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Problem Statement: How do I attach a stream to a unit operation using VBA? | Solution: The following example VBA code demonstrates how to attach streams (new and existing streams of material and energy type) to a new unit operation. In this particular case, an expander unit operation is used, but analogous coded can be used for other unit operations (e.g. compressor, etc.):
Dim hyApp As HYSYS.Application
Dim hyCase As HYSYS.SimulationCase
'We are attaching to the running instance of HYSYS
Set hyApp = CreateObject(HYSYS.Application)
'Attaching to the case currently loaded
Set hyCase = hyApp.ActiveDocument
'Define Expander operation
Dim myExp As ExpandOp
'Define Streams (material and energy) to be used
Dim myStrmFeed As ProcessStream
Dim myStrmProd As ProcessStream
Dim myStrmEner As ProcessStream
With hyCase.Flowsheet
'Creating Expander unit operation on flowsheet
Set myExp = .Operations.Add(K-101, expandop)
'Setting the Existing Feed stream
Set myStrmFeed = .MaterialStreams(YOUR EXISTING STREAM)
'Creating a New material stream for Product
Set myStrmProd = .MaterialStreams.Add(Product)
'Creating a New energy stream for Expander
Set myStrmEner = .EnergyStreams.Add(W-K101)
End With
With myExp
'Allocating the Expander Feed stream
.FeedStream = myStrmFeed
'Allocating the Expander Product stream
.ProductStream = myStrmProd
'Allocating the Expander energy stream
.EnergyStream = myStrmEner
End With
The user can expand the code to include other actions by modifying the following code segment in the Excel file attached with thisSolution.
Keywords: VBA, stream, attach
References: None |
Problem Statement: In the Batch Extractor Interface you may need more time to run a query. This can be due to a slow connection, busy SQL server or a long query for example. | Solution: Some of the Batch Extractor interface does not have a built in option to change the Timeout settings. The Default timeout is 1 minute.
For example the vDBIS_interface does not have this option. So to change the timeout you will have to follow the steps below to create the necessary registry key:
1. Open Regedit and navigate to the location
\\HKEY_LOCAL_MACHINE\Software\AspenTech\BXE\CMDProc\
2. Create a DWord key named SQLPlusTimeout
Note: the key name is case sensitive.
3. Set the value in the new key. The value is in tenth of seconds.
Keywords: Batch Extractor
Interface
vBDIS
Query timeout
References: None |
Problem Statement: What does the ‘Unable to start solver calculation: No calculable sources’ message mean and how to get rid of it? | Solution: The following message will be displayed by Aspen Flare System Analyzer (AFSA) every time that the mass flow (design flow) of either a Relief Valve or a Control Valve is set to 0.0.
Since AFSA performs both an overall mass and energy balance from active source(s) to flare tip and then back calculates pressures from flare tip to source(s) until the backpressure at the outlet flange of the relief device is calculated, it is mandatory to enter a mass flow rate to start and perform calculations, otherwise this message will be displayed and no calculations will be performed.
Keywords: Sources, Relief Device, Relief Valve, Control Valve, Calculation, Solver, Mass Flow.
References: None |
Problem Statement: When Fortinet FortiGate is being deployed in the network, user will encounter the following error when adding a remote Aspen Calc server. | Solution: When adding a remote Aspen Calc server, a DCOM connection is made to the server. However, the Fortinet FortiGate has a session helper called DCE-RPC session helper (dcerpc) which also listens on TCP and UDP ports 135.
When using Process Monitor (https://technet.microsoft.com/en-us/sysinternals/processmonitor.aspx) to capture information of adding remote Aspen Calc server in Aspen Calc, entry such as following:
calc_client_hostname:64774 -> calc_server_hostname:http
Whereas for those remote Aspen Calc server which can be successfully added, the entry will appear as follow.
calc_client_hostname:64962 -> calc_server_hostname:5019
The firewall engineer will need to be engaged to disable the DCE-RPC session helper.
Keywords: Failed to connect to <server>: The remote server machine does not exist or is unavailable
References: None |
Problem Statement: If I accidentally have both the LOADSOL in table CASE and also enabled option Input | Solution: at the run dialog box but pointing to a differentSolution file which one will be used?
Solution
Entries in table CASE are meant to supersede the ones from run dialog box. The exact rules are: For multiple cases solved one after the other, the first case is treated as a single case. For subsequent cases, if you provide a LOADSOL in CASE, then that supersedes any entries.
If there is no LOADSOL, and the Load Previous CaseSolution is checked, then that setting is dominant and the previous caseSolution file is used.
If that Load Previous CaseSolution is unchecked and aSolution file is designated in the execution dialog, then that numberedSolution file is loaded for each and every case.
Keywords: None
References: None |
Problem Statement: In the new pipeline system (v8.7 & above), how are the Gantt Bars displayed for linked pipeline product shipment events, as opposed to the previous versions? | Solution: For product pipeline events, consider this situation:
Before V8.7:
Product Pipeline PLM1 has a capacity of 925 MBbl. So if I create a couple of events like the following for the pipeline:
Note that the second event is linked to the first event.
The pipeline is LONG.
For the first event APS flushes out the 925MBbl line fill into the destination, and then puts in 1075MBbl (2000-925) into the destination tank of the event T251, as seen on the Gantt
Since the next event starts as soon as the first event ends, the remaining 925MBBl of the first pipeline event is discharged when the second event starts:
In these versions before v8.7, these are shown as two Gantt events (of the same eventID)
8.7 and above:
In the DemoDSS model, there is a segment HTAT, with a capacity of 150MBbl. The following couple of pipeline events are created:
Note that, the second event begins as soon as the first is done. Also, in 8.8, with the new pipeline functionality, each event is tracked with an internally generated “Shipment ID”, as highlighted in both the above screenshots.
After Simulate ALL, we can see that the first event, which was split into 2 receipts in 7.3, is now shown as a single receipt in 8.8, since the following event starts right away, and keeps the pipeline in flow.
The reason is that the receipts are now grouped by the shipment ID, so since the two events are happen right after one another, the receipt for the first event is grouped as shown below:
To summarize, when there are product pipeline events that are
Linked
No link, but the second pipeline event begins at the end of the previous,
Then versions v8.7 and above group the receipts into the receiving tank of the first event, whereas versions before v8.7 split them up.
Keywords: None
References: None |
Problem Statement: We are not able to generate Full | Solution: report in Excel format, it is only available in HTML and TXT format. However, some users would like to perform calculation using the content of FullSolution report, therefore, viewing FullSolution in Excel would be more convenient. The question is, how do we view FullSolution report in Excel when PIMS does not generate FullSolution report in Excel format?Solution
To view FullSolution in Excel format:
Run PIMS model and generate FullSolution report in HTML format
Open a new Excel file (outside of PIMS)
Select File | Open
Browse for the FullSolution HTML report generated by PIMS in the model folder (from step1)
Double click the FullSolution HTML Report, you can now view it in Excel format
Keywords: Full
References: None |
Problem Statement: How to create a Unit Parameter Report using Report Wizard in APS? | Solution: In the demo model, look up the CCU unit on the Gantt Screen:
There are 3 unit parameter events here:
As seen above, there is a change in parameter 3, which controls Cat Cracked diesel disposition.
To pull the unit parameters to the refinery report wizard template, please use the following steps
- Turn on Memory Cache
- Reload Simulator and Simulate All
- Open Report Wizard now:
- A new excel window opens, choose “New Template” from the “Aspen Refinery Report” excel add-in
- Choose “Unit Parameter” template and then navigate tom Unit ID -> CCU. Now click the “ >” button as shown below:
- Clicking the “>” handle sends the unit to the “Selected Information” pane
- Click Next.
- From the following screen, choose the name of the template that is to be created. Also choose the layout desired by dragging and rearranging the column headers/row headers
- Click Next, keep following the wizard and add the desired options (conditional formatting/group constraints etc – this may not be applicable for this report, until you get to the following screen:
- Click Create Template. Report Wizard will construct a template with all these selected details
- Now, in this template, go back to the “Aspen Refinery Report” add-in, and click “Preview Report”
- From the following menu, choose the model horizon you want to see results, and then select “Periodic” This reports the unit parameters every period:
- Click OK, this should report out the following excel sheet, with CCUs parameters over the horizon
- If you are satisfied with the template created, you can go back to the template and save it to the database. Next time onwards you could run your report from this template.
Keywords: None
References: None |
Problem Statement: How does MBO behave when there is negative beginning inventory for a tank? | Solution: When there is a negative beginning inventory value for a component tank, MBO reports it in the Validation report (Model-> Validate Model). As far as the optimization is concerned, MBO tries to avoid that component in the finalSolution, and reports infeasibilities in the fullSolution report.
Example: Here’s a negative volume for TLNP, and also all component rundowns for the tank for the horizon are also erased (so that the tank stays negative)
Go to Model-> validate Model, MBO reports this as an invalid value
The current blend screen before optimization involves this component tank, as seen below:
After Optimization, MBO tries to not use this component owing to its invalid value. From the finalSolution, the component wasn’t used in the blend horizon. The following was reported in the Blend Report:
Infeasibilities are reported against the unused component for all periods in the MBO model horizon. (The amount is 12 because the inventory of the tank is -1 and the tank minimum limit is 11)
Keywords: None
References: None |
Problem Statement: How do you install the Aspen Properties Excel Calculator Add-In? | Solution: The Aspen Properties Excel Calculator Add-In provides rigorous physical properties as Excel built-in functions. These functions are easy-to-use, can be integrated in spreadsheet calculations, and provide full access to all the property methods and models available in Aspen Properties. You can use these functions to calculate physical properties of pure components and mixtures, as well as to perform phase equilibrium calculations.
The attached PDF is an installation guide outlining how to install the Aspen Properties Excel Calculator for Office 2007, 2010, 2013, or 2016. This is applicable for versions 7.3 to 8.8 of Aspen Properties. The guide also includes troubleshooting advice and tips. In V9 of Aspen Properties, the Excel Add-In is installed by default.
Keywords: Aspen Properties, Excel Add-In, Excel Calculator, PHFlash, PVFlash, THFlash, TVFlash, PSFlash, Unit Conversion
References: None |
Problem Statement: How to report calculated total bed mass from all the “Fixed” inputs like inter/intra particle voidage, adsorbent density, bed height, diameter etc.? | Solution: The total bed mass calculation depends on whether we are using the CSS models or the dynamic models. In the CSS models, there is a variable in the sorbent layer submodel called SWeight which corresponds to the total sorbent weight. The path to the variable is, for example, B1.Layer(1).SWeight
For the dynamic models, the total weight is not calculated by default. However, it can be calculated from specified variables as the user describes. Since the specified adsorbent density is the bulk density, the particle voidage is not relevant. If the bed diameter is constant along the axis and the bed is vertical, it is very straightforward to calculate the weight:
weight = B1.Layer(1).RhoS * B1.Layer(1).Vol * B1.Layer(1).Nodes
For a horizontal or radial bed:
weight = B1.Layer(1).RhoS * SIGMA(ForEach (i in B1.Layer(1).FDESet) VolH(i))
weight = B1.Layer(1).RhoS * SIGMA(ForEach (i in B1.Layer(1).FDESet) VolR(i))
Key Words
Bed Mass, Density, Layer
Keywords: None
References: None |
Problem Statement: How to incorporate effects of high pressure on the rate of initiator decomposition in free radical polymerization process? | Solution: The rate of initiator decomposition is determined from the modified Arrhenius equation:
There are three parameters in this rate calculation: pre-exponential factor (k0), activation energy (Ea) and activation volume (V). The activation volume parameter is supplied to account for any dependency on pressure. For high pressure process this parameter has a non-zero value which can be determined by regressing experimental data.
Key Words
High Pressure, Initiator, Activation Volume
Keywords: None
References: None |
Problem Statement: Which models can be chosen to model a heat exchanger in a Aspen HYSYS Dynamics simulation? | Solution: There are three models available in the Heat Exchanger unit operation (‘Dynamics’ tab, ‘Model’ page):
1-Basic: This model uses an Overall UA factor, which can reflect dependency on the flowrate, if reference values for this variable on the shell and tube side are introduced.
2-Intermediate: This model allows the introduction of information pertaining heat transfer in each of the spatial domains (area and transfer coefficient in shell and tube, as well as tube mass and specific heat).
3-Detailed: This model also requires the introduction of these individual phase coefficients, but incorporates more details regarding the exchanger configuration (namely, number of shell and tube passes, and zones per shell pass).
Keywords: Heat exchanger, Dynamics, Model, Detailed, Intermediate, Basic, UA
References: None |
Problem Statement: What is the consequence of changing the ‘Source inlet velocity basis’ option in the Calculation Options Editor, shown below? | Solution: This option influences the velocity used at the inlet of the source element (valve) for purposes of calculating the kinetic energy in the energy balance across the valve only. It is not a velocity specification. Thus, when the option ‘Zero Velocity’ is chosen, the static pressure upstream the valve does not equal the total pressure (i.e. the dynamic pressure is still calculated with the Inlet Pipe Velocity). In this case, the difference in enthalpy across the valve (hence, downstream pressure and temperature) will depend only on the velocity at the outlet, and not influenced by the inlet pipe size.
If the ‘Inlet Pipe Velocity’ is chosen as basis, a dependence on downstream pressure and temperature on inlet pipe size appears (specified in Valve Editor, ‘Inlet piping’ menu), since the velocity upstream the valve now influences the energy balance across the valve (in the kinetic energy term).
Keywords: Source, Inlet Velocity, Basis, Zero Velocity, Inlet Pipe, Kinetic energy
References: None |
Problem Statement: How can I minimize some objective functions, while maximizing others in the same Optimizer problem? | Solution: The individual items of the objective function are included in the Derivative Analysis associated with the optimizer. Some items may be associated with cost and some with revenue. The differentiation of cost and revenue items are done by the parameter called “Price” providing positive or negative value. A negative value can be entered for cost items and positive for the revenue items.
If the value for this parameter is positive then the function will be minimized or maximized according to what is defined in the Optimizer menu.
If the value for Price is defined as negative, then the objective for that particular function will be the opposite of the one defined in the optimizer menu.
Keywords: SQP Optimizer, Objective functions, Derivative Analysis
References: None |
Problem Statement: For streams with significant amount of light components, the calculated Reid vapor pressure is usually off. Why is that? Are there any guidelines for using Reid vapor pressure? | Solution: Reid vapor pressure is the absolute pressure exerted by a mixture (in pounds per square inch) determined at 100 F and at a vapor-to-liquid volume ratio of 4 (ASTM Method D 323. RVP is intended for characterizing the volatility of gasoline and crude oil, with a typical range of 1 to 20 psia. Out of this range, the accuracy may be poor. Therefore, RDV should not be applied to very light or very heavy streams.
See alsoSolution 3126 How is Reid vapor pressure calculated & can it be used as design spec?
Keywords:
References: None |
Problem Statement: How can I limit volume-based capacities for Vacuum towers in a weight-based model when the feed is a type 2 cut? | Solution: Most atmosphere tower residual cut is type 2 cut, which means the atmosphere residual can be routed to both VAC tower and other dispositions. Aspen PIMS automatically creates a weight-based capacity for the vacuum units (CVTx). To convert CVTx to volume-based capacity in weight based model, it is treated differently. In this weight-based sample model, the residual cut is AR1, and it is type 2 cut defined in table CRDCUTS.
In order to convert stream AR1 from weight-based to volume-base, you have to know specific volume, SPV for AR1, and the volume-to-weight conversion factor for the model (VTW).
Then, VOL = WT * SPV / VTW
1. Make sure SPV is defined in all the ASSAYS tables, i.e. ISPVAR1 data needs to be defined in every ASSAYS table. Enter 999 for AR1 in the column SPV in table PGUESS. VTW is defined in Model Settings | General, and for this sample model it equals to 0.1587.
2. Run the model and use the matrix analyzer to verify the column name for running atmosphere residual (the type 2 cut) to the vacuum unit. For example, if the type 2 cut is AR1 for CD1, the column is probably SCD1A!1 where the R is replaced by an exclamation point. PIMS builds this structure.
3. In table ROWS, add an E row as EBALAR1 with a -1 intersection in the column SCD1A!1. If this is a new table, attach the ROWS worksheet to the ROWS branch of the model tree.
* TABLE
ROWS
Table of Contents
*
User Defined Rows
TEXT
FIX
FREE
MAX
SCD1A!1
SCD2A!2
***
*
WBALRFL
Refinery Fuel
1.00000
WBALTGT
SRU Tail Gas
1.00000
WBALLN1
Lgt Naphtha
1.00000
WBALWN1
Whole Naphtha
1.00000
WBALCCS
Cat Slurry
1.00000
WBALLOS
Loss
1.00000
WBALH2S
Hydrogen Sulfide
1.00000
UBALKWH
Electricity
1.00000
EBALAR1
AR1 to vac unit 1
-1
EBALAR2
AR2 to vac unit 2
-1
4. Add a new submodel SVAC. Include the EBALAR1 row with a +1 in column AR1. Include an ESPV row, ESPVVU1 with a -999 in column AR1 and the model's VTW factor in column VU1. Then add a CCAP row, CCAPVU1 and put a +1 in column VU1.
* TABLE
SVAC
Table of Contents
*
Vacuum Tower Capacity, BPD
TEXT
AR1
VU1
AR2
VU2
***
*
CCAPVU1
Vac Tower #1, BPD
1
EBALAR1
AR1 To Vac Unit 1
1
ESPVVU1
AR1 Specific Volume
-999
0.15867
*
CCAPVU2
Vac Tower #2, BPD
1
EBALAR2
AR2 To Vac Unit 2
1
ESPVVU2
AR2 Specific Volume
-999
0.15867
***
*
NOTES:
*
1. See T. ROWS.
5. Add CVU1, CVU2 to table CAPS with the volume limits in columns MIN and MAX.
* TABLE
CAPS
Table of Contents
*
Process Capacities ('000)
TEXT
MIN
MAX
REPORT
***
*
CR01
Crude Section
-1
CR02
====================
-1
CAT1
Crude Unit #1 T/D
100
CAT2
Crude Unit #2 T/D
100
CVT1
Vac Unit #1 TPD
CVU1
Vac Unit #1 BPD
18
CVT2
Vac Unit #2 TPD
CVU2
Vac Unit #2 BPD
30
6. Add SVAC to table SUBMODS and attach the SVAC worksheet to the SVAC submodel branch of the model tree.
* TABLE
SUBMOD
Table of Contents
TEXT
***
SVAC
Vac Tower #1, BPD
This is from theSolution report,
Capacity Utilization Summary
Process Capacity
Activity
Minimum
Maximum
% Maximum
Marg Val
Crude Section
====================
AT1
Crude Unit #1 T/D
799
100,000
0.799
AT2
Crude Unit #2 T/D
8,375
100,000
8.375
VT1
Vac Unit #1 TPD
376
VU1
Vac Unit #1 BPD
2,511
18,000
13.952
VT2
Vac Unit #2 TPD
4,646
VU2
Vac Unit #2 BPD
30,000
30,000
100.000
-10.689
Keywords: Vacuum Tower
Capacity
References: None |
Problem Statement: I have an old ABE code which has been used in previous ABE versions before ABE V10 release. When using a Visual Studio environment to debug this code the following error appears:
“A project with an Output Type of Class Library cannot be started directly.”
How can I debug this old ABE code to be used in a new ABE version? | Solution: In order to debug this code (project) Visual Studio environment has to be used. One has to add an executable project to thisSolution which references the library project and set the executable project as the start-up project following these instructions:
1) Go to:Solution Explorer | Properties | Expand Common properties | Select Start-up Project | Change to (Single Startup project) from.dll to .web | Select your project name.
2) Having done that, then try to debug it. Now one will be able to debug it without issues.
Keywords: Debuging, VB.NET code.
References: None |
Problem Statement: Is it possible to use correlations other than the built-in ones in rate-based distillation? | Solution: Aspen Rate-Based Distillation uses well-known and accepted built-in correlations to calculate binary mass transfer coefficients for the vapor and liquid phases, interfacial areas, heat transfer coefficients, and liquid holdup; however, we have the option to use the rate-based generalized correlations which were developed at AspenTech to provide a framework for specifying other correlations besides the ones built into Aspen Rate-Based Distillation. These generalized correlations are written in terms of the Sherwood (Sh) and Nusselt (Nu) numbers, dimensionless groups which include the mass transfer and heat transfer coefficients.
For trays, the mass transfer and interfacial area correlations are:
For packing:
The correlations for heat transfer are:
Where:
Sh = Sherwood number
Re = Reynolds number
Sc = Schmidt number
We = Weber number
Fr = Froude number
Nu = Nusselt number
Pr = Prandtl number
c = correlation constant
ϕ = orifice ratio
ε = void fraction of the packing
m, n, p, s, t, m', n', p', r', s', t', m'', n'', q'', r'', s'', t'' = Exponents for mass transfer dimensionless groups
α, α′, β, β′, γ, γ′, δ, δ′ = Exponents for heat transfer dimensionless groups
Since V9, you need to open the RadFrac column and go to Rate-Based Modeling | Rate-based Setup | Sections and specify Generalized the methods for calculating mass transfer coefficient, heat transfer coefficient, and interfacial area to use the Generalized Correlations.
For V8.8 and earlier versions, the specification is on a different RadFrac form, Sizing and Rating | Tray/Packing Rating | Rate -based | Correlations.
Once you choose the generalized correlation for any of the three methods, you must also choose (or create) a correlation ID specifying a particular generalized correlation and then specify the parameters for that correlation on the Generalized Transfer Correlations form (Rate-Based Modeling | Generalized Transport Correlations). These parameters will be the exponents for dimensionless groups used for the generalized mass transfer, interfacial area and heat transfer correlations.
Keywords: Generalized transport correlations, Rate-Based Distillation, mass transfer, interfacial area.
References: None |
Problem Statement: When using the Jones-Dole model to calculate the liquid mixture viscosity of an Electrolyte, the IONMOB parameter doesn't seem to have an effect. | Solution: The Jones-Dole model has 3 different equations, the Jones-Dole, the Breslau-Miller and the Carbonell.
The equation used is dependant on the parameters given:
Parameters Available Equation Used
IONMOB and IONMUB Jones-Dole*
IONMUB Breslau-Miller*
- Carbonell
Note: Even if both the IONMOB and IONMUB parameters are available the Jone-Dole equation is not used if the apparent electrolyte, ca, concentration is above 0.1 kmol/cum. If it is above this limit then the Breslau-Miller equation is used.
Keywords: MUL
ELECNRTL
References: None |
Problem Statement: The values of mass exergy reported for a stream are different than the ones the user is expecting. | Solution: This is most likely due to different reference conditions in the calculation. Even though for certain properties Aspen HYSYS uses 15 deg C (60 deg F) as the reference temperature, exergy uses by default a value of 25 deg. C. To change this, access the Correlation manager and set the desired values of temperature and pressure for the reference state.
The definition of exergy follows the expression described in KBSolutions 3384 and 109771.
Keywords: Exergy,
References: , Correlation Manager |
Problem Statement: How to specify minimum mass flow across each stages of a multistage turbine to avoid surge condition? | Solution: To avoid surge condition, each stage of a multi-stage compressor must have a minimum mass flow across them. Currently the compressor model does not have an option to add surge curve data. However a specific minimum mass flow rate can be assigned for each stages. To accomplish this, please follow:
Right click on Multi-stage Compressor > Forms > OptimisationLimits. Please assig appropriate mass flow rate for variable “sMinFlow(stage number)”
Key Words
Compressor, Minimum Flow, Stage
Keywords: None
References: None |
Problem Statement: What is the validated process for Aspen Unified PIMS? | Solution: This KBSolution includes the Validated Process for Production Planning (Aspen Unified PIMS)
Planning is the process of estimating for a future time the optimum crude slates, refinery operations, and production to meet demand and maximize margins. Aspen Unified PIMS is used for many functions within a refinery or chemical plant. However, this initial V10 version of this document will concentrate on the following commonly used functions:
Run and Analyze an existing Base Model. This assumes that the Base Model has already been created and tested
Perform Feedstock Selection for an upcoming month. This involves creating individual Case Studies to determine the profitability of purchasing and processing a large number of feedstocks, normally crudes
Validated processes are system tests using real-world reference architecture and real-world models/data to test the rigorously defined end-to end business process.
The Validated Process documents serve the following purposes:
- To describe the scope of process-oriented testing for a particular business process.
- To provide implementation guidance by illustrating detailed use cases.
Instructions
You can download all AspenTech product documentation from the online Technical Support Center.
To access the documentation attached to thisSolution, follow the Instructions below.
.PDF Files
Printable documentation is published in Adobe Portable Document Format (.pdf). You must use the Adobe Acrobat Reader to view these read-only product-specific documents.
To view a .pdf document in your browser, select a document link. To print a .pdf document, select the print icon in the Adobe toolbar after the document loads in your browser. To download a document to your local drive, select Download icon in the Adobe toolbar.
Keywords: None
References: None |
Problem Statement: How can the temperature difference between two unit operation blocks be set to a specified value? | Solution: Attached is an example of using a parameter variable to set a temperature difference between two Heater blocks.
See file parameter.bkp.
For more information see the Aspen Plus Help topic Simulation and Analysis Tools -> Sequential Modular Flowsheeting Tools -> Accessing Flowsheet Variables.
In this example, a design specification manipulates a user-defined variable (Parameter 1), which represents the temperature difference between two heaters. A Fortran block retrieves the parameter (DELT) and the temperature of the first heater (T1), and uses these variables to set the temperature of the second heater (T2).
Keywords: None
References: None |
Problem Statement: What is the validated process for Collaborative Demand Management? | Solution: This KBSolution includes the Validated Process for Demand Management (Aspen Collaborative Demand Manager)
There are two major workflows within Collaborative Demand Management. The Demand Management workflow allows demand planners to collect data and use it to create a forecast for market demand. The Collaborative Forecasting workflow is used by the sales force to provide up to the minute sales and forecasting data. Updates from Collaborative Forecasting are used in Demand Management to adjust the forecast.
Validated processes are system tests using real-world reference architecture and real-world models/data to test the rigorously defined end-to end business process.
The Validated Process documents serve the following purposes:
- To describe the scope of process-oriented testing for a particular business process.
- To provide implementation guidance by illustrating detailed use cases.
Instructions
You can download all AspenTech product documentation from the online Technical Support Center.
To access the documentation attached to thisSolution, follow the Instructions below.
.PDF Files
Printable documentation is published in Adobe Portable Document Format (.pdf). You must use the Adobe Acrobat Reader to view these read-only product-specific documents.
To view a .pdf document in your browser, select a document link. To print a .pdf document, select the print icon in the Adobe toolbar after the document loads in your browser. To download a document to your local drive, select Download icon in the Adobe toolbar.
Keywords: None
References: None |
Problem Statement: When user open Schedule Property Bias from Simulator | Schedule Property Bias, schedule bias screen will freeze at taskbar and not able to open, see screenshot below. | Solution: To resolve, please try these:
Delete the two files in Layouts\Forms of under the APS working folder:
SchedBiasGridAll.xml
SchedBiasFormAll.xml.xml
Then open the dialog and see if it works.
2) Check the size of the table ATORIONPropBiasData. If the size is too big, the dialog may have trouble displaying the items.
3) When the program is frozen, open Task Manager and check its CPU consumption.
4) Please check the versions of .Net and Infragistics on the machine.That dialog was implemented in C#(Winform) using third-party controls from Infragistics. The issue is platform dependent. Therefore the versions of .Net and Infragistics (and defects of them) could be the cause.
To find the version of Infragistics, go to C:\Program Files\AspenTech\Aspen Petroleum Scheduler. You can find a file with a name like Infragistics4.Win.UltraWinGrid.v15.1.dll, whose version is then 15.1.
MS has an instruction for finding the .Net versions at https://msdn.microsoft.com/en-us/library/hh925568(v=vs.110).aspx
Which is as following:
#############################
To find .NET Framework versions by viewing the registry (.NET Framework 1-4)
On the Start menu, choose Run.
In the Open box, enter regedit.exe.
You must have administrative credentials to run regedit.exe.
In the Registry Editor, open the following subkey:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\NET Framework Setup\NDP
The installed versions are listed under the NDP subkey. The version number is stored in the Version entry. For the .NET Framework 4 the Version entry is under the Client or Full subkey (under NDP), or under both subkeys.
System_CAPS_noteNote
The NET Framework Setup folder in the registry does not begin with a period.
To find .NET Framework versions by viewing the registry (.NET Framework 4.5 and later)
On the Start menu, choose Run.
In the Open box, enter regedit.exe.
You must have administrative credentials to run regedit.exe.
In the Registry Editor, open the following subkey:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\NET Framework Setup\NDP\v4\Full
Note that the path to the Full subkey includes the subkey Net Framework rather than .NET Framework.
System_CAPS_noteNote
If the Full subkey is not present, then you do not have the .NET Framework 4.5 or later installed.
#########################################
Keywords: Schedule bias screen, freeze, SchedBiasGridAll.xml, SchedBiasFormAll.xml.xml, ATORIONPropBiasData, .Net, Infragistics
References: None |
Problem Statement: How to access the historic time point value of a variable during dynamic run? | Solution: Currently, there is no specific variable that holds the value of a variable at a given time. However this can be accomplished by using a flowsheet constraint.
For example, to access the current temperature of the liquid in the condenser the variable is B1.Condenser.LiqOut.T. If we wanted to access the temperature at time of 0.1 hour before current time, following code can be used in a flowsheet constraint:
T as Temperature;
TDelay as Temperature;
T = B1.Condenser.LiqOut.T;
TDelay = Delay T by 0.1;
T will then contain the current value of the Condenser temperature at any given time. TDelay will contain the condenser Temperature 0.1 hrs before the current time.
Please see the attached file as an example.
Key Words
Time Point, Variable, Dynamic, Flowsheet Constraint
Keywords: None
References: None |
Problem Statement: What is the procedure to migrate custom plots in Aspen Production Control Web Server when upgrading to a new version? | Solution: When you create a plot list trough history tab / Plot lists
And then click on Plot All it will show the history plot display:
If you then go to File / Save as you will be able to save an IP.21 Browser Plot Configuration file (*.xml). Save the file under the C:\inetpub\wwwroot\AspenTech\ACOView\plots directory (This location is available in the PCWS)
After that the plot will be available in the PCWS / history / Plot files:
If you are going to upgrade from V7.3 to V8.0 consider the following:
1. The DMCplus Controller name should be the same on the new servers.
2. Confirm the new ID for Aspen Watch Maker:
3. Take note of the new names of the Online, PCWS and Aspen Watch servers.
4. The *.xml file pulls the data from the ADSA directory Server, if you open the *.xml you will see it is calling to the source name, Map and Tag Name
In my example I am going from V7.3 (APCV73SAM) to V8.0 (APCV8) server. These are the steps I followed:
1. Copy the *.xml file on the new APCV8 server under C:\inetpub\wwwroot\AspenTech\ACOView\plots
2. Open the *.xml file with note pad and replace “Old server name” with “New server name”.
3. Replace CXX with CYY, where XX is the collection ID from the old Aspen Watch server and YY is the collection ID of the new Aspen Watch server.
With the above procedure the plot file now opens on the new V8.0 server:
Keywords: Migrate Custom plots
PCWS
References: None |
Problem Statement: How to run component splitter in series in HYSYS Dynamics? | Solution: When ever you connect two component splitter with a valve, do NOT check the pressure flow relation check box. Component splitter will calculate the flow rate and pressure for the downstream unit. If you check the pressure flow relation check box(on the Dynamics Tab for valve) then it will be over specified. Check the Equation Summary view under Simulation menu option.
Note: You may get flash failure message while running component splitter in Dynamics. It is due to unrealistic temperature of one of the outlet stream. Specify temperature to the outlet streams and add a duty stream to the component splitter to avoid flash failure message.
Keywords: Component, Splitter, Component Splitter, Dynamics
References: None |
Problem Statement: How to increase branching and crosslinking extent in free radical polymerization process? | Solution: Usually branching and cross linking takes place by formation of live polymer directly formed from monomer. Thermal and radiation initiation (INIT-SP) can be utilized to generate live polymer from monomer. This type of reactions do not contribute to generation of free radicals like in Initiator decomposition. To incorporate INIT-SP, please go to Reaction > Add New Reaction
This type of reactions often contribute to formation of undesired cyclic dimers and trimers during polystyrene process which need to be removed during devolatilization process.
Key Words
Monomer, Radiation, Thermal, Initiation
Keywords: None
References: None |
Problem Statement: How can the steam use in a flowsheet be optimized using sequential modular mode? | Solution: Attached is an example of how to optimize the operating margin for a simple flowsheet.
Use optimization to maximize or minimize a user-specified objective function by manipulating decision variables (feed stream, block input, or other input variables).
The objective function can be any valid Fortran expression involving one or more flowsheet quantities. The tolerance of the objective function is the tolerance of the convergence block associated with the optimization problem.
You have the option of imposing equality or inequality constraints on the optimization. Equality constraints within an optimization are similar to design specifications. The constraints can be any function of flowsheet variables computed using Fortran expressions or in-line Fortran statements. You must specify the tolerance of the constraint.
Tear streams and the optimization problem can be converged simultaneously or separately. If they are converged simultaneously, the tear stream is treated as an additional constraint.
Aspen Plus solves optimization problems iteratively. By default Aspen Plus generates and sequences a convergence block for the optimization problem. You can override the convergence defaults, by entering convergence specifications on Convergence forms. Use the SQP and Complex methods to converge optimization problems. For more information, see the Aspen Plus Help topic Using the Simulation Environment -> Flowsheet Convergence -> Convergence Methods -> Complex Method and SQP Method topics.
The value of the manipulated variable that is provided in the Stream or Block input is used as the initial estimate. Providing a good estimate for the manipulated variable helps the optimization problem converge in fewer iterations. This is especially important for optimization problems with a large number of varied variables and constraints.
Optimization problems can be difficult to formulate and converge. It is important to have a good understanding of the simulation problem before adding the complexity of optimization.
The recommended procedure for creating an optimization problem is:
Start with a simulation (instead of starting with optimization). There are a number of reasons for this approach:
It is easier to detect flowsheet errors in a simulation.
You can get a good feel for what reasonable specifications are.
You can get a good feel for a reasonable range of decision variables.
You can get a good estimate for the tear streams.
Perform sensitivity analysis before optimization, to find appropriate decision variables and their ranges.
Evaluate theSolution using sensitivity analysis, to find out if the optimum is broad or narrow.
See file Opt.bkp.
In a dichloro-methane solvent recovery system, two flashes, TOWER1 and TOWER2 are run adiabatically, with a 200 psi steam feed to each flash: STEAM1 and STEAM2, respectively. There is a constraint specifying the maximum allowable concentration of Dicloro-methane in the effluent stream from TOWER2. Optimization is used to find the steam flow rates.
The mass flow rate of stream STEAM1 and STEAM2 are the sample variables for the optimization. These variables are called STEAM1 and STEAM2, respectively.
The optimization objective function is STEAM1 + STEAM2.
The optimization problem is converged when STEAM1 + STEAM2 is at a minimum.
Fortran expressions, such as STEAM1 + STEAM2, can be used in any part of the optimization problem.
The mass flow rates of the steam streams are also the manipulated variables. The optimization convergence block finds the flow rates that make STEAM1 + STEAM2 a minimum.
The manipulated variable is specified in the streams, just as if there were no optimization. The specified value is the initial estimate used by the optimization convergence block.
You do not have to specify convergence of the design specification. ASPEN PLUS automatically generates a convergence block to converge the specification.
There is one constraint associated with the optimization problem, called EFFL.
The constraint EFFL is satisfied when the concentration of dichloro-methane is less than 150 ppm.
The constraint is expressed in logarithms.
For more information see the Aspen Plus Help topic Simulation and Analysis Tools -> Sequential Modular Flowsheeting Tools -> Optimization.
Keywords: None
References: None |
Problem Statement: How to separate the excel instances that I open outside of APS?
In older versions APS would automatically start an excel instance for the units workbook. Every other excel file that is opened by double clicking (Outside of APS), would start a “non-APS”(separate) excel instance. In V8.8. we don’t see that anymore, every excel file opened would open in the APS excel (being the first instance opened), so no separate instance anymore. This could lead to quite some problems with custom tools and could interfere with simulation speed. | Solution: There is a setting keyword named EXCEL_IGNORE_REMOTE_REQ that will control whether external excel sheets are opened in a separate excel instance or grouped with APS’s instance.
If EXCEL_IGNORE_REMOTE_REQ -> Y, then each excel file is opened in a separate instance.
The issue is that EXCEL_IGNORE_REMOTE_REQ used to be defaulted to Y in previous versions and in 8.8 it is defaulted to N. Setting that keyword with a value of Y will resolve the issue.
Keywords: None
References: None |
Problem Statement: How do I get started on creating simulation models for batch (or integrated batch-continuous) flowsheets in Aspen Plus V10? | Solution: The attached Jump Start Guide provides you with all the necessary information to get started on using the new capabilities of Aspen Plus V10 for modeling batch, semi-batch and integrated batch-continuous processes in the same environment.
The document includes a complete overview, as well as step-by-step instructions, of all the key functionalities including:
Fundamentals of batch flowsheeting in Aspen Plus V10
Supported unit operation models (and step-by-step instructions on how to use them)
Defining batch recipes in Aspen Plus
Monitoring simulation progress and retrieving model results
Keywords: Aspen Plus, Batch, Batch Modeling, Semi-batch, Integrated Batch and Continuous, Jump Start, Guide
References: None |
Problem Statement: How do I calculate a price for electricity generated by a turbine? | Solution: Unlike a compressor which consumes power to run, a turbine creates power that can be used for applications such as driving an electric generator. The following article describes how to calculate a price for the electricity generated. Please see the attached file which accompanies the content below.
After setting up a flowsheet with a turbine and ensuring it converges, open the turbine block and click on the Utility tab. Then click the drop-down box for Utility ID and select <New>.
Provide a name for the utility (or accept the default) and then click on the drop-down box for Copy from: and select Electricity. Click OK.
Next, run the simulation and view the results for the turbine. Go to the Utility Usage tab. Note the Utility cost is a positive (+) dollar amount, indicating it’s a cost. This would be appropriate for a compressor or a pump; however, a turbine produces energy and therefore this cost should be a negative (-) amount.
To correct the sign to a negative value, first expand the Utilities folder in the Navigation Pane and select the newly-added utility.
Then, change the Purchase price to a negative dollar amount on the Specifications tab.
Now, re-run the simulation and view the utility results. The utility results may be viewed from either the Turbine Results | Utility Usage tab or from the U-1 Results form. The cost of the electricity for the turbine will show as negative, indicating the electricity is produced.
Please note that since the newly-added utility has been given a negative cost, it should not be used for compressors, pumps, or other equipment which consume power. Instead, a second electrical utility with a positive cost should be created and applied. In the example provided, the utility ELEC has a positive price and has been applied to the compressor and pump. The utility ELECGEN has a negative purchase price and has been applied to the turbine.
Keywords: Turbine, Utility, Electricity, Cost, Purchase Price
References: None |
Problem Statement: Is it possible to have different phase temperatures in a holdup volume? | Solution: Yes. If non-unity flash efficiencies are specified for the holdup then it is possible to see different temperatures for the phases within the holdup. In Dynamics | Holdup | Advanced, the user is able to specify the efficiencies, including Recycle efficiency, Feed/Product Efficiencies, as shown below:
Those efficiencies determine how rapidly the system reaches equilibrium. If the values are 1, then the equilibrium reaches instantaneously. If the values are smaller than 1, the system takes longer to reach equilibrium. Therefore, if user specify different flash efficiencies for each phase, it is possible to see different phase temperatures.
Keywords: Non-Equilibrium Flash, Efficiency
References: None |
Problem Statement: Is it possible to have different phase temperatures in a holdup volume? | Solution: Yes. If non-unity flash efficiencies are specified for the holdup then it is possible to see different temperatures for the phases within the holdup. In Dynamics | Holdup | Advanced, the user is able to specify the efficiencies, including Recycle efficiency, Feed/Product Efficiencies, as shown below:
Those efficiencies determine how rapidly the system reaches equilibrium. If the values are 1, then the equilibrium reaches instantaneously. If the values are smaller than 1, the system takes longer to reach equilibrium. Therefore, if user specify different flash efficiencies for each phase, it is possible to see different phase temperatures.
Keywords: Non-Equilibrium Flash, Efficiency
References: None |
Problem Statement: During the | Solution: of a Mixed Integer model (MIP) with the XPRESS optimizer, the model generates a message such as:
During Optimize, N_Status error code=2
or
During Optimize, XPRS_LPSTATUS error code = 2
Solution
Though this message may mean that the model is integer infeasible occasionally it can also mean that the solver is struggling with a very constrained MIP model.
If the MIP is really infeasible then the best way to identify the cause of the infeasibility is to start relaxing the constraints until you can get a feasibleSolution. Through a trial and error process, you can identify the infeasibility.
If the error message appears in spite of the MIP surely being feasible it indicates that the solver is struggling with a highly constrained case.
Several options have been known to help. Here they are listed in order in which they should be tried out:
1) Turning IFPRES off if it has been turned on. This will usually make the solver somewhat slower as the presolve is disabled. However the wider options for starting point have been know to help MIP insolvability.
2) Turning FIXBAL off if it has been turned on. Even though FIXBAL has been known to help greatly in model stability turning it off can also sometimes help solver reach an integer feasibleSolution.
3) Performing a PGUESS update. A feasible, converged run without any of the recursed qualities being limited by min/max should be used to update the values in PGUESS.
Keywords: None
References: None |
Problem Statement: Standard Gas Flow（MMSCFD）とMolar Flow（MMSCFD）で値が異なる | Solution: HYSYSでは、すべての流量はkgmole/s単位で内部保存されており、ディスプレイ上にはユーザー指定された単位系に単位換算されて表示されます。
Molar Flowの表示単位としてMMSCFDもしくはm3/day(gas)を使用する場合、まずプログラム内にハードコードされた換算係数（std_m3/kgmole）を用いて標準状態での体積流量に変換されますが、このときの標準状態の定義は、MMSCFDの場合には60F、1atmが、m3/day(gas)の場合には15℃、1atmが適用されます。これらの換算係数はプログラム内でハードコードされているため、お使いの温度単位によって変わることはありません。
一方、Standard Gas Flowで使用される標準状態はお使いの温度単位によって異なり（詳細は”技術情報（KB 147356）：Standard Gas Flowの標準状態について”を参照ください）、℃、Ｋをお使いの場合は15℃、1atmが、またＦ、Ｒをお使いの場合は60Ｆ、1atmが標準状態となります。
以上より、もし温度単位として℃をお使いの場合、Molar Flow（MMSCFD）の標準状態は60F、1atmであるのに対して、Standard Gas Flowの標準状態は15℃、1atmと、双方の標準状態が異なるため、それぞれの数値間に約0.2％の誤差が生じる原因となります。温度単位としてＦもしくはＲをお使いいただければ双方の標準状態が一致しますので、値が異なることはありません。（実際には極微小なズレが生じますが、これは丸め誤差が原因です。）
【例示】温度単位として℃を使用する場合、Molar Flow(MMSCFD)とStd Gas Flow(MMSCFD)は値が異なる（それぞれの標準状態が異なるため）。温度単位としてＦを使用すると、両者の値は一致する。
Keywords: Standard Gas Flow, MMSCFD
References: None |
Problem Statement: How to convert Hetran /BJAC / TASC /ACOL / APLE /STX / ACX files to EDR files?
How to use file conversion utility? | Solution: On a Windows desktop click on:
Start\All Programs\AspenTech\Exchanger Design and Rating V7.x\File Conversion Utility
The following window appears
At the top of the window select the file type to be converted to EDR
Select the file to be converted to EDR
Select the destination folder for the converted File
Click on the Convert button
This feature is not supported after V8.4.
Keywords: hetran, EDR, .edr, bjac, b-jac, acol, aple, acx, stx, file conversion utility
References: None |
Problem Statement: How can I configure Publish Sets in APS? | Solution: Publish Sets are a way for the APS user to customize his publishing. He controls which refinery variables he wants to see (Tank/Stream) and also which properties to publish.
Additionally, the user can also control specific timestamps to publish at (not obeying APS time periods) Publish sets are a way to speed up publishing, especially while evaluating a specific part of the refinery between different cases
Configuring Publish Sets:
For configuring publish sets: go to simulator-> publish -> publish setup. There are three tabs:
Data: Choose from all the streams/tanks and their properties that you would like to publish
Event Based Times/ Daily Times: Choose the time periods when your data is published for the selected streams/tanks
In the above screenshot, there is a created publish set SET1, which is designed to publish just the finished regular gasoline tanks T87A and T87B, and for VOL and RVP. The following are examples for publishing at different time periods:
Using Aspen Petroleum Scheduler Periods:
If the checkbox below is on, then the selected tanks and properties will be published for all the time periods in the horizon.
Using Event Based Times:
The screenshot above means that the tanks T87A, T87B will be published at the time periods corresponding to the start and end of blend events for the first 3 days of the horizon.
In specific, the “Begin Days” field will have a number until which the selected entities will be published at the START of any blend event across the event screens
The “End Days” field will have a number until which the selected entities will be published at the END of any blend event across the event screens.
Looking at a sample of table ZTANKS for the above example, the timestamps of the results will be either start or end of blend events in the first three days.
3. Using Daily Times:
For the selected tanks, instead of using Event-based times, if you use the Daily times, we can control the daily table/period table reporting times of these tanks:
In the above screenshot, we set the publish time to 5 AM. The _TANKS and the _ZTANKS tables will have published information at timestamp 5:00 AM, for the first 5 days of the horizon. The following are screenshots of this above set:
The exception is that, to allow for re-initialization of tank/stream volumes, the automatic time period 00:00:10 is always published. This tab helps in controlling specific times at which the information should be published every day, in both the _XX tables and the _ZXXX tables.
Keywords: None
References: None |
Problem Statement: Why model clean-up doesn't delete the AO | Solution: files such as XNLP_Solution.001? When I do model clean-up I would like to delete all the outputs and have the model as small as possible.
Solution
These files are not deleted as we deliberately wanted to leave them for the next run. Logic of clean-up is that you delete everything that can be reproduced by re-running. If you have used your inputSolution to get a good result in the first place then deleting it would mean that you cannot reproduce your run. If you look at it as an output then it looks like something that should be deleted. If you look at it as an input then you see why we chose not to have it deleted.
Keywords: None
References: None |
Problem Statement: What are the new tables that store pipeline inventory in APS versions 8.7 and above? | Solution: Here is a sample line fill on the dialog
Segment name: TTLRA
Number of batches: 1
Crude Composition: 50% ARL and 50%BAC
Destination Tank: T254
Tables Involved:
PIPELINE_SEGMENTS: Match the segment name
ROUTES: Route that the batch is a part of
PIPELINE_INV: Baseline IDs for the specific dates
PLINV_COMP: Obtain crude composition of the batch
PLINV_DEST: Obtain the destination tank of the batch
MATERIAL_ATTRIB: Table to identify crude names
Schema:
Warning: It is not recommended to edit these tables outside of the APS interface. This is for informational purposes only!
Keywords: None
References: None |
Problem Statement: What is the new feature of AUTO linking events in APS? | Solution: A new feature of Auto-Linking of events has been added to versions v8.4 & above. This feature means that dragging an event bar close to the end of another event bar located on the left hand side automatically links the dragged event to the left event if the distance between the event edges becomes small enough.
This feature can be enabled or disabled in two ways.
1. Enable or disable auto-linking via the Setting Dialog (page Event Default):
a. If auto-linking is disabled, dragging an event bar close to the end of another event bar should not link events. During the dragging, the gap rectangle should not be drawn.
b. If option “Enable Auto-Linking” is checked auto-linking should work as before.
The 2- day zoom and the 30-day zoom fields are just more of a way for APS to decide when to link two events (That is, how close two events need to be to be auto-linked) In the example above, when there is a two day zoom on the gantt, two events will be auto linked if an event is dragged to 30 minutes close to another event. For a 30 day zoom on the Gantt, two events need to be dragged to 450 minutes apart to be auto linked. The other zoom intervals will be interpolated from these two values set.
2. Via the main-toolbar button. This button enables or disables the auto-linking without opening the Setting dialog.
Keywords: None
References: None |
Problem Statement: How do I create custom edit in excel templates in APS? | Solution: Events on the Gantt screen can be pulled over to Excel for editing. For this, you would have to click and drag over the events that you wish to edit, right click against the selection and hit “Edit in Excel”. However, before that, templates have to be created before use, for every event type. When Edit in Excel is opened first time (without any templates created), APS automatically generates default templates for each event type. However, the following steps can be followed to customize your own template that can be used going forward to modify an event type:
Go to Events -> Multi Event Editor Templates
On entering the menu, APS default templates, but they can be edited upon and saved
The user created templates can be stored to database, so it’s accessible by all
From the following menu, choose the event type
The greyed out fields in the bottom pane are the mandatory fields that will be displayed in the template. User the “>” and the “<“ handles to add/remove other fields to the template
Click Next when done
Control the order of the fields in the top pane
Move Up and Move Down buttons
Name the template in the bottom section
Click create template
For customized templates, these steps have to be repeated for each event type
Keywords: None
References: None |
Problem Statement: In a weight-based model, we usually recurse SPV value of streams, so that SPV value can be used to convert weight into volume to calculate volume-based property or controlling volume capacity.
Volume = Weight /Density = Weight /(SPG * VTW) = Weight * SPV/VTW
By design, when PIMS report volume of a stream in a weight-based model, it is using SPG value instead of SPV value. We would then recurse SPG value of the stream for reporting purpose. However, there is no relation that enforce SPG*SPV = 1 if we recurse both SPG and SPV of a stream separately.
To ensure consistency of SPG and SPV, we can recurse SPG value from the recursed SPV value. | Solution: Let us use attached simple LP model as reference. Note that this is a simple LP model that is used for demonstration purpose and does not represent a full refinery configuration.
I have a pooling submodel SABC where I recursed SPV value of the pool ABC.
This recursed SPV value is then used to control volume of ABC feed into unit SXYZ.
ESPVVOL row is used to retrieved recursed SPV of ABC to convert weight of ABC into volume in column “VOL”
CCAPXYZ row is then controlling the volume capacity of the unit SXYZ
Next, I would like to recurse SPG value of ABC so that the volume of stream ABC can be reported correctly. If SPG value is missing (even though SPV value exists), PIMS would assume SPG value as 1 and convert weight into volume by using SPG = 1 in the report. However, I need to make sure that SPG*SPV = 1 when I recursed SPG and SPV. Hence, I would develop the structure below to recurse SPG value from the recursed SPV value.
Use an E-row (EBALFED) to drive weight of ABC into a new column AB1 as pool component column
Use an E-row (ESPVKKK) to retrieve SPV of ABC and create a new column AB2 as WEIGHT/SPG
Use R-row (RBALAB3 and RSPGAB3) to recurse SPG value of AB3 based on the recused SPV value.
We will then PCALC SPG of AB3 to SPG of ABC
Note that this is a non-standard structure and PIMS would generate warning W671 which can be ignored in this case.
Keywords: SPG, SPV, recursion, SPG*SPV = 1, reporting, weight to volume conversion
How to recurse SPG of a stream using the recursed SPV value?
References: None |
Problem Statement: Conversion Reactionの順位付けについて | Solution: 添付PDFファイルをご覧ください。
Keywords: JP-
References: None |
Problem Statement: How Exchanger Design & Rating works with Autodesk Inventor products? | Solution: Shell&Tube Mechanical has the capability to export drawings to AutoCAD as following:
Results | Drawings | All Drawings | Modify | Export
When DXF Export button is activated:
Shell&Tube Mechanical calls Autodesk Inventor during exporting sequence.
Inventor is running in the background and creates the 3D model. Then user gets out of EDR, brings up Inventor and 3D model can be further manipulated.
Please note that Autodesk Inventor software must reside in the same computer as EDR.
Keywords: Drawings, Shell&Tube Mechanical, export drawings, AutoCAD, Autodesk
References: None |
Problem Statement: What is the validated process for Aspen Fleet Optimizer? | Solution: This KBSolution includes the Validated Process for Sales & Operations Planning (Aspen Fleet Optimizer)
Fuels marketing processes rely on the ability to receive, use, and manage accurate data. This data can be sales and inventory information collected from customers or up-to-date loading and delivery information, for example. Accurate and timely data can contribute to improved dispatch efficiency, accurate demand planning, effective use of resources, and enhanced productivity.
The workflow describes the general activities of performing dispatch duties for the day shift
Validated processes are system tests using real-world reference architecture and real-world models/data to test the rigorously defined end-to end business process.
The Validated Process documents serve the following purposes:
- To describe the scope of process-oriented testing for a particular business process.
- To provide implementation guidance by illustrating detailed use cases.
Instructions
You can download all AspenTech product documentation from the online Technical Support Center.
To access the documentation attached to thisSolution, follow the Instructions below.
.PDF Files
Printable documentation is published in Adobe Portable Document Format (.pdf). You must use the Adobe Acrobat Reader to view these read-only product-specific documents.
To view a .pdf document in your browser, select a document link. To print a .pdf document, select the print icon in the Adobe toolbar after the document loads in your browser. To download a document to your local drive, select Download icon in the Adobe toolbar.
Keywords: None
References: None |
Problem Statement: How does APS behave when there are no beginning line fill entries for a pipeline segment on the model start date? | Solution: This behavior is applicable from v8.7. When the user rolls forward and APS does not find beginning pipeline inventory present for the day in the PIPELINE_INV and associated tables, it auto-populates a beginning line fill for the pipeline segment.
From v8.8 CP4 onwards, there will be a warning message to the user, when random beginning inventories are auto-generated by APS, something like below:
These are the following scenarios when the following message box will be displayed in v8.8:
- Open model on a day without a baseline
- Change model start date to a day without baseline
- On Model -> Pipeline -> Routes dialog, adding one or more pipelines to a new or existing route, and after closing this dialog
Keywords: None
References: None |
Problem Statement: How do I prevent the message, Error > 'GC - 1' A single stage compressor should be used? | Solution: This error will be issued if user has selected a multistage compressor, e.g Centrifugal Compressor - Integral gear is selected. This type of compressor has a minimum number of impellers of 2. If user selects this type of compressor for a single stage compressor, APEA will issue error GC - A single stage compressor should be used.
For the centrifugal integral gear compressor we are using polytropic compression. So the relationship between the temperature and pressure is
(T2/T1) = (P2/P1)^((gamma -1)/(gamma * np))
Where
T2 = absolute temperature at outlet of stage
T1 = absolute temperature at inlet of stage
P2 = absolute pressure at outlet of stage
P2 = absolute pressure at inlet of stage
gamma = Cp/Cv = specific heat ratio
np = polytropic efficiency (assumed to be 0.7)
By default the specific heat ratio, gamma = 1.4. So the value of the exponent to the pressure ratio is (1.4 – 1)/1.4*0.7 = 0.408
When you change the specific heat ratio to 1.09 for example, the value of the exponent becomes (1.09 – 1)/1.09*0.7 = 0.12
The stage calculation is based on the fact that the temperature at the outlet of the stage (i.e. intercooler inlet temperature) cannot be > 270 F. Since the temperature ratio will be much lower in the second case (Cp/Cv = 1.09) the compression can be achieved only in 1 stage. So in this case you get the error message.
The user can also lower the maximum interstage temperature if desired and if 270 F is too high.
Keywords: Compressor, multistage, error > 'GC
References: None |
Problem Statement: How can I design, rate, and debottleneck a demethanizer and deethanizer using Column Analysis? | Solution: In this Aspen Plus example, you will design demethanizer and deethanizer distillation columns using the new Column Analysis feature. Further, you will be performing rating studies to investigate the feasibility to increase ethylene throughput. These studies will all be in the context of a feasibility operating envelope based on hydraulic constraints. The new Column Analysis tool gives intuitive visual insights and feedback regarding potential design/operation issues.
Note the two zip files attached. Ethylene Column Analysis V10 Example.zip and Ethylene Back End Column Analysis.zip include detailed step-by-step guide.and the simulation files in V10 and V9 respecitvely.
Keywords: Aspen Plus, Column Analysis, Column Analyzer, TPSAR, Demethanizer, Deethanizer, ethylene, ethane, c2 splitter, c-2 splitter, column, design, rating, flood, hydraulic, RADFRAC, downcomer, weir, tray, packing, fractionation, distillation, refrigeration, troubleshoot
References: None |
Problem Statement: How can a stream be copied to other streams? | Solution: Attached is an example of a stream copied to other streams using a Transfer block. See file transfer-str.bkp.
It is possible to use a transfer block to copy the values of flowsheet variables from one part of the flowsheet to another. You can copy to any number of destinations:
Whole streams
Stream composition and flow rate
Any flowsheet variable (for example, block variables)
The most common application is to copy one stream into another
For more information see the Aspen Plus Help topic Simulation and Analysis Tools -> Sequential Modular Flowsheeting Tools -> Transferring Information etween Streams or Blocks.
This example shows how to use a transfer block to copy stream F-STOIC into streams F-CSTR, F-PLUG, and F-GIBBS.
Keywords: None
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: User is not able to make batch runs. When he tries to start the batch run he gets a window saying Batch Job Started, then it changes to Batch Job Submitted, and at the end he gets Simulation Failed.
The customer has only one Aspen Plus license. | Solution: At least two licenses are required to run Batch Jobs. One for the current session and one for the batch job.
When an Aspen Run in initiated, a license is checked our for the run. Since the customer has only one license for Aspen Plus, there are no more licenses to be awarded to the batch process, therefore the batch process fails to run. Users need at least two license if they wants to take advantage of the batch option.
Keywords: batch
Failed
References: None |
Problem Statement: The semi-ideal heat capacity ratio Cp/(Cp-R) is available in Aspen HYSYS Material Stream Properties tables. This article describes how to report this property in Aspen Plus. | Solution: Cp/(Cp-R) can be calculated and reported in Aspen Plus using property sets and calculator blocks. The attached simulation file consists of a 100% ethane stream, characterized by the Peng-Robinson property method, passing through a heater block. These steps explain how to set up a calculator block reporting Cp/(Cp-R).
1. Create a Property Set for the constant pressure heat capacity of a mixture (CPMX). Choose units J/kmol-K.
2. Create a Calculator by either choosing the Calculator block form the Manipulators section of the Model Palette, or add a calculator under the Flowsheeting Options on the Simulation Explorer.
3. You'll need to create two variables in the Define sheet of the Calculator block:
(A) The first variable is the mixture heat capacity that you defined in the Property Set. This variable can be called CPMX and is of type Stream-Prop, for stream FEED, and uses property set CPMX. This variable is a Import variable, this means that the direction of information flow is into the Calculator block.
(B) The second variable is the heat capacity ratio Cp/(Cp-R). Name this variable RATIO. This variable doesn't fit into any of the predefined variable types as it is dimensionless and doesn't have a physical type. Therefore, choose Type: Parameter for the ratio. Give the parameter a number, this allows you to use this global parameter is other calculator blocks, or in design specifications or sensitivity analyses. Physical type is Dimensionless and it is unitless. This parameter is the variable we are calculating, so it is an export variable, meaning that the information flow is out of the Calculator block.
4. Once the variables are defined, go the Calculate sheet. Here, we define the equation for the semi-ideal heat capacity ratio. Write in the Fortran Statement
RATIO = CPMX/(CPMX-8.314*1000)
The units for the gas constant must correspond to the mixture heat capacity units.
5. The Calculator block results report the RATIO in Results | Define Variable. There it is seen that the written value is 1.18852.
6. Attached is an Aspen Hysys file, using the same property setup as the Aspen Plus file (the Aspen Plus properties were imported to the Hysys file), and the Cp/(Cp-R) values reported in Stream 1 of the Hysys file match the Aspen Plus results, at 1.189.
Keywords: None
References: None |
Problem Statement: Can backward calculations be calculated using a Balance block? | Solution: The attached file, Balance1.bkp, is an example of backward calculations using a Balance block.
You can use a Balance block to calculate heat and material balances around an envelope of one or more unit operation blocks. The Balance block updates stream variables entering or leaving the envelope with the calculated results. For example, the Balance block can calculate:
Flow rate of make up streams in recycle calculations. (This eliminates Calculator blocks.)
Feed stream flow rate and conditions, based on other stream and block information. (This eliminates design specifications and convergence loops.)
For more information see the Aspen Plus Help topic Simulation and Analysis Tools -> Sequential Modular Flowsheeting Tools -> Balance Blocks..
This example shows how to do a mass-only calculation around a HeatX block. The objective is to demonstrate the capability of a balance block to do backward calculations. Flow rates of the two outlet streams from HeatX are given. Flow rates of the two inlet streams into HeatX need to be calculated. Both the inlet and the outlet streams are specified, but the flow rates specified for the two inlets are just dummy numbers. On the results form, the final values for the calculated variables and for the balance equations are tabulated. The final values for the calculated variables are found on the Calculated Variables sheet. In this example, the mass flow of the two inlet streams, H2OIN and MECHIN are calculated. The final values for the balance equations are found on the Equations sheet. The number of equation in the problems is shown; here there are two mass balance equations.
Keywords: None
References: None |
Problem Statement: Pool boiling is defined as boiling from a heated surface that is submerged in a volume of stagnant liquid. If the temperature of the liquid is below the saturation temperature the process is known as subcooled or local boiling. If the liquid is maintained at saturation temperature then the process is known as saturated or bulk boiling.
Some definitions/terminology often used is as below;
Saturation temperature (Tsat): Boiling point temperature at prevailing pressure. For a mixture this will be the bubble point.
Superheat: Excess temperature over the saturation value (T - Tsat). Wall superheat (Tw - Tsat).
Subcooling: Opposite of superheat given by (Tsat-T). | Solution: In the diagram below, different representations of boiling are shown for increasing wall superheat or heat flux.
Single phase (Natural convection): Temperature gradients are set up within the pool and heat is removed by natural convection from the surface. The liquid near the heated surface is slightly superheated and subsequently evaporates when it rises to the liquid surface.
Nucleate boiling: In this region the wall superheat is sufficient to cause vapour nucleation at the heating surface, the Onset of Nucleate Boiling (ONB). These bubbles can break away from the surface and may be dissipated into the liquid (condense in superheated liquid). As the wall superheat is increased further, bubbles form rapidly and rise to the surface of the liquid and finally vapour patches and columns are formed close to the heating surface. The Critical Heat Flux (CHF), Burnout or Critical Point marks the upper limit of nucleate boiling where the interaction of the vapour leaving the surface prevents the inflow of the liquid supply to the heating surface.
Transition: Here there exists an unstable vapour blanket over the heating surface that releases large patches of vapour. Re-wetting of the surface by liquid is then believed to occur. This region is only studied under conditions of constant wall temperature.
Film boiling: Eventually a stable vapour film covers the entire heating surface. Heat is transferred by conduction and convection through the vapour film, with radiation becoming important as the wall superheat is further increased.
Results of pool boiling are normally plotted as heat flux (or heat transfer coefficient) against the wall superheat, which is the wall minus the saturation temperature. This produces different regimes as described previously for the wall temperature controlled case.
In the situation when the heated surface is heat flux controlled, as the critical heat flux is just exceeded, the temperature jumps sharply to the film boiling curve, missing the transition region as shown by the dashed line. As the heat flux is reduced the temperature follows the film boiling curve until the transition boiling region where it then “jumps” to the nucleate boiling curve.
Keywords: Pool boiling, Critical heat flux, Onset of nucleate boiling
References: None |
Problem Statement: This article delivers a list of new feature document of Aspen InfoPlus.21 starting from V7.1 to V10. | Solution: Solution
From V7.1 to V8.0, all the new feature document of IP.21 can be found in the Help file of InfoPlus.21 Manager.
After V8.0, all new features are introduced only in the release notes of every version. Users can find them in below related link of Release Notes on AspenTech Support website.
V7.1 to V8.0 Open IP.21 Manager, press ’F1’, find in What’s new in Aspen InfoPlus.21
V8.2 https://esupport.aspentech.com/S_Article?id=000006986
V8.4 https://esupport.aspentech.com/S_Article?id=000004006
V8.5 https://esupport.aspentech.com/S_Article?id=000003956
V8.6 N/A
V8.7 https://esupport.aspentech.com/S_Article?id=000004093
V8.8 https://esupport.aspentech.com/S_Article?id=000004107
V9.0 https://esupport.aspentech.com/S_Article?id=000004118
V9.1 N/A
V10.0 https://esupport.aspentech.com/S_Article?id=000044834
Keywords: InfoPlus.21 new feature
Release Notes
References: None |
Problem Statement: In the Initialization tab in EO, what is the difference between Single Pass and Single Pass Changed? | Solution: We can use the Initialization field to limit the extent of the SMSolution. This option may be useful when troubleshooting convergence issues related to the addition of new blocks.
The following options have different effects during the initialization run.
Solve : Fully converges the SMSolution
Single Pass : Executes new blocks and blocks with changed input, and blocks affected by them, once each.
Recycle loops and SM Design-Specs are ignored. We can click the run button again to execute another pass through recycle loops. Note that convergence blocks and design specs may show errors and unconverged status for SM.
Single Pass: Changed : Executes only new blocks and blocks with changed input, once each. Affected blocks are not run; this is otherwise the same as Single Pass.
Keywords: Equation Oriented Initialization, Solve, Single Pass, Single Pass Changed
References: None |
Problem Statement: When using Gas Turbine model, in TempTable, HeatTable and FlowTable there are specific values which show Maximum number of points on Temperature, Heat and Flow curves. In each of this table, and in Power_Vals table one can find also value No. of points in performance curve (NPoints). What is the difference between these values? Which one should be used? | Solution: The value No. of points on each performance curve (NPoints) setup the number of points for all performance curves which user want to specify, so Flow, Heat and Temperature.
By default, this value is 10 and all number of points are set to this value.
If user leaves Maximum no. of points on Temperature curves (NP_TempMax), Maximum no. of points on Heat curves (NP_HeatMax) and Maximum no. of points on Flow curves (NP_FlowMax), as default value (blue) then it will be changed when changing No of points for each performance curve (NPoints).
Value NPoints was copied to more than one table, but in all of them it means exactly the same, for example if user change it in Block_Name.Power_vals Table, it will be changed in Block_Name.TempTable Table.
Note, that when having different number of points on Temperature, Heat or Flow curves user should use specification for each performance curves separately, so NP_TempMax, NP_HeatMax or NP_FlowMax.
NPoints can be useful only when few/ all performance curves have the same number of points.
Keywords: Gas Turbine, NP_TempMax, NP_HeatMax, NP_FlowMax, NPoints
References: None |
Problem Statement: Is it possible to add ASCII tags in the Input Calculation and Output Calculation modules from Aspen IQ? | Solution: No, IQ only supports real numbers for IC and OC input/output variables. Inside IQ runtime code, we have to populate the Aspen Calc input variables with values that are either calculated in IQ or read from DCS (via CIM-IO), and these values are assumed to be floats. Similarly, after the IC or OC calculation has finished we copy the results to floating point entries within IQ which can then be written out to DCS.
If you add an ASCII tag in an IC/OC module you will see a Real value in the IQ. If you save the file you wona??t see any warnings:
If you force the IQ in note pad to read the value as ASCII and change
.ICIPNTVAL~~~READ~~~R4~~~0.~~~MATRIKON6::Bucket Brigade.String:ASC:
To:
.ICIPNTVAL~~~READ~~~CH(64)~~~test~~~MATRIKON6::Bucket Brigade.String:ASC:
You will have these error messages when trying to load the IQ:
IQP: Error 15135 from cb_Add for 02ICIPNTVAL0001
IQP: Error 15101 from cb_Store for 02ICIPNTVAL0001
2 errors encountered during Loading IQF values into Common Buffer
Keywords: Aspen IQ, Aspen Calc, ASCII
References: None |
Problem Statement: How do I export Column Internal stream to the main flowsheet? | Solution: To export a stream from the column subflowsheet to the main flowsheet, double click on the Column | Flowsheet | Internal stream | Add a new stream | (enter stream name) | Select the top stage | Select Net | Click the Export Check box)
User can create a flowsheet stream that represents any phase leaving any stage within the Column. Any change that occurs to the column, new information is automatically transferred to the stream which user has created.
Follow the Steps given below:
Click the Add button.
In the Stream drop-down list, type the name of the stream named Liquid.
In the Stage drop-down list, select stage which locates the selection in the list.
In the Type drop-down list, select the phase that you want to represent. The options include Vapor, Liquid or Aqueous.
From the Net/Total drop-down list, select either Net or Total.
- Net represents the material flowing from the Stage you have selected to the next stage (above for vapor, below for liquid or aqueous) in the column.
- Total represents all the material leaving the stage (for example, draws, pump around streams, and so forth).
Note: If the stream is hanging on one side (Connected to unit operation on only one side) then go to the Design and Connection and connect to main PFD stream.
Keywords: export, stream, column environment, main, column
References: None |
Problem Statement: Is it possible to execute Aspen Plus Control Panel Functions from VBA? | Solution: The Aspen Plus Control Panel in Visual Basic is associated with the simulation engine. All of the control panel functions such as Step, MoveTo and Reinitialize may be invoked from stand-alone Visual Basic (VB) or Visual Basic for Applications (VBA) within other software such as Microsoft Excel.
The IHAPEngine object type can be used along with IHapp which is used to describe an active Aspen Plus GUI object. The following code fragments illustrate how control panel functions can be executed from a Visual Basic application.
In addition to declaring a global object for the current simulation, declare a global object for the simulation engine:
Global go_Simulation As IHapp
Global go_APengine As IHAPEngine
After activativing the GUI using the GetObject VB function, copy over the address of the object for the simulation engine to which the GUI session is connected:
Set go_Simulation = GetObject(test.bkp)
Set go_APengine = go_Simulation.engine
Now that an object is defined for the simulation engine, make the control panel visible, step the simulation engine and move to block B4:
APengine.ControlPanel = True
Call APengine.Step
Call APengine.MoveTo(IAP_MOVETO_BLOCK, B4)
The IAP_MOVETO_BLOCK built-in variable can be selected in Excel97 from the popup menu that is automatically activated after typing the ( to start the argument list. The best reference for the Aspen Plus object properties and methods is the Object Browser. Select the Object Browser from the Visual Basic View pull-down. Then select Happ for the Aspen Plus type library.
SeeSolution 102365 for an example of how to use Visual Basic to Reinitialize a simulation.
Keywords: VBA, ActiveX, Control Panel, Step, Move to, Reinitialize
References: None |
Problem Statement: Which components in the PURExx pure component databanks have a solubility parameter (DELTA) taken from the FLOWTRAN databank? | Solution: The Solubility Parameter (DELTA) at 25C is used in the Scatchard-Hildebrand model (GMXSH) that calculates liquid activity coefficients used in the CHAO-SEA property method and the GRAYSON property methods. This parameter is in the PURExx and NIST-TRC databanks. In addition, it can be estimated by the Aspen Property Physical Property System from the definition. To perform the calculation, the Aspen Physical Property System requires:
Normal boiling point
Critical temperature
Critical pressure
Heat of vaporization
Liquid molar volume
In PURE36, there are 93 components that have the parameter DELTA. Below is the list of components in the original PURE databank for which the solubility parameter (DELTA) were taken from the FLOWTRAN databank.
ACETYLENE C2H2
ARGON AR
BUTADIENES C4H6-5
BUTYLENES C4H8-6
CARBON-DIOXIDE CO2
CARBON-DISULFIDE CS2
CARBON-MONOXIDE CO
CIS-2-BUTENE C4H8-2
CIS-2-PENTENE C5H10-3
CYCLOPENTANE C5H10-1
DIMETHYL-SULFIDE C2H6S-2
DIMETHYLACETYLENE C4H6-2
ETHANE C2H6
ETHYL-MERCAPTAN C2H6S-1
ETHYLACETYLENE C4H6-1
ETHYLENE C2H4
HYDROGEN H2
HYDROGEN-SULFIDE H2S
ISO-BUTANE C4H10-2
ISO-BUTENE C4H8-5
ISO-PENTANE C5H12-2
METHANE CH4
METHYLACETYLENE C3H4-2
N-BUTANE C4H10-1
N-PENTANE C5H12-1
NEO-PENTANE C5H12-3
NEON NE
NITROGEN N2
OXYGEN O2
PROPADIENE C3H4-1
PROPANE C3H8
PROPYLENE C3H6-2
SULFUR-DIOXIDE O2S
SULFUR-TRIOXIDE O3S
THIOPHENE C4H4S
TRANS-2-BUTENE C4H8-3
TRANS-2-PENTENE C5H10-4
VINYLACETYLENE C4H4
1-BUTENE C4H8-1
1-PENTENE C5H10-2
1,2-BUTADIENE C4H6-3
1,3-BUTADIENE C4H6-4
2-ME-1-BUTENE C5H10-5
2-ME-2-BUTENE C5H10-6
Keywords:
References: None |
Problem Statement: What is | Solution: strategy for the co-current convective dryer?
Solution
TheSolution of the mass balance and the heat balance depends on the flow regime (co-current, counter-current, or cross-flow). TheSolution of these balance equations is different for different flow regimes.
A Co-current (solids in plug flow, gas in plug flow) dryer is shown below:
The mass balance equations(mass balance of moisture for the solid phase and the gas phase) can be formulated as follows:
Mass balance of moisture for the solid phase
Here ṀS is the dry solids mass flow, X the dry-based moisture content of the solids, Ṁ the evaporation rate of one particle (local evaporation rate), NP the total number of particles, z the axial coordinate, and L the total length of the dryer.
Mass balance of moisture for the gas phase
Here ṀG is the mass flow-rate of dry gas, Y the dry-based moisture content of the gas and Np the number of particles.
If the dry solids mass flow and the particle size distribution is known the number of particles Np can be calculated as described in the Convective Dryer Mass Balance. The solids moisture content of the particles at the solids outlet can be computed by integration of the solid phase moisture equation. Therefore, the dryer is discretized into balance cells with the length Δz. This leads to:
Similarly the moisture content of the vapour phase leaving the dryer Yout can be obtained by integration of the gas phase moisture equation:
The heat balance equations for the solid phase and the gas phase are given as:
Here ṀG is the mass flow-rate of the gas in the dryer, cp,G the specific heat capacity of the dry gas, TG the temperature of the gas, Q. the heat flow-rate, NP the total number of particles, z the axial coordinate, L the total length of the dryer, and Q.ind,G the rate of heat transferred to the gas (calculated as for the contact dryer).
Heat balance for the solid phase
Here ṀS is the mass flow-rate of the solids in the dryer, cp,S the specific heat capacity of the dry solids, X the dry-based moisture content of the solids, cp,M the specific heat capacity of the liquid phase (moisture), TS the temperature of the solids, Ṁ the evaporation rate of one particle (local evaporation rate), Δhv the enthalpy of evaporation, and Q.ind,S the rate of heat transferred to the solids (calculated as for the contact dryer).
Similarly to the mass balance equations, the heat balance equations are integrated. This results in:
By use of the four integration equations it is possible to calculate the moisture content and the temperature at the outlet of the dryer for the vapour and the solids phase.
Keywords: Co-current convective dryer, mass balance, energy balance
References: None |
Problem Statement: When using Boiler there are following variables in the input specification which can be included: PerFact, FanCoeffB and FanCoeffC. What is the meaning of these variables? | Solution: PerFac is described as performance factor.
PerFact is a tuning parameter and used to correct Boiler efficiency calculated from the user specified efficiency curve in order to match the plant measurements when Lookup Table option is selected for the boiler efficiency. It is primarily used in the Data Reconciliation/Estimation run.
From practical point of view, PerfFact is used to correct vendor's efficiency curve against plant measurements. If the vendor's curve is considered as accurate and reflect the plant operation, then PerfFact is kept as 1.
FanCoeffB is described as First order coefficient for fan power linear correlation, and
FanCoeffC is Constant coefficient for fan power linear correlation.
FanCoeffB and FanCoeffC are the two parameters in the linear correlation to estimate the total horsepower required in the boiler fans. Note the boiler model does not distinguish ID (Induced draft) and FD (forced draft) fans so the correlation should include both.
Coefficients are used in Boiler Calculations in the following equation:
FanPower = FanCoeffC + Fair * (100+ FlueGasRecirc) /100 * FanCoeffB
Where:
FanPower – Power consumed by boiler fans
Fair – inlet air flow
FlueGasRecirc – Fluegas recirculation in %
Keywords: PerFact, FanCoeffB, FanCoeffC, Boiler Specification
References: None |
Problem Statement: How does the Rackett liquid volume model handle temperatures above Tc and below melting point? Tc is either the critical temperature of a component or an average Tc defined by the model. | Solution: The Rackett equation has a formula involving an exponent of 1+(1-Tr )2/7 which is invalid above the critical temperature. As a result, a special extrapolation method is required for this equation. This method involves the calculation of an intermediate temperature T00 near the critical temperature. When the temperature exceeds T00, the volume is constant at the critical volume. When the temperature is between 0.99Tc and T00, a circle equation is used to smoothly interpolate the volume between the value and slope at 0.99Tc and the constant value at T00.
Details
First the volume V0 at 0.99Tc and the critical volume Vc are calculated:
Then the volume difference is calculated, as well as the temperature difference required for the circle equation:
From this, the required intermediate temperature T00 can be calculated:
Then the volume V00 at the circle's center can be calculated:
Finally, the equation of the circle is used to determine any point (T,V) for 0.99Tc < T < T00:
The lower temperature bound is not defined in Aspen Plus. If the temperature is lower than a component's melting point, the model may have a larger error.
For details of the Rackett liquid volume models for liquid mixtures, refer to the
Keywords: None
References: Manual - Physical Property Methods and Models. |
Problem Statement: How do you calculate the make-up flow rate for a recycle loop? | Solution: It is possible to calculate the make-up stream flow using a Calculator block.
In the attached example, the mass flow rate of make-up stream MAKEUP is determined by the amount of benzene in the outlet streams from the flowsheet. The variables are selected in the Calculator block. In order for the simulation to converge correctly, the Tear Fortran Write Variables option needs to be selected on the Convergence | Options | Defaults | Sequencing sheet.
See file - Makeup.bkp
For more information see the Help Topics - Using Aspen Plus | Calculator Blocks and In-Line Fortran
Keywords: None
References: None |
Problem Statement: How can a flowsheet be optimized to maximize product using sequential modular mode? | Solution: Attached is an example of how to optimize the product for a simple flowsheet.
See file Optimize.bkp.
For more information see the Aspen Plus Help topic Simulation and Analysis Tools -> Sequential Modular Flowsheeting Tools -> Optimization.
The value of a reactor product stream is a function of the flow rate of the desired product, P, and the undesired byproduct, G.
Value = P - 30 * G Optimization is used to find the reaction temperature that maximizes the product value.
The molar flow rate of components P and of G in stream PROD are the sample variables for the optimization. These variables are called P and G, respectively.
The optimization objective function is ( P - 30*G ).
The optimization problem is converged when ( P - 30*G ) is at a maximum.
You can use Fortran expressions, such as ( P - 30*G ) in any part of the optimization problem.
The reactor temperature is the manipulated variable. The optimization convergence block finds the reactor temperature that makes ( P - 30*G ) a maximum.
The manipulated variable is specified in the reactor block, just as if there were no optimization. The specified value is the initial estimate used by the optimization convergence block.
The optimization convergence block will not try a temperature less than 300F or greater than 400F, even if theSolution to the objective function lies outside this range. The limits become alternative specifications, if the objective cannot be achieved. The initial estimate entered in the reactor block lies within these limits.
You do not have to specify convergence of the design specification. ASPEN PLUS automatically generates a convergence block to converge the specification.
This optimization problem does not have any constraints associated with it.
Keywords: None
References: None |
Problem Statement: Can the make-up water rate in a flowsheet be calculated using a Balance block? | Solution: The attached file, Balance3.bkp, is an example of calculating a make-up water rate using a Balance block.
You can use a Balance block to calculate heat and material balances around an envelope of one or more unit operation blocks. The Balance block updates stream variables entering or leaving the envelope with the calculated results. For example, the Balance block can calculate:
Flow rate of make up streams in recycle calculations. (This eliminates Calculator blocks.)
Feed stream flow rate and conditions, based on other stream and block information. (This eliminates design specifications and convergence loops.)
This example shows the use of a Balance block to calculate a make-up water rate to a column. The Balance block only uses the relevant blocks and not the entire flowsheet.
For more information see the Aspen Plus Help topic Simulation and Analysis Tools -> Sequential Modular Flowsheeting Tools -> Balance Blocks..
Keywords: None
References: None |
Problem Statement: Is it possible to tabulate reaction selectivity versus reactor temperature? | Solution: Attached is an example of tabulating reaction selectivity versus reactor temperature using Sensitivity. See file Sensitivity.bkp.
Sensitivity analysis is a tool for determining how a process reacts to varying key operating and design variables. You can use it to vary one or more flowsheet variables and study the effect of that variation on other flowsheet variables. It is a valuable tool for performing “what if” studies. The flowsheet variables that are varied must be inputs to the flowsheet. They can not be variables that are calculated during the simulation.
You can use sensitivity analysis to verify if theSolution to a design specification lies within the range of the manipulated variable. You can also use it to perform simple process optimization.
For more information see the Aspen Plus Help topic Simulation and Analysis Tools -> Sequential Modular Flowsheeting Tools -> Sensitivity.
This example tabulates the effect of temperature in the RGibbs block REACT on the selectivity of component ESTER versus ETOH in the reactor outlet. An initial specification for the temperature of block REACT has been entered on the RGibbs | Setup | Specifications sheet. The selectivity which is the ratio of FESTER to FALC can be entered as the Fortran expression FESTER/FALC on the Tabulate sheet.
Keywords: None
References: None |
Problem Statement: What is the BOBYQA Solver? | Solution: The BOBYQA solver is available for solving constrained optimization problems without tear streams. This solver provides better robustness than the other optimization solvers in problems with noisy derivatives.
From the help:
You can use the BOBYQA (Bound Optimization BY Quadratic Approximation) method for flowsheet optimization for simultaneous convergence of optimization problems with constraints (equality or inequality).
BOBYQA utilizes a trust region method. Variables must be scaled by the range of their bounds to ensure that magnitudes of the expected changes are similar. Each variable is scaled so that if a ≤ x ≤ b, then for the scaled variable x*, -1 ≤ x* ≤ 1.
Constraints are supported by the use of a penalty function that is added to the objective functions. The constrained optimization problem can be written as:
This is rewritten as an unconstrained problem:
Where:
γ = 1 for linear penalty type, 2 for quadratic penalty type
β = constraint tolerance
ρ = penalty prefactor
To solve a constrained optimization problem, an iterative approach is used in which the penalty prefactor is increased until theSolution enters the feasible region. You can specify how much the prefactor is increased with each iteration.
You can control the BOBYQA method by specifying:
Field Default To specify
Maximum Flowsheet Evaluations 1000 Maximum number of flowsheet evaluations
Number of interpolation conditions 2n+1 BOBYQA uses a quadratic approximation of the problem which has this many interpolation points. You can choose the number of points but it must be at least n+2 and may not exceed (n+1)(n+2)/2, where n is the number of variables being optimized. Values in excess of the default are not recommended.
Initial trust region radius 0.1 Limit on norm of scaled step size at the start of convergence. The scaling is such that the range in which the scaled manipulated variables can vary is -1 to 1. This is gradually reduced to the final value as iteration proceeds. Typically, this should be set to about 0.1. The maximum allowed value is 1.
Final trust region radius 10-6 Accuracy required in final values of the variables. This must be equal to or smaller than the initial trust region radius.
Initial prefactor value 1 ρ for first iteration. Minimum 10-10.
Initial prefactor growth factor 10 Factor by which ρ is increased after the first unconverged iteration due to constraint violation. Must be greater than 1. 10 is recommended.
Final prefactor growth factor 10 Factor by which ρ is increased after the second and subsequent unconverged iterations. Generally this should be equal to or greater than the initial prefactor growth factor.
Equality constraint penalty type Linear Can be Linear or Quadratic; controls exponent γ applied to equality constraints.
Inequality constraint penalty type Linear Can be Linear or Quadratic; controls exponent γ applied to inequality constraints.
Penalty scaling Yes Can be Yes or No. Specifies whether scaling is used on constraint penalties.
Keywords: None
References: M.J.D. Powell, The BOBYQA Algorithm for Bound Constrained Optimization without Derivatives. Report, Department of Applied Mathematics and Theoretical Physics, Cambridge University. DAMTP 2009/NA06. |
Problem Statement: On a system Running Infoplus.21 you see high CPU usage which may cause Windows or Aspen products to run slow or freeze. In the Windows Task Manager and Performance tab you can see high CPU usage and in the Processes tab you will see CMON.EXE with high CPU usage. | Solution: The high CPU Usage is caused by the Compliance.21 CMON.exe running as External Task in the Infoplus.21 manager. To resolve this issue will depend on your configuration;
1. If you do not use Compliance.21 but wish to keep the External task then turn off the 'Auto Restart' feature and check 'Skip during startup' and press 'Update'
button, then press STOP Task in the Infoplus.21 Manager.
2. Alternatively you can remove the External task by making sure the task is selected and press the 'Remove' button.
Keywords: CPU, CMON.exe, CMON, Compliance.21, Infoplus.21, Manager
References: None |
Problem Statement: How can I include in my model an isotherm that is not included in Aspen Adsorption? | Solution: The users can select a “User Procedure” or “User Submodel” if the isotherm required is not included in the software or for the case of components using different isotherms at different concentration/pressure regions, etc.
The custom isotherms can be added to the program by using flowsheet constraints written in the software language (user submodel approach) or by an external user Fortran subroutine (user procedure approach). User submodel approach is the preferred approach as the customization is done inside the adsorption file itself in ACM language.
The attached example file demonstrates the single bed approach for the simulation of a full multibed process and the use of flowsheet level constraints to provide a user defined isotherm. To execute this example (after loading), select the dynamic run mode and execute the dynamic run.
These are the steps to specify the user isotherm via Flowsheet Constraints:
1) Open the configure tab in the model. Double click on the bed model to bring the Configure Block/Stream bed form
2) In the Isotherm tab, select User Submodel for the Isotherm Assumed for Layer field. Select also the Isotherm Dependency from the options available i.e. Concentration or Partial Pressure
3) In the explorer tab, select the Flowsheet menu and double click on the Flowsheet icon. This will open up the Constraints-Flowsheet window and you can type in the code for your isotherm as shown below.
4) Once you are done, compile the code by pressing F8 with the editor window active or right click in the window and select compile. If there are any errors they will show up in the simulation messages windows.
5) Once the compilation is successful, the specification status indicator would change from a red triangle to a green square.
Keywords: Flowsheet constraint, user isotherm, User submodel
References: None |
Problem Statement: Aspen Plus does not generate distillation curves for a stream containing 3 pseudo-components. Why? | Solution: To generate a distillation curve, a stream must contain at least 4 pseudo-components of non-zero flow to generate distinctive data points at 0%, 5%, 10%, 30%, 50%, 70%, 90%, 95%, 100%.
In the Control Panel, you will see the message:
* WARNING WHILE GENERATING REPORT FOR STREAM: IN (WHILE EVALUATING
PROPSET: PETRO)
AT LEAST FOUR COMPONENTS MUST BE PRESENT TO CALCULATE A
DISTILLATION CURVE POINT; ONLY 3 ARE PRESENT.
DISTILLATION CURVE CALCULATION IS BYPASSED.
For more information see the Aspen Plus Help topic Aspen Plus
Keywords:
References: -> Physical Property Data Reference Manual -> Property Sets -> Petroleum-Related Properties for Mixtures -> Distillation Curves |
Problem Statement: Why you can select more units for some properties in property-set than in Stream Summary table? In addition, some units seem unreasonable. For example, H is enthalpy for a pure component, but you can select kJ/hr as the unit. | Solution: In lower versions of Aspen Plus (V8.8 and lower versions), some properties allowed two or more of mole-based, mass-based, and flow units, such as enthalpy in kJ/kmol, kJ/kg, and kJ/s. Starting in V9, these properties have all been separated into different properties with different names. That is, all property-set properties now have only one physical type. This will make it clearer what a given property represents than ever.
In new versions (V9.0 and higher versions), the old property name is used for the mole-based property and new property names are applied to other kinds of properties (such as mass-based, flow units). For compatibility, the mole-based property sets still support other kinds of units, but we recommend you choose the correct property for the desired unit type. There are limitations in using molar property sets with non-molar units within the new Stream Summary.
More information can be found in What’s new topic in Aspen Plus V9.0 Help.
Keywords: Property-set Unit Stream Summary mole-based mass-based flow units
References: None |
Problem Statement: How can a stream be copied to other streams? | Solution: Attached is an example of a stream copied to other streams using a Transfer block. See file transfer-str.bkp.
It is possible to use a transfer block to copy the values of flowsheet variables from one part of the flowsheet to another. You can copy to any number of destinations:
Whole streams
Stream composition and flow rate
Any flowsheet variable (for example, block variables)
The most common application is to copy one stream into another
For more information see the Aspen Plus Help topic Simulation and Analysis Tools -> Sequential Modular Flowsheeting Tools -> Transferring Information etween Streams or Blocks.
This example shows how to use a transfer block to copy stream F-STOIC into streams F-CSTR, F-PLUG, and F-GIBBS.
Keywords: None
References: None |
Problem Statement: Please provide information about the requirements for configuring cluster processing of Aspen PIMS. | Solution: Cluster processing allows the Aspen PIMS user to define multiple nodes to use multiple machines in parallel (each machine having multiple processors). The Aspen PIMS model must use PIMS-AO with XLP for this functionality. The user’s machine that is initiating the PIMS runs will be referred to as the Primary machine. The machines whose processors are used will be referred to as Secondary machines.
PRIMARY MACHINE
The primary machine must fulfill the regular installation requirements for Aspen PIMS.
The primary machine will run Aspen PIMS, checking out PIMS Advanced Optimization (PIMS-AO) tokens and must be configured for cluster processing under MODEL SETTINGS | Non-linear Model (XNLP) | Parallel Processing tab. This node configuration can be done with a configuration file (more information about a configuration file is at the bottom of this document) or directly in the dialog box per the instructions below:
a. Check the box for “Use multiple Nodes / cluster”
b. Select the number of nodes
c. In the Node Configuration box, indicate the name of each node and how many processors to use.
i. Enter the node configuration information. You need to specify the corresponding node name and processors pairs. For example, if you indicate that three nodes are to be used and the node names are ABC, XYZ and LMN, the configuration information would look something like this:
ABC 2 XYZ 4 LMN 8
ii. You should use the whole computer name if nodes are on different domains making the configuration information look like this: ABC.headquarters.mycompany.com 2 XYZ.localsite.mycompany.com 4
Needs a port open for communication to the secondary machines
PIMS can be configured for ACCESS or SQL - SQL may reside on a completely different machine from everything else for optimal performance.
Model directory will typically be on the primary machine, but can be on a shared file server
Firewall on all machines must have these files listed in the exceptions:
a. CaseParallel
b. Multistartparallel
c. PIMSWIN
d. Smpd
e. Mpiexec
SECONDARY MACHINES
Can be real or virtual
Must have PIMS installed
Will not consume PIMS tokens (only solver is running, not the PIMS application)
User does need full control and access to the installation directory of PIMS on the secondary machine (C:\Program Files\Aspentech\Aspen PIMS or C:\Program Files (x86)\Aspentech\PIMS depending on OS).
Firewall on all machines must have these files listed in the exceptions:
a. CaseParallel
b. Multistartparallel
c. PIMSWIN
d. Smpd
e. Mpiexec
There is no need for the primary user to be logged in to the secondary machine
OPTIONAL CONFIGURATION CONTROL FILE
A configuration control file can be used instead of defining the nodes in the settings dialog box. This allows the user to configure through a script how the execution proceeds.
– User Configuration File
Select this option for more flexibility in cluster configuration. It should only be used by advanced users. It can be used to configure the MPI parameters so that the referenced applications reside and execute on the child machines instead of the parent machine.
The creation of a configuration file named MPI_CLUSTER_CFG.DAT is required. This file must reside in the model directory. The configuration file should contain MPI parameters to be used in the MPIEXEC command. The application(s) specified for the MPI command should be caseparallel.exe along with its application options. The file path should be included when referencing caseparallel.exe.
The caseparallel.exe options to include are:
o Working directory
o Model path
o MPI_CASE_INFO.DAT
o Trace level with valid values being 0 to 3 (0=no tracing, 1=low, 2=medium, 3=high)
o Number of periods
o IP address of master machine
o port number of 11150
Example 1 of MPI_CLUSTER_CFG.DAT
This example uses the PIMS Weight Sample model and has the case parallel processes running locally on the child machines. In the MPI_CLUSTER_CFG.DAT file, each line defines the following:
o child machine with the number of processors
o local path for the caseparallel.exe application
o caseparallel.exe application options.
In this example, the model is located on another machine and has been opened in PIMS using the UNC path.
-hosts 1 childmachine1 4 C:\Program Files (x86)\AspenTech\Aspen PIMS\caseparallel.exe C:\Program Files (x86)\AspenTech\Aspen PIMS \\modelmachine1\Users\Public\Documents\AspenTech\Aspen PIMS\Pims\Weight Sample MPI_CASE_INFO.DAT 3 0 XX.XX.XXX.XXX 11150
-hosts 1 childmachine2 12 C:\Program Files (x86)\AspenTech\Aspen PIMS\caseparallel.exe C:\Program Files (x86)\AspenTech\Aspen PIMS \\modelmachine1\Users\Public\Documents\AspenTech\Aspen PIMS\Pims\Weight Sample MPI_CASE_INFO.DAT 3 0 XX.XX.XXX.XXX 11150
Example 2 of MPI_CLUSTER_CFG.DAT (This applies only for PIMS V8.x versions - not PIMS V9 and up)
This example uses the PIMS Weight Sample model and has the case parallel processes running locally on the child machines. In the MPI_CLUSTER_CFG.DAT file, each line defines:
o child machine with the number of processors
o local path for the caseparallel.exe application
o caseparallel.exe application options.
In this example, the model is located on a shared drive and has been opened in PIMS using the shared drive. The MPIEXEC parameter of “-map” has been used to allow the MPIEXEC to map this drive to the child machines.
-hosts 1 childmachine1 1 –map M:\\modelmachine1\ppims C:\Program Files (x86)\AspenTech\Aspen PIMS\caseparallel.exe C:\Program Files (x86)\AspenTech\Aspen PIMS M:\PPIMS Weight Sample MPI_CASE_INFO.DAT 3 0 XX.XX.XXX.XXX 11150
-hosts 1 childmachine2 32 –map M:\\modelmachine1\ppims C:\Program Files (x86)\AspenTech\Aspen PIMS\caseparallel.exe C:\Program Files (x86)\AspenTech\Aspen PIMS M:\PPIMS Weight Sample MPI_CASE_INFO.DAT 3 0 XX.XX.XXX.XXX 11150
NOTES:
1. Parallel Processing/Cluster Processing are different than PIMS Distributed Processing (PIMS-DP) and PIMS-DP cannot be used together with either Parallel Processing or Cluster Processing
2. While the primary machine will require appropriate PIMS and PIMS-AO licensing, there is no licensing required for the secondary machines other than during installation.
Keywords: parallel processing, cluster, nodes, core, multi-core
References: None |
Problem Statement: How to change column widths for all tables in Aspen Custom Modeler (ACM)? Is there any place to change it automatically for all columns, or one have to do that manually in each table? | Solution: User can modify column widths for table using registry settings.
To do that use the following steps:
In start type Regedit to open the Registry editor
Navigate to location: HKEY_CURRENT_USER\Software\AspenTech\QuickTable\<version_number>\AttributeColWidths
Please note <version_number> is the same as user can find when open Help-> About Aspen Custom Modeler, for example for version V7.3 it was number 25, for V9 it is 35, for V10 one can see number 36.
Edit values as required.
Note that user can also delete this key and ACM will use default values, but make sure that this key is saved before for precaution.
Keywords: Column width
References: None |
Problem Statement: Knowledge article number 000045880, titled Equation-Oriented Simulation: Using Homotopy to Improve Convergence, describes when to include homotopy to improve convergence. As described in article 000045880, the option to include homotopy and configure its settings can be set via the Convergence/EO Conv Options/Solver input form, but this article details how to set homotopy parameters via the OOMF command line on the EO Control Panel.
How do I include homotopy in the solver settings using the command line?
How do I set options for homotopy solvers?
What are the OOMF command line prompts for setting options for homotopy solvers?
How do I set options such as names of parameters to be treated as homotopy parameters, target values for these parameters, etc? | Solution: To include homotopy in the DMO and LSSQP solvers, use the command:
SOLVER HOMO_DMO to use Dynamic Multi-objective Optimization with homotopy
SOLVER HOMO_LSSQP to use Large-scale Sparse Successive Quadratic Programming algorithm with homotopy
Then, to set the homotopy parameters in the command line, use the command:
HOMOTOPY PARAMETERS [variable name, target value {optional target value UOM },initial value {optional initial value UOM}]
This information can be found in the Aspen Plus application with the command: HELP HOMOTOPY, where the following information will be given:
Keywords: None
References: None |
Problem Statement: Error Failed to load the help contents when launching help using Aspen Properties Excel Calculator addins | Solution: ThisSolution article will show you how to resolve Aspen Properties Excel Calculator help loading issue.
Please follow below steps on the user machine:
1. Close Excel and all AspenTech applications.
2. Create and run a registry file using following command.
Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\AspenTech\Aspen Properties\36.0\mm]
HtmlHelpRoot=file:///C:/ProgramData/AspenTech/Aspen Properties V10.0/HtmlHelp/aspenproperties.htm
HtmlHelpExtractor=C:\\Program Files (x86)\\AspenTech\\Aspen Properties V10.0\\GUI\\xeq\\APropHtmlHelp.exe
Note: Version number (36.0) needs to be updated depending on the product version. 36.0 is for V10, 35.0 is for V9 and 34.0 is for V8.8.
3. Open a Command prompt as administrator and call regsvr32 /s C:\Program Files (x86)\AspenTech\Aspen Properties V10.0\Engine\Xeq\APXLAddinLoader.dll command.
If you still could not load Help, please contact our AspenTech Support [email protected]
Keywords: Excel Addins
Help
HtmlHelp
Aspen Properties
References: None |
Problem Statement: What is the difference between PROP-SETs SG and SGSTD? | Solution: There is no difference between SG and SGSTD. Both calculate the specific gravity at 60 F and 1 atm. The calculation uses component specific SG values from the databank and averages them. This data that was intended for petroleum applications using API methods.
Keywords: None
References: : CQ00607983, CQ00563507 |
Problem Statement: How can a flowsheet be optimized using sequential modular mode? | Solution: Attached is an example of how to optimize the product flow for a simple flowsheet.
See file Optnh3.bkp.
For more information see the Aspen Plus Help topic Simulation and Analysis Tools -> Sequential Modular Flowsheeting Tools -> Optimization.
In this example, Optimization is used to find the maximum product flow. The reactor temperature, the cooler temperature, and the bleed fraction are manipulated to find the optimum. Optimization is used to find the reaction temperature that maximizes the product value.
The molar flow rate of stream PRODUCT is the sample variable in the optimization. This variable is called PRODFL.
The optimization problem is converged when PRODFL is at a maximum.
There are three manipulated variables: the reactor temperature, the cooler temperature, and the bleed fraction. The optimization convergence block finds the combination of values that makes PRODFL a maximum, subject to the constraints.
The manipulated variables are specified in the blocks, just as if there were no optimization. The specified value is the initial estimate used by the optimization convergence block.
You do not have to specify convergence of the design specification. ASPEN PLUS automatically generates a convergence block to converge the specification.
There are four constraints associated with the optimization problem. They are called ADIAB, PRES, PURGE, and PURITY.
The constraint ADIAB is satisfied when the reactor duty equals zero.
The constraint PRES is satisfied when the pressure in block STAGE2 equals the pressure in block RECOMPR.
The constraint PURGE is satisfied when molar flow of NH3 in the stream BLEED has a concentration of less than or equal to 2 lbmol/hr.
The constraint PURITY is satisfied when mole fraction of NH3 in the stream PRODUCT is greater or equal to than 0.999.
Keywords: None
References: None |
Problem Statement: Why do Data Regression (DRS) Evaluation results differ from Property Analysis results? | Solution: The Evaluation option in DRS is a convenient way to get a feel for how good the model parameters are compared to a set of data. If you have several sets of data, or different models, it can provide an easy way to make comparison. However sometimes the results from an Evaluation can be different from those of a flash calculation.
The reason why the DRS evaluation is different from the flash calculation is because the evaluation is not doing a flash calculation in the same way. In the evaluation the physical property parameters are fixed but the regression system is still trying to minimize the objective function by manipulating the actual data values until the objective function is minimized, ie. distributing the errors. The objective function by default is a maximum likelihood method that includes every variable, both inputs and outputs, that have a standard deviation. With a flash calculation you are fixing some of the conditions and then using the parameters and the physical property models to determine the others. This is why there can be a difference.
Similarly, the results of a DRS regression run will also differ from Property Analysis results for the same reasons.Solution 102388 illustrates the difference using an example of vapor pressure vs. temperature data.
You can use the evaluation run as an initial check of the parameters but you should do the flash calculation, using the Property Analysis (formerly called Prop-table flashcurve) to be sure. You do not need to do every point but should take a cross section of values and look at the shape of the curves rather than each value.
Another way to explain this discrepancy is to consider the basic equation being solved (or constaints being met).
For flash,
phase equilibrium condition: y(i)Phivmx(i) = x(i) philmx(i) or K(i) = philmx(i)/phivmx(i)
material balance z(i)F = y(i)V + x(i) (1 - V)
sum of mole fractions sum x(i) = 1 and sum y(i) = 1
For DRS evaluation, only the equilibrium condition and the sum of mole fractions are met.
is not the constraint. So if we assume F (feed mole flow) to be 1, and x(i) is fixed (std-dev set to zero), then there are many possibleSolutions for y(i) depending on the value of V.
Keywords: DRS, Evaluation, Flash curve, Prop-Table, Analysis,
References: None |
Problem Statement: Is it possible to access an entire stream vector? | Solution: Attached is an example of Accessing a Stream Vector. See file Stream-vec.bkp
You can use the vector variable types to access an entire block profile, stream or substream at once. Aspen Plus interprets the variable you assign to the vector as an array variable. You do not need to dimension it.
This table shows the vector variables:
Variable type Description
Block-Vec Unit operation block vector
Stream‑Vec Stream vector
Substream‑Vec Substream variable
Compattr‑Vec Component attribute vector
PSD‑Vec Substream Particle Size Distribution (PSD) vector
Un‑Cor‑Vec Temperature‑dependent unary property parameter
Bi‑Cor‑Vec Temperature‑dependent binary property parameter vector
Aspen Plus generates a variable by adding the letter L to the beginning of the Fortran variable name which you assign to the vector. The value of this variable is the length of the vector. You can use the variable in Fortran statements, but you cannot change its value.
You can use the Stream‑Vec and Substream‑Vec variable types to access an entire stream or substream at once. Aspen Plus interprets the variable you assign to the stream as an array variable. You do not need to dimension it.
A stream vector contains all the substream vectors for that stream class. The order of the substreams is defined on the Setup | Stream Class | Stream Class sheet).
The variables in a stream or substream vector are always in SI units.
This is the layout of the substream vector for substream MIXED and for Stream‑Vec, when accessing the default stream class CONVEN:
Array Index Description
1, . . . , NCC Component mole flows (kg‑moles/sec)
NCC + 1 Total mole flow (kg‑moles/sec)
NCC + 2 Temperature (K)
NCC + 3 Pressure (N/m2)
NCC + 4 Mass enthalpy (J/kg)
NCC + 5 Molar vapor fraction
NCC + 6 Molar liquid fraction
NCC + 7 Mass entropy (J/kg‑K)
NCC + 8 Mass density (kg/m3)
NCC + 9 Molecular weight (kg/kg‑mole)
NCC is the number of conventional components specified on the Components Specifications Selection sheet. The order of the component mole flows is the same as the order of components on that sheet. All values are in SI units, regardless of the Units specification on the Define sheet.
Aspen Plus generates a variable by adding the letter L to the beginning of the variable name, which you assign to the substream or stream vector. The value of this variable is the length of the vector (NCC + 9). You can use the variable in Fortran statements, but you cannot change its value.
A Fortran block is used to write the mole fractions of stream HX1-OUT to the terminal. On the Define sheet of the Calculator block, the variable SOUT, of the type Stream-Vec, is defined. On the Calculator Calculate sheet, these Fortran statements are included:
NCOMP=LSOUT-9
WRITE(NTERM,30)
DO 10 I=1, NCOMP
X(I)=SOUT(I)/SOUT(NCOMP+1)
WRITE(NTERM, 20) I, X(I)
10 CONTINUE
20 FORMAT (10X, I3, 2X, F10.4)
30 FORMAT ('STREAM HX1-OUT MOLE FRACTIONS')
On the Fortran Declarations sheet, the following statement allows for up to 20 components:
DIMENSION X(29)
Keywords: None
References: None |
Problem Statement: Exported Aspen SQLplus query results can be directly imported in Excel spreadsheets. This | Solution: provides examples of queries that create CSV files that can be opened by Microsoft Excel.Solution 142709 describes several techniques you can use to create CSV files.
Solution
As a basic example, the following query lists all tags within an Aspen InfoPlus.21 database to a CSV which can be opened by Excel:
SET COLUMN_HEADERS = 1;
SET VALUE_BETWEEN =',';
SET HEADER_BETWEEN =',';
SET HEADER_LINE = '';
SET Output 'C:/Temp/Result.csv'; --Change this for a path on your system
Select RecId, Name, Definition from all_records;
SET Output Default;
Opening Result.csv file using Excel looks like:
Note that this method does not work properly for tag names with a comma , character as part of the name:
You can use the following code if this is an issue
SET Output '\\MyIP21Server\Temp\Result.csv';
Write 'RecordId, RecordName, DefinitionType';
For
(Select RecId RecordId, Name as RecordName, Definition as DefinitionType from all_records)
Do
Write RecordId||','||RecordName||','||DefinitionType;
End
Here the query surrounds the tag name with single quotes to cause Excel to ignore the comma in the tag name.
Both methods can be used to retrieve different lists from the Aspen InfoPlus.21 database as follows:
1) List of records processed by TSK_IQ1 with last execution time and schedule interval
SET COLUMN_HEADERS = 1;
SET VALUE_BETWEEN =',';
SET HEADER_BETWEEN =',';
SET HEADER_LINE = '';
SET Output '\\MyIP21Server\Temp\Result.csv'; --Change this for a path on your system
Local IQTask;
IQTask = 'TSK_IQ1';
Select Name, status, CAST(Last_Executed AS CHAR FORMAT 'DD-MON-YY HH:MI') as Last_Execution, Reschedule_Interval from QueryDef CompQueryDef ProcedureDef TextViewDef ViewDef;
SET Output Default;
Result in Excel:
2) List of Tags used by all get transfer records for a logical device.
Local LogicalDeviceName;
LogicalDeviceName = 'IOSIMUL'; --Change this for your logical device
SET Output '\\MyIP21Server\Temp\Result.csv'; --Change this for a path on your system
Write 'cimio_devName, TransferRecordName,IP21TagName,TagName';
For
(select io_main_task->io_device as cimio_devName, Name as TransferRecordName, IO_VALUE_RECORD&&FLD as IP21TagName, io_tagname as TagName
from iogetdef IoLongTagGetDef IoLLTagGetDef where io_main_task->io_device = LogicalDeviceName)
Do
Write Trim(cimio_devName)||','||Trim(TransferRecordName)||','||Trim(IP21TagName)||','||Trim(TagName)||',';
End
Result in Excel:
Keywords: SQLplus, Output, CSV, Export, Excel
References: None |
Problem Statement: After installing the Aspen Simulation Workbook, the ASW toolbar icons do not appear in Excel 2003 and the Aspen menu does not appear in the Excel 2003 menu structure. | Solution: If only the toolbar icons do not appear, it is possible that they have not be selected to be displayed. To rectify this, select View | Toolbars from the In Excel main menu, and ensure that both icons in the ASW toolbar are selected.
When both the toolbar icons and Aspen menu item are missing, the toolbar may be disabled by Excel. To check for this scenario:
1. Open Excel.
2. Click Help | About Microsoft Excel.
3. Click Disabled Items. If Aspen Simulation Workbook appears in the list, remove it.
If the above procedure fails to resolve the problem:
1. Click Tools | Customize.
2. Select the Commands tab.
3. Under Categories, click Tools.
4. In the Commands list, select COM Add-Ins.
5. Click the Tools menu and drag the COM Add-Ins item to this menu, just below the Add-Ins command.
6. Close the Customize dialog box.
7. Run the COM Add-Ins command you just added to the Tools menu.
8. Verify that Aspen Simulation Workbook is in the list. Ensure that it is checked (enabled) and its path is ASWXLAddinLoader.dll in the Aspen Simulation Workbook installation folder.
Keywords: Aspen Simulation Workbook, Excel 2003, Link, OSE Workbook
References: None |
Problem Statement: What are the .his, .for, .appdf, and .ads files that get saved when one saves an apw file? | Solution: These files are complementary to the .apw file and are automatically saved when you save an apw file.
The .his file is an ASCII file that stores the run history including all the run time messages rolled out on the control panel since your last reinitialization. After you load your apw file back in Aspen Plus, you can go to /view/history, then Aspen Plus will display the file in notepad format. If you delete the .his file, Aspen Plus would say that the history is not avaialble.
The .for file is a Fortran source file generated for inline fortran. If you do not have inline fortran, this file would have a size of zero.
The .appdf file is a binary file that stores all the intermediate physical property and run data used. If you have this file and you load the .apw file, your re-execution of the run will take no time since all run data are in the .appdf file. If you go to /view/report, you will get a report file generated right away. On the other hand, if you delete the .appdf, you would not be able to generate a report file. You must rerun the simulation and a temporary .appdf file will be regenerated. The execution will have to start from the input translation and behave as if you have done a reinitialization
With the APW file by itself, any charts/plots generated by the user are saved (no .appdf file is necessary to save the plots).
The .ads file is an “Aspen Data Share” file. This is an XML data store used to transfer data between Aspen Plus and adjacent applications (Economics, Energy Analyzer, etc.). As part of the process to improve the speed and robustness of the activated applications we are moving away from using automation to extract data from Aspen Plus; instead, Aspen Plus stores the required information as it is calculated during simulation. For V8.4 and higher, this is used in the new activated economics workflow (for example, displaying costs on the flowsheet).
Keywords: File type
apw
his
for
appdf
References: None |
Problem Statement: Where is the Comments button in newer versions of Aspen Plus? | Solution: In order to make Comments more visible, they are now added on the Comments or Information tab of a form. All forms (blocks, streams, design specs, sensitivity, property parameters, etc.) have a Comments sheet. The Comments tab will have a check if comments have been added. Comments from files created in earlier versions will be seen on the tab.
Keywords: navigation, menu, icons, buttons, comments, user interface
References: None |
Problem Statement: Why do Evalulation results depend on the objective function? | Solution: If TPXY data is entered and two evaluation runs are performed: one with the maximum likelihood, the other with the ordinary least squares, the results are different.
The difference is that the least square objective function will fix the x for TPXY data and x is not part of the objective function whereas the maximum likelihood includes every variable in the objective function and also there is a weight factor for each variable.
When a standard deviation for T,P,x, and y is entered (i.e. the standard deviation value is not equal to 0), Evaluation fixes the parameters (eg. binary interaction parameters for activity coefficient model) but all T, P, x, and y would be included in the evaluation. Since each variable contains a standard deviation, the exact value used requires the objective function.
For example, the temperature data is 50 with a standard deviation of 5%. This temperature data contains uncertainty due to the standard deviation. Then during evaluation, instead of using the value 50 for temperature, Aspen uses a value that produces the best fit for P, x and y. In other words, the temperature must be evaluated as well. With the default maximum likelihood objective function, Aspen Plus produces an overall best fit for the objective function including every variable that has a standard deviation with the binary interaction parameters fixed. Only in this way, can all variables (T,p,x and y) be evaluated.
Keywords: data regression, evaluation, objective function
References: None |
Problem Statement: Is it possible to accessing the entire temperature profile of a RadFrac column? | Solution: Attached is an example of accessing the entire temperature profile of a RadFrac column.
You can use the vector variable types to access an entire block profile, stream or substream at once. Aspen Plus interprets the variable you assign to the vector as an array variable. You do not need to dimension it.
This table shows the vector variables:
Variable type Description
Block-Vec Unit operation block vector
Stream‑Vec Stream vector
Substream‑Vec Substream variable
Compattr‑Vec Component attribute vector
PSD‑Vec Substream Particle Size Distribution (PSD) vector
Un‑Cor‑Vec Temperature‑dependent unary property parameter
Bi‑Cor‑Vec Temperature‑dependent binary property parameter vector
Aspen Plus generates a variable by adding the letter L to the beginning of the variable name which you assign to the vector. The value of this variable is the length of the vector. You can use the variable in Fortran statements, but you cannot change its value.
You can use the Block‑Vec variable type to access column profiles for the following multi‑stage separation models:
In this model Variables depend on
RadFrac Stage and composition
MultiFrac Stage, section, and composition
Extract Stage
PetroFrac Stage, composition, and stripper number
SCFrac Section and composition
You can also use Block‑Vec to access the following block result profiles:
MHeatX zone analysis
RBatch time profiles
RPlug length profiles
Aspen Plus automatically:
Interprets the variable you assign to the profile as an array variable
Dimensions the variable
Aspen Plus generates a variable by adding the letter L to the beginning of the variable name which you assigned to the block vector. The value of this variable is the length of the array. You can use the variable, but you cannot change its value.
The order of values in the array depends on which variable you select. All values are in SI units, regardless of the Units specifications on the Define sheet.
The layout for vector variables is dependent on stage section or segment number follows.
Array Index Value for
1 Stage or segment 1
2 Stage or segment 2
.
.
N Last stage or segment
N denotes the number of stages or segments in the column.
Examples of variables dependent on stage number are temperature and flow profiles in RadFrac, MultiFrac Extract, or PetroFrac.
For more information see the Aspen Plus Help topic Simulation and Analysis Tools -> Sequential Modular Flowsheeting Tools -> Accessing Flowsheeting Variables.
In the attached example the temperature profile of a RadFrac block is written to the Control Panel, using a Calculator block.
On the Define sheet of the Calculator block, variable TPROF of the type Block-Vec is defined using the Variable Definition dialog box. On the Calculator Calculate sheet, these Fortran statements are included:
WRITE(NTERM,20)
DO 10 I = 1, NSTAGE
WRITE(NTERM,30) I, TPROF(I)
10 CONTINUE
20 FORMAT (' *** TEMPERATURE PROFILE ***')
30 FORMAT (10X, I3, 2X, F10.2)
Keywords: None
References: None |
Problem Statement: What is Carbon\Sulphur\Nitrogen Index (CI\SI\NI) and Oxygen Demand (OD) in the Fuel Model? What is the calculation formula for these? | Solution: CI, SI, NI index of the fuel are used to calculate the total CO2, SOX and NOX emissions in the emission blocks.
Carbon index (CI) is calculated as mass CO2 generated by burning the fuel per mass of fuel.
Similar:
Sulphur Index (SI) is the SO2+ SO3 (SOx) mass generated per mass of fuel, and
Nitrogen index (NI): NOX emissions produced by fuel per mass of fuel
In Aspen Utilities Planner these variables are used to calculate emissions based on the following equations:
TotalSOX = Fmass_out*SI;
TotalCO2 = Fmass_out*CI;
TotalNOX = Fmass_out*NI;
Where:
Fmass_out= Mass of fuel
TotalSOX = SOX emissions produced by fuel
TotalCO2 = CO2 emissions produced by fuel
TotalNOX = NOX emissions produced by fuel
The oxygen demand (OD) of a fuel is the mass ratio: oxygen to fuel under stoichiometric conditions. In other words: OD is the amount of oxygen which is required for a combustion of 1kg/tonne/mass unit of fuel under stochiometric conditions.
Keywords: Carbon Index, Sulphur Index, Nitrogen Index, CI, NI, SI, Oxygen Demand, OD, Fuel Feed Specification
References: None |
Problem Statement: How do I transfer an Aspen Economic Evaluation template from one computer to another? | Solution: Template files in the Aspen Economic Evaluation suite allow users to configure their own Project Basis to use in multiple projects.
If any user wishes to share this file with another user or migrate into a new PC, it is necessary to perform a manual Copy/Paste process of the files from the first machine to the second one.
The user can track the location of the template files by opening any Aspen Economic Evaluation product and reviewing the Template tab of the palette.
By clicking the Templates folder, the user can show the full route where the templates are located.
The default Templates route is Archive: C:\ProgramData\AspenTech\Economic Evaluation VX.X\EE_Templates
Once the user has located the required template file(s), user has to transfer it to the new system and place it in the Template folder of the second machine.
The second machine should have Aspen Economic Evaluation already installed. User can confirm the Templates folder route the same way as above or use the default route if this has not been changed.
Keywords: Template, migration, palette.
References: None |
Problem Statement: ABML_MTM_RON calculation method is used for blending RON property in a model. However, sometimes it seems to be calculating an incorrect RON for the stream, even when it blends into an empty tank. | Solution: In the case that MON is zero or any other bad value, it could cause erroneous RON calculations through this ABML method. This could also occur if the MON is greater than the RON.
In general for MTM ABML to work as expected, APS assumes RON>=MON. There is a new error handling code for the case of RON<MON that would be available in later version than 8.5.
A suggestion would be selecting a linear calculation for RON. There is a box called Linear Except for Blend when selecting the Property dialog box. APS will mix components or streams rundown with tank inventory linearly if you select it for RON:
Linear Except for Blend:
Select this option to apply non-linear blending correlations only during blend events. Most non-linear blending correlations are designed for blending a wide mix of components and not for mixing the same materials. The latter would occur during component rundowns or transfers and receipts. For these types of mixing, if this option is selected, this property of the mix will be calculated linearly.
Keywords: -Properties
-ABML correlations
References: None |
Problem Statement: Why Should I use the Aspen Properties Enterprise Database Instead of the Legacy Databanks? | Solution: The Aspen Properties Enterprise Database (APED) is a framework for creating relational databases that can be used with Aspen Plus, Aspen Properties and other products that make use of Aspen Properties. The databases are created using SQL Server, therefore, SQL Server engine, such as SQLExpress must be available (installed). By default, SQLExpress is installed automatically when Aspen Plus or Aspen Properties is installed, unless you already have a SQL Server engine (SQL Server 2003 or 2005) on your machine. SQLExpress does not require a separate license.
APED is a replacement of the legacy databanks and has been deployed since version 2006. To allow our users time to transition to the new database, we continue to support both systems. Starting with V7.0 APED is used by default, thus increasing its awareness among our users. We anticipate that the legacy databanks will be completely phased out by V9.0.
There are many significant benefits of APED:
? APED contains much more data than the legacy databanks. In particular the new NIST-TDE database is only available in APED. This pure component database contains data for 18,840 compounds. By comparison, the PURE22 databank contains data for 1,800 components.
? The relational database allows us to store much more types of data than the legacy databanks, in particular meta data such as literature citations, uncertainties, notes.
? We can store pure component, binary, electrolyte pair and reaction chemistry data in the same database.
? The users can more easily create and manage user databases. There is no need to customize both the simulation engine and the User Interface, as is the case for the legacy databanks. Once the APED database is created and registered, it is available for use.
? The databases can be shared by all Aspen Tech's applications that rely on Aspen Properties. For example, the same databases are used by Aspen Plus and Batch. Any customization you made to the databases will be available to all the programs.
The database can be deployed locally on a user's PC as well as centrally on a database server. This is important for companies that have their own property databanks and want to be able to centrally control its content and usage. For example, they want to be able to update the databases to change/add property values or to add new components and have these changes available to all of their users automatically without having to update each users' machine. They may also want to restrict access to a particular database to certain named users or users within a certain organization.
? The new database allows a much greater level of data security.
o The data values are encrypted and can only be viewed using the Aspen Properties Database Manager or Aspen Plus/Aspen Properties.
o The database can be secured such that it can only be used within your company (i.e., it cannot be used at another company), so that your proprietary property data/parameters are not inadvertently taken and used by a departing employee.
o The new database can be secured such that it can be used by a 3rd party (e.g., technology partner) when running the Aspen Plus (or Aspen HYSYS) simulation model, but the parameter values cannot be viewed in any way. This allows your proprietary data to be used to execute joint projects without compromising them.
? To use Aspen Properties from Aspen HYSYS, APED must be enabled. If the legacy databanks are used, the Aspen Properties features will NOT be available in HYSYS.
Keywords: None
References: None |
Problem Statement: How do I collect a crash dump for aspenONE Engineering Products? | Solution: One of the aspenONE Engineering suite product crashes for no reason and to understand the root cause AspenTech Support has requested an application crash dump.
The following procedure describes how a .dmp file can be created and sent to the AspenTech support team so that the software developers can identify the root cause.
1. Download and install Debug Diagnostic Tool v2 Update 2 (a diagnostic tool from Microsoft) from https://www.microsoft.com/en-us/download/confirmation.aspx?id=49924 link.
2. Launch the DebugDiag 2 Collection application from Start Menu.
3. Select the Rule Type Crash and click Next.
4. Select A specific process and click Next
5. In the text box type the application exe name for which you want to capture the dmp file. Ensure This process instance only box is NOT checked, and click Next.
6. Example: AspenHysys.exe for Aspen HYSYS
7. Set a max number of user dumps limit to 5 (10 is the default), Click Next.
8. Enter a name for the rule (the default should be OK) and browse to the location. Click Next.
9. Note: Make sure the path location you have selected has enough disk space to hold big dump file (in GB).
10. Select Activate the rule now and click Finish.
11. The application crash rule will get created. Allow Debug Diagnostic Tool to run.
12. Launch the application which needs to create crash dump.
13. Example: Aspen HYSYS
14. If the application crashes automatically, the crash dump will be created. Otherwise perform the operation which crashes the application.
15. Once the application is crashed you will find the Userdump Count is increased by one.
16. Collect the .dmp file from Userdump Path and send it to AspenTech Support Team to investigate.
Keywords: Crash
Dump
Dmp
Application dump
DebugDiag
References: None |
Problem Statement: This article discusses how to publish graphics into AspenONE Process Explorer using Aspen Process Graphics Editor. | Solution: After graphics are created in Aspen Process Graphics Editor, user can follow below steps to publish them onto AspenONE Process Explorer.
1, Click on 'Tools - Options' in Aspen Process Graphics Editor toolbar, confirm the publish path (The default folder is 'Public' folder.)
2, Click 'File - Publish to aspenONE Process Explorer'
3, Then user can go to AspenONE Process Explorer and check if the graphics is correctly published as expected.
For more information, KB (https://esupport.aspentech.com/S_Article?id=000033779) explains how to publish standard Aspen Process Explorer plots to aspenONE Process Explorer
Keywords: AspenONE Process Explorer
Aspen Process Graphics Editor
References: None |
Problem Statement: When using Simulation Links in MS Excel interface, some blocks names are displayed as Blocks(“AUP_Block_name”). How can this issue be avoided? | Solution: This is by design that when using Simulation Links in MS Excel for blocks which names start from the number (for example 01T, 23GT) additional Blocks phrase is added in the beginning of the name.
Then in the Simulation Links user can see for example names: Blocks(“01T”), Blocks(“23GT”), etc.
Even when names are changed, inputs are still used in Aspen Utilities Planner in the background and results are display properly.
To make sure that name of the block will not be modified, user should start block names with letters, and then exact names will be visible in MS Excel interface.
Keywords: Simulation Links, blocks, different name,
References: None |
Problem Statement: If I wanted to produce a phase diagram in Aspen Plus with solid, liquid and gas (i.e., a P-T diagram showing the sublimation, the melting and the vapor pressure curves), how would I do it? | Solution: This is possible using Property Analysis; however, the properties must be very accurate and may need to be tuned. ThisSolution will demonstrate how to create the plot for two different components, CO2 and N-Butane, using CO2 as the main example. The files for both CO2 and N-Butane are attached for reference.
1. Approach
Such a phase diagram involves 3 types of equilibria (vapor-liquid, liquid-solid, vapor-solid) that must be calculated separately in Aspen Plus. In fact, we are only interested in the pressure-temperature (= P-T) projection of these equilibria.
V-L equilibrium: Calculate the vapor pressure from an equation of state (e.g., RK-SOAVE) as described inSolution 103646
L-S equilibrium: Calculate the freeze-out temperature of liquid as described inSolution 102343
V-S equilibrium: Calculate the freeze-out temperature of vapor CO2 as described inSolution 102343.The data can then be combined into a single plot.
The Aspen Plus pure-component databanks include the critical point and triple point along with the freezing point (FREEZEPT) and normal boiling point (TB). These can be retrieved by clicking Retrieve Parameters from the tools section of the Properties Home ribbon (see picture below):
For CO2:
Critical point (TC, PC): 304.21 K, 7383 kPa
Triple point (TPT, TPP): 216.58 K, 518.672 kPa
Freezing/Melting point: 216.58 K
Normal boiling point: 194.7 K
For N-Butane:
Critical point (TC, PC): 425.12 K, 3796 kPa
Triple point (TPT, TPP): 134.86 K, 0 kPa (these properties can be obtained from the databanks, as described inSolution 3008 or from NIST).
Freezing/Melting point: 134.86 K
Normal boiling point: 272.65 K
These points can be added to the plot or be used to check the consistency of the data from 1. to 3.
2. Method
Perform a property analysis (see V-L in the attached *.bkp files) and calculate the total pressure as a function of temperature starting from the triple point (TPT; TPP) up to the critical point (TC; PC). A vapor fraction of either 0.0 or 1.0 is equivalent for a one component mixture that vaporizes or melts at a single temperature.
The flash convergence has been tightened on the Setup \ Simulation Options \ Flash Convergence sheet to get accurate results near the critical point. If the convergence is not tightened, the Equation of State liquid volume route is extrapolated and the properties not calculated.
FLASH RESULTS ARE WITHIN TOLERANCE, BUT MAY BE UNSATISFACTORY BECAUSE EXTRAPOLATED EOS LIQUID VOLUME ROOT WAS USED FOR PROPERTY CALCULATIONS. PROPERTIES WILL NOT BE CALCULATED DUE TO FLASH FAILURE.
ERROR WHILE GENERATING PROP-TABLE: V-L
2. Property analysis L-S: Calculate property 'Liquid TFREEZ' as a function of pressure from the triple point pressure to the critical pressure (or even higher pressures).
To use TFREEZ, the PHIS property route should be PHIS06, and should reference the same liquid PHIL route as the overall property method which is PHIL13 for RK-SOAVE.
The temperature in the Analysis needs to be below the freezing point at that pressure in order for TFREEZ to be calculated.
3. Property analysis V-S: Calculate property 'Vapor TFREEZ' as a function of pressure from atmospheric pressure up to the triple point pressure.
The flash does not connverge at the triple point in this example.
Combine the P-T data from all three property analysis objects into one plot using the Add New Curve option in the Plot menu. To use the Add New Curve feature, select the column of data for the x-axis, and define it as such by selecting X-axis Variable from the Plot menu. Similarly, select the column of data for y, and select Y-axis Variable from the Plot menu. Once the X and Y variables are defined, Add New Curve is enabled in the Plot menu.
The only point to note is that in the V-L Analysis results tab, temperature is the x-axis variable and pressure is the y-axis variable, while for L-S and V-S the selection must be vice versa. Map the y-axis (pressure) data from all 3 tables in one by right-clicking on the plot, selecting Axis Map, and choosing All in One).
Keywords: vapor-liquid equilibrium; liquid-solid equilibrium; vapor-solid equilibrium; sublimation curve; melting curve; vapor pressure curve; freeze-out temperature; phase diagram; CO2; N-Butane;
References: None |
Problem Statement: Is it possible to modeling a SF6 and N2 system using Aspen Plus? | Solution: The purpose of this report is to show an example of modeling SF6 and N2 system, including property analysis and a simple process simulation using separator.
1. Compound parameters and property method
Parameter values of SF6 (sulfur hexafluoride) and N2 (nitrogen) are retrieved from Aspen database (most of them from the PURE22 databank), including pure and binary interaction. Three more parameters are needed and obtained from DIPPR database:
DCPLS, (Difference between liquid and solid Cp at triple point): 656 J/kmol-K for SF6.
DGSFRM, (Solid free energy of formation at 25 ºC): -1.11653E9 J/kmol for SF6.
DHSFRM, (Solid enthalpy of formation at 25 ºC): -1.22047E9 J/kmol for SF6.
A commonly used property method PENG-ROB (Peng-Robinson equation of state) is selected in this simulation.
2. Property analysis: calculating Tfreeze at 1 atm
Aspen Plus can calculate the Freeze-out temperature (TFREEZ) of SF6 from vapor phase at 1 atm. Below is the list of Freeze-out temperature of SF6 at various N2 composition. The initial guess of TFREEZ is 205 K.
N2 Mole fraction
SF6 vapor TFREEZ (K)
0.025
208.8682
0.05
208.4418
0.075
208.0069
0.1
207.563
0.125
207.1097
0.15
206.6464
0.175
206.1532
0.2
205.6642
0.225
205.1628
0.25
204.6484
0.275
204.1199
0.3
203.5766
0.325
203.0174
0.35
202.4411
0.375
201.8466
0.4
201.2323
0.425
200.5968
0.45
199.9382
0.475
199.2546
0.5
198.5437
3. Process simulation: Separating stream using RGibbs block:
The input stream is at 250 K, 1 MPa, and contain 80% SF6, 20% N2. To separate this stream by phase, RGibbs block is selected since it is for rigorous reaction and/or multiphase equilibrium based on Gibbs free energy minimization. In this block, the temperature is set to 180 K, which is below freeze-out temperature of this composition. The results of each outlet stream are shown below. The outlet 2 (OUT2) contain solid mass flow of SF6.
INPUT
OUT1
OUT2
OUT3
From
RGIBBS
RGIBBS
RGIBBS
To
RGIBBS
Substream: ALL
Mass Flow
KG/SEC
612.24
30.37
581.87
0
Mass Enthalpy
WATT
-4933911000
-23464030
-4956670000
0
Substream: MIXED
Phase:
Mixed
Vapor
Solid
Missing
Component Mole Flow
SF6
KMOL/SEC
4
0.02
3.98
0
N2
KMOL/SEC
1
1
0
0
WATER
KMOL/SEC
0
0
0
0
Mole Flow
KMOL/SEC
5
1.02
3.98
0
Mass Flow
KG/SEC
612.24
30.37
581.87
0
Volume Flow
CUM/SEC
5.52
1.46
0.23
0
Temperature
K
250
180
180
Pressure
N/SQM
1000000
1000000
1000000
Vapor Fraction
0.59
1
0
Liquid Fraction
0.41
0
0
Solid Fraction
0
0
1
Molar Enthalpy
J/KMOL
-986782300
-23092010
-1244179000
Mass Enthalpy
J/KG
-8058798
-772694.4
-8518480
Enthalpy Flow
WATT
-4933911000
-23464030
-4956670000
Molar Entropy
J/KMOL-K
-332449.9
-39765.49
-447612.2
Mass Entropy
J/KG-K
-2715.03
-1330.62
-3064.65
Molar Density
KMOL/CUM
0.91
0.7
17.46
Mass Density
KG/CUM
110.86
20.85
2550.15
Average Molecular Weight
122.45
29.89
146.06
Substream: CISOLID
Component Mole Flow
SF6
KMOL/SEC
0
0
0
0
N2
KMOL/SEC
0
0
0
0
WATER
KMOL/SEC
0
0
0
0
Mole Flow
KMOL/SEC
0
0
0
0
Mass Flow
KG/SEC
0
0
0
0
Volume Flow
CUM/SEC
0
0
0
0
Temperature
K
Pressure
N/SQM
1000000
Vapor Fraction
Liquid Fraction
Solid Fraction
Molar Enthalpy
J/KMOL
Mass Enthalpy
J/KG
Enthalpy Flow
WATT
Molar Entropy
J/KMOL-K
Mass Entropy
J/KG-K
Molar Density
KMOL/CUM
Mass Density
KG/CUM
Average Molecular Weight
If we increase the temperature setup in RGibbs block from 180 K to 250 K, which is above freeze-out temperature of this composition, and run the simulation again, the results show there is no solid phase.
INPUT
OUT1
OUT2
OUT3
From
RGIBBS
RGIBBS
RGIBBS
To
RGIBBS
Substream: ALL
Mass Flow
KG/SEC
612.24
612.24
0
0
Mass Enthalpy
WATT
-4933911000
-4905804000
0
0
Substream: MIXED
Phase:
Mixed
Vapor
Missing
Missing
Component Mole Flow
SF6
KMOL/SEC
4
4
0
0
N2
KMOL/SEC
1
1
0
0
WATER
KMOL/SEC
0
0
0
0
Mole Flow
KMOL/SEC
5
5
0
0
Mass Flow
KG/SEC
612.24
612.24
0
0
Volume Flow
CUM/SEC
5.52
8.67
0
0
Temperature
K
250
250
Pressure
N/SQM
1000000
1000000
Vapor Fraction
0.59
1
Liquid Fraction
0.41
0
Solid Fraction
0
0
Molar Enthalpy
J/KMOL
-986782300
-981160800
Mass Enthalpy
J/KG
-8058798
-8012890
Enthalpy Flow
WATT
-4933911000
-4905804000
Molar Entropy
J/KMOL-K
-332449.9
-310289.5
Mass Entropy
J/KG-K
-2715.03
-2534.05
Molar Density
KMOL/CUM
0.91
0.58
Mass Density
KG/CUM
110.86
70.64
Average Molecular Weight
122.45
122.45
Substream: CISOLID
Component Mole Flow
SF6
KMOL/SEC
0
0
0
0
N2
KMOL/SEC
0
0
0
0
WATER
KMOL/SEC
0
0
0
0
Mole Flow
KMOL/SEC
0
0
0
0
Mass Flow
KG/SEC
0
0
0
0
Volume Flow
CUM/SEC
0
0
0
0
Temperature
K
Pressure
N/SQM
1000000
Vapor Fraction
Liquid Fraction
Solid Fraction
Molar Enthalpy
J/KMOL
Mass Enthalpy
J/KG
Enthalpy Flow
WATT
Molar Entropy
J/KMOL-K
Mass Entropy
J/KG-K
Molar Density
KMOL/CUM
Mass Density
KG/CUM
In summary, based on the example above, the Aspen Plus with proper setting is capable to model process of SF6 and N2 system, such as freeze-out temperature calculation and multiphase separation under various temperature and pressure.
Keywords: None
References: None |
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