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Problem Statement: What does the following error message mean: >ERROR> 'CD - 1' ENTER EITHER %DFM OR %ADJ - %ADJ WILL BE IGNORED | Solution: This error message shows up when the user has specified two different fields for the Equipment Rental estimation in one or more contractors.
To remove this error, go to Project Basis View | Contractors, and open the Contractor Assignment Tree.
Open the contractor number shown in the error message (e.g. 'CD-1' means the over specification is contractor 1) by right clicking and selecting edit.
Scroll down to the EQUIPMENT RENTAL fields, you should notice that the data for the two percent options Equipment rental percent DFL and Equipment rental pct calculated has been manually entered (input is shown in black numbers).
A user can only enter a value for one of these two fields, removing one of them will allow the user to remove the error message.
If the user enters the Equipment Rental percent DFL, (or the Equipment rental cost[USD]), the program will use this numbers to replace the system calculated values.
If the user would rather have the system calculate the equipment rental costs and perform an adjust based on that, the value in Equipment Rental pct calculated should be specified instead.
Keywords: PCT, CD, DFL, Contractors, Indirects, Adjust, Percent
References: None |
Problem Statement: Is there a way to change distillation data using Aspen Simulation Workbook (ASW)? | Solution: There is a way to change the distillation data via ASW, using Petroleum Assay Manager. Follow the steps below to connect and modify the data.
1. Go to a material stream on your flowsheet.
Select Petroleum Assay page from Worksheet tab. Then Create the input assay using the Single Stream Properties option as shown.
2. Next, check Auto-Characterize option and then Characterize Assay.
3. To Add the Input Assay to the ASW table, browse through the connected case, required stream.
4. Scroll to the AssayDistData-Input Folder and select all the cuts.
Keywords: Petroleum Assay Manager, ASW, Distillation Data
References: None |
Problem Statement: Back to Basics: How do I build a multi-plant model (also called Global model or MPIMS)? What tables are required? | Solution: A global model links multiple local models together and allows for interaction between them. To set up a global model, follow the steps below:
1) You must first have the local models that are to be linked. Make sure each model is running and converging well and all execution log warnings have been addressed. All the models (global and local) will need to reside in a single parent directory. Place the local models in the desired location.
2) Create a new PIMS model (MODEL | NEW). Select the location and name of the new model in the dialog box as shown below. Remember to create the global model within the same parent directory that holds the local models. By default PIMS makes new models STANDARD models. On the model tree, right click on the model name and select Model Type, then select Global as shown below.
Now the global tables need to be constructed. The required tables are listed below. This document provides an overview of the function of each table and shows an example. However this document does not go into the details of each table’s format and requirements. For more detailed information about each individual table you can refer to the PIMS Help system.
A) Table MODELS must be built. Below is an example of this table. This table designates a model identifier and the full name for each local model.
B) Table SUPPLY identifies which materials can be purchased at each plant. It also defines plant-specific constraints and costs for materials and material groups. An example is shown below.
C) Table GSUPPLY defines global constraints and costs for materials or material groups. Below is an example of this table.
D) Table DEMAND identifies plant-specific constraints on product sales. It also provides plant-specific prices for material or material group sales. The example below shows what this table looks like.
E) Table MARKETS designates a market identifier for the available markets in the model. Below is an example.
F) Table DEMALLOC has three functions:
1) designate which plants can satisfy the demand for each product in each market,
2) define any demand allocation constraints,
3) define marketing and distribution costs associated with each material or material group
G) Table MODES defines how material is transported from a plant to a market or to another plant. It designates the mode identifier and description for each mode of transportation. An example is shown below.
That is a review of the tables required to setup a multi-plant model. There are many other optional tables that are commonly used. In particular Table TRANSFERS defines material that can go from one plant to another. Additional information about all the tables discussed here can be found in the PIMS Help system ? including more detailed explanations of the format and setup.
Keywords: MPIMS
global
References: None |
Problem Statement: How can I restrict the members of each group that may modify event screens? | Solution: Table SCREEN_RIGHTS can be used to list events screens that members of each group may modify. If a screen is included for a particular group, then members of that group may change the screen, meaning that they may add or delete control variables and trends. When you add a new event screen, all member of that group will automatically have edit rights for that screen.
In the following example the CRD_SCHED group may modify screen A, the UNIT_SCHED group may modify screen B, and the PROD_SCHED group may modify screen D.
If a user in PROD_SCHED group tried to modify screen A, a message will prompt to communicate the user that the changes will not be saved.
The screen corresponding to the letters A, B, C, can be founded in Table GANTT_LIST
Keywords: None
References: None |
Problem Statement: How to model swing cuts in APS | Solution: APS does not have the function to optimize swing cuts as PIMS does for crude units. In APS, we need to provide input parameters for swing cuts, e.g. percentage, volume or FBP values.
And the input parameters can be used in the calculations set up in the logic unit for the crude units in Units excel workbook. Following is an example from crude unit 1 logic unit in demo model.
Keywords: None
References: None |
Problem Statement: How properties are calculated and managed in APS and MBO? | Solution: This Tech Tip gives a brief description of how How properties are calculated and managed in APS and MBO.
APS calculates them based on the method defined for the property, while MBO will try to achieve the spec that is defined by the recipe Spec:
Calculation Method
Enter the calculation method for the selected BML property:
Linear – Select this option to use a linear calculation method.
Excel Index – Select this option to convert the property value using Excel to index during calculation.
Interaction – Select this option to use interaction coefficients during calculation. Note that interaction coefficients only work on a volume basis.
ABML/UBML - Select this option to use an ABML or UBML calculation method. Selecting this option displays the BML Correlation (select) option. For versions after 2006.5, if UBML methods are missing, you will receive error messages when attempting to simulate. Simulation will not occur until the UBML methods are added.
Linear Except for Blend
Select this option to apply non-linear blending correlations only for 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.
If the option is selected, the system will calculate the property linearly using available properties for non-blend events.
If this option is not selected, it may be impossible to calculate the desired property value if all of the required inputs are not available.
Keywords: None
References: None |
Problem Statement: I checked the Quick result of an operation. I opened the Operation and changed the purge gas used, but when I ran the Quick Results again and checked the results in the operation, the purge gas showing in the Quick Results was not what appeared in the Operation dialog box. | Solution: The Aspen Batch Process Developer database didn't have time to refresh because the buttons were clicked too quickly. Wait a moment after closing the Quick Results dialog box before opening the Operation.
Keywords: Quick results, missing
References: None |
Problem Statement: What are the supported ProII Versions for Aspen Basic Engineering? | Solution: The table below summarizes all the supported ProII Version for Aspen Basic Engineering.
ABE Version Supported ProII Version
V8.0 with CPs 5.01, 5.1, 5.11.1, 5.5, 5.55, 5.6, 5.61, 6.0, 6.01, 7.0, 7.1, 8.0, 8.1, 8.2, 8.3,9.0,9.1
V8.4 with CPs 5.01, 5.1, 5.11.1, 5.5, 5.55, 5.6, 5.61, 6.0, 6.01, 7.0, 7.1, 8.0, 8.1, 8.2, 8.3,9.0,9.1
V8.8 5.01, 5.1, 5.11.1, 5.5, 5.55, 5.6, 5.61, 6.0, 6.01, 7.0, 7.1, 8.0, 8.1, 8.2, 8.3,9.0,9.1
V9.0 5.01, 5.1, 5.11.1, 5.5, 5.55, 5.6, 5.61, 6.0, 6.01, 7.0, 7.1, 8.0, 8.1, 8.2, 8.3,9.0,9.1
V10.0 with EP07 5.01, 5.1, 5.11.1, 5.5, 5.55, 5.6, 5.61, 6.0, 6.01, 7.0, 7.1, 8.0, 8.1, 8.2, 8.3,9.0,9.1, 9.3, 9.4, 10.1
V10.1 5.01, 5.1, 5.11.1, 5.5, 5.55, 5.6, 5.61, 6.0, 6.01, 7.0, 7.1, 8.0, 8.1, 8.2, 8.3,9.0,9.1
To install the latest CP's for ABE please use the links below:
V8.0 CP's: https://esupport.aspentech.com/apex/S_SoftwareDeliveryDetail?id=a0e0B00000BbqrcQAB
V8.4 CP's: https://esupport.aspentech.com/apex/S_SoftwareDeliveryDetail?id=a0e0B00000Bbrm0QAB
V10.0 EP07: https://esupport.aspentech.com/apex/S_SoftwareDeliveryDetail?id=a0e0B00000DUQWOQA5
If users want to request or add their current ProII version into the supported list, please contact AspenTech Support ([email protected]).
Keywords: ProII Versions
References: None |
Problem Statement: When we use P-rows in submodel table, the 8th character could control the number of decimals reported.
While in T.ASSAYS, the 8th character controls not the numbers of decimals, but the logical unit that the P-row applies.
But if I want to control decimals in T.ASSAYS, how can I use P-row? | Solution: There is no way to control decimals for P-rows in T.ASSAYS. Since the 8th character in a P-row is the logical crude unit designation character, not a decimal.
There is a workaround to deal with this query.
We could create a dummy submodel which could use P-rows with decimals control. Meantime, we could add E-rows in both T.ASSAYS and submodel to associate calculations. Details could be found in below example.
Assume that I would like to report average TAN in crudes and control the number of decimals to 4.
But I couldn’t use PTANAVG4 because the 8th character couldn’t control decimals.
So I add two E-rows as below to drive numerator and denominator activities to a dummy submodel.
The upper E-row represents numerator row, the coefficient is the same with Row 6 (TAN property). The lower E-row represents denominator row.
And in the dummy submodel we add two P-rows to report the activities for these two E-rows. With the 8th character ‘4’,we could control the number of decimals.
Results in fullSolution as below.
Keywords: P-row, ASSAYS, decimal
References: None |
Problem Statement: I have two competing reactions in my Reaction Editor dialog box. The first reaction goes to 95% completion. The second consumes the remaining raw material. However, when I simulate the Step, I have leftover reagent. Why? | Solution: Consider the following reaction scheme:
Reaction 1: A + B à C with 95% of A charged to the reactor converted to C.
Reaction 2: A + D à E with 5% of A charged to the reactor converted to E.
Consider how Aspen Batch Process Developer views this series of reactions. To model the case above, you could enter the conversion data shown below.
Keywords: Leftover reagent, Reactions
References: None |
Problem Statement: Why is the pressure drop calculation using the Aspen HYSYS Pipe Sizing Utility not the same as using the Pipe Segment? | Solution: The reason why the pressure drop results are not the same is because the pipe segment always uses at least 2 elements, each of which will be evaluated at slightly different conditions, whereas the Aspen HYSYS Pipe Sizing Utility gives a pressure drop per unit length based upon the single set of specified conditions for the stream.
This alone will give slightly different results for low velocity cases. At higher velocities, the sensitivity of the physical properties is greater so the difference will be greater.
In addition, the Gregory-Aziz-Mandhane correlation method (horizontal pipes only) is being used in the Aspen HYSYS Pipe Sizing Utility while in the pipe segment you have the option to select other methods.
Keywords: Pressure drop, Pipe Sizing Utility, Pipe segment
References: None |
Problem Statement: How to model a reverse flow from a refinery to a terminal and why do I obtain Warnings W1086? | Solution: When modeling a reverse flow in APS you will obtain Warning W1086, this is because if a batch is pushed out in reverse direction if you are working with Long Pipelines, APS will report it as a warning.
There are 2 possible ways to resolve this issue, you can either use Short Pipelines or you can use a Destination Change Event for all the batches that are not going to their original direction.
If you want to use Short Pipelines, you can just set up in the dialog box he destination tank as in the following event
If you want to continue to use Long Pipelines you will require to use a Destination Change Event for the batches that are not going to their original intended destination. In Long Pipelines, the batches know where are supposed to go, for example Destination Tank A in Destination A. So if you want to change the destination to a location in this case Destination “ Source”, you need to specify this to the batches that are going back.
To use a destination Change Event:
From the Event interface, click Events | Add Event | Pipeline Fill Destination Change. Alternatively, click from the toolbar drop-down, or, double-click on the event you wish to view or edit. Then fill all the required information with the desired Destination for the Tank:
Keywords: None
References: None |
Problem Statement: How do I change the icon of an extension in the Model Palette? | Solution: When registering a new extension, it will be available on the Model Palette under External Model shown as a general extension icon.
With several extensions registered it may difficult to identify each one of them if the icon is the same. However, you can customize the icons and update the view by following these steps:
Save the new icon as *.ico or *.png format in the extension's folder
The default path for the extensions is: C:\Program Files (x86)\AspenTech\Aspen HYSYS Vxx.x\Extensions
Rename the icon file to the same name as *.dll and *.edf files
Open Aspen HYSYS and verify that the icon in the Model Palette has been changed.
Keywords: extension, icon, Model Palette, customize
References: None |
Problem Statement: I have written scripts using run and pause commands separately in each, but the task calling them fails to be executed. Why? | Solution: The ‘Application.Simulation.Run’ and ‘Application.Simulation.Pause’ commands cannot work together in the same task.
Hence, if the user only wants the simulation to run dynamically for a small amount of time and then give control back to the script, then the simulation.step command (‘Application.Simulation.Step’) can be used which will only increment the dynamic simulation by one time step.
Keywords: Task, Scripts, Commands, Application, Simulation, Run, Pause, Step.
References: None |
Problem Statement: Can I delete a Property Bias that have factor and constant values equal zero without having an impact on my model results? | Solution: Can I delete a Property Bias that have factor and constant values equal zero without having an impact on my model results?
A Property Bias is a value added to (positive) or subtracted from (negative) a property value. You can add a property bias to Products and Units
If the original bias setup has both factor and constant as zero. That means no matter what value it was in the simulation for this property, the biased number is always zero.
Now you have removed these bias setting, in other words the calculated property has no bias calculation applied at all, and should be whatever the number from the simulation
Therefore, there should be no impact on your model results if you erase Property Bias that have both factor and constant values equal to zero.
Keywords: None
References: None |
Problem Statement: Where can we give layer pattern in Aspen Plate Fin Exchanger Program? | Solution: We can provide the layer pattern in Exchanger Geometry>General > Layer Pattern.
Layer pattern can be specified as
–A BABABA C BABABA C BABABA C BABABABABABA C BABABA CB
–or
–A (BA*3) C (BA*3) C (BA*6) C (BA*3) C B
Keywords: Layer Pattern
References: None |
Problem Statement: Is it possible to model dual flow trays in Aspen HYSYS i.e sieve tray without a downcomer/weir? | Solution: Currently, dual flow trays i.e sieve tray without a downcomer/weir cannot be modeled in Aspen HYSYS.
If the user has plant data, he/she can tune some of the parameters such as aeration factor multiplier, system factor etc. to match their data. We will support dual flow trays in the future versions.
Keywords: Column Internals, Dual Flow Trays, sieve tray without a downcomer/weir, V9.0, V10.0
References: None |
Problem Statement: This | Solution: provides examples on how to execute stored procedures from a MSSQL Server using Aspen SQLplus and possibilities on how to retrieve the result.
Solution
EXEC and EXECUTE statement are used to execute queries on remote database, EXEC command will also return the return set. Since these commands can execute queries that can be specific to the particular database syntax, it is possible use them to run a store procedure saved on MSSQLServer with the same syntax as used on that application. In this case, the general syntax is as follow:
EXEC ‘[<MSSQL Database>].[MSSQL schema].[MSSQL stored procedure] ’ on <SQlplus link>
For example:
Here, MSSQL_Link is a SQLplus link to MSSQL Server created following instructions onSolution 116533.
If the store procedure has parameters, the syntax is as follow:
EXEC ‘[<MSSQL Database>].[MSSQL schema].[MSSQL stored procedure]@<parameter name> = <parameter value> ’ on <SQlplus link>
For example:
The EXEC command will retrieve all columns from the result set of the stored procedure. There is no other ways using SQLplus syntax to retrieve selective column result from a MSSQL stored procedure, however, it is possible to represent the whole result of the stored procedure as a VIEW on MSSQL server and read only specific columns from the view on SQLplus, for example:
To create a VIEW of the stored procedure:
Here, “10.36.48.202” is MSSQL Server link object pointing to same server, so that, the stored procedure is create on the selected database with the whole result set of the stored procedure. Then on Aspen SQLplus you just need to point a query to read specific columns form the view:
Keywords: MSSQL Server
Stored procedures
Aspen SQLplus
References: None |
Problem Statement: Why does my Object Palette only show some unit ops and not all as I've seen in the documentation? | Solution: The cause of this is that you are not in the Main Flowsheet, and you are currently in sub-flowsheet environment such as Column Environment, or Sulsim environment. To go back to the Main Flowsheet environment, you can click on Flowsheet/Modify tab > Go to Parent.
If this option is greyed out, it is likely that the Main Flowsheet is already opened in a tab. You can go back to the Main Flowsheet by opening that tab.
Keywords: None
References: None |
Problem Statement: Is it possible to make Standard Basis information from a single scenario available for use in all scenarios? | Solution: Follow the steps below to make the basis information from a single scenario available as a library item for all projects.
Open the scenario containing the modified standard basis information in Aspen Icarus.
Use Windows Explorer to browse to the following location, \Program Files(x86)\AspenTech\Economic Evaluation VX.X\ic_cache\Projects\<Project Name>. This directory is the location to which the contents of the .izp and .szp compressed files are unpacked when a scenario is open in Aspen Icarus.
In this folder find the five files named STD.d01 - STD.d05. This files contain the standard basis information for the project.
Copy these five files to the location of the Basis for Capital Costs Library. The default locations for the libraries are \Program Files(x86)\AspenTech\Economic Evaluation VX.X\StdBasis_<Application_Name>\ip (for inch-pound projects) and \Program Files(x86)\AspenTech\Economic Evaluation VX.X\StdBasis_<Application_Name>\met (for metric projects). Application name depends on the estimate type accessed, Econ_Project for Capital Cost and Econ_Process for Process Economic Analyzer.
You can confirm the location of the Basis for Capital Costs directory by going to the Libraries tab in the Palette View, expanding the Basis for Capital Costs folder, and clicking on the appropriate units of measure (Inch-Pound or Metric). The exact directory path will appear in the Properties Window.
Rename of the STD.d01 - d05 files file to give them appropriate names. Each of the names before the extensions must be the same. The extensions must remain .d01 - .d05. For example, the following five files would create a single basis with the name COMPANYSPECS.
COMPANYSPECS.d01
COMPANYSPECS.d02
COMPANYSPECS.d03
COMPANYSPECS.d04
COMPANYSPECS.d05
Create a new scenario or open an existing one in Aspen Icarus.
Go to the Project Basis View tab in the scenario and right click on the entry for Basis for Capital Costs. You can then select the renamed basis that was placed in the library location.
Keywords: base, basis, location, specifications, library
References: None |
Problem Statement: This article describes in details about the steps to put a query record under automatic schedule, in Aspen InfoPlus 21. | Solution: The primary requirement to automatically schedule a query is, to save the query in form of record in the InfoPlus21 database.
1. Save the query in form of record, in IP21 database.
In the below example, the query name is Query1 and is saved under QueryDef.
2. Initially the record status will be inactive as we have yet not activated it.
3. Increase the value for #OUTPUT_LINES, anticipating how many lines required for saving the result of this query.
4. Increase the value for #SCHEDULE_TIMES to 1. This will allow us to enter 1 automated schedule for this query. Example shown below:
5. Navigate to the #SCHEDULE_TIMES, either by double clicking on the fixed area field or by going through repeat area section on left hand side pane.
6. Specify the schedule time as a future time from now. This will be the time you want record to be activated for the first time.
7. Specify the reschedule interval. This section is to mention the interval of execution. Example shown below, with 10 sec as reschedule interval.
8. For activating the record, come back to fixed area section and select YES in drop down for fixed area field called “EXECUTE”. Selecting YES and press enter will execute the record. The result will still show NO, which is ok.
9. LAST_EXECUTED field should show most recent timestamp and also ensure that the query is getting executed automatically after the reschedule interval is crossed.
Keywords: Automatic schedule
SQL plus query
IP21 query record
Query def
References: None |
Problem Statement: What does level number indicate in PSCP Xpress Optimizer message? | Solution: PSCP will log a message in the execution log every time a text line is output by the Xpress Optimizer. The level number returned to the execution log indicates the type of output message:
1 information messages;
2 not used in execution log;
3 warning messages;
4 error messages.
Keywords: None
References: None |
Problem Statement: When using the Scale Up function, I get an error message stating that the Batch Size for the Step could not be calculated or is zero. How do I fix it? | Solution: First make sure that you have correctly specified the Key Output Intermediate for the Step. By default this is listed as Nitrogen.
To change this:
Click the Information button on the Process Explorer.
Change the Key Output Intermediate to whatever your key product in this Step is.
Make sure that your Step is actually producing a non-zero amount of this Key Output Intermediate.
Keywords: Scaleup, Intermediate
References: None |
Problem Statement: How do I increase the accuracy of my gas_bed adsorption model? | Solution: The gas_bed dynamic model is spatially discretized. Increasing the number of discretization points can increase the accuracy of theSolution. Open the bed’s configure form and then the configure form for each layer. The number of nodes is under the general tab of each layer’s configure form. The default value is 20 nodes.
Be aware that increasing the number of nodes will slow the simulation. A balance exists between the number of nodes and the accuracy.
Keywords: Adsorption, accuracy
References: None |
Problem Statement: The desired product is not produced in my Step. The problem occurs in a React Operation. Why is my reaction not producing any product? | Solution: The problem may be that the reactant pure components do not exist in the same phase that is defined in the Reaction. Check that components that should occur in the liquid phase have been dissolved in a Charge or Heat operation or that the material was added to the process using the correct phase.
You can use Quick Results for each Operation to see the amounts in each phase. Check that the phases have been correctly defined in the Reaction Stoichiometry dialog.
Keywords: Reaction, Desired product
References: None |
Problem Statement: The Aspen PIMS Execution Log shows different information when using PIMS AO (Advanced Optimization), versus PIMS DR (Distributive Recursion). The convergence criteria is also different in the two technologies.
A description of the main items in the Execution Log and the differences is included here. | Solution: Execution Log with DR
An excerpt of the Execution Log using DR shows the following information:
Convergence Criterias with DR
When DR is used, PIMS converges on one or two criterias:
1) Properties
a. Changes to property values between recursion passes must be smaller to either ATOL or RTOL (defined in Models Settings | Recursion | Tolerances) for a property to be converged,
b. For the model to be converged, all properties must be converged (or as the message shows, 0 properties not within convergence tolerance).
2) Error Distributions
a. Changes to error distribution coefficients between recursion passes must be smaller than DTOL (defined in Models Settings | Recursion | Tolerances).
b. This convergence criteria is optional and can be enforced by checking the FCONVDST setting in Model Settings | Recursion | Tolerances.
Execution Log with PIMS AO
The Execution Log shows the following main information:
Convergence Criteria with AO
When the XSLP solver is used, PIMS converges on two criterias:
1) Residual Convergence Tolerance
a. Set in the XSLP Tolerances Setting page (Model Settings | XSLP | Tolerances). Default value is 1e-005.
b. Defined as the maximum residual scaled by the marginal value plus any infeasibility. In other words, this is the tolerance for summation of all the scaled error vectors.
c. Must be met to stop iterations.
2) Objective Convergence Tolerance
a. Set in the XSLP Tolerances Setting page (Model Settings | XSLP | Tolerances). Default value is 0.001.
b. Defined as (Current Objective Function ? Previous Objective Function) / Previous Objective Function.
c. Can be relaxed after the trust region is activated (optional).
Note: The Variable Convergence Function value is not used as a convergence criteria
a. Not controlled internally as a convergence criteria, and there is no setting to control it.
b. Defined as the maximum of (Current - Previous)/Previous for all nonlinear variables.
c. Displayed in the Execution Log.
A description of all items in the Execution Log can be found below:
Statistic Description Comment
Major Iteration Major Iteration Number Each Major Iteration typically involves solving a single LP. The smaller the value the better.
Variable Convergence Function Differences Between the Current and Previous Variable Values Indicates the degree to which the variables are changing.
Note: This value is not used as a convergence criteria.
The smaller the value the better; although, it is not critical for optimumSolution.
Residual Convergence Function Nonlinear Equations at the Optimum Indicates the degree to which the nonlinear constraints are satisfied.
Note: This value must be lower than the tolerance specified in the XSLP Tolerances settings.
The smaller the value the better.
Objective Convergence Function Potential for Improvement of the Objective Function at the Optimum Note: This value must be lower than the tolerance specified in the XSLP Tolerances settings.
The smaller the value the better; although, it is not critical for optimumSolution.
Objective Function Value Objective Function Value The user-specified quantitative measure of the plan. This is usually a monetary value. The higher the value the better.
Non Linearity Ratio Measure of Nonlinearity The closer the value is to one (1) the better. This value is not used to determine an optimalSolution, but it is an indicator.
Time Time Stamp The current time.
Keywords: Execution Log
Convergence Criteria
XSLP
DR
Tolerances
References: None |
Problem Statement: When activating an SQLplus script (named “calc_something” in this example) that itself is calling another stored procedure record (named “debug_write” in this example), the following error message is observed:
Expecting FUNCTION or PROCEDURE, found end of file
at line 1, record: debug_write
Running the query using Aspen SQlplus Query Writer results in the following error dialog box:
Oddly, you may find that the error does not occur when debugging the script in the Aspen SQLplus Query Writer by stepping into the code using the menu option Debug | Step Into (F8). In fact, it successfully steps into the script for the debug_write record itself.
What is happening here and how can it be resolved? | Solution: For a SQLplus script that calls another stored procedure or compressed query, when debugging using the Step Into option (F8 function key), the SQlplus Query Writer will open the appropriate sql text file found in the $COMPRESS_SOURCE folder.
Typically, $COMPRESS_SOURCE folder resolves to: C:\ProgramData\AspenTech\InfoPlus.21\db21\group200\sql
Alternatively, if you choose to activate the query or Run the query in the Query Writer (F5 function key), the encrypted code stored in the #QUERY_LINES repeat area of the ProcedureDef/CompQueryDef is processed.
The error message is displayed if the #QUERY_LINES repeat area sizing field is zero.
To repair the #QUERY_LINES, use SQlplus Query Writer to open the record mentioned in the error and simply save it (Record | Save). The #QUERY_LINES consequently get rebuilt, refresh the Aspen InfoPlus.21 Administrator and you will see that the #QUERY_LINES sizing field is no longer zero.
Keywords: development
warning
References: None |
Problem Statement: What should I check when my column complains of finding two liquid phases on one of the stages? | Solution: The normal HYSYS columnSolution algorithms cannot rigorously handle two liquid phases on the column trays.
If you have a steam stripped hydrocarbon column where the second liquid phase is water and it is forming on the top stages of the column, you may be able to add a water draw to the stages to remove the second liquid phase.
In order to rigorously solve a distillation column which truly has multiple liquid phases, the only solver which supports this is the Sparse Continuation Solver. You can enable this on the Parameters tab | Solver page in the Solving Method box. There is also the Two Liquids Check Based On option which allows you to specify a check for two liquid phases in the column.
Then go to the Parameters tab | 2/3 Phase page and enable two phase checking on the trays where two phases were reported. The 2nd Liquid type radio button determines whether the solver checks only for pure water as the second phase (Pure), or any kind of liquid (Rigorous).
Note: The Sparse Continuation Solver can take considerably longer than the normal HYSYS solvers to converge the column.
Keywords: Column, two liquid phases, Sparse Continuation Solver, 2nd Liquid type, Pure, Rigorous
References: None |
Problem Statement: The drawings from Aspen Shell and Tube Mechanical don’t match the drawings from Aspen Shell and Tube Thermal program | Solution: The thermal program has a layout written by HTFS. The mechanical program has a layout written by BJAC. These are two different programs coming from past software. Consequently, these layouts will always be different.
If the geometry is identical, you should select the most appropriate layout.
When the data is transferred from thermal to mechanical, the mechanical program has all input parameters related to the tube layout greyed out. This means the mechanical program is using the thermal layout created by the thermal program ‘as is’:
If you change to ‘Create a new layout’, then there are two options from the mechanical program, the thermal layout (HTFS) or the mechanical layout (B‐JAC):
The thermal layout from mechanical uses a separate program but identical to the thermal program except that all the inputs come from the mechanical side. This means that if the inputs are slightly different, the layouts will be slightly different.
The layout from All drawings is always the mechanical (B‐JAC) layout.
Keywords: Layout, drawings, thermal, mechanical
References: None |
Problem Statement: Sometimes, the administrator of the Aspen InfoPlus.21 database may have a need to start the database without starting the History Repositories.
For example,
1. They may want to make some configuration changes to the Repositories or History Filesets.
2. Another possibility is that problems with History prevents the database from starting, and troubleshooting is required.
3. A third possibility might be that initial database configuration is being performed and there either is no existing history, or what is there is actually invalid.
The first two possibilities above would actually require a slightly different | Solution: than for the third possibility.
Solution
1. To bring up the Aspen InfoPlus.21 database without History, and allow somebody to view and or modify the History configuration, the administrator should manually start very selective tasks only!
NOTE: By manually starting a task we mean that one would double-click on the task in the top left corner of the Aspen InfoPlus.21 Manager (Defined Tasks), and then single click on the RUN TASK button in the middle left of the Manager display.
Assuming that all tasks have been shut-down in the Aspen InfoPlus.21 Manager:
a) First manually start TSK_DBCLOCK
b) Next manually start TSK_H21T
c) Next manually start TSK_ADMIN_SERVER
'Optionally' manually start TSK_SQL_SERVER if the Aspen SQLPlus Query Writer will be required.
'Optionally' manually start TSK_SAVE if you expect to make changes to database records or database record security.
The Aspen InfoPlus.21 Administrator, can now be started. All sections related to the database can be viewed, including the Historian section, but the Repositories will show Red (not started). Changes can be made to such as the History Configuration.
d) Finally, from the Aspen InfoPlus.21 Manager, click on the STOP InfoPlus.21 button. The database will shut-down and any history configuration changes will be saved to the Config.Dat file.
NOTE: if TSK_SAVE was also started then a new snapshot will also be saved.
Subsequent restarting of the database in the normal way will now recognize any changes that have been made.
2. To bring up the Aspen InfoPlus.21 database without History, but ALSO disallow any viewing or modifications of the History configuration, as per the third possibility above, the procedure is almost the same as (1) above, but with the following two changes
a) Add the NOHIS switch to TSK_DBCLOCK before starting
b) Do NOT start TSK_H21T
In other words :-
Assuming that all tasks have been shut-down in the Aspen InfoPlus.21 Manager..
1. First manually start TSK_DBCLOCK (including the NOHIS switch)
2. Next manually start TSK_ADMIN_SERVER
'Optionally' manually start TSK_SQL_SERVER if the Aspen SQLPlus Query Writer will be required.
'Optionally' manually start TSK_SAVE if you expect to make changes to database records or database record security.
3. The Aspen InfoPlus.21 Administrator, can now be started. All sections related to the database can be viewed and modified with the EXCEPTION of the Historian section.
4. Finally, from the Aspen InfoPlus.21 Manager, click on the STOP InfoPlus.21 button. The database will shut-down. Note that if TSK_SAVE was also started then a new snapshot will be saved on shutdown.
NOTE: Remember to remove the NOHIS switch and updated the TSK_DBCLOCK parameters, before trying to start all the tasks in the normal way.
Keywords: NOHIS
Without History
IP21 start no history
References: None |
Problem Statement: How can I get oxygen and nitrogen to appear in my Excel material balance report? | Solution: Click the Tools | Options | Excel Reports tab.
On the Step Material Balance list, click the last option: With Vent Streams, With Gas Phase Streams in by Stream, as shown below.
Keywords: Excel report, material balance
References: None |
Problem Statement: How do I bring in equipment from another project into an Aspen Batch Process Developer simulation? | Solution: Navigate to the folder in which source project file is present. Notice file <Projectname>.eqm available in the same folder. This file is created when you save an Aspen Batch Process Developer project.
In the target project file, on the Main Menu, click Data | NetworkSelect | Equipment
Browse the directories to select the equipment file for current project (<Projectname>.eqm)
From the Bring Equipment to drop down list, select the facility to bring this Equipment to. The equipment in this file appears in the Source Equipment list.
You can now select which items you want to move into the simulation.
Keywords: Parallel, ABPD
References: None |
Problem Statement: How is the heat duty calculated in the Dry and Air-Dry operations? | Solution: For the Dry operation, the heat duty of the utility is calculated based on the heat of vaporization and temperature change in the vessel contents.
The heat duty for Air Dry is calculated based on the drying gas flowrate (either user specified or an Aspen Batch Process Developer default value), and the temperature change in the drying gas (user specification). The heat duty does not take into account the heat of vaporization and temperature change in the vessel contents.
Keywords: Dry, Duty
References: None |
Problem Statement: Simulation failed during a dynamic run at 0 hours, and now it no longer can initialize. How to fix the problem? | Solution: This can happen if you do not rewind to your initial conditions before trying a dynamic run again. Even if a dynamic run fails at 0 hours, the solver has already changed variable values. It is necessary to revert back to correct initial values before trying another dynamic run.
Keywords: Adsorption, rewind, initialization
References: None |
Problem Statement: What to do if dynamic run fails at time t = 0? | Solution: Accurate initial conditions are crucial to successfully start a dynamic simulation.
Were the compositions of connected units initialized to be the same? For example, a bed, and its tank voids might have different default initial compositions from the corresponding bed boundary conditions, which is not physically realistic. Make sure initial compositions of connected units are close, and make sure all initial compositions are realistic.
Also double check the units of any input, the parameter values for bed layers, the isotherm parameters, parameters relating to bed geometry, particle radius, and mass transfer coefficient. These parameters are crucial to a physically realistic simulation, but errors often occur while entering them.
Keywords: Adsorption, convergence
References: None |
Problem Statement: How can I make changes to Aspen Online exported files (tags and variables) using Excel? | Solution: In Aspen Online, users may need to do make changes to a large number of variables or tags. You can accomplish this task by following these steps in Microsoft Excel:
Opening the Aspen Online Exported file in Excel
Export the variables or tags text file in Aspen Online using the normal methods. If unfamiliar with this, please check the Aspen Online documentation.
Open Excel, and browse to the location where the exported text file is saved. In the “Open” dialog, be sure to select “*.prn; *txt; *.csv” file type.
Select the text file and a dialog will pop up
Click the “Next” button
In the next popup, uncheck “Tab” and check “Semicolon”. In some versions of AOL, the delimiter is not a semicolon. In that case, in this step, make sure to check the correct delimiter.
Click “Finish”.
Importing the .csv file into Aspen OnLine
After making changes, save the file as a CSV file. Follow the following steps to import this file into Aspen OnLine.
Open the newly saved .csv file, preferably using Notepad.
Open the original exported file (i.e. the file exported from Aspen OnLine before the changes) also in Notepad.
Replace the top three lines in the .csv file with the top three lines in the original file. Refer to the diagram below for reference.
.csv file top three lines
Original file top three lines
Change “Delimiter=;”, shown above, to “Delimiter=,” in the .csv file.
5.
Keywords: Excel
Aspen Online
export
import
References: None |
Problem Statement: This article explains how to solve: Xpress licensing error 1: The license file (C:\Program Files(x86)\AspenTech\Aspen PIMS\xpauth.xpr) could not be read. No such file or directory. Please ensure you have installed it according to the instructions in the FICO Xpress READMEs.
This error indicates xpauth.xpr file is missing from the Aspen PIMS folder. | Solution: The error message appears when xpauth.xpr is missing from the Aspen PIMS folder.
Go to C:\Program Files(x86)\AspenTech\Aspen PIMS and verify xpauth.xpr file is there.
If the file is missing, you can request it from AspenTech’s Support Center but problem might persist if other files are missing.
To solve the issue you will have to do a software re-installation. If you do not have the installation media you can submit a media request through the Support Center.
To avoid having this issue in the future, it is highly recommended NOT to alter or delete any of the AspenTech’s files. Each file has a specific function that will impede the software from running properly if missing.
Keywords: PimsWin, xpauth
References: None |
Problem Statement: How OBJFN values are calculated in PPIMS model using Distributive Recursion (not PIMS-AO) | Solution: In PPIMS model that is not using PIMS-AO, the OBJFN value is calculated in following method:
OBJFN = Sp(LENp * OBJFNp)
LENp represents the length of each period.
OBJFNp represents the objective function value of each period.
For example, in the 3-period PVOLSAMP sample model:
OBJFN = 31*OBJFN001 + 28*OBJFN002 + 31*OBJFN003
The Objective Function for period p (where p is any period except the last) is calculated as follows:
Where:
The Objective Function for the last period (period n) is calculated as follows:
Where:
Keywords: None
References: None |
Problem Statement: Why I cannot change the elevation on the pipelines in BLOWDOWN? | Solution: The only pipe that you can change the elevation value in BLOWDOWN is on the tailpipe boundary. This is because the pressure drop is only calculated on this pipe. There is no pressure drop calculation in any other pipe.
Keywords: Pipe, BLOWDOWN, elevation
References: None |
Problem Statement: How can I automate splitting events in APS, as part of event reconciliation? | Solution: To do this, there is an automation call named SplitEvent(). This call requires the Event ID and the split time to be passed as inputs. The user can gather the required unit operation event IDs from event automation and then split each of them using the above call.
Attached is a sample model that illustrates the above concept, and it can be elaborated as per the user’s requirement. The model archived is the demo model and the VBA module that contains this code is named “SplitEvent”
The code takes the following input from the worksheet named “SplitEvent”
The code will search for unit operation events that exist between the start/stop dates inclusive (6/1/2011 – 6/4/2011) , but end after the stop date (6/4/2011), and then split them.
The “When to split” section has the date when the events found will be split.
Additional search criteria is added as VBA code comments to filter out events of a specific unit (E.g “VT1”), but as mentioned, the user could customize the code to add/remove more filters for the events that they would like to see.
Keywords: None
References: None |
Problem Statement: Vessel pressure is increasing unexpectedly. What could be the cause? | Solution: If the pressure is increasing through the Charge or other operations, first check the Run History under Notepad Results for operations occurring earlier in the recipe to see if the vent on a vessel was closed as part of an operation.
For example, the vent on a vessel is closed if a blanket of gas is specified on the Optional form of the Purge operation.
Also check for an Open-Close vent operation in the recipe.
The following operations will possibly change the vent status from open to close:
Vacuum or pressurized Distill, Concentrate, React-Distill, Reflux-Through-Dean-And-Stark, and Continuous Distill
Pressure Transfer
Pressurize, Evacuate
Keywords: Vessel, pressure
References: None |
Problem Statement: Is there a way to dynamically modify the Pipe connectivity through VSTA? | Solution: You can use the Connect Pipe function to dynamically modify the pipe connectivity: ConnectPipe(Pipe ID, From, To)
This function allows you to dynamically change the From element and the To element for pipes.
Parameter(s) Type
Description
Notes
Pipe ID Integer User-specified pipe Must exist in the flow diagram.
From String
Pipe's starting point
Must exist in the flow diagram. Specify by using the element's enumeration character and its ID number. For example, a unit with an ID of 2 would be specified as u2.
To String Pipe's ending point Must exist in the flow diagram. Specify by using the element's enumeration character and its ID number. For example, a tank with an ID of 3 would be specified as t3.
Key words
ConnnectPipe
Keywords: None
References: None |
Problem Statement: Is there a way to turn off/hide the pipe labels? | Solution: Starting from V10 CP5, the show diagram connection labels option in the User Settings menu can be used to toggle on/off the pipe labels.
Key words
pipe labels
Keywords: None
References: None |
Problem Statement: This | Solution: describes the recommended method for preparing time-series historian data for import into Aspen Mtell using the “CSV Imported Tags” historian option.Solution
Aspen Mtell’s “CSV Imported Tags” Plant Historian option expects the data file in the format of one reading per row, with the tag name, tag value, tag timestamp, and optionally, the tag description, all separated by commas. This can be achieved by outputting these values in a flat file by separating the different readings with commas or by saving a Microsoft Excel spreadsheet using the “Save As” option to save the spreadsheet as a csv file.
The file is required to have a single row of headers indicating the purpose of each of the columns in the csv file. The column names do not matter as long as 1) the user is able to distinguish which columns should be assigned to “Sensor Name”, “Value”, “Value Date”, and “Sensor Description” and 2) the same column names are used if multiple csv files are to be imported across the same file format (see below on explanation of file formats).
To import csv files into Aspen Mtell, a new csv historian must be defined using the “Add Data Source” button in the ribbon from the “Sensor Data Sources” option under the “Configuration” tab in the Aspen Mtell System Manager. Once the historian name is defined, select the “Plant Historian” from the Source field and “CSV Imported Tags” from the Historian field. Click on the “File Formats” button and create a new csv file format name. You may create many different csv file formats if there are many different header formats for the csv data files being imported. Select one of the csv data files that fit the desired format and Aspen Mtell will begin to parse the first row of the csv file for available headers. Once this is done, match the correct header to the correct field and click next. If this is the only csv file with this format, check the “Import CSV File” checkbox before clicking “Finish”; otherwise, click “Finish” and select the option to “Import Files” from the Aspen Mtell System Manager.
In the new pop-up box, click the “Select Files” button and select as many csv files as desired for import. Once they are all selected, click the “Import” button to begin the import process. Once all the files have a green checkbox on the right, the csv import has been completed.
Keywords: Import CSV historian
References: None |
Problem Statement: How can I ensure that I don’t overfill a reactor (or underfill it below the minimum stir volume for operations that may require agitation, such as reactions)? | Solution: First, make sure that you have specified a Maximum Fill Factor and/or Minimum Stir Volume for appropriate pieces of equipment in your equipment database. In order to check whether you are meeting the Min/Max requirements, you can take the following actions.
Generate the Equipment Contents Excel report by clicking Results | Excel Reports | Equipment Contents. This shows you:
The volume in your equipment vs. time.
The minimum and maximum volumes for that equipment.
Generate the Equipment Capacity Excel report (Results | Excel Reports | Equipment Capacity) or the Excel Executive Summary (Results | Excel Reports | Executive Summary). These reports show you the maximum size utilization over the course of the batch for each equipment item.
Click Tools | Options | Simulation Batch tab. Make sure that the Check Overflow of Equipment Units option is selected. If you are interested in checking to see whether minimum stir volumes are met for certain operations, make sure that the Check Underflow of Equipment Units option is selected on the Simulation Batch tab as well. You can also specify which types of operations you want Aspen Batch Process Developer to check for minimum stir volumes on the Minimum Batch Size Calculation tab. This will ensure that notices about overfilling or underfilling equipment will appear in the Quick Results and Run History reports.
Keywords: Overfill, Underfill, Reactor
References: None |
Problem Statement: I specified Comments or Ranges in my Aspen Batch Process Developer Operation, but they do not appear in the text recipe. Why? | Solution: You need to specify which (if any) Comment types or Range types will appear in the text recipe.
To specify comment types to display on Text Recipe view:
Click Tools | Options | Text Recipe tab.
Click Comments in the Text Recipe view.
On the Comments drop down list, click the types of comments you want to have displayed in the Recipe Text.
Click OK.
To specify range types to display on Text Recipe view:
Click Tools | Options | Text Recipe tab.
Click Ranges in the Text Recipe view.
On the Ranges list, click the ranges you want to have displayed in the Recipe Text.
Click OK.
Keywords: Comments, ranges
References: None |
Problem Statement: Are binary interaction parameters (BIPs) estimated when pseudocomponents are generated from assays? From documentation, it is stated that there are API methods available for estimating RKSKBV. However, when I go to Methods | Parameters | Binary Interaction | RKSKBV-1, I don’t see any value for the pseudopomponent pairs. | Solution: Aspen Plus does not display all the property parameters on the parameters form, so first we need to go the Home Ribbon and select Tools | Retrieve Parameters. After that, the RKSKBV parameters will be available under Methods | Parameters | Results | Binary Interaction | T-Dependent. See example attached.
Please note the RKS binary interaction parameters (RKSKBV) are estimated for each pseudocomponent in pairs with only certain light gases which are present in the simulation:
API 1978 (3rd Ed): By default, the ASPEN method is used in estimating parameters of pseudocomponents. In this method, RKS binary interaction parameters for the light gases, CO2, CO, H2S and N2, with pseudocomponents are estimated using the API 1978 (3rd edition) method, which is a function of solubility parameter
API 1987 (5th Ed): There is a second method for estimating the RKS binary parameters which is based on the API 1987(5th edition). This method estimates the interaction parameters for CO2, H2S, N2, H2, CH4 and sets the CO value to zero. This correlation is also a function of the solubility parameter. Note that this method will only estimate RKSKBV of pseudocomponents-CH4 for pairs where the molecular weight of the pseudocomponents is equal to (or larger than) 140. If the molecular weight is less than 140, the RKSKBV value will be set to zero.
To select the characterization method API 5th Ed, go to Components | Petro Characterization | Selected Methods, and create a New method. Accept the default ID P-1. From P-1, chose a Base method and then go to the EOS tab and select it from RKS interaction parameters
In addition, go to Components | Petro Characterzation | Generation, and create a New object. On the Specifications sheet, select P-1 in the Pseudocomponent property options field.
You can also estimate the values for the NRTL and UNIQUAC pseudocomponent-water binary parameters. For additional details, see theSolution Is it possible to model Electrolyte Chemistry and Pseudocomponents? Are binary parameters generated?.
Keywords: Pseudocomponent, RKSKBV, RKS, Binary Interaction, Estimation, Characterization
References: None |
Problem Statement: Is General Foreman cost included in Direct Field Labor? | Solution: There is only one Foreman associated with each crew. General Foreman are not available in Direct Field Labor. There is no distinction made between General Foreman and Foreman. The Foreman is paid either a fixed rate or a percentage multiplier of the highest paid craft in each crew.
Keywords: Foreman, General Foreman, field, labor.
References: None |
Problem Statement: How do you enter limits for MIP (Mixed Integer Programming) variables in MPIMS?
For example, you might want to define the purchase of a stream as a semi-continuous variable (i.e. either buy zero, or buy more than a threshold value). This limit could be either at a specific plant, or for all the plants. | Solution: To enter MIP (Mixed Integer Programming) specifications in MPIMS, you need to use the global table MIP under the global model's Miscellaneous branch, and the global variable names as used in the matrix.
For example, to define the purchase of stream NC4 as a semi-continuous variable in ALL models, you need to define the following in global table MIP:
That is, the variable accessed is called PURCNC4.
However, if you want to define the purchase of stream NC4 as a semi-continuous variable in model A only, you need to define the following in global table MIP:
In this case, the variable that is accessed is called PURCNC4A.
To use MIP variables in XPIMS (multi plant, multi period model), please refer to the Help File for table MIP, X-PIMS Example of Table MIP.
Keywords: MIP
Mixed Integer Programming
LBD, UBD
References: None |
Problem Statement: How can I design the orifice size by using the blowdown analysis? | Solution: Design orifice size by using blowdown analysis requires to add the adjust block. We can add orifice diameter as the adjusted variable and blowdown vessel final pressure as the target variable. HYSYS will try to run blowdown analysis several iterations to find the adequate valve size for the target pressure.
User can use the example file in the installation folder as your reference (blowdown>designing and rating a blowdown valve.hsc)
Keywords: Blowdown, Sizing, Design Orifice
References: None |
Problem Statement: I transferred out 50% of my reactor contents with one Transfer Operation and the other 50% with a second Transfer Operation. However, I still have material in my reactor. Why? | Solution: If you intend to have two equal Transfers of product out of a reactor (each Transfer being half of the total reactor contents), you need to specify:
The first Transfer is for 50% of the reactor contents.
The second Transfer is for 100% of the reactor contents.
You must do this because these are sequential operations. Therefore, the second Transfer operation is based on whatever is left in the reactor after the first Transfer. So, you specify 100% to Transfer all of the remaining reactor contents.
Keywords: Transfer, React
References: None |
Problem Statement: How to model a reactor with a condenser? | Solution: The ‘React-Distill’ model can be used for modeling a reactor with condenser. It has both options – reaction and distillation. If you do not want to model distillation (separation), then you can change the parameters in the ‘Standard Separation’ tab accordingly and basically turn the separation characteristics off.
This model has a ‘Column condenser’ tab in the ‘3.Auxiliary Information’ tab.
Keywords: Reactor, Condenser
References: None |
Problem Statement: How can I implement constraints for stream transfers between local models in MPIMS? | Solution: The column naming convention for transfer streams in MPIMS is following:
TxxxABM: Transfer of Material xxx from source plant A to destination plant B via mode M
Therefore you need to identify your column names and introduce the new constraint via T.ROWS in the global model.
Please refer to below example:
Streams HYH, PGS, PYX are transferred from plant C to A via mode P. Total amount is limited up to 4 units/day
* TABLE
ROWS
Table of Contents
*
User Defined Rows
USER
THYHCAP
TPGSCAP
TPYXCAP
RHS
*
LTRANSF
1.00000
1.00000
1.00000
1.00000
4.00000
Please note that in MPIMS you need to use column USER with a non-blank entry to introduce new constraints.
The effect in the solved matrix is shown below
Keywords: MPIMS
Transfer
References: None |
Problem Statement: Report Wizard reports are created based on cached memory, not the published database. Only for comparison purpose, here we list database tables, which contains same category of data as those created from Report Wizard. | Solution: Report Wizard Sections Reported Information
Blending Information Blending events information
Same as Type 17 events in Table _EVENTS
Crude Consumed Crudes consumed in each crude unit on daily basis
Same as values in Table _CRDRUNS
Crude Inventory Crude tank inventory at each time stamp, which is snapshot value at midnight
Same as values in Table _TANKS
Crude Properties At each time stamp, crude vol%/property value of each crude tank
Snapshot at midnight. Same as values in Table _STRMS
Crude Receipt Total receipts for each crude on daily basis.
Same as Table _RECEIPTS
Crude Unit Consumption Total crudes consumption in each crude unit on daily basis
Same as Table _CRDRUN
Daily Stream Properties Stream property value
Daily average
Event Information Event Information: Xseq, Type ID, Start, Stop, Rate, Vol, ProdCode
Same as published data in Table _Events
Property Property value
Data for each time stamp is the snapshot at midnight
Unit Parameter Unit parameter value
It is snapshot value at midnight for the scheduled value in unit operation events.
Same as values in Table _PARAMS
Volume and Weight VOL/WGT values of STRM/TANK
It is snapshot value at midnight.
Keywords: None
References: None |
Problem Statement: What are the differences between simple staggering blowdown and rigorous staggering blowdown? | Solution: Users can use Blowdown Technology to model multiple blowdown valves release staggeringly. There are two approaches to achieve that.
Simple staggering blowdown: Simple Analysis generate the volume flow plot by adding each blowdown valve release curve together. The superimposed volumetric flow based on blowdown valve opening time may be conservative. Accumulation of fluid in flare headers downstream of Blowdown Valve is not modeled.
Rigorous staggering blowdown: Rigorous Analysis rebuilt the pipe connection for all the vessels and re-calculate the volume flow plot dynamically. User can convert the Simple Analysis to Rigorous Analysis to model the accumulation in flare headers with flow coming from multiple blowdown valves. This is the most accurate blowdown analysis for multiple valve blowdown analysis.
Keywords: simple staggering blowdown, rigorous staggering blowdown, multiple blowdown valves
References: None |
Problem Statement: This technical guide is intended to show the user how to develop custom Excel Spreadsheets for reporting results of a Dynamics model using Aspen Simulation Workbook. | Solution: This tutorial explains the use of several features in Aspen Simulation Workbook and how to take advantage of them to report and manipulate variables in a HYSYS Dynamics simulation.
The user will learn:
How to access Aspen Simulation Workbook
How to connect an Aspen HYSYS model to Aspen Simulation Workbook
How to add custom tables
How to create dynamics plots in Excel
How to include drop down menus in Excel to modify dynamics variables.
Keywords: Excel, ASW, Dynamics, Custom, Plots.
References: None |
Problem Statement: Why is the heat from the Fired Heater not changing with the air temperature? | Solution: At steady state, Aspen HYSYS Fired heater assumes that the process streams in the radiant zone are heated through combustion only, no other forms of heat transfer between fuel mixture and the process stream. Hence, the air temperature is not considered in the model to calculate the heat. The model only takes into account the combustion efficiency.
The heat of combustion at steady state is calculated as below (where xi is the molar fraction, H is molar enthalpy, F is molar flow rate):
Air and Fuel enter Fired heater and are mixed together. The mixture properties (P, T1, xi_1, H1, F1) are calculated through PH flash and mass/heat balance.
Then the mixture is assumed to react/burn at constant T1, the reaction products properties (P, T1, xi_2, H2, F2) are calculated through PT flash and reactions.
Next, the heat generated by reaction/combustion all is used to raise the temperature of products. The pseudo-final products properties (P, T3, xi_2, H3, F2) can be obtained with PH flash, where H3=H1*F1/F2.
The total heat combustion Q is then calculated from the difference of H3 and H2.
The amount of heat used to heat process stream depends on the combustion efficiency, eta. The value of eta*Q is assigned to heat radiant process stream, while the left one, (1-eta)*Q, is used to heat flue gas. Then do PH flash in these process streams and flue gas to obtain their final properties such as temperature.
When air temperature increases, the mixture temperature T1 goes up too, which results in H2 and H3 increase. If H3 doesn't increase much greater than H2, as a result, the total heat of combustion won’t change. That means with fixed combustion efficiency, the process stream got the same heat than before.
A case study can be used to vary the efficiency and see the increase in outlet temperature. To test how the air temperature affects process streams, you can specify flue gas temperature instead of efficiency. In this way, the amount of heat assigned to flue gas is fixed, all extra gain of heat from air/fuel goes to process streams.
Keywords: Efficiency, temperature, Fired heater
References: None |
Problem Statement: When I try running the Excel reports in Aspen Capital Cost Estimator (ACCE) I get the following error: Error#-2147319779 Method '~' of object '~' failed. What does this error mean and how can I get around it? | Solution: There are a number of possible causes for this error message:
1. ACCE was not installed by a user with administrator privileges.
2. Corrupted installation of Microsoft Office.
3. ActiveX is not enabled in Internet Explorer.
4. Microsoft Office security settings are set as High.
5. The scrrun.dll file has become corrupted or a wrong version of this file is installed
For cause 1. and 2:
The first thing to try is a re-registration of MS Office. Follow these steps for the re-register:
i) . Open C:\Windows\System32 directory from Windows Explorer and then run cmd.exe (Command Prompt) as administrator (right mouse click on cmd.exe and select Run As and select Administrator).
ii). Type following at the Command Prompt
For Windows XP:
C:\Program Files\Microsoft Office\Office14\Winword.exe /r
For Windows 7-64 bit with MS Office 2010 (32 bit):
C:\Program Files (x86)\Microsoft Office\Office14\Winword. exe /r
If the problem still exists then un-install Office and the Aspen Economic Evaluation (EE) Suite and re-install first Office and then ACCE. Make sure that you are logged in with an account that has Administrator rights when doing these installations and use the default paths for the installation folders.
If that doesn't solve the issue, check for cause 3. To do so follow the next steps:
i). From the Tools menu (the gear icon in IE) | Select Internet Options.
ii). Select the Security tab.
iii). Click Internet as the zone to change.
iv) Click Custom Level. The Security Settings - Internet Zone dialog box appears.
v). Scroll down to the options below Internet ActiveX Controls and Plugins and enable the following:
vi) Run ActiveX Controls and Plugins
vii) Script ActiveX Controls Marked Safe for Scripting
vii) Click OK to save your settings and exit the Internet ActiveX Controls and Plugins dialog box.
viii). Click OK to close the Internet Options dialog box.
If that doesn't solve the issue, then check the security settings for Excel, Cause 4. To do so follow the next steps:
i). Click the Microsoft Office Button, and then click Excel Options.
ii). Click Trust Center, click Trust Center Settings.
iii). Choose Enable all controls without restrictions and without prompting under ActiveX Settings
iv). Choose Enable all macros under Macro Settings.
If that still doesn't fix the problem with the reporter, then try re-registering the scrrun.dll file Cause 5. To do so follow the next steps:
Open a DOS command prompt (go to START - RUN, then type CMD and hit OK). Then change directories to c:\windows\system32, then type in regsvr32 scrun.dll and then hit enter.
Keywords: Icarus Reporter, Excel Reports, Error, MS Office.
References: None |
Problem Statement: What does the plate thickness in the LNG exchanger in Aspen HYSYS refer to? | Solution: The plate thickness refers to the plate that goes in between layers. This is the same to all the layers.
This is also called Parting Sheet. This is the value located in line 10 TEMA sheet.
Keywords: plate thickness, parting sheet
References: None |
Problem Statement: User experienced unusual slow performance to load and display Aspen Unified PIMS Web UI application. | Solution: This could occur when the user accesses the application under a Domain account with bad or slow network connection to Domain controller. By default, UnifiedPIMS settings are to use Windows Authentication (Negotiate/NTLM).
The recommendation is to switch to use Basic Authentication for such cases.
Configure UnifiedPIMS Authentication (IIS 7)
Close any previously opened browser sessions to UnifiedPIMS application
Open IIS Manager and navigate to Sites/Default Web Site/AspenTech and select AspenUnifiedPIMS application. For information about opening IIS Manager, see Open IIS Manager (IIS 7).
In Features View, double-click Authentication.
On the Authentication page, select Basic Authentication.
In the Actions pane, click Enable to use Basic authentication with the default settings.
On the Authentication page, select Windows Authentication.
In the Actions pane, click Disable
The changes will be in effect immediately. Open a new browser session to UnifiedPIMS and user will be prompted to provide credentials. The page load performance issue is expected to be resolved.
Keywords: None
References: None |
Problem Statement: How do I print the Phase Envelope plot? | Solution: In order to print the Phase Envelope plot:
Right-click on the plot and select the Print Setup.
From the Print Setup window, select the printer as Microsoft Print to PDF (you can select this or any other PDF generator software). When you finish, click OK.
Finally, right-click again on the graph and select Print Plot. The action will show up a new window with the Saving location.
The plot will be saved as pdf in the selected location.
Keywords: print, graphic, pdf, analysis, stream
References: None |
Problem Statement: How do I specify the diameter of a Tee block in Aspen Flare System Analyzer? | Solution: The size of a Tee operation in Aspen Flare System Analyzer (AFSA) is not directly specified inside the object form. Instead the tee will be able to use the same diameter as the pipes that are connected to it.
This is controlled by selecting the Body type of the Tee. There are four options available to configure the body size of this operation:
Run - The tee will use the same diameter as the inlet pipe (Red node)
Tail - The tee will use the same diameter as the outlet pipe (Blue node)
Branch - The tee will use the same diameter as the branch pipe (Pink node)
Auto - Flare System Analyzer will identify and set the largest diameter between the inlet and branch pipe diameters.
If the user finds a suspicious pressure drop across a tee, it is important to review that these objects have been configured to use the correct size that the user expects according to the legend described above.
Keywords: Run, Branch, Tail, Tee, T, Mixer, Size, Body, Diameter, Schedule
References: None |
Problem Statement: How PIMS sets up material balance rows in PPIMS model | Solution: In a PPIMS model that is not using PIMS-AO, material inventories need to be considered in the material balance calculations, and the material balance rows are setup for each of the periods, e.g. VBALp or WBALp
In general, the material balance rows are:
(Production)p + (Consumption)p – (Inventory)p-1 + (Inventory)p = 0
For the 1st period, VBALtag or WBALtag are:
– Prodtag1 – OpenInvtag1/LEN + Consumptiontag1 + CloseInvtag1/LEN = 0
Also, CloseInvtag1 = Targettag1 +IEXCtag1 – IDEFtag1
Then, -Prodtag1 – 1/LEN * IDEFtag1 + Consumptiontag1 + 1/LEN * IEXCtag1 = (OpenInvtag1 – Targettag1)/LEN
where, LEN – Length of that Period
IDEFtag = TARGET – CLOSE (Deficit from Target)
IEXCtag = CLOSE – TARGET (Excess from Target)
( Note only one of the two has activity at a time )
For pth period (except 1st), VBALtag or WBALtag are:
- Prodtagp – IDEFtagp/LEN + Consumptiontagp + IEXCtagp/LEN = (OpenInvtagp – Targettagp)/LEN
OpenInvtagp = CloseInvtagp-1 = Targettagp-1 +IEXCtagp-1 – IDEFtagp-1
Then,
- Prodtagp – 1/LEN * IDEFtagp + 1/LEN * IDEFtagp-1 + Consumptiontagp + 1/LEN * IEXCtagp – 1/LEN * IEXCtagp-1 = (Targettagp-1 – Targettagp)/LEN
Where:
IDEFtag = TARGET – CLOSE
IEXCtag = CLOSE – TARGET Only one of the two has activity at a time
Keywords: None
References: None |
Problem Statement: Why is the Acid Gas page not available inside a column when the Acid Gas Package is used in the simulation? | Solution: The Acid Gas page doesn't appear because Specify Efficiencies is checked (Parameters | Efficiencies). In this case, Aspen HYSYS will use the user-specified efficiencies and will not re-calculate the CO2, H2S efficiencies. After un checking Specify Efficiencies, the acid gas page will appear.
Keywords: Acid Gas, column, efficiencies
References: None |
Problem Statement: How MAXPASS1 setting will impact model performance in PIMS DR | Solution: MAXPASS1 setting is used to identify the maximum number of recursion passes allowed before invoking MIP constraints in the model. MIP constraints are entered in Table MIP, BLNMIP.
The default value of MAXPASS1 is set to be 10 and based on performance users can tune MAXPASS1 setting value to improve model performance.
If MAXPASS1 value is set to smaller value than the actual number of recursion pass to trigger MIP, it is possible to cause local optima issue or convergence issue as the constraint is too tight at first couple of recursion passes and it may impact the optimization path.
If the MAXPASS1 number is a large number, DR calls the MIPS algorithm immediately upon convergence for a single pass and then resume recursions with all the discrete variables fixed.
Keywords: None
References: None |
Problem Statement: Unit conversion of temperature difference values in EDR | Solution: EDR reports several temperature differences (e.g. Overall effective MTD, LMTD, one pass counterflow MTD).
Because these are “differences” and not “absolute” values, none of them follow the regular unit conversion rules. Any temperature reference will be ignored and only the multipliers will be accounted for.
For example, if converting a temperature difference between K and C units, temperature reference of +-273.15 will be ignored and only multiplier will be considered, which for this units is 1 (so the result of the conversion will be the same). The same case applies between F and R units.
Between F/R and C/K units, temperature references will be ignored too, and the multipler of 1.8 (or 1/1.8) will be applied.
Keywords: Temperature difference, MTD, units, EDR
References: None |
Problem Statement: What is the physical meaning of the Gradients reported for Pipe Segments under Performance | Profile? | Solution: The gradient results are evaluated per each increment in the pipe and represent loss in pressure per unit length between all these segments. The number of increments can be entered and controlled from the Rating | Sizing section of the Pipe Segment unit.
The definition of each gradient is the following:
Friction Gradient: Pressure loss per unit length [Pressure/Length] due to the effect of friction over the pipe increment.
Static Gradient: Pressure loss per unit length [Pressure/Length] due to gravity effects in the increment. Value will be 0 if there are no elevation changes in a specific segment of the pipe.
Accel Gradient: Pressure loss per unit length [Pressure/Length] due to density changes in the pipe fluid across the increment. Most relevant when phase change occurs inside the pipe segment or multi-phase flow is present in the increment. Value comes very close to 0 when single-phase flow is present in the segment.
The dP results shown next to each of these gradients represents the absolute pressure drop value on each increment due to the same effects mentioned above.
Keywords: Empty, Profiles, Pressure, Drop, Static, Acceleration, View
References: None |
Problem Statement: There are times when your flare system network may become too large to print in one single paper sheet and you may choose to print only small a section of it. This article describes how you can print a certain selection of your flowsheet in Aspen Flare System Analyzer. | Solution: Suppose you have a flowsheet similar to the one from the illustration below and would like to print only the part within the red box.
To print this selection, follow the steps described next:
1. Drag the mouse from a blank space within your flowsheet passing it over the objects you would like to include in your print selection. They should be marked as in the picture below. Tip: Adjust the zoom in the PFD to make the selection of the objects easier.
.
2. Once you have selected the objects to include, go to the Format Ribbon and change the dropdown list from All – Single Page to Selected.
3. Click now on the Print Preview button to check whether your selection is correct.
Note: in the Print Preview page| File | Page Setup you can configure the page format (margin, paper sheet, etc).
Keywords: Print; AFSA; Selection; Flowsheet;
References: None |
Problem Statement: What does the perforation percentage field in the LNG exchanger in Aspen HYSYS represent? | Solution: The perforation percentage is the percentage of perforation with respect to the total fin area. Hence, it cannot be 100%. In Aspen Exchanger Design and Rating, it is called porosity.
For perforated fins, Aspen Exchanger Design and Rating gives a rule of thumb value of 5%. This only applies to perforated fins. Serrated fins will have zero as perforation percentage.
Keywords: Perforation, LNG exchanger
References: None |
Problem Statement: This article explains what is 'Engineer Request' entry in PCWS control page. | Solution: Each variable in an Aspen APC controller has the concept of 'In Service' or 'Out of Service', it allows the variable to be turned OFF for the controller, but not at the DCS level.
'Engineer Request'is the service switch for an variable. It permits engineers to assign any of the following modes that determine whether the variable is included or excluded from the controller's influence on the plant.
It contains 3 options for Independent Variable:
0 (Off) Not included in controller calculations
1 (On) Included in controller calculations
2 (Prediction) Included in controller calculations for prediction only (Manipulated inputs only)
It contains at 2 options for Dependent Variable:
Controlled Variables:
0 (Off) Not included in controller calculations
1 (On) Included in controller calculations
If the service request of a variable is set to OFF, the variable is bad.
Keywords: Engineer Request
PCWS
entry
References: None |
Problem Statement: How can I solve a memory error in PSCP? | Solution: When facing a memory error in PSCP, we can try following methods to solve the problem:
1. Run PSCP on a 64-bit operating system with at least 4 GB of RAM. More RAM would improve performance but will not give PSCP more than 4 GB of virtual memory, which is a limitation for 32-bit applications. Users can also try to manually set the virtual memory page size following the instructions from Microsoft.
2. If possible, dedicate the machine to PSCP, so there won't be other resource demanding processes running at the same time.
3. If the model has many MIP variables, try to be very conservative with running the model using multiple threads. Try running the model with a single thread first, and if the performance is not satisfactory, use 2 threads. PSCP MIP parallel is controlled by XPRESS to ensure the sameSolutions are returned from each run, so the threads do not run in parallel all the time. More threads will introduce more overhead in thread synchronization, memory page fault, etc. All these factors can lead to a slower execution or even memory errors.
4. If the problem still exists, the mode is very likely a very difficult MIP. Try to tune the MIP search stop criteria such as nodes to explore, run time, and MIPSolution gap.
5. Alternatively, try to find a more favorable set of XPRESS control parameters to run the model: node selection, cut strategy, presolve, etc.
Keywords: None
References: None |
Problem Statement: Starting for V9.1 a new feature called Alerts has been released in AspenONE Process Explorer (A1PE). At a certain point customer could ask where the list of tags that they are subscribed is saved. This | Solution: explains it.
Solution
The AspenONE Process Explorer List of alerts that a user is subscribed to is saved in Aspen InfoPlus.21 database. A new family records was introduced in V9.1 called AlertUserDef.
The list of subscribed tags is by A1PE user and the record will be named in the same way as the user.
Keywords: A1Pe Alerts
AlertUserDef
References: None |
Problem Statement: How do I add a new utility inside Aspen HYSYS? | Solution: Energy streams in Aspen HYSYS can be mapped to a process utility, which can allow the user to calculate which would be the required mass flow of this utility. Mapping these utilities can also help to refine an Economic Estimate and Carbon Emission analyses.
The list of available utilities can be found by clicking under Home | Utility Manager.
In this menu, the user can see the inlet/outlet temperatures for each utility, the heat transfer coefficient of each and the cost index, as well as further physical properties for the utility.
To add a new utility simply locate the **New** cell at the bottom of the utility list and enter a utility name.
If the user wants to add a Work associated utility (e.g. Electricity) the only input that is required is the Cost index of this. If required, the Emissions Data Source and Fuel Type can be changed as well, this allows a more accurate analysis of the plant’s carbon footprint.
If the user wants to add a Heat associated utility (e.g. New Refrigerant) then all the thermodynamic information should be entered for a correct calculation of the utility flow.
If the user wants to use one of the already existing utilities as basis for the new one, it’s recommended to use the Clone Utility button (Highlighted in green). This allows the user to copy the information of an existing utility (e.g. HP Steam - 1) and perform quick modifications such as the operating temperature of these.
Keywords: Utility, Heat, Cost, Energy, Optimize, Create, Manager
References: None |
Problem Statement: How does a Process in the Production Plan work? | Solution: In Aspen Batch Process Developer Production Plan, you can select Steps or Processes to build a plan. Aspen Batch Process Developer calculates how many batches of each step are required to meet the target.
For example, assume Process A – Input Intermediate X, Output Intermediate Z – contains three steps:
Step 1: Input Intermediate X 100kg, produce Output Intermediate Y 50kg;
Step 2: Input Intermediate Y 300kg, produce Output Intermediate Z 200kg;
Step 3: Solvent recovery step, Input Intermediate Butanol, Output Intermediate Butanol
If you specify Process A one batch in a Production Plan, Aspen Batch Process Developer simulates how many steps are required to produce 200kg of Z, which is one batch of Step 2, and six batches of Step 1, but zero batches of Step 3, because Step 3 is not related to either Input or Output Intermediate.
Keywords: Process, ABPD
References: None |
Problem Statement: Troubleshoothing SPARSE messages in Aspen Custom Modeler | Solution: When you get SPARSE lines in the Message Panel, that is just a very generic error message. SPARSE is the name of the solver, which is a variant of Newton method.
This type or error just means that the solver failed to solve the non-linear equations. To troubleshoot the problem, you can try a couple of things:
Change parameters in the Integrator tab of the Solver Options window (F10), such as Minimum step size, the Integration method, or even the Error tolerances, which can also be modified from the Tolerances tab in the same Solver Options window. This approach is generic, and even when it might help convergence, it won't deal with the direct issue if it's cause by a specific variable or equation.
A more specific method is to try to figure out which equations or which variables are having more problems to solve. To identify these equations and/or variables, you need to go to Run | Solver Options | Non-Linear Solver tab. Then, at the bottom, in the Diagnostics section, you can modify two parameters:
Highest variable steps: This will allow you to enter the number of variables shown that take the largest steps between successive non-linear solver iterations, basically the variables that are making more difficult to get aSolution.
Highest residuals above tolerance: This is very similar to the previous one, only this time is for equations intead of variables. With this parameter you can see the equations which have the highest residuals and usually it's a good place to start to try to understand what's going wrong. Keep in mind only the residuals that are above the absolute equation tolerance are displayed.
This method can be tricky since there might be a lot of information to check, but it will give you a better understanding of the possible problem and a better idea on where to start looking.
Keywords: SPARSE, ACM, custom modeler, solver
References: None |
Problem Statement: I am modeling the Free-Radical polymerization of a defined monomer. I want to obtain the results for the z-average molecular weight (MWZ), the polymer weight average molecular weight (MWW) and the polymer number average molecular weight (MWN).
Results show that the value of MWZ is lower than the value of MWW and MWN. Typically, the average values are related to each other as follows MWN < MWW < MWZ. Where is the error? | Solution: The attribute MWZ is a class 0 attribute used to specify the polymer z-average molecular weight. MWZ is calculated as the average segment molecular weight (MWSEG) multiplied by z-average degree of polymerization (DPZ).
The degree of polymerization is a class 0 attribute used to specify the polymer weight average degree of polymerization. During convergence DPZ is calculated from class 2 attributes using:
The default built-in attribute group for the free radical selection is shown below:
As it can be seen in the screenshot above, MWZ is not in the default list. To report the MWZ results, the following attributes must be included: MWZ and also DPZ, TMOM, SMOM, LSMOM. If using catalyst one should also include LSSMOM (but if you do not use a catalyst and include this attribute, you will get an error).
The same applies if you want to track the live composite, site-based, live site-based and associated polymer average molecular weights. The following table summarizes the attributes that need to be added to the default list in these cases.
Attribute to be reported Needs to add the following attributes to the built in list.
Composite
MWZ MWZ, DPZ, TMOM, SMOM, LSMOM
Live composite
LMWN LMWN, LDPN, LZMOM, LFMOM
LMWW LMWW, LDPW, LFMOM, LSMOM
Site-based
SMWN SMWN, SSFLOW, SSFRAC, SDPN, SZMOM, SFMOM
SMWW SMWW, SSFLOW, SSFRAC, SDPW, SFMOM, SSMOM
SMWZ SMWZ, SSFLOW, SSFRAC, SDPZ, STMOM, SSMOM.
Live site-based
LSMWN LSMWN, LSSFLOW, LSSFRAC, LSDPN, LSZMOM, LSFMOM
LSMWW LSMWW, LSSFLOW, LSSFRAC, LSDPW, LSFMOM, LSSMOM
Associated polymer
AMWN AMWN, ASFLOW, ASFRAC, ADPN, AZMOM, AFMOM
AMWW AMWW, ASFLOW, ASFRAC, ADPW, AFMOM, ASMOM
After including all the attributes required for the calculations, the distribution of average molecular weight should be as MWN < MWW < MWZ.
Keywords: Polymer average molecular weight, moment of chain length distribution, live composite, site-based, live site-based, associated polymer
References: None |
Problem Statement: How does Aspen Batch Process Developer calculate Henry's constant? | Solution: When calculating Vapor Emissions for an Operation, in the Operation Editor it is possible to use Aspen Properties for the calculation:
Values calculated by Aspen Batch Process Developer (ABPD) will then be reported in the Quick Results summary:
However, these results may be different from those calculated in the Aspen Properties file embedded in the ABPD simulation.
The reason is that the two calculation methods are different. Aspen Properties will report the Henry constant for components that are labeled as Henry components, which also requires additional binary parameters as inputs (from databanks with the Henry parameters required for example).
In contrast ABPD will calculate the Henry constant from the fugacity: Hi = fi/xi = phii*P
where:
H: Henry’s constant of component i
f: fugacity of component i
x: mole fraction of component i
phi: fugacity coefficient of component i
P: system pressure
To compare with Aspen Properties results, either divide FUGMX by MOLEFRAC for each component or multiply PHIMX by the specified system pressure to get the same Henry’s constant.
Keywords: Henry’s constant, vapor emissions, Henry component
References: None |
Problem Statement: How can I force multiple operations to begin at the same time (run in parallel) in Aspen Batch Process Developer? | Solution: To specify that operations are in parallel, use the Edit | Insert Parallel command to add the following structure to your recipe:
Start Parallel
Series
Operation 1 (or a set of Operations)
Series
Operation 2 (or a set of Operations)
End Parallel
Keywords: Parallel, ABPD
References: None |
Problem Statement: Prior to V10, users could not initiate Aspen PIMS-AO Parametric Analysis runs via automation. | Solution: V10 added an automation code to allow running PIMS-AO’s Parametric Analysis. The detailed syntax of the automation call are:
RunParametricAnalysis(long nCase, long nInputSolution, bool bWriteDB, bool bGenerate)
Argument
· nCase -- The PIMS Case.
· nInputSolution -- The inputSolution file number.
· bWriteDB -- Boolean to indicate if all of the individual parametric solves should be persisted to the output database.
· BGenerate -- Boolean to indicate if the PIMS case should be generated.
See Aspen PIMS HELP for more information about running Aspen PIMS via automation and what automation codes are available.
Keywords: None
References: None |
Problem Statement: User may find data collection of certain controller in Aspen Watch Maker has stopped on its own. After checking the collection task of that controller, the task has stopped without any logs in Windows Event Logs. Hence, it is a good practice to set Aspen Watch collection tasks in IP.21 Manager to 'Auto Restart' to prevent potential data loss in the future. | Solution: In Aspen Watch Maker, we can check which tasks is used for the controllers.
Open Aspen Infoplus.21 Manager, we can find all the tasks used for data collection, check the 'Auto Restart' box. We can also modify the restart options.
This will make TSK_AW01 ~05 auto restart after any failure.
Keywords: Aspen Watch Maker
Infoplus.21
task auto restart
References: None |
Problem Statement: Why can I not connect to workspaces due to broker login error? | Solution: This error occurs due to loss of broker login information. You also might see the following error during the installation:
Error starting AZ191Broker due to Login failure.
<AZError Desc=The service did not start due to a logon failure. Src=CMainFrame::OnFileOpenWorkspace HR=0x8007042d />
<AZError Desc=The service did not start due to a logon failure. HR=0x8007042d File=.\MainFrm.cpp Line=398 />
<AZError Desc=The service did not start due to a logon failure. Src=AZWorkspace::Connect Activity=Connecting to Workspace HR=0x8007042d />
<AZError Desc=The service did not start due to a logon failure. Src=AZCWSpaceSvr::Connect-URL HR=0x8007042d />
<AZError Desc=The service did not start due to a logon failure. Src=AZCBrokerSvcs::Connect Activity=Connecting to Business Server HR=0x8007042d />
<AZError Desc=The service did not start due to a logon failure. Src=AZCBrokerSvcs::ConnectToBusinessServer Activity=Connecting to Broker HR=0x8007042d File=.\AZCBrokerSvcs.cpp Line=201 />
<AZError Desc=The service did not start due to a logon failure. HR=0x8007042d />
In such cases once the installation is completed follow these steps:
Go to the Administrative Tools | Computer Management | Services and Applications | Services | AZ1XXBroker from Control Panel
Right click on the AZ1XXBroker to display the menu and select Properties
In the new window, go to the Logon tab in order to re-enter the login information. When finish, click OK.
Re-start the broker service.
Note that for ABE V9.0 service name is AZ181Broker and for V10.0 is AZ191Broker
Keywords: Logon, AZBroker, login failure, can not connect to workspace
References: None |
Problem Statement: Tips on modeling the depressurization of a filled vessel using the Dynamic Depressuring Utility. | Solution: Since a small change in the vessel holdup of a filled vessel impacts the pressure of the vessel significantly, the first and foremost requirement of performing the depressurization calculation of a liquid filled vessel using the dynamic depressuring utility is to use a smaller time step. The time step should be small enough to provide a stableSolution. In general, a smaller time step gives a more accurateSolution (it takes more time to run the model though). Some other tips which may help are:
1. Increase all of the Calculation Execution rates, by going to Simulation | Integrator | Execution. Setting all of them equal to 1 guarantees accurate results. Note that this will slow down the depressuring calculations, though accuracy of the simulation results is improved.
2. Delete the components with zero composition from the stream. If you have too many heavy hypothetical components with zero or negligible composition, try to reduce the number of those hypothetical components. Sometimes, the presence of heavy hypothetical components with very small (tiny) compositions may cause flash failures during the calculation. Remove the odd components (e.g. TEG, Amine(s)) if they have zero composition.
3. Use reasonable values for the Heat Flux Parameters (Design | Heat Transfer). For example, using too big (unreasonably high) a number for the heat duty may create instability in the model. Similarly, check your valve Cv / area and make sure you have not entered a large number inadvertently.
4. If you are depressuring supercritical fluids, check the results very carefully and use your engineering judgement while analyzing the results.
5. Go to Simulation | Integrator | Options and uncheck the following two options:
Truncate large volume integration errors
Reduce recycle efficiency for small time steps
6. Go to Simulation | Integrator | Options and check the following option:
Close component material and energy balances
7. Decrease the Time Step Size (Depressuring window | Design | Operating Conditions). By default Aspen HYSYS uses 0.5 seconds, however 0.1 seconds or less is recommended. Again, this is going to slow down the simulation, but with this accuracy of the results is improved. If a fire model is required, time in cell B8 of Duty spreadsheet should be no more than twice the time step size.
8. Press several times the Run button, until the numbers in the Perfomance tab do not change.
9. Make sure that the PV Work term contribution values is appropriate for your system. This value affects the slope of the P vs. T curve, which can used as an indication of the appropriate value to use. Using 100% Aspen HYSYS will predict the lowest temperature profile (isentropic process), and 0% will correspond to the highest temperature profile (isenthalpic process).
10. Use the envelope utility to have a preliminary idea of the path the system is going to follow while it undergoes the depressuring process.
11. If you have accesories attached to the vessel, or if the heads are not flat, enter the extra amount of mass in the corresponding Correction Factor (Design | Connections).
Keywords: Dynamic depressuring utility, filled vessel, time step, supercritical fluid, Integrator
References: None |
Problem Statement: What standard is used by EDR to calculate the shell-to-bundle clearance? | Solution: EDR uses TEMA standards for this purpose. TEMA starts with shell to baffle OD clearance (See Table RCB-4,3), then considers enough to be able to build the bundle and remove the bundle when removable. Typical fabricator clearances tube-OD-to-shell-ID is 1/2 on diameter (1/4 on radius) for fixed tubesheet units and U-tubes. Variable for floating heads to make sure the rear head can be removed.
Keywords: Shell, Bundle, Clearance
References: None |
Problem Statement: Is it possible to model Electrolyte Chemistry and Pseudocomponents? How are binary parameters generated? | Solution: The NRTL and UNIQUAC binary parameters for water and pseudocomponents are intended for use in LLE calculations, as water and hydrocarbons tend to form two liquid phases. These interaction parameters are estimated from the mutual solubility data. The solubility of water is estimated from one of the methods described below. The solubility of pseudocomponent in water is estimated from the API procedure 9A2.17:
To determine the Pseudocomponent formula (ATOMNO/NOATOM parameters), we assume that the pseudocomponent is hydrocarbon consisting of only C and H atoms. We compute the number of C and H atoms from the molecular weight and the Carbon to Hydrogen ration (C/H ratio). (Note that C/H ratio is estimated using procedure in TECHNICAL DATA BOOK - PETROLEUM REFINING, VOL. 2 (FIGURE 2B6.1), AMERICAN PETROLEUM INSTITUTE, 1983.) We further assume that the component is paraffin and adjust the number of carbon atoms to obey CnH2n+2. As a result, H is a whole number, but C may be fractional.
Then we estimate solubility of water in hydrocarbon (from the WATSOL parameters which can be estimated using either the Aspen method, the Kerosene line, or user-supplied method) and solubility of HC in water (API PROCEDURE 9A2.17.)
Since water and hydrocarbons are essentially immiscible, the mutual solubilities are very low. As a result, the solubility is inversely proportional to the infinite dilution activity coefficients. For infinitely dilute binary system, binary interaction parameters for the NRTL and UNIQUAC models can be computed directly from infinite-dilution activity coefficient data.
Now, Aspen Plus does not display all the property parameters on the parameters form, so we need to go the Home Ribbon and select Tools | Retrieve Parameters to be able to check the NRTL/UNIQ parameters. They will be available under Methods | Parameters | Results | Binary Interaction | T-Dependent
Keywords: Pseudocomponent, NRTL, UNIQUAC, Binary Interaction, Estimation.
References: None |
Problem Statement: The drawings from Aspen Shell and Tube Mechanical don’t match the drawings from Aspen Shell and Tube Thermal program | Solution: The thermal program has a layout written by HTFS. The mechanical program has a layout written by BJAC. These are two different programs coming from past software. Consequently, these layouts will always be different.
If the geometry is identical, you should select the most appropriate layout.
When the data is transferred from thermal to mechanical, the mechanical program has all input parameters related to the tube layout greyed out. This means the mechanical program is using the thermal layout created by the thermal program ‘as is’:
If you change to ‘Create a new layout’, then there are two options from the mechanical program, the thermal layout (HTFS) or the mechanical layout (B‐JAC):
The thermal layout from mechanical uses a separate program but identical to the thermal program except that all the inputs come from the mechanical side. This means that if the inputs are slightly different, the layouts will be slightly different.
The layout from All drawings is always the mechanical (B‐JAC) layout.
Keywords: Layout, drawings, thermal, mechanical
References: None |
Problem Statement: Sometimes, the administrator of the Aspen InfoPlus.21 database may have a need to start the database without starting the History Repositories.
For example,
1. They may want to make some configuration changes to the Repositories or History Filesets.
2. Another possibility is that problems with History prevents the database from starting, and troubleshooting is required.
3. A third possibility might be that initial database configuration is being performed and there either is no existing history, or what is there is actually invalid.
The first two possibilities above would actually require a slightly different | Solution: than for the third possibility.
Solution
1. To bring up the Aspen InfoPlus.21 database without History, and allow somebody to view and or modify the History configuration, the administrator should manually start very selective tasks only!
NOTE: By manually starting a task we mean that one would double-click on the task in the top left corner of the Aspen InfoPlus.21 Manager (Defined Tasks), and then single click on the RUN TASK button in the middle left of the Manager display.
Assuming that all tasks have been shut-down in the Aspen InfoPlus.21 Manager:
a) First manually start TSK_DBCLOCK
b) Next manually start TSK_H21T
c) Next manually start TSK_ADMIN_SERVER
'Optionally' manually start TSK_SQL_SERVER if the Aspen SQLPlus Query Writer will be required.
'Optionally' manually start TSK_SAVE if you expect to make changes to database records or database record security.
The Aspen InfoPlus.21 Administrator, can now be started. All sections related to the database can be viewed, including the Historian section, but the Repositories will show Red (not started). Changes can be made to such as the History Configuration.
d) Finally, from the Aspen InfoPlus.21 Manager, click on the STOP InfoPlus.21 button. The database will shut-down and any history configuration changes will be saved to the Config.Dat file.
NOTE: if TSK_SAVE was also started then a new snapshot will also be saved.
Subsequent restarting of the database in the normal way will now recognize any changes that have been made.
2. To bring up the Aspen InfoPlus.21 database without History, but ALSO disallow any viewing or modifications of the History configuration, as per the third possibility above, the procedure is almost the same as (1) above, but with the following two changes
a) Add the NOHIS switch to TSK_DBCLOCK before starting
b) Do NOT start TSK_H21T
In other words :-
Assuming that all tasks have been shut-down in the Aspen InfoPlus.21 Manager..
1. First manually start TSK_DBCLOCK (including the NOHIS switch)
2. Next manually start TSK_ADMIN_SERVER
'Optionally' manually start TSK_SQL_SERVER if the Aspen SQLPlus Query Writer will be required.
'Optionally' manually start TSK_SAVE if you expect to make changes to database records or database record security.
3. The Aspen InfoPlus.21 Administrator, can now be started. All sections related to the database can be viewed and modified with the EXCEPTION of the Historian section.
4. Finally, from the Aspen InfoPlus.21 Manager, click on the STOP InfoPlus.21 button. The database will shut-down. Note that if TSK_SAVE was also started then a new snapshot will be saved on shutdown.
NOTE: Remember to remove the NOHIS switch and updated the TSK_DBCLOCK parameters, before trying to start all the tasks in the normal way.
Keywords: NOHIS
Without History
IP21 start no history
References: None |
Problem Statement: What are the best practices while coding in VSTA? | Solution: Aspen Technology recommends implementation of the following as an absolute minimum for best coding practices:
Commenting- Helps another modeler understand the underlying principles of the code's purpose. Comments also help you when you return to the code after not seeing it for some time.
Indenting- Left justified blocks of code are almost impossible to interpret by anyone. Structures, such as loops and if / then / else, should be indented to make them more readable.
Option Explicit- Aspen Fidelis Reliability generate models with this statement by default. Presence of this statement in a model forces you to explicitly declare used variables throughout the code.
Consistent Variable Naming Convention- Camel notation is a popular choice for variable naming convention. The first three letters indicate the variable type and a descriptive name with the beginning words capitalized. For example, the variable intTotalOperationalUnits could be an integer that represents the total number of operational units. This naming convention obviously shows the variable type and purpose at a glance.
Modularity - If you find yourself executing the same sequence of code more than once, then the code might be better placed in a subroutine or a function. This way, the code only has to be changed, debugged, or maintained in one place and makes the code portable to other models.
Key words
VSTA, coding
Keywords: None
References: None |
Problem Statement: Modifications to the cycle are not being carried out during the dynamic run | Solution: After making structural changes in the cycle organizer, you must regenerate the task for those changes to be implemented. So-called structural changes include adding a step or adding a manipulated variable. Changing the numerical value of a variable is not a structural change. Check the status at the bottom of the cycle organizer window. If the status is “Generate recycle”, then the task does need regeneration.
Note that when a change is made, but the cycle was not yet regenerated, a prompt to save appears if the cycle organizer window is closed. Saving changes is not the same as regeneration.
To regenerate:
In the cycle organizer window, under Cycle, click Generate Task.
Run the simulation. The steps will be executed as specified in the Cycle Organizer.
Keywords: Adsorption, cycle organizer
References: None |
Problem Statement: For different OPC servers, the maximum Cim-IO list size may need be changed from default value. | Solution: The Cim-IO list size determines the number of lists into which the collection tags are divided.
For example, for Cim-IO to CM50S, if there are 304 collection tags, and the listsize is specified to be 100; then, internally, the tags will be divided into four internal lists. Three of the lists will contain 100 tags and one will contain four tags. Likewise, if the list size is 30, then the number of internal lists will be 11.
If a -1 is entered for this parameter, then the list size will be the number of collection tags.
To change it, user needs to open Configure Online Server, click on 'edit source' with the demanded IO Source highlighted.
Now user can modify the list size accordingly.
Keywords: Cimio
List size
OPC
DMC3 controller
References: None |
Problem Statement: How does EDR account for Expansion Joints? | Solution: In Shell & Tube Mechanical, the consideration of Expansion Joints in fixed tubesheet designs can be changed directly in the program. Under Input | Exchanger Geometry | Expansion Joints, there are 3 options:
Program: This is the default option. The program will check and add expansion joints if necessary.
Yes: The program adds expansion joints, even if they are not required.
No: The heat exchanger is designed with expansion joints. The program will evaluate if the unit is overstressed
Keywords: Expansion joint, EDR, mechanical
References: None |
Problem Statement: This article explains what is 'Service Request' entry in PCWS control page. | Solution: Each variable in an Aspen APC controller has the concept of 'In Service' or 'Out of Service'
'Service Request 'is the operations service switch for an variable. It permits operations (or other e.g. engineer) personnel to assign any of the following modes that determine whether the variable is included or excluded from the controller's influence on the plant.
It contains 3 options for Independent Variable:
0 (Off) Do not use the variable for prediction or control.
1 (On) Use for prediction and control.
2 (Prediction) Use the variable for prediction only, so it is included in Controller calculations, but is excluded from controlling plant regulatory systems (manipulated variables only).
It contains at most 3 options for Dependent Variable:
Controlled Variables:
0 (Off) Do not use the variable for prediction or control.
1 (On) Use for prediction and control.
2 (Prediction) Use the variable for prediction only, so it is included in Controller calculations, but is excluded from controlling plant regulatory systems. Not used for filter variables.
Filter Variables:
0 (Off) Do not use the variable for prediction
1 (On) Use for prediction
If service request of a variable is set to OFF, the variable is bad.
Keywords: Service Request
PCWS
entry
References: None |
Problem Statement: When using multiple steps to model a process, how do I get material to flow from one step into the next? | Solution: First, make sure that you check the Transfer total amount of Output Intermediate from previous Step in Process check box in the Simulation Batch tab of the Tools | Options menu.
Then simulate the Steps sequentially. If you later make changes to a Step, you must re-simulate it and then re-simulate all subsequent Steps to get updated results for each Step. If you are running a Production Plan, you must re-simulate all steps that have been changed (or that haven’t been run yet) as well as re-simulate Steps subsequent to the changed Steps in order to get correct Plan results.
Keywords: Transfer, Steps
References: None |
Problem Statement: How do I save the CAP_REP.cpp file after an evaluation of a project scenario? | Solution: There is no Save/Save As options included in the Report Editor due to issues with MS Rich Edit Control with the ccp file splitting.
If you need to retrieve the ccp file, you can find it in the cache directory. For typical installations, the cache is located in:
C:\Users\<UserName>\AppData\Local\AspenTech\Economic Evaluation <version>\Projects
You have to navigate to the open project folder to find the ccp report.
Keywords: ccp report, Report Editor, AppData
References: None |
Problem Statement: What to do if the Rewind button is grayed out? | Solution: Open Run/Run Options and enter 0 into the Time now field.
The Rewind button can be used now.
Keywords: Adsorption, rewind
References: None |
Problem Statement: How can I ensure that I don’t overfill a reactor (or underfill it below the minimum stir volume for operations that may require agitation, such as reactions)? | Solution: First, make sure that you have specified a Maximum Fill Factor and/or Minimum Stir Volume for appropriate pieces of equipment in your equipment database. In order to check whether you are meeting the Min/Max requirements, you can take the following actions.
Generate the Equipment Contents Excel report by clicking Results | Excel Reports | Equipment Contents. This shows you:
The volume in your equipment vs. time.
The minimum and maximum volumes for that equipment.
Generate the Equipment Capacity Excel report (Results | Excel Reports | Equipment Capacity) or the Excel Executive Summary (Results | Excel Reports | Executive Summary). These reports show you the maximum size utilization over the course of the batch for each equipment item.
Click Tools | Options | Simulation Batch tab. Make sure that the Check Overflow of Equipment Units option is selected. If you are interested in checking to see whether minimum stir volumes are met for certain operations, make sure that the Check Underflow of Equipment Units option is selected on the Simulation Batch tab as well. You can also specify which types of operations you want Aspen Batch Process Developer to check for minimum stir volumes on the Minimum Batch Size Calculation tab. This will ensure that notices about overfilling or underfilling equipment will appear in the Quick Results and Run History reports.
Keywords: Overfill, Underfill, Reactor
References: None |
Problem Statement: I specified Comments or Ranges in my Aspen Batch Process Developer Operation, but they do not appear in the text recipe. Why? | Solution: You need to specify which (if any) Comment types or Range types will appear in the text recipe.
To specify comment types to display on Text Recipe view:
Click Tools | Options | Text Recipe tab.
Click Comments in the Text Recipe view.
On the Comments drop down list, click the types of comments you want to have displayed in the Recipe Text.
Click OK.
To specify range types to display on Text Recipe view:
Click Tools | Options | Text Recipe tab.
Click Ranges in the Text Recipe view.
On the Ranges list, click the ranges you want to have displayed in the Recipe Text.
Click OK.
Keywords: Comments, ranges
References: None |
Problem Statement: Are binary interaction parameters (BIPs) estimated when pseudocomponents are generated from assays? From documentation, it is stated that there are API methods available for estimating RKSKBV. However, when I go to Methods | Parameters | Binary Interaction | RKSKBV-1, I don’t see any value for the pseudopomponent pairs. | Solution: Aspen Plus does not display all the property parameters on the parameters form, so first we need to go the Home Ribbon and select Tools | Retrieve Parameters. After that, the RKSKBV parameters will be available under Methods | Parameters | Results | Binary Interaction | T-Dependent. See example attached.
Please note the RKS binary interaction parameters (RKSKBV) are estimated for each pseudocomponent in pairs with only certain light gases which are present in the simulation:
API 1978 (3rd Ed): By default, the ASPEN method is used in estimating parameters of pseudocomponents. In this method, RKS binary interaction parameters for the light gases, CO2, CO, H2S and N2, with pseudocomponents are estimated using the API 1978 (3rd edition) method, which is a function of solubility parameter
API 1987 (5th Ed): There is a second method for estimating the RKS binary parameters which is based on the API 1987(5th edition). This method estimates the interaction parameters for CO2, H2S, N2, H2, CH4 and sets the CO value to zero. This correlation is also a function of the solubility parameter. Note that this method will only estimate RKSKBV of pseudocomponents-CH4 for pairs where the molecular weight of the pseudocomponents is equal to (or larger than) 140. If the molecular weight is less than 140, the RKSKBV value will be set to zero.
To select the characterization method API 5th Ed, go to Components | Petro Characterization | Selected Methods, and create a New method. Accept the default ID P-1. From P-1, chose a Base method and then go to the EOS tab and select it from RKS interaction parameters
In addition, go to Components | Petro Characterzation | Generation, and create a New object. On the Specifications sheet, select P-1 in the Pseudocomponent property options field.
You can also estimate the values for the NRTL and UNIQUAC pseudocomponent-water binary parameters. For additional details, see theSolution Is it possible to model Electrolyte Chemistry and Pseudocomponents? Are binary parameters generated?.
Keywords: Pseudocomponent, RKSKBV, RKS, Binary Interaction, Estimation, Characterization
References: None |
Problem Statement: What are the differences between efficiencies model and advanced model in Acid Gas Column Modeling? | Solution: Efficiency Model: Column tray and packing information can be defined to calculate component efficiencies. Efficiency approach only calculates efficiencies for CO2 and H2S.
Advanced Modeling: Column calculations can be converted from the default Efficiency-based calculation to an “Advanced Modeling” approach which allows for a full, rigorous rate-based model for the entire column. Better suited for separations including mercaptans, COS, and/or CS2.
Keywords: Efficiencies Model, Advanced Modeling, Rate-Based Model
References: None |
Problem Statement: Will related equipment affect equipment availability?
Note: Related Equipment refers to equipment listed on the Related Equipment tab under the Data | Equipment dialog box. | Solution: Related Equipment will not be used for equipment availability checking. For models such as Vesselpak, if the related agitator and jacket are not specified for the main vessel, Aspen Batch Process Developer checks the related equipment to see if they are specified. These pieces of equipment are listed in the Equipment Data spreadsheet.
Keywords: Availability, related equipment
References: None |
Problem Statement: Are light gases not reported in the emission results? | Solution: The Emissions calculations concern the maximum composition of the liquid components going into the vapor. If these components do not appear in the liquid phase, then they are not reported in the Emissions results.
A component charged to equipment will be assigned to the phase defined by the Phase parameter found in Data | Pure Components. For example Nitrogen taken from the Pure Component databank is a gas. Water is a liquid. This parameter can be changed under on the Data | Pure Componentdialog.
Keywords: Emissions, light gases
References: None |
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