008
Keywords: Fortran, C++, Visual Basic, compiler, developer studio
References: None |
Problem Statement: How is the order of workspaces decided in administration tool? | Solution: Workspaces are listed in same order as defined in 'workspaces.lst' file under ..\AspenZyqadServer\Basic Engineering16.2\Workspaces. If you want to change the order in administration tool, you should open 'workspaces.lst' with notepad and modify it.
Keywords: configuration, display
References: None |
Problem Statement: How do I delete a bridge? | Solution: You can delete a bridge from the explorer tool. To do that:
Open Explorer tool
Create new folder
Add bridge to that folder which you want to delete
Once bridge is added to the folder you can right click on bridge and delete it.
Keywords: delete, bridge delete
References: None |
Problem Statement: How to include the class store in new library? | Solution: When you create a new library, then engineeringmodel.azcs is included in it by default. If you want to include any other class store, you should place it under C:\Program Files\AspenTech\Basic Engineering Vx.x\WorkspaceLibraries\DataModel.
After placing it, Open the command to create new library and pressure New(insert) icon (highlighted in red in the snapshot) to include the desired class store.
Keywords:
References: None |
Problem Statement: When you try to compile edi_emulation.c that is supplied with ACM, you get the following error message:
Microsoft (R) 32-bit C/C++ Optimizing Compiler Version 12.00.8804 for 80x86 Copyright (C) Microsoft Corp 1984-1998. All rights reserved.
edi_emulation.c
atutcfor.h(357) : fatal error C1189: #error : WHAT IS YOUR PLATFORM? | Solution: You have to define two preprocessor symbols to activate the proper macros.
For the command line compilation you need the options /DWIN32 /DINTEL_X86
If you build from a Visual Studio project, follow these steps:
go to Project, Settings
select the Settings For: to All Configurations
go to the tab C++
select the Category Preprocessor
enter in the preprocessor definitions: WIN32, INTEL_X86 (WIN32 is probably already present)
Note that makefiles (MakeUserCode) generated by ACM contain the proper options.
Keywords:
References: None |
Problem Statement: How is the Face Velocity calculated in Aspen Air Cooled Exchanger? | Solution: In Aspen Air Cooled Exchanger, the face velocity is calculated by the total actual volumetric flow rate over the total bundle face area (as there is only one output, it cannot considered the number of fans that are off).
Where:
M = Air Mass Flow
Rho = Air Density
Lt =Tube Length (Effective length)
N = Number of tubes per row
Pt = Transverse pitch
Keywords: Face velocity, Air Cooled
References: None |
Problem Statement: Why am I able to enter my option in some drop-down cells in the datasheet editor but not in others? | Solution: There are two reasons that you cannot enter own options in drop-down cells beside the list of options that are already available:
1. The field in datasheet editor is mapped to an attribute of closed enumeration type.
2. When options for the field are defined using datasheet definer and those are defined as closed
Please note that you can enter options in the datasheet editor beside those that are there, but only if the field options are of the open type.
Keywords:
References: None |
Problem Statement: In a cylindrical coordinate system, a volume average of temperature (in a system with no angular dependence) is given by:
Tavg = 2/(R^2 * L) * DoubleIntegral( T(r,z) * r * dr * dz)
with integration limits of r = 0 to R, and z = 0 to L.
How can I do this in ACM? | Solution: In version 12.1 it is possible to evaluate the integral of distributed quantities. So, you need to create a new distribution with the quantity you want to integrate:
Model Example
Radius as lengthparameter (1);
L as lengthparameter (2);
pi as realparameter (4*atan(1));
r as lengthdomain (length:Radius);
z as lengthdomain (length:L);
T as distribution2D (XDomain is r, Ydomain is z);
Tr as distribution2D (XDomain is r, Ydomain is z, integrals:idxdy);
Tavg as realvariable;
for ir in [0:r.EndNode] do
for iz in [0:z.EndNode] do
Tr(ir, iz) = T(ir, iz)*r(ir);
endfor
endfor
for ir in [0:r.EndNode] do
for iz in [0:z.EndNode] do
T(ir, iz) = 3*r(ir);
endfor
endfor
Tavg = 2*pi*sigma(Tr.idxdy)/ (pi*Radius^2*L);
End
Keywords:
References: None |
Problem Statement: How to change the value of a global variable using Visual Basic for Applications without explicitly qualifying the variable, e.g.
Flowsheet.Global.GlobalVarName is currently required,
why not
Flowsheet.Global(GlobalVarName) or Flowsheet.Globals(GlobalVarName) | Solution: The statements Flowsheet.Global(GlobalVarName) or Flowsheet.Globals(GlobalVarName) are incorrect. However you can easily achieve this with the Resolve function.
Example for a flowsheet script:
on error resume next
vname = Tamb ' this is the variable name
v = Global.Resolve(vname)
if err.number <> 0 then
err.clear
application.msg no such variable
else
application.msg v.value
end if
In a VBA subroutine:
Sub Example()
Set acmobj = GetObject(d:\demo.acmf)
On Error Resume Next
vname = Tamb
v = acmobj.Application.Simulation.Flowsheet.Global.Resolve(vname) If Err.Number <> 0 Then
Err.Clear
MsgBox no such variable
Else
MsgBox v.Value
End If
End Sub
Both examples will print the value of the global variable Tamb if it exists.
Keywords:
References: None |
Problem Statement: How to create multiple line field in a datasheet? | Solution: You should define that particular field as multiple line in datasheet definer as below.
Open Datasheet definer and connect to workspace.
Open that particular datasheet for which you want a field to be multiple line
Map that field to appropriate line (see help file for detail on how to map a field)
Select that particular field
Click on Datasheet menu from toolbar and select properties | Field properties
It will open a new dialogue box as shown below. From here, change the number of lines option as you would like to see in your datasheet.
? Click Ok and generate a template and save it at appropriate location.
Close the workspace and close datasheet editor.
Reload the workspace from Aspen Basic Engineering Administration tool.
Open that particular datasheet from datasheet editor and you should see multiple lines for that field.
Keywords: multiple lines
References: None |
Problem Statement: This is a simplified version of a real application for reactor modelling with ACM.
A structure is used to store the kinetic data.
Structure KinDataStructure
K as realvariable (fixed, 42);
End
A reaction model is then used for the calculation of reaction rates:
Model reaction
kin as external KinDataStructure;
r as realvariable;
r = kin.K;
End
and finally, the reactor model is:
Model reactor
n as integerparameter (10);
reac([1:n]) as reaction;
r as realvariable;
r = sigma(reac.r);
End
How can one ensure that each instance of the reaction submodel in reactor uses the very same structure, and can be specified just once instead of having to specify it for each instance of reaction individually? | Solution: To provide the same reference in sub-models as in the parent model declare a structure reference in the sub-model, and give the parent reference as an argument to the sub-model instance. For this specific example: two changes are required in the reactor model, as shown below.
Model reactor
kin as external KinDataStructure; // change 1
n as integerparameter (10);
reac([1:n]) as reaction (kin: kin); // change 2
r as realvariable;
r = sigma(reac.r);
End
Keywords:
References: None |
Problem Statement: How to manually uninstall Aspen Custom Modeler models from your machine. | Solution: You can uninstall models that have been exported both as windows installer packages and as dll files. The method will vary depending on the file type chosen:
- For dll files, open the ACM version from which the model was exported. Go to Tools / Delete Exported Model or Structure dll. A new window will open with the list of models. Select and delete.
- For a model exported as MSI package, you can uninstall it through the Windows Control Panel.
The aforementioned methods are the standard procedures to uninstall ACM models, however, if ACM is no longer available in your computer or if the windows installer failed during the process, you can still have them fully removed from your machine. These are the steps needed:
Go to C:\ProgramData\AspenTech\AES and open apmodelcatalog.xml with notepad. To get access to this location you need to have selected in folder options: show hidden files and folders.
The file should look something like this:
Remove the line as shown in the picture above and save the file. In this example the model to be deleted is called Example_Model.dll.
Finally, delete the folder pointed in the xml file, in this case:
C:\ProgramData\AspenTech\AES\AMModels\25.0\Exmple_Model
Now the model is fully removed from your computer.
Keywords: ACM, export models, uninstall, xml, dll.
References: None |
Problem Statement: How do I export multiple datasheet of a particular object together using datasheet editor? | Solution: You can create xml files for all datasheets of a particular object at one time. This is how it works
1. Select one or more datasheet to export to xml format in datasheet editor, as below
2. This will generate 1 xml file
3. Load Excel Datasheet Generator =>pull up generate menu and browse to relevant xml file. As the xls file is generated, you will be prompted for name and location to save the xls file. If you have selected more than 1 datasheet to export in point 1, it will save the datasheets xls separately and prompts you for each datasheet name each time.
Please note that, it will takes time for xls files to load if you will select multiple datasheets.
Keywords: None
References: None |
Problem Statement: Why do I not see AZ162 workspace for V7.3 64 bit install? | Solution: ABE (Aspen Basic Engineering) V7.3, 64 bit version does not support OOTB (Out Of The Box) Access workspace. So you will not see AZ162 workspace on your system.
You need to create a new workspace using SQL Server or Oracle database. For more information on supported version of database, please refer to Installation guide on our support website.
Keywords: AZ162, workspace, connect to workspace
References: None |
Problem Statement: In the Exchanger Design and Rating (EDR) suite of programs, users own enhancement data may be entered into the program to model enhanced surfaces on the outside or inside the tubes.
The purpose of this | Solution: is to describe the different methods available to enter the X-side enhancement for Aspen Air Cooled Exchanger, where if a Tube shape, other than round is used ( Input > Exchanger Geometry > Tubes > General tab ) then enhancement data must be entered.
The enhancement outside the tubes is entered from Input > Program Options > Methods/Correlations > Outside Enhancement tab. Clicking on the scroll down button in the first column, the various options to enter the data are given below.
If Enhancement data is not entered into the program, then the error as below will be given.Solution
It is possible to input performance data for extended surface types, which are not one of the standard fin types for round tubes as shown in Input > Exchanger Geometry > Geometry Summary > Geometry tab. The data may be input in terms of a heat transfer and pressure drop parameter as a function of the flow parameter, either as points or curves. The form in which this may be entered is shown below.
Heat Transfer Pressure Drop Flow Input Methods
1 htc pd per row mf Points
2 j factor friction factor Re do Curves
3 Nu Eu Re dh
These are defined as follows;
htc heat transfer coefficient corrected for surface effectiveness,
pd per row mean crossflow pressure drop over one row
mf X-side mass flux based on the bundle face area
heat transfer j factor
friction factor f
Re do Reynolds No. based on the tube outer diameter,
Re dh Reynolds No. based on the bundle hydraulic diameter,
Nu Nusselt No.
Eu Euler No.
where;
is the pressure drop per row
fluid density
fluid viscosity
fluid thermal conductivity
fluid specific heat capacity
Prandtl Number
flow length from leading edge of the first row to the leading edge of a tube row that would follow the last tube row, were another row present
maximum mass flux between the tubes
bare tube diameter
bundle hydraulic diameter
minimum flow area between the tubes
total heat transfer area
When entering data as points, enter two values for each parameter on a log-log scale and ensure that the points entered cover all likely values which will be calculated by the program. Extrapolating data introduces uncertainties compared to interpolating data.
If curves are entered, then the input coefficients and exponents for the heat transfer and pressure drops are of the form;
Heat transfer: A, coefficient, m exponent
Pressure drop: B, coefficient, n exponent
Keywords: flat tubes, oval tubes, enhancement data, result error 4028
References: None |
Problem Statement: How to select which variables to declare in ports and streams? | Solution: It is a difficult question to answer which variables to pass in ports, and the discussion below gives some pointers and ideas.
You can stick to the Connection stream type instead of creating your own stream types. This avoid completely the decision of which variables to define in streams. This minimizes the number of variables. It may not always minize the development effort, as using equations in streams gives more modeling power.
For simulations with physical properties, one objective is to avoid duplication of physical property calculations. So it is a good idea to declare in the port all the properties, such as T, p, h, s, rho, etc. But on the other hand, this means that all the models will have to evaluate these properties. Let's say for example that one model requires the viscosity, and you were to declare it in the port. Then all your models would have to evaluate the viscosity, even if they wouldn't need it for themselves.
In Aspen Dynamics, we declare F, T, p, h, rho (or actually the molar volume) and the composition as molefractions. One could add vf the vapor fraction. It's sometimes useful to use partial flowrates instead of compositions, although there is no clear evidence on which approach is best.
The rule is then that a model is responsible for the calculation of the properties of the outlet ports. The handling of feed streams can be done with a feed block, as was done in SPEEDUP. Or by using the equations in the stream type. You simply disable the calculations within the stream with a structural condition based on whether the port is connected.
stream example
in_f as input mainport;
out_p as output mainport;
if not in_f.isconnected then
// equations for properties because this is a feed stream
end if
end
More generally, the variables to declare in a port are not selected on a specific model, but on the information you want to pass from one model to another.
Remember that when you connect a stream to a block, you actually connect the output port of the stream to the input port of the block, so you effectively connect two ports.
You can use the port inheritance to add variables on an existing port type.
port TP
T as temperature;
p as pressure;
end
port TPX uses TP
x(componentlist) as molefraction;
end
so that you have some flexibility when designing and reviewing your simulation. The ismatched property can be used to check if a variable is present in the port
Model mmm
in_f as input TPX;
if in_f.x.ismatched then
//
endif
End
Another point to consider is that ACM compresses the equations, so that if you have x = y; y = z;, this is actually only one variable (equivalence_xxxx) which replaces x, y and z. So only 1 variable instead of 3. This implies that one should not have to worry too much about duplicating variables.
About equations in streams, the handling of feed streams has been already mentionned (and product streams if you need pressure driven specs, or handle reverse flow; see http://support.aspentech.com/webteamcgi/SolutionDisplay_view.cgi?key=110354). It is useful to declare local variables in the stream, even if these are duplicates of input and output port variables. The reason is that you can put them on tables, select their spec, etc.
stream ssss
in_f as input TPX;
out_p as output TPX;
T as temperature (description:temperature, 123);
p as pressure (description:pressure, 34);
x(componentlist) as molefraction (1/size(componentlist);
xn(componentlist) as molefraction (1/size(componentlist));
if not in_f.isconnected then
T : fixed;
p : fixed;
xn : fixed;
x*sigma(xn) = xn;
endif
in_f.T = out_p.T;
in_f.P = out_p.p;
in_f.x = out_p.x;
T = in_f.T;
p = in_f.p;
x = in_f.x;
end
The shorter names look better on tables and plots, ie T instead of in_f.T.
If we look again at the viscosity example, if you wanted to report the viscosity, you could add the equation in the stream type (but not in the port). And if you believe this property is required only for some streams, not all, you can use a parameter to control this, and let the user select if the property has to be calculated or not. This minimizes the risk that an error would occur in the calculation of a property that is actually not wanted by the user.
stream ssss
in_f as input TPX;
out_p as output TPX;
T as temperature (description:temperature, 123);
p as pressure (description:pressure, 34);
x(componentlist) as molefraction (1/size(componentlist);
xn(componentlist) as molefraction (1/size(componentlist));
if not in_f.isconnected then
T : fixed;
p : fixed;
xn : fixed;
x*sigma(xn) = xn;
endif
in_f.T = out_p.T;
in_f.P = out_p.p;
in_f.x = out_p.x;
T = in_f.T;
p = in_f.p;
x = in_f.x;
// viscosity calculation
mu as viscosity;
CalculateViscosity as YesNo (No);
if CalculateViscosity == Yes then
call (mu) = pMu (T, p, x);
endif
end
Beyond all this advice, it's a matter for you to work out what is best for you because the language is giving you quite a bit of flexibility. Of course, if you can easily avoid duplicating variables, you should do it. That is based on the principle of keeping things simple, which is probably the best guideline one can follow.
Keywords:
References: None |
Problem Statement: How to handle multidimension arrays and single dimension arrays as input/ouput arguments of a procedure? | Solution: It is possible to use a slice of a multidimensional array as an argument to a procedure which expects a single dimension array. The single dimension array is build from the list of the elements specified from the multidimension array.
For example, the procedure pTestArray takes one single dimension array as input arguments.
Procedure pTestArray
library: testarray.dll;
call: testarray;
implementation: subroutine testarray.f;
language: fortran;
inputs: real(*);
outputs: realvariable;
End
The model declares a two dimension array C. The first call will send the vector { C(1,1), C(1,2], C(1,3), C(1,4), C(1,5) }. The second call will send the vector { C(1,1), C(2, 1), C(3, 1) }. In other words, the procedure does not see the shape of the ACM array.
Model TestArray
C([1:3], [1:5]) as realvariable (fixed);
x as realvariable;
x1 as realvariable;
// a column of C
call (x) = pTestArray (C(1, [1:5]));
// a row of C
call (x1) = pTestArray (C([1:3], 1));
End
See the attached file for the full code and model for this example.
Keywords:
References: None |
Problem Statement: Can Aspen Basic EngineeringV 7.3 coexist with other versions? | Solution: V7.3 will not coexist with V7.1 or V7.2. It can coexist with Aspen Zyqad 2006.5, Aspen Basic Engineering V7.0 (or previous versions). Aspen Basic Engineering V7.3 will update versions V7.1 or V7.2 ? it will use the
same workspaces and workspace libraries.
Keywords: coexist, co-exist
References: None |
Problem Statement: Why dosen't the Browse operation show all existing/accessible workspaces? | Solution: This behaviour is seen when you have special xml character in workspace name or special xml character in workspace description while creating a workspace. Special character are neither allowed in workspace name nor in workpspace description
To fix workspace name issue you can refer toSolution ID 128378 and change workspace name.
To change workspace description, you can open privileges.xml file (located under that particular workspace name folder) with notepad and change the description.
Keywords: Workspace name, browse does not work
References: None |
Problem Statement: How to handle multiple process streams in a single Air Cooled Exchanger? | Solution: You cannot setup multiple services in a single Air Cooled Exchanger file. Aspen Air Cooled Exchanger allows the plenum width being greater than the width of each of the tube bundles, and for different air flowrates over each tube bundle. In this case, the user has to set up separate Air Cooled file for each service.
In order to model this, two additional inputs are required:
1. Flow fraction of the air.
- User needs to enter the fraction of the air flowrate corresponding to the process data for the service defined in the data file
2. Bay width
- Enter the width of the bay that contains multiple services.
Air Cooled uses the total air flowrate and the input air flow fraction to calculate pressure loss and heat transfer over the tube bundle.
Here are the steps to apply multiple services in a bay:
1. Set up separate .EDR files for each service.
2. Select Yes for Multiple Services in Bay in the Applications form.
3. Enter the same total air flowrate in the Process Data in all files.
4. Enter the fraction of the air for each service in the appropriate file. The fractions must sum to unity.
5. Enter a bay width in all files that is consistent with the sum of the tube bundle widths.
6. Run each file separately.
7. Examine the airside tube bundle pressure drops. You should adjust the input air flow fractions and re-run the files until the calculated airside pressure drops are equal within a reasonable tolerance.
AspenTech provides an Excel spreadsheet to perform the iterative calculations required in Step 7. You can find the template file and demo case in Examples folder, C:\Program Files\AspenTech\Aspen Exchanger Design and Rating\Examples\AirCooled.
Keywords: Multiple process streams, air cooled
References: None |
Problem Statement: How do I run the backup utility from Aspen Basic Engineering explorer? | Solution: If both the client and Server components are installed on the machine, then you can run AZBackup utility from ABE Explorer. Below are the steps:
1. Open ABE Explorer.
2. Click on Tools=>Customize. Below window will appear:
3. Press 'Add' button and Browse for location of AZBackup.exe file in command box. By default it is located at C:\Program Files (x86)\AspenTech\Basic Engineering VX.x\DataServices\bin\AZXXXBackup.exe
4. Press OK. It will be listed in the Tools options. You can always run it from there.
Keywords:
References: None |
Problem Statement: How do I change Textbox Font Size to Metric or English units for dumb text in drawing editor? | Solution: You can change this from Control Panel | Regional settings | Click on Customize button and choose appropriate Measurement System as shown in screen shot below.
Keywords: change unit
References: None |
Problem Statement: What is the default value of atmospheric pressure in Aspen Basic Engineering? | Solution: The default value of atmospheric pressure is 101325 Pa.
Keywords: default values, pressure
References: None |
Problem Statement: Within the Aspen Air Cooled Exchanger, the bundle geometry can be entered in two ways, as described by | Solution: #125260. The bundle “Tube layout” can be set, where from the number of tubes in a row, the fin tip diameter and the traverse pitch, the bundle width is determined. Solution
The bundle width will depend upon the type of bundle selected, where this may have the same number of tubes in each row, where adjacent rows may be staggered or in line, or odd or even rows could have an extra tube.
From the Input > Exchanger Geometry > Geometry Summary > Geometry tab, two of the traverse, longitudinal pitch or tube layout angle should be entered.
Depending upon the bundle type, the bundle width can be determined.
Staggered bundle - left or right
Bundle Width = (N - 0.5) * Traverse pitch + Fin tip diameter + (Traverse pitch - Fin tip diameter)
where N is the number of tubes in a row
Inline
Bundle Width = (N - 1) * Traverse pitch + Fin tip diameter + (Traverse pitch - Fin tip diameter)
where N is the number of tubes in a row
Extra tube in even/odd row
Bundle Width = (N - 1) * Traverse pitch + Fin tip diameter + (Traverse pitch - Fin tip diameter)
where N is the largest number of tubes in the odd or even rows
The bundle width is displayed from Results > Mechanical Summary > Exchanger Data > General tab.
Keywords:
References: None |
Problem Statement: I created .ztx files for my legacy datasheet .ztf templates using a batch migration via the Datasheet
Migration Tool. I am able to open the migrated datasheets under the legacy Datasheet editor but
get the below error when trying to open migrated datasheets in Excel Datasheet Editor. In the end,
datasheets cannot be opened.
System.Exception: Failed to Open Workspace with lower level info! An entry with the same key already exists. at System.ThrowHelper.ThrowArgumentException(ExceptionResource resource)
at System.Collections.Generic.SortedList`2.Add(TKey key, TValue value)
at AZExcelDSAddin.RequestDelegate.setDescriptiveTexts()
at AZExcelDSAddin.RequestDelegate.OpenWorkspace(Int32 pHwnd, List`1 handlers)
at AZExcelDSAddin.RequestDelegate.OpenWorkspace(Int32 pHwnd, List`1 handlers)
at AZExcelDSAddin.DatasheetDirector.ConnectToWorkspace()
at AZExcelDSAddin.DatasheetFacade.OpenWorkSpace() | Solution: Corrupted lines in DescriptiveText.txt (WorkspaceLibraries\AdditionalFiles) is the cause why Opening
Workspace fails in Excel Datasheet Editor.
Corrupted lines come possibly from corrupted Unicode symbols which makes the server fails to load data.
When entering Unicode symbols into descriptiveText.txt (which is completely valid), the file must be saved in UTF8 format to preserve the Unicode, this is essential. Saving the file as ANSI will corrupt any previously entered Unicode characters.
TheSolution is to remove offending lines on DescriptiveText.txt file.
Keywords: DescriptiveText.txt, Unicode symbols, Migrated ztx templates, Datasheet
Migration Tool, Excel Datasheet Editor.
References: None |
Problem Statement: What are different ways to export data from Aspen Basic Engineering to different interfaces and formats? | Solution: You can export data to several interfaces and to several formats.
Interfaces and format you can use are as follows:
A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A
1. Thermal design interface:
Using this interface, you can transfer data to detail heat exchanger design software like Exchanger design and rating suite, HTRI. For detail instruction on using Thermal design interface, please refer to online help for Thermal design interface.
2. Costing Interface:
Using this interface, you can transfer data to Aspen Capitol Cost Estimator to evaluate the cost of your project and equipments. For detail instruction on using Costing interface, please refer to online help for Costing interface.
3. Bridge Interface:
Using this interface you can transfer data to Microsoft Excel -OR- Microsoft Word, format for this would be *.xls file and *.doc file. For detail instruction on using Bridge interface, please refer to online help for Bridge interface.
4. Excel Datasheet:
Using this interface you can transfer data to Microsoft Excel -OR- Microsoft Word, format for this would be *.xls file and *.doc file. For detail instruction on using Bridge interface, please refer to online help for Bridge interface.
5. Report:
You can create text file report using Datasheet editor for select attributes of the datasheet. For detail on creating the report please refer toSolution ID: 122955
6. Package:
You can use package to export some part of the workspace or some part of the drawing and it will create file with extension *.zpkg or *.zsec respectively, which is in xml format. For detail information on how to import and export data using package please refer to online help for explorer tool andSolution ID: 119470
7. Drawing Editor:
Using drawing editor you can export drawing to Autocad, Microstation, *.ZYQ format, XML format and to *.zsec format as mentioned in step 6.
8. Workspace backup:
You can use this option to export data for whole workspace using AZ162backup.exe tool. Please refer toSolution ID: 127109 to see detail instruction.
9. SmartPlant Export:
You can export data to smart plant from Explorer tool. For detail information, please refer to Explorer tool online help. Please refer toSolution ID: 122203 to see detail instruction.
Keywords: None
References: None |
Problem Statement: What kind of change in excel datasheet definition file (*.xls) does not require workspace re-load when using Excel Datasheet Editor? | Solution: If you use the Excel Datasheet editor, you can change the cell format in datasheet template and the change can be seen the next time you open the datasheet. This is because the excel source file is used at run-time and this will not require workspace re-load.
If you change something related to the field attribute properties, you will need to reload the workspace because this will change ZTF/ZTX (template) files and it is loaded when you open your workspace first time
Keywords: template creation, re-load workspace, workspace reload
References: None |
Problem Statement: For a process that repeats in cycles, I want the variable of a dynamic simulation to reinitialize itself after a certain condition has been met. How do I do this? | Solution: The model can be written as:
Model cycle
a as notype (0, initial);
b as notype (0, initial);
$a = 1;
$b = $a;
End
Write the task to flowsheet level as below:
Task MyTask Runs At 0;
 B1.a : 0;
 B1.b : 0;
Â
Restart When B1.b >= 10 ;Â
End
Keywords: Restart When, Cycles, Reinitialize, Task
References: None |
Problem Statement: How to know the workspace is registered with which SPF plant? | Solution: With the Explorer tool, add the <F-1 GlobalClass> object into a folder. Double-click on the object to see the attributes. You should see a Plant subobject which has the SPF plant name specified under the name attribute.
Keywords: SPF, smart plant foundation, name, workspace name
References: None |
Problem Statement: How do I determine the unit of measure (UOM) when the label only displays a number in the 'value' field? | Solution: Ideally, the label should have value field as well as UOM field. If the label has only value field, it will pick the unit of measure from the quantity type for the attribute as specified the Class library editor. The UOM display order defined for the quantity type decides the unit of field when Unit set is selected in the drawing editor.
For example, if the quantity type of an attribute is length (in). The display order only has in for this Quantity Type. That means that when the label does not specify a UOM for the Nominal Pipe Size, the unit of measure can either be in or nothing.
If the Unit Set is Metric in the drawing editor, the unit is considered missing since it cannot be in within the metric unit set. When a unit is missing, the base unit for the quantity type is used, which is meters in this case, i.e., Factor = 1 and Offset = 0.
Having both in and mm in the Display Order will make sense for this application since these are the only two units defined as the default for all four unit sets. Both Imperial and US have in as the default, and Metric and SI both have mm within this Quantity Type.
Keywords: units, display, configuration
References: None |
Problem Statement: What geometry do I select for AirCooled / crossflow Exchangers? | Solution: The following is a quick guide on how air-cooled exchanger geometry is selected:
Tube outside diameter - for the process industry 25.4mm (1) tends to be the most common.
Tube wall thickness - there is no short cut for deciding this.
Keywords: Geometry selection, air cooler, air cooled, quick guide
References: must be made to a recognized pressure vessel code.
Tube length - for a given surface area the longer the tube length the cheaper the exchanger, although a long thin exchanger may not be feasible. API 661 requires that an axial flow fan covers at least 40% of the face area of tube bundle it services. In addition, fewer fans and motors per unit generally leads to a cheaper design.
Tube layout - A 30-degree layout is often selected as it provides a good compromise between thermal performance and geometric flexibility.
Tube pitch - This is normally selected to give a minimum fin tip clearance of 3 mm (1/8 inch).
Number of tube passes - is usually one or an even number (not normally greater than 16). Increasing the number of passes increases the heat transfer coefficient but care must be taken to ensure that the tube side Rho*V**2 is not greater than about 10000 kg/m s2.
Nozzles - for tube side nozzles, the maximum Rho*V**2 should not exceed 2230 kg/m s2 for non-corrosive, non-abrasive single phase fluids and 740 kg/m s2 for other fluids.
Fin Diameter - conventional manufacture of tension wound aluminum fins results in a common maximum of 57 mm (2 1/4 inch) on 25.4 mm (1 inch) outside diameter tubes. This will be varied to optimize.
Fin Frequency - for cost, heat transfer and pressure drop a common maximum for commercially manufactured aluminum finned tubes is 433 fins/m (11 fins/inch).
Fin Thickness - thicker fins give higher fin efficiency however the cost of aluminum dictates a thinner fin, 0.4mm (.016 inch) is a common minimum. |
Problem Statement: When I want to hide objects from a PFD, I change the category of objects and filter them. However this cannot be done with arrows. Arrows return to their original category instead of keeping the one assigned to them. | Solution: Create a new arrow symbol with Graphics Definer and assign as default category the one that will be used to filter out the new arrow on PFD?s. Name the new arrow symbol with a suffix that differentiate it from the original one.
Keywords: Arrows, hide objects on PFD?s.
References: None |
Problem Statement: There are many calculation options in the standalone version of Aspen Exchanger Design and Rating (EDR). Are all of these options available in Aspen HYSYS? | Solution: The supported simulation calculation options for air coolers using EDR in HYSYS are the following:
1.- Outlet temperatures on both sides (method 1)
3.- Outlet temperatures on both sides and X-side flow
5.- Process flow and X-side outlet temperature
6.- X-side flow and X-side outlet temperature
If there is not an outlet stream temperature, the calculation option defaults to 1.
If the inlet stream temperature is unknown, the calculation option will default to option 3.
If the inlet stream flow rate is unknown, then the calculation method defaults to 5.
If process inlet and outlet are fully specified, then the calculation option used is 6.
Keywords: AirCooled, air cooler, integration
References: None |
Problem Statement: How is inheritance used in Aspen Custom Modeler? | Solution: The use of inheritance within ACM is pretty common. It enables you to create new types which build upon existing ones. It helps avoid declaring same types again and again. Instead you can use an inheritance relationship between two type definitions with the keyword USES.
Example in Variable type:
In the following example, the variable type Vapor_viscosity inherits all the properties and default values from the variable type visco_vap but overrides the default value for the property Value.
VARIABLE Vapor_viscosity USES visco_vap
value: 0.10;
END
Example in Model type:
In the following example, the model Mixer_M inherits from the model FLASH_M. It extends FLASH_M by modifying Inp port as multiport and adding a mass balance equations
MODEL Mixer_M USES FLASH_M
Inp AS INPUT MULTIPORT OF FlowPort;
out.F=sigma (inp.connection.F);
END
Example in Parameter type:
In the following example, the Parameter ColorParameter inherits from the model StringParameter. It extends StringParameter by modifying StringSet
PARAMETER ColorParameter USES StringParameter
Valid AS StringSet([RED, BLUE, GREEN, WHITE]);
Value: GREEN;
END
Example in Port type:
The following example shows the definition of the port type FlowTempPort. This passes a molar flow rate and a temperature:
PORT FlowTempPort
F AS Flow_mol;
T AS Temperature;
END
Below Material_M port inherits all default properties in FlowTempPort and add P as pressure variables
PORT Material_M USES FlowTempPort
P AS Pressure;
END
Keywords: Inheritance, USES
References: None |
Problem Statement: How do I export an Aspen Custom Modeler model to Aspen PIMS? | Solution: You can export ACM models for use in Aspen PIMS. Please follow the procedure describe below:
1. In the Simulation Explorer, under Custom Modeling, Models, right-click on the modeland select the Export to DLL command.
2. Select a convenient folder where XX.dll is to be installed and click OK.
3. Exit Aspen Custom Modeler.
4. Next step is to add this dll in PIMS. Open Aspen PIMS with your model, browse for folder PIMS-AO || XXXX.
You will add external dll as you created by right clicking on external model .
Keywords: PIMS, dll
References: None |
Problem Statement: Earlier versions of Aspen Custom Modeler allowed users to use an OnStartRun script. This script works correctly in earlier versions, but does not work correctly in V7.3. This knowledge base article describes how to prevent the OnStartRun script from running recursively. | Solution: In Aspen Custom Modeler V7.3, the automation method Simulation.Run has been changed to add a 2nd optional argument to accommodate a request by Aspen Batch Distillation.
Normally when a user executes the method Simulation.Run, it will automatically call the user's OnStartRun script if it is defined. However, often users call Simulation.Run from within their OnStartRun scripts, in which case we do not want the Run command to call the OnStartRun script again (recursively). The a 2nd argument controls whether OnStartRun is invoked by Run command. The default value for the 2nd argument is a??Truea??.
For example, if calling Simulation.Run outside your OnStartRun script you would normally use only the first argument and enter:
Simulation.Run False
which is same as: Simulation.Run False True (the 2nd argument set to True invokes the OnStartRun script).
However, if you call Simulation.Run from within OnStartRun, you must enter:
Simulation.Run False False
To suppress execution of the OnStartRun script recursively.
Keywords: Run, Simulation.Run
References: None |
Problem Statement: Aspen DMCplus Desktop applications are crashing, appears to be related to OS | Solution: Machine in question is an HP8510 notebook PC, Windows xp SP2, Multi-Language version with HP Tools including finger print log-in support.
By removing finger print program (HP Protect Tolls Security Suite 2.10 A1
Installer: SP37721.exe version 4.0.100.1189) build started to work properly. It can open and save col5x3.ccf file.
Following is the procedure to remove the program.
Remove following 6 programs using control panel - program install/uninstall tool in this order.
1. Credential Manager for HP Protect Tools
2. Device Access Manger for HP Protect Tools
3. Drive Encryption for HP Protect Tools
4. Bios Configuration for HP Protect Tools
5. Embedded Security for HP Protect Tools (Security Chip might have to be disabled)
6. HP Protect Tools Security Manager
Keywords: crash, operating system, laptop, language, fingerprint
References: None |
Problem Statement: How do I simulate natural convection with fan off? | Solution: 1.Use Simulation mode.
2. Select Outlet temperature on both sides, and X-side flow (natural convection) under Simulation Calculation.
3. Specify Forced or Induced type of fan even though fans are not included in the natural convection calculations. Program will give an error if you select No Fan.
4. Provide an air side flow. Your flow rate will be used as initial estimate. After you run the file and check results, you will see a different air flow rate.
Keywords: Natural convection, no fan
References: None |
Problem Statement: How do I add notes or comments to a model? | Solution: In Simulation Explorer, right click on the flow sheet folder and select properties, there is an Add Notes tab on the property dialog where user can add comments.
In fact, drill down the flow sheet folder, one may add notes similarly at blocks and streams level.
Keywords: Comment, note, annotation, description
References: None |
Problem Statement: This | Solution: shows why you should not use the ABS function in the definition of the objective function for an optimization problem.
Solution
The attached example illustrates the problem. The model is simply:
MODEL example
x1 as realvariable (fixed, 0.1, lower:0, upper:10);
y1 as realvariable;
y1 = 1 - exp(-x1);
y1spec as realvariable (fixed);
diff as realvariable;
diff = abs(y1 - y1spec);
// diff = sqr(y1 - y1spec);
END
The exponential function causes the value of y to be limited to 1 even for large values of x. The value of x must be in the range [0, 10]. The idea is to find the value of x that gives a specified value of y (yspec). As there is not always aSolution, we pose this problem as an optimization case. The objective function is to minimize the variable diff.
When we define diff = abs(y - yspec), most optimizers (expected Nelder-Mead) may fail to find theSolution or require a large number of iterations. This is because the optimization is essentially based on trying to find the point where the gradient of the objective function with respect to the decision variables is zero. This means that the algorithm evaluates the derivative of diff with respect to x. When the value of y can actually be made equal to yspec (e.g. theSolution is diff=0), the gradient will oscillate between positive non-zero value and negative non-zero value, but cannot be equal to zero, because the derivative of the absolute value function is never equal to zero.
d(abs(x))/dx = 1 if x is > 0 or -1 if x < 0
The recommended approach is to define diff as (y-yspec)^2. This function has the required properties (e.g. increase when y is away from yspec), but has a continuous derivative for y = yspec. If you modify the attached example to use the square function, you will see that the optimization works better. It takes 6 iterations instead of 59 to find theSolution.
Note about Nelder-Mead: Nelder-Mead is a direct optimization method which does not use the derivatives of the objective function. It is therefore not affected by this issue. While Nelder-Mead may appear as being more robust, you need to be aware that it is not as efficient (e.g. it requires a lot more iterations to find aSolution).
Keywords:
References: None |
Problem Statement: How is the value, entered for an open enumeration, stored in database? | Solution: New options entered in an open enumeration are saved in the database and available in all attributes which use this enumeration. It is stored in the GlobalClass object under EnumerationOptions attribute
It is possible to delete new options entered in an open enumeration using the tool Enumeration Management available under the menu Edit in the ABE Explorer application.
Keywords: None
References: None |
Problem Statement: How do I exit Gap/Ungap mode? | Solution: To exit out of Gap/Ungap mode, uncheck Gap/Ungap check box so that it will look as shown in screenshot below.
Keywords: Gap, ungap, exit
References: None |
Problem Statement: How do I insert a page into a datasheet? When I try to insert the page using the insert command in right-mouse click, it doesn't work. | Solution: If you want to insert a page in an existing datasheet, you should use insert page command in the right- mouse click or you should go to Datasheet menu and pick pages=>insert. When you right click on the page and pick insert, it will not work. It is an excel command. Excel datasheet editor command is insert page.
Keywords:
References: None |
Problem Statement: EDR gives the same default value of airside allowable pressure drop in Aspen Air Cooled Exchanger. How does EDR calculate this value? | Solution: This value is determined by the limitations of commercial axial flow fans and the noise regulations that might take place. For low fan noise operation, the generated pressure drop will be in the range of 100-200 Pa (0.014-0.029 psi).
If a higher value has to be used, make sure your equipment will be able to operate in such conditions.
Keywords: Air Cooled, allowable pressure drop
References: None |
Problem Statement: In Aspen Air Cooled Exchanger, values for vapour and liquid flow in the ‘Results ¦ Calculation Details ¦ Interval Analysis – Tube Side’ menu, differ from those reported in other menus, such as Results Summary. | Solution: The values in Interval Analysis refer to the flow in a single tube of the bundle (in a given row and pass). In order to retrieve the overall values in the Results Summary menu, the user should multiply the value for an individual tube by the number of tubes in the rows and by the number of inlet or outlet rows. To understand the flow direction in each row, you can monitor the flow profile in the ‘Plots’ tab of the Interval Analysis menu.
Keywords: Air Cooled, Interval Analysis, Tube Side, Flowrate, Vapour, Liquid
References: None |
Problem Statement: How do I import my Aspen Custom Modeler (ACM) simulation into Aspen Basic Engineering (ABE)? | Solution: Yes, the ability to import an Aspen Customer Modeler simulation (.acmf file) was introduced in 2006. It is necessary that Aspen Custom modeler is installed on the client machine and a valid license is also required.
1. Load Aspen Basic Engineering Simulation Importer
2. Browse to relevant acmf file, simulation case name and case and Import
Note that there are no ACM-specific class views delivered out- of-the-box for data transfer as opposed to Aspen Plus, Hysys and PRO-II. Users will need to create their own class views to map their custom models to the relevant UO classes.
Keywords:
References: None |
Problem Statement: How do I make a new folder in the Symbols directory appear in the drawing editor? | Solution: The structure of symbols in Drawing editor depends on the folder structure of Symbols folder. If you have created a custom directory in Symbols library, you also need to make sure that you add this directory to Pfd.xml file which is located in the Templates folder. You can open this file using Notepad and make additions in there. Make sure you reload the workspace after any change in configuration.
Keywords: None
References: None |
Problem Statement: How do I modify the default value of atmospheric pressure? | Solution: The default value of atmospheric pressure is 101325 Pa, but it can be overridden by setting the local value of attribute at the Global objects. To do that:
1. Open ABE explorer.
2. Add Global object in new folder.
3. Double click on the global object to open attribute view. To show all attributes, press Options|show all attributes.
4. Modify 'atmospheric pressure' value to the desired number.
5. Reload the workspace to see the effect.
Keywords: settings, default, override
References: None |
Problem Statement: Is it possible to use Aspen Custom Modeler (ACM) automation methods when the simulation is launched by Aspen Simulation Workbook (ASW)? For example, I cannot figure out how to change the specification of a variable with ASW, while it is possible with ACM. | Solution: You first need to get the name of the active simulation by using the formula =ASWActiveSimulation(), then the full path of the simulation file (with =ASWSimulationPath(<name of the active simulation>)).
You can then invoke the GetObject function (to use the currently running ACM session with the same simulation) and then use any automation method of ACM. See ACM on-line help, Automation reference for more information.
For example, if you want to change the specification property of a variable, use the Resolve function to convert the name of the variable into the variable object, then change the Spec property of the variable. Note that the spec displayed in ASW tables will update correctly when you click the refresh toolbar button, while it is actually updated directly in the ACM simulation.
The attached example illustrates the discussion above.
Keywords: None
References: None |
Problem Statement: Sometimes we need to define an extra fan on our exchanger. How can we define this? | Solution: You can add spare fans and also determine the amount of flow going through each of the fans.
If you go to Input | Program Options | Outside Distribution you can specify the flow going through each of the fans.
Let's assume that we have a line of 3 fans. This should look like this:
If for example, you want to specify that you want to be turning a fan off, you can do it in the following way:
Keywords: Extra fan
Air cooler
References: None |
Problem Statement: How do I avoid having two Modeler libraries when I create my own library? | Solution: Modeler library is automatically attached when you start Aspen Custom Modeler. This causes any library you create to refer to Modeler, even if none of your custom types actually use Modeler types.
This does not cause the library to be any bigger, nor does it cause extra memory usage or load time.
If you wish to prevent the Modeler library from being automatically opened when you start Aspen Custom Modeler, you need to modify the registry.
The key is
HKEY_LOCAL_MACHINE\SOFTWARE\AspenTech\Aspen Custom Modeler\11.1\Default Libraries
You need to remove the item Modeler.acml.
(Export the key before you do this operation, so that you can easily revert back to the default installation settings).
Keywords:
References: None |
Problem Statement: Need method to extract DMCplus VEC files from PI database | Solution: See attachment which contains below instructions along with an executable and dll and an excel spreadsheet.
How to extract PI data automatically and output directly a CLC file compatible with DMCplus Model
This can be useful if the customer has already a PI database installed and if you wish to use DMCplus Model with such data.
Instructions :
1. Create a text file containing a list of tags that you want to extract from PI (check the spelling in PI first). List each tag on a separate line. Save the file with a CSV extension.
2. Run Pi_2_file2_4.exe and click on DMC and then on ?Executer?
3. In the DMC dialog, click on ?Base de tag? to locate your text file. Once you have located your file, click ?Ouvrir? to select it.
4. By default, the output file will be saved to the same location as the application with the name ?resultat.clc?. Modify the name of the output file by clicking the ?Fichier de resultat? button if desired.
5. Enter the start and end dates using the local PI date format (i.e., 13-Jan-04 10:34:00)
6. Enter the sampling period ?Pas de l?echantillonnage? in minutes.
7. Select the fragmentation option if you want to have several output files of 1 Mo each.
8. Click ?Executer? and be patient.
9. Once finished, you can click the ?Voir? button to see the results.
Keywords:
References: None |
Problem Statement: How to assign Fluid medium object to Stream using a method. | Solution: The attached KB file includes a method which can be used to link a Fluid Medium object to a stream. The KB file can be loaded in the workspace by coyping the two attached files in the KBS directory of the library and then adding the name AssignFluidMedium in the KBScripts section of the library configuration file (*.cfg). The method will be available the next time the workspace is started.
User can launch the method with the following procedure
- With the ABE Explorer tool, select a Stream object
- Select the function Run=>Local method and then the method Assign Fluid Medium to Stream.
- A list of Fluid Medium object will be presented to the user for selection.
Keywords: Method
Fluid medium
References: None |
Problem Statement: How to access the ionic charge for electrolytes in ACM | Solution: To access the ionic charge of electrolytes, the procedure pParam can be used. An example code can be seen below and the file can be found in the attachment.
The aspen properties file needs to be configured prior to accessing this parameter.
Model test
chargg(ComponentList) as RealVariable;
call (chargg)=pParam(CHARGE,1);
End
Keywords: ionic charge, pParam, electrolyte
References: None |
Problem Statement: In Aspen Air Cooled Exchanger on Results | Mechanical Summary | Exchanger Data | Fan Details tab in Fan Noise Level section, there are two groups of data being reported - ''Low Performance'' and ''High Performance''. What do these outputs mean? What is the differentiation between the ''Low Performance'' and ''High performance''? | Solution: Noise is defined as unwanted sound. Sound is caused by the oscillation of air-molecules, which cause a sound wave to be propagated. The oscillation of the air-molecules causes a vibration from the normal atmospheric pressure and this is characterized by the rate at which the vibration occurs and the magnitudes of the vibration are called the frequency and amplitude respectively. The frequency determines how sensitive the sound can be heard and the amplitude of a sound wave determines the loudness of the sound and is measured in decibels (dB).
Both ''Pressure Level'' and ''Power Level'' can be used to represent how relatively intense the sound (noise in this case) is. They are calculated by conducting certain mathematical comparisons between the actual noise pressure and the reference pressure of minimum audible sound pressure, and between the actual noise sound power and the reference sound power of the minimum audible sound power.
Being able to supply a fixed air flowrate, different fan configurations (diameters, number of fans etc) will results in different fan speed (RPM) and different level of noise (power level and/or pressure level, in dB). ''Low Performance'' fans are relatively inexpensive, since they have a small number of narrow cord blades. They will rotate at a relatively high angular speed for a given air flow and will therefore generate a relatively high level of noise.
''High Performance'' fans have a large number of wide cord blades and, with the same air flow rate, rotate at a relatively low angular speed compared to ''Low Performance'' fans and will therefore generate a relatively low level of noise.
For more details about the noise performance of the fans, users need to consult with the corresponding manufacturers.
Keywords: Fan Noise Level, Low Performance, High performance, Power Level, Pressure level, Rotational speed
References: None |
Problem Statement: It is very useful to package certain calculations within submodels for modularity, easier maintenance and re-usability of code. When modelling partial differential equation systems, distributed variables may need to be used in submodels and they required to be defined in as general way as possible so they can be easily handled by the calling model. | Solution: We describe below the procedure to implement a submodel using distributed variables and we include an example to illustrate its use.
The example used is a modified version of the Heated Slab example included in the Aspen Custom Modeler installation. It was modified to contain a temperature dependent thermal conductivity term, instead of constant diffusion coefficient.
The thermal conductivity calculation will be implemented in a submodel called Conductivity, which will then be instanced in the MetalPlate model and used in the heat transfer equations. The example is illustrative only and the data for heat capacity, density and thermal conductivity was actually obtained from Aspen Plus for water at 25C.
The steps required are summarised as follows:
1 - Create the problem as usual in ACM, defining all required types.
2 - Then create a submodel to calculate the thermal conductivity. As thermal conductivity is a temperature dependent function and temperature is a distributed variable, we also want to calculate the conductivity in every node.
3 - Instance your model and use the variable calculated by it in another model.
Implementation of step 2
We have two domains defined in the main model so the submodel should also have two domains defined. However the submodel domains should be defined as general as possible and then mapped to the right domain when the submodel is instanced. Hence we create two external domains in a submodel called Conductivity:
Model conductivity
XDomain as external Domain;
YDomain as external Domain;
The variables required in the Conductivity model are temperature, T, and thermal conductivity, K. For simplicity we also define T as external, which means we do not need to map it when instancing the model and the variable T in the main model will be used directly.
T as external Distribution2D;
As there is no derivative term, and the temperature is distributed over 2 domains we need to create also a Distribution2D for thermal conductivity with highest order derivatives of zero as there is no derivative term in the conductivity expression.
K as Distribution2D(value: 1; HighestOrderXDerivative: 0, HighestOrderYDerivative: 0);
Now we can write the equation of K as a function of T. Using FOR loops makes the code much easier to read, so the expression for conductivity will be written as below.
for iX in [0:XDomain.endNode] do
for iY in [0:YDomain.endNode] do
conductivity: K(iX,iY)=0.487653 +1.487E-3 *T(iX,iY) - 5.6346E-6 *T(iX,iY)^2 +0.16E-8 *T(iX,iY)^3;
endfor
endfor
When finished typing in, compile the model and correct any errors.
Implementation of Step 3
Now we can instance the model in the main model, so we can use K in the equations. We will concentrate on the use of the submodel only in this example. For more information on the Heated Slab original example please consult the Examples PDF manual.
In the main model, MetalPlate, we have two domains defined:
X as LengthDomain(DiscretizationMethod:BFD1, HighestOrderDerivative: 2,
Length:1, SpacingPreference:0.1);
Y as
LengthDomain(DiscretizationMethod:BFD1, HighestOrderDerivative: 2,
Length:1, SpacingPreference:0.1);
And the distributed variable T
T as Distribution2D (XDomain is X, YDomain is Y) of Temperature(10);
The Conductivity model is using this variable T directly in its calculations because we declared it as external in it. We also had to define two extra variables in the usual way for the equations:
cp as cp_mol_liq (69.47, fixed);
rho as dens_mol_liq (55.216, fixed);
Now we need to instance the Conductivity submodel to use here. We instance the model in the usual way and we map the domains XDomain and YDomain from the submodel, to the domains we want to use from the model MetalPlate, which are X and Y. These have been defined as LengthDomain, see above.
cond as conductivity( XDomain is X, YDomain is Y);
I have chosen not to map any variables between the model and submodel because I am using T as external in the submodel and I will use K from the submodel directly in the heat transfer equations below. Again I re-arranged these equations in two nested FOR loops to make them easier to write and read. To refer to variable K in the submodel we use model_name.variable_name as usual. However, don't forget that K is a distributed variable so you should always include the index(es), otherwise you will find your problem over- or underspecified by an enormous amount of variables. That is a good indicator that you have something wrong in the equations.
// Heat transfer equations
for iX in X.Interior do
for iY in Y.interior do
HeatTransfer: cp *rho *$T(iX, iY) = cond.k(iX,iY) *T(iX, iY).d2dx2 +cond.k(iX,iY) *T(iX, iY).d2dy2;
endfor;
endfor;
Once finished writing the equations and including any initial and boundary conditions, the model is ready to be compiled.
Keywords:
References: None |
Problem Statement: I don't want to see the branch points when I print out the PFD. How can I make them invisible? | Solution: When branches are created between connectors in Drawing Editor, it automatically inserts the black circle indicating where the branch is located. These black dots are called 'branch points'. If you don't want to see the branch points on PFD, you can hid them. All you have to do is open drawing, go to View -> Filter by Category and turn off the 'branch points' by unchecking it.
Keywords: None
References: None |
Problem Statement: I see a Hierarchy under Custom Modeling, Models and another under Modeler, Models. Why are there two and how should I use them? | Solution: The models are identical and can be used interchangeably. Usually, when you are creating your own models you are working in Custom Modeling, so the Hierarchy model is there to ease the work flow and avoid having to switch between libraries to obtain the models required while building the flowsheet.
However there are instances when you are simply working on the flowsheet with the Custom Modeling option disabled. For instance if you only have license for one of our other products, which have their own libraries. You are still able to edit the flowsheet and create hierarchies. In that case you have to use the Hierarchy model contained in the Modeler library because Custom Modeling is not available to you.
Keywords:
References: None |
Problem Statement: An Even Driven Task that worked fine in 10.2 and earlier versions now in 11.1 loops repeatedly after they have finished processing. The message is similar to the following:
Task 't1': Task ran successfully at 2.830000 but waiting for other conditions.
Task 't1': Looking for next (re)start condition.
Task 't1': Task Completed successfully at 2.830000.
Task 't1': Task ran successfully at 2.830000 but waiting for other conditions.
Task 't1': Looking for next (re)start condition.
Task 't1': Task Completed successfully at 2.830000.
It is necessary to use Run / Interrupt to halt the simulation. | Solution: Tasks are handled more strictly starting in version 11.1 - if you only intend theSolution to run only one time then you should include the keyword ONCE in the conditional expression that triggers the task.
For example, in 11.1 this task loops repeatedly when run:
TASK t1 RUNS WHEN TIME == 2.83
Tank1.FlowIn.Flow : 5.0;
END
This task loops because at time 2.83 the task starts, assigns a value to a variable then immediately checks again the current time. As integration has not proceeded the task runs again immediately and so loops continuously.
TheSolution is to add the keyword ONCE to the trigger conditional Statement
TASK t1 RUNS ONCE WHEN TIME == 2.83
Tank1.FlowIn.Flow : 5.0;
END
Now when the variable assignment is made, the task becomes inactive.
An alternativeSolution is to include a RESTART statement as the last command in the task:
TASK t1 RUNS WHEN TIME == 2.83
Tank1.FlowIn.Flow : 5.0;
RESTART WHEN Tank1.H == 10.0;
END
This change was made to be consistent in how a task works in terms of running multiple times.
Keywords: event driven
task
repeat
loop
References: None |
Problem Statement: How do you save the plots and tables screen display so that you see the same screen layout after re-opening a simulation? | Solution: Use the screen capture feature, available from the Tools menu under Capture Screen Layout... This saves the layout of the forms by auto generating a script in the Flowsheet folder. This script is saved for use next time you run the simulation.
To re-open the plots and tables go to Flowsheet folder in the Simulation Explorer window and double click on the script that you saved during the Screen Capture Layout step.
If you cannot see the Simulation Explorer window, go to the Tools menu and choose Explorer.
Note that in release 11.1 of Aspen Engineering Suite, the capture screen layout feature is extended to include the size and location of all flowsheet windows (including hierarchies) and all Explorer windows and the Simulation Messages window.
Keywords:
References: None |
Problem Statement: How to solve: The required version of Visual Studio for exporting models was not found - compilation aborted. | Solution: Visual Studio provides the compiler and linker for ACM to export models into Aspen Plus or Aspen HYSYS. The official supported version of Visual Studio can be found in the ACM documentation under Compatibility Notes. Although the compatibility is version specific, if a different release of Visual Studio is installed in your machine, there is a simple way to try to compile and export your model by modifying the system environment variables . Please do the following:
1. Go to Start > right click on computer and select properties or go to Control Panel > System and Security > System
2. Click on Advanced system settings and then click on Environment variables
3. Under system variables you should see a variable that defines the path for Visual Studio components called VSxxxOMNTOOLS, where xxx is the number of the version installed in your machine, for example for VS 2008 the variable will be VS90COMNTOOLS. In this path there is a batch file called vsvars32.bat that sets the environment variables required to make use of Visual Studio capabilities such as compiler and linker. ACM will look for this environment variable (for the supported version only) in the exporting process. The table below shows the compatibility and variable name for each version of ACM:
ACMÂ Â Â Â VSÂ Â Â Â Â Enviroment Variable name
V8.0Â Â Â Â 2008Â Â Â Â Â Â Â Â VS90COMNTOOLS
V8.4Â Â Â Â 2008Â Â Â Â Â Â Â Â VS90COMNTOOLS
V8.8Â Â Â Â 2013Â Â Â Â Â Â Â VS120COMNTOOLS
4. Create a new user variable with the name of the specific version of Visual Studio supported for the version of ACM installed in your machine
5. Copy the value of the existing VSXXXCOMNTOOLS variable into the value of the one just created.
6. Click OK to the dialog forms.
Now ACM should be able to export your model. Please note that from V9 on, ACM already includes all the require components to export the model, therefore no third party program installation is required any more.
Keywords: ACM, model export, compiler, Visual Studio
References: None |
Problem Statement: Where can I set default symbol type if I am importing equipment from capitol cost estimator? | Solution: For every Class of particular object, you will see an attribute with name DefaultSymbol, which should have default symbol path and name defined. You can change this to meet your requirement.
Keywords: Default symbol type.
References: None |
Problem Statement: How to migrate data from previous versions to V 7.0 or V7.1? | Solution: To migrate a workspace configuration to Aspen Basic Engineering V7.0 or V7.1:
1) Copy the library from the older version and paste in the newer version.
a) In Windows Explorer, locate the library in the older version of Aspen Zyqad, which is usually located in C:\AspenZyqadServer\AspenZyqadXX.X\WorkspaceLibraries and has the name <yourlibraryname>LibrarySet.cfg, where <yourlibraryname> is the name of your specific library.
b) Copy and paste this file into the appropriate folder in the newer version of Aspen Basic Engineering, usually located in the folder C:\AspenZyqadServer\BasicEngineeringXX.X\WorkspaceLibraries
c) Repeat steps 1 and 2 for any folders with templates, datasheets, symbols, etc. that have been customized.
2) Update data in the standard library configuration file.
a) Check Library for Errors (Tools | Check Library) and create a class store.
b) Using a text editor such as Notepad, open the <yourlibraryname>LibrarySet.cfg file in the newer version of Aspen Basic Engineering.
c) Make the following changes:
On a separate line, add the IDWF parameter with the initial value of false:
IDWF = False
On the line for the KBScripts parameters, remove PlantBreakdownStructure and DocumentManagement from the list of scripts.
If you are migrating to V7.0, add the following on a separate line:
DataServiceModules = PlotPlan161.PPDataSvc, ABE161IDWFDlg.IDWFDialog, ABE161IDWFDataSvc.IDWFDataSvc, PlantBreakdownStruct161.DataServiceImpl, DocumentManagement161.DataServiceImpl
If you are migrating to V7.1, add the following on a separate line:
DataServiceModules = PlotPlan162.PPDataSvc, ABE162IDWFDlg.IDWFDialog, ABE162IDWFDataSvc.IDWFDataSvc, PlantBreakdownStruct162.DataServiceImpl, DocumentManagement162.DataServiceImpl
If you are migrating from 2006.5 or earlier to V7.0 or V7.1, add the line: Enable_v2006.5toV7.0Migration=1
d) Save the file.
3) Add the configuration files to the Library list set.
a) Using a text editor such as Notepad, open the LibrarySets.lst file of the newer version of Aspen Basic Engineering, usually located in the same file as your workspace library.
b) Add your library to the list in the format:
LIBRARY <yourlibraryname> <yourlibraryname>LibrarySet.cfg a description of your library
c) When creating a new workspace, select this new library when prompted.
To migrate the workspace:
1 Using the AZ<old version>backup.exe utility in the older version of Aspen Zyqad or Aspen Basic Engineering, create a backup of the workspace. Take note of the location to which you save the backup file.
2 Using the AZ<new version>backup.exe utility in the newer version of Aspen Basic Engineering, restore the backup file to the appropriate workspace.
Keywords: Migrate, upgrade, backup, version.
References: None |
Problem Statement: How can I change workspace description for existing workspace? | Solution: You can change workspace description from privileges.xml file by opening it with notepad and change the highlighted part as shown in screenshot below to meet your requirement.
Keywords: Change description, modify workspace description
References: None |
Problem Statement: What is the effect of louvers on the outside pressure drop? | Solution: Louvers are used to provide process side temperature control and prevent damage to the bundle due to climatic conditions. Louvers affect the outside bundle pressure drop and the price estimate.
The type of louver affects the total outside pressure drop as it presents an additional resistance to the flow. If the louver is fully open then the increase in pressure drop is very small (or none) depending on type of louver. In Aspen Acol+, you can enter the louver opening angle (for louver types A-D) or the loss coefficient (for louver type K). The default setting No louver.
The angle of the louver (in degrees) can be changed via input item Louvre opening angle or Louver pressure loss coefficient on the Exchanger Geometry | Unit Geometry | Accessories tab. A maximum angle of 90 degrees can be specified for fully closed louvers. As the angle increases above 0, the pressure drop will increase. One can view the contribution of louvers to the pressure drop in the Outside pressure drop entry on the Acol+ Summary
Keywords: louver, pressure, loss, outside, drop
References: None |
Problem Statement: Within Aspen Air Cooled Exchanger, from the Input > Exchanger Geometry > Geometry Summary > Geometry tab, two of the traverse, longitudinal pitch or tube layout angle should be entered to define the bundle layout. | Solution: The relationship between the traverse, longitudinal pitch and layout angle is shown below.
The transverse pitch of the tubes is the distance between the centre-lines of consecutive tubes in the same tube row. The default is 2.3 times the tube outer diameter.
For the longitudinal pitch of the tubes, if you have a standard TEMA tube layout, i.e. triangular (30°), rotated square (45°), rotated triangular (60°) or square (90°) then enter the layout angle. If you have a non-standard tube layout then enter the longitudinal pitch.
There is no default longitudinal pitch value, where the value will be calculated from the transverse tube pitch and layout angle.
The layout angle is defined with respect to the flow direction. The tube patterns are shown below in order from left to right for the layout producing the highest film coefficient and pressure drops to the lowest.
Keywords: Traverse pitch, longitudinal pitch, tube layout angle, Tubular Exchanger Manufacturers Association (TEMA)
References: None |
Problem Statement: In simulation of compressors or other shutdown systems, it is quite common to have multiple events to trigger the same sequence of actions. How can this be implemented in ACM? | Solution: An apparently simple way is to use callable tasks, for example, with two tasks which call the same callable task.
Task T2 runs once when tank2.flowin.flow > 3.1
Call subtask1 ; End
Task T3 runs once when tank3.flowin.flow > 3.1
Call subtask1 ; End
Task SubTask1
Ramp(Tank1.flowin.flow, 4.0, 5.0);
End
It could be that both T2 and T3 events will be satisfied. It could therefore happen that the same callable task will be called twice, causing the variable tank1.flowin.flow to be ramped simultaneously by two ramps, which is not correct.
The issue is not specific to callable tasks. This can be simplified to:
Task T2 runs once when tank2.flowin.flow > 3.1
Ramp(Tank1.flowin.flow, 4.0, 5.0);
End
Task T3 runs once when tank3.flowin.flow > 3.1
Ramp(Tank1.flowin.flow, 4.0, 5.0);
End
A better way to analyse this is to separate events, actions and states concepts from tasks. You have two states, un-tripped and tripped. Create a variable for that, trip. Fixed to 0 in untripped state, and 1 in tripped state. You then have 3 events: tank2.flowin.flow > 3.1, tank3.flowin.flow > 3.1, and when trip > 0.5.
Add one variable in flowsheet, which represents the state:
trip as realvariable (fixed, 0);
Add one task, which is the event and action:
Task ramp_flow runs when trip > 0.5
Ramp(Tank1.flowin.flow, 4.0, 5.0);
End
And finally, the other two tasks, again implementing event and action:
Task T2 runs once when tank2.flowin.flow > 3.1
trip : 1; End
Task T3 runs once when tank3.flowin.flow > 3.1
trip : 1; End
This will do what you want. And the trip variable may actually be useful to know in which state is your plant. You can also bury the trip change inside the callable task:
Task T2 runs once when tank2.flowin.flow > 3.1
Call subtask1 ; End
Task T3 runs once when tank3.flowin.flow > 3.1
Call subtask1 ; End
Task SubTask1
if trip < 0.5 then
trip : 1;
Ramp(Tank1.flowin.flow, 4.0, 5.0);
endif
End
This shows that once tripped, no other ramp should be started.
If you create the variable trip but use it only in a task (ie not in any equation), the variable is only marginally active. It shows up properly on the variable tables, but in version 12.1 when you restart the simulation the variable is not rewound to its value at time 0. In short, first run is ok, then the second run starts with trip = 1, as if the plant was tripped.
Here's a very easy workaround: instead of having just
trip as realvariable (0, fixed);
using in the flowsheet section:
trip as realvariable (0, fixed);
dummy as realvariable;
dummy = trip;
This make trip an genuine active variable, and restart, snapshots, etc will work correctly.
(We will look at fixing this in a future version.)
Keywords: task
ESD
snapshot
restart
rewind
ramp
sramp
References: None |
Problem Statement: How to install an ACM DLL manually if the Windows installer fails? | Solution: On the Export Save As dialog uncheck the Delete Intermediate Files option
Click OK to export the DLL
Your directory will now contain model DLL plus source code and object files. The source code and object files can be deleted.
Using Notepad or another editor, edit C:\Documents and Settings\All Users\Application Data\ASPENTECH\Aspen Plus 12.1\apmodelcatalog.xml
The location of this file depends on the setup of your machine and it may be hidden. If you cannot find it, first check the value of the ALLUSERSPROFILE environment variable which will tell you where the All Users directory is, and also make sure that Windows Explorer is set to show hidden files and folders by modifying the settings using Tools > Folder Options... > View Tab
You can also determine ALL Users directory by looking in the registry. The entry to look for is:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Shell
Folders\CommonAppData
To install a model add a new line within the <Class Id=ACM Block> and </Class> markers
The line added has the format:
<Unit Id=name of your model DLLName=location of your dll
/>
The name used to identify your model must be the same as the name shown on the Model Package Properties dialog for the model you have exported.
As an example. If the model name is MyFlash2 and the dll location is d:\aspentech\working folders\Aspen Custom Modeler 12.1\myflash2 and the apmodelcatalog file contains only the MyPipe specifications::
<?wsx version=1.0 ?>
<APModelCatalog>
<Class Id=ACMBlock>
<Unit Id=MyPipe DLLName=C:\Program Files\AspenTech\AMModels
12.1\MyPipe\MyPipe.dll />
</Class>
<Class Id=ACMReaction />
<Class Id=Solver />
</APModelCatalog>
To register myflash2 you should change the contents to:
<?wsx version=1.0 ?>
<APModelCatalog>
<Class Id=ACMBlock>
<Unit Id=MyPipe DLLName=C:\Program Files\AspenTech\AMModels
12.1\MyPipe\MyPipe.dll />
<Unit Id=MyFlash2 DLLName=d:\Aspentech\Working Folders\Aspen Custom
Modeler 12.1\MyFlash2\MyFlash2.dll />
</Class>
<Class Id=ACMReaction >
</Class>
<Class Id=Solver >
</Class>
</APModelCatalog>
Save the modifed file
Start Aspen Plus
Using the
Keywords:
References: s menu item on the Library menu make sure that ACM Models is checked
Check to see that your model appears on the model palette
If you model relies on procedure dlls (other than any supplied with your ACM application) make sure that they are located in the same directory as the model DLL.
If your model relies on any .OCX files for custom forms create a folder called Formfiles in the same Folder as the model dll and place the OCX files there. If your model has help (.hlp) files, you need to create helpfiles folder too and place the help files there.
The instructions are the same for the installation of a reactiom model, except that the new line is added within the <Class Id = ACMReaction> </Class> markers.
As an example, if the reaction model name is MyAcmRxn and the dll location is d:\program files\Aspentech\AMModels 12.1\myacmrxn and the apmodelcatalog file contains:
<?wsx version=1.0 ?>
<APModelCatalog>
<Class Id=ACMBlock>
<Unit Id=MyPipe DLLName=C:\Program Files\AspenTech\AMModels
12.1\MyPipe\MyPipe.dll />
</Class>
<Class Id=ACMReaction >
</Class>
<Class Id=Solver >
</Class>
</APModelCatalog>
To register MyAcmRxn you should change the contents to:
<?wsx version=1.0 ?>
<APModelCatalog>
<Class Id=ACMBlock>
<Unit Id=MyPipe DLLName=C:\Program Files\AspenTech\AMModels
12.1\MyPipe\MyPipe.dll />
</Class>
<Class Id=ACMReaction >
<Unit Id=MyACMRxn DLLName=D:\Program Files\AspenTech\AMModels
12.1\MyACMRxn\myACMRxnRxnModel.dll />
</Class>
<Class Id=Solver >
</Class>
</APModelCatalog> |
Problem Statement: How do I map a symbol to an expansion template while creating PPID from PFD drawing? | Solution: To map a PFD symbol to an expansion template follow these steps,
1. Open PPID drawing
2. Open Stockpile and select Organise By drop down box to By diagram
3. Go to your PFD diagram from which you want to create PPID diagram.
4. Right click on the Symbol in stockpile for PFD drawing and choose Symbol Map Option.
5. This will open Select Symbol for Diagram Conversion from PFD window.
6. Select the tab for the appropriate diagram being created
7. Select the expansion template symbol from folder structure on the left hand side and click on Add button.
8. This will add expansion template symbol on right hand side, make sure you select this symbol and click OK.
9. Drag symbol from stockpile and drop it on drawing and this will show up as expansion template symbol on drawing.
Keywords: Use expansion template, draw expansion template
References: None |
Problem Statement: When I declare a variable as external in a submodel, it seems I must declare the corresponding variable with exactly the same name in the parent model using the submodel. Is there a way to avoid this limitation? | Solution: You can change the default mapping of external properties. The examples below illustrate the syntax to be used.
Note that the main purpose of the external keyword is to reduce the total number of variables in the simulation, but it causes some limitations (e.g. you may not specify the attributes of the variable such as value, specification, bounds in the submodel) and the advantage is not always significant (since equivalenced variables are eliminated anyway).
Let's say you have created a submodel saturation which has the following syntax:
model saturation
A as realparameter (-10);
B as realparameter (-2000);
C as realparameter (100);
T as external temperature;
psat as external pressure;
psat = exp(A + B/ ((T+273.15) + C)); // saturation pressure calculation
end
To use this submodel, you could use the following syntax:
model tank
T as temperature (fixed);
psat as pressure;
psat_calc as saturation;
end
This is actually the same as typing explicitly the following:
model tank
T as temperature (fixed);
psat as pressure;
psat_calc as saturation (T is T, psat is psat);
end
Let's say now that you you don't want to use T and psat as the name of the variables in your main model. In that case you need to explicitly specify the name of the external variables.
Model tank1
T1 as temperature;
psat1 as pressure;
psat_calc as saturation (T is T1, psat is psat1);
End
This would also for example the same sub-model to used twice in the same model.
Model tank2
T1 as temperature;
psat1 as pressure;
T2 as temperature;
psat2 as pressure;
psat_calc1 as saturation (T is T1, psat is psat1);
psat_calc2 as saturation (T is T2, psat is psat2);
End
Note however it is not possible to create an array of such submodels as the is keyword may only be used in the declaration line of the submodel. On the other hand, you can modify the submodel:
model saturationn
A as realparameter (-10);
B as realparameter (-2000);
C as realparameter (100);
n as external integerparameter;
T([1:n]) as external temperature;
psat([1:n]) as external pressure;
psat = exp(A + B/ ((T+273.15) + C)); // saturation pressure calculation
end
With the modified model you can use arrays in the main model (default mapping):
Model tankn
n as integerparameter (10);
T([1:n]) as temperature (fixed);
psat([1:n]) as pressure;
psat_calc as saturationn;
End
Modified mapping:
Model tankn1
n as integerparameter (10);
T1([1:n]) as temperature (fixed);
psat1([1:n]) as pressure;
psat_calc as saturationn (T is T1, psat is psat1);
End
The attached file contains those examples.
Keywords: external, submodel, mapping, is
References: None |
Problem Statement: How can I make ABE (Aspen Basic Engineering) Query as a registered file type on my computer? | Solution: ABE query file has an extension .AZQ.
If your computer does not recognize this extension then you can follow these steps to fix this,
1. Open My Computer or Windows Explorer.
2. Click on Tools | Folder option from the tool bar. (You can also use short cut key alt + T on your key board in case you don't see the toolbar).
3. Under folder option select FIle Types tab, it may take few seconds to show all file types in your computer.
4. Click on New button in file type tab, it will bring up a Create New Extension window as shown in screen shot below.
5. Define File Extension AZQ and click ok button, that will bring you to the File Types tab in Folder Options window.
6. click on AZQ extension in File Types tab and click on Change... button as shown in screen shot below.
7. This will bring up Open With window, make sure you have selected the check box Always use the selected program to open this kind of file as shown in screen shot below.
8. Click on Browse... button and browse to choose AZQueryEditor.exe program. You can find this program inside AspenTech directory on your computer. The default folder for version V7.1 is C:\Program Files\AspenTech\Basic Engineering V7.1\UserServices\bin
9. Click on OK button after selecting this program on Open With window.
10. Click on Close button in file type tab. Now you should be able to open AZQ file type by double clicking on it.
Keywords: Query editor, file type, register, register extension
References: None |
Problem Statement: When using XLDSE, why are the printed datasheets less than 100% zoom? | Solution: Using XLDSE, for existing datasheets, the printouts may appear less than 100% zoom. This occurs if the worksheet has something defined outside the normal print area - e.g. calculations which may be used by the datasheet.
To solve this problem, simply Set Print Area to the borders of the datasheet, save the XLS and regenerate the ZTX file.
Keywords: XLDES, Datasheet, ZTX
References: None |
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