question stringlengths 19 6.88k | answer stringlengths 38 33.3k |
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Problem Statement: The steam table property methods used in Aspen Plus are out of date. IAPWS-1995 is the current standard. When will this be added to Aspen Plus/Properties? | Solution: The IAPWS-95 property method is the current standards for steam table based on the International Association for the Properties of Water and Steam (IAPWS) formation 1995 for the thermodynamic properties of ordinary water substance for general and scientific use. This method will be available in Aspen Plus V7.... |
Problem Statement: Is it possible to run just one block in a multi-block simulation file? If so, how can I do it? | Solution: Various simulation objects can be activated and deactivated. When deactivated, they still need to be completely specified to run the problem, but deactivated simulation objects other than streams are ignored during simulation. Blocks and Streams can be deactivated and activated by clicking the right mouse bu... |
Problem Statement: RGibbs reports this error:
** ERROR WHILE EXECUTING UNIT OPERATIONS BLOCK: B5-1 (MODEL: RGIBBS)
(GIBBS.19)
UNABLE TO BALANCE ATOM S (or other atom) in RGibbs block
Cause
This occurs in a number of situations where RGibbs cannot... | Solution: Compare the product restrictions with possible reactions and the feed composition and ensure there is some combination of products which satisfies the mass balance and the product restrictions. You may need to remove restrictions, modify specified product flows or fractions, or add additional compounds as all... |
Problem Statement: What is the difference between KLL and TXX or TPXX mixture data types for data regression of liquid-liquid equilibrium data. What is the definition of KLL? Why do I have to enter KLL, since it can be calculated from the first and second liquid phase compositions? | Solution: The data types are very similar.
The KLL data type expects the user to enter KLL = X2 / X1.
As to redundancy of data, while it is true, by explicitly entering KLL data, these data will be included in the objective function and new constraints will be added. This can alter the regression results. Basically, wh... |
Problem Statement: When performing consistency tests, the results show either failed or not performed. What is the cause of this? | Solution: The Aspen Physical Property System tests the binary vapor-liquid equilibrium (VLE) data for thermodynamic consistency only when both of the following conditions are satisfied:
1. Composition data for both the liquid and vapor phases.
2. At least five data points, not counting pure component data point... |
Problem Statement: How can I include multiple parts and unit models within a Hierarchy User Model block in Aspen Plus? | Solution: In order to include multiple parts and unit models within a Hierarchy User model block in Aspen Plus. The below procedure will help:
1. Select with the mouse the streams and unit models that you want to move to the hierarchy:
2. Then, right-click on the selected items and select ‘Move Selection':
3. ... |
Problem Statement: When one makes a property set for GMTRUE (called property set A), which is the activity coefficient of a true species in a mixture, and a separate property set for MTRUE (called property set M), one may specify them using the Stream-Prop variable under | Solution: When referring to a Prop-set variable, it is not possible for this particular case to access the definition inside this. Hence, it has to always be the first variable defined in the Prop-set. In other words, the first value of the Prop-set. E.g.: If in the qualifiers tab for Prop-set A, if you defined compone... |
Problem Statement: VBA and VB.NET example: Creating a new simulation from the ground up through COM Automation. | Solution: This attached example in VB.NET and VBA illustrates how to set up a simple simulation from the ground up through ActiveX interfaces in Aspen Plus.
The code will allow to:
- Create a new simulation
- Entering components and selecting the property method
- Create streams and a heater block
- Attach the streams ... |
Problem Statement: How do you write Fortran expressions? | Solution: We are adding a new help topic with some simple instructions on how to use Fortran since so many new engineers have no experience with it. It is important to note that Fortran expressions are used not only in the Calculator block, but on other forms such as Design specification and Sensitivity. Also, basic Fo... |
Problem Statement: How can I check the results of the downcomer geometry of a RadFrac column? | Solution: When the user does not specify any information about the downcomer geometry (widths/weir lengths), it is possible to check the dimensions considered by Aspen Plus in the Report of the RadFrac column. To do so, the user needs to run the model, then click on the Report option in the Home ribbon:
Then, select th... |
Problem Statement: When modelling a process in Aspen Plus, is it possible to transfer the flowsheet (streams, unit operations) to a PDF file format.
I am using PDF-XChange 4.0 writer, but sometimes some unit operation symbols are not displayed in the PDF file. | Solution: There is another software which is called XPS Document Writer, that allows the user to create a file with the flowsheet drawing. This software belongs to Microsoft, so it is installed by default when using this operating system.
To “print” the flowsheet as a document, go to File | Print and select from the dr... |
Problem Statement: Could not start Aspen InfoPlus21 database with error - Not enough space for nnnn word database | Solution: This KB article describes steps to follow in case the Aspen InfoPlus21 database could not be started post upgrading the snapshot. And the error says - Not enough space for nnnn word database
1. Double click on the TSK_DBCLOCK task in the Defined task list (left hand side top section) in IP21 manager.
2. In th... |
Problem Statement: How do you report a ratio of selected components in a Prop-Set? | Solution: In the attached file (built in Aspen Plus V8), the total light gas composition is calculated by summing the mass compositions of hydrogen, nitrogen, and methane and reporting it as a single value in the stream summary results.
To report a summation of component fractions:
1. Navigate to the Properties Pro... |
Problem Statement: How is vapor pressure PL calculated in an Analysis table when using an equation of state (EOS) property method? | Solution: In version 2006 and higher, it is possible to choose PL in the Tools -> Analysis -> Property -> Pure dialog for an equation of state property method. Before V8.0, PL tabulates vapor pressure as calculated from the Antoine coefficients for the component not from the equation of state used. Note that this only ... |
Problem Statement: When should I connect a heat stream on the HXFLUX block? | Solution: It is optional to connect a heat stream to HXFLUX; therefore, you may do as you see fit. Note that if you connect a heat stream as input, you must also connect a heat stream as output. If you connect a heat stream as output, you must also connect a heat stream as input. You may connect only up to one heat str... |
Problem Statement: What are the Typical Values of Overall Heat Transfer Coefficients? | Solution: The following values based on heuristics are proposed for short-cut design methods of heat exchangers. The upper values are good for particularly favorable conditions such as high flow velocities, thin fluid layers, optimum mass flow ratios, and clean surfaces. The lower values are recommended for particularl... |
Problem Statement: How to obtain results for user defined compounds VLE binary interaction properties using UNIF-DMD property method? | Solution: In order to obtain results for user defined compounds VLE properties using UNIF-DMD property method:
1) Run the attached example .aprbkp simulation file and some errors will be shown in the Control Panel:
2) Go to Components | Molecular Structure | B and C | Functional Group (tab), change the Method ... |
Problem Statement: How to display stream property on Flowsheet other than temperature, pressure & flow. | Solution: From Aspen Plus V8 onwards any stream property can be displayed on the Flowsheet in addition to the standard options from earlier releases.
Click on Stream Results as per below image:
Activate label & write label name which you want to display then select stream property from Prop-Set drop down menu as per be... |
Problem Statement: Uninstalling one version of Aspen Plus removes all of the Aspen Plus shortcuts for the other versions that are still installed. | Solution: When you uninstall a newer version of Aspen Plus (including beta versions), the shortcuts for the previous version get broken (e.g., “open with Aspen Plus V8x”). Running the Set Version utility found in the Start Menu in the AspenTech -> Process Modeling V8.x -> Aspen Plus folder will restore the shortcuts. T... |
Problem Statement: If I want to restore a database created in a specific server version using Aspen Properties Database Manager (APED). How can I determine the Microsoft SQL Server version installed on my computer? | Solution: The way to find out the version of an SQL server instance is from Registry. Each SQL instance has a unique name that will be used by APED. On 64-bit machine, you can look at this key for all 64-bit SQL server versions:
1) Go to Start and type ‘regedit’ at the ‘Search programs and files’ command line.
... |
Problem Statement: When estimating properties, there are warning and error messages that are generated when running the case file. Why does this happen? | Solution: When we select “estimate all missing parameters”, our Property Constant Estimation System (PCES) will attempt to generate the functional groups for the corresponding estimation methods to be used. If no specific method was selected for a certain property, our system will go through the estimation methods avai... |
Problem Statement: How does Aspen Plus calculates MTRUE (molality) and activity coefficient of true species in a mixture on molality basis (GMTRUE)? | Solution: RelatedSolution 103517
The activity of true species on a molality scale is given by:
a(ionic species) = xm(ionic species) * gamma(ionic species)
in which:
a(ionic species) is the activity of true species on molality basis
xm (ionic species)=: molality of ionic species
gamma (ionic species)= activity coeffici... |
Problem Statement: When creating SQLADef tags, users might want to set the value of the IP_STEPPED field to either Interpolated or Stepped to use this setting as a default for Process Explorer (checked on unchecked Stepped column). However, in order to accomplish this task, the map record for SQLA tags (IP_SQLAMap) mus... | Solution: To modify the SQLA map record, follow these simple steps:
1. Locate IP_SQLAMap, defined by AtMapDef.
2. Set the filed MAP_#Maps to 1 to add an occurrence.
3. Go to the first occurrence and add 'STEPPED' to Map_Attribute and 'IP_STEPPED' to MAP_FieldName. This step allows IP_SQLAMap to match t... |
Problem Statement: 왜 rate-based distillation column 플래시계산에서 온도가 서로 다른가? | Solution: Rate-based stage에서 증기성분과 액상성분은 상평형을 이루지 않는다. 기액상평은 오직 경계면에서만 발생한다고 가정하기에 이를 화학평형으로 볼 수 있다. 때문에 rate-based stage에서는 플래시 온도가 다를 수 밖에 없고 출구유체에서 기액상평형과 화학평형을 이루어질 수 없다.
Keywords: None
References: : CQ00357921
Please find |
Problem Statement: If I have to repair file sets from many repositories, can I run multiple copies of H21ArcckWizard.exe (History Arc Check Wizard) at the same time? | Solution: If you have to repair file sets from multiple repositories, you can start concurrent copies of the history archive checking wizard (H21ArcckWizard).
Keywords: repair file set
References: None |
Problem Statement: Listed here are the two most likely occasions when you might see the error:
Licensed Point Count must be 'nnnnnn' Minimum
(where 'nnnnnn' might be any number between 1 and 2097151)
You might see this in the Output file for Loaddb when the Aspen InfoPlus.21 startup fails at loaddb.
Another time mi... | Solution: Shutdown the Aspen InfoPlus.21 database if it is currently running - the problem cannot be solved with it running.
From the Left hand pane of the Aspen InfoPlus.21 Administrator, under InfoPlus.21, right click on the name corresponding to the database in question.
Choose Set Point Count
It is the number seen ... |
Problem Statement: How do I check the license status on my Aspen InfoPlus.21 server? | Solution: The License Status tab displays the current status of the InfoPlus.21 server.
To view license information:
1. In the InfoPlus.21 Administrator, right-click the InfoPlus.21 database and select Properties from the context menu.
2. On the Database Properties dialog box, click the License Status tab. The... |
Problem Statement: How does Aspen InfoPlus.21 use the field FIELD_NUMBER (hex) in records defined by FieldNameDef and FieldLongNameDef? | Solution: Aspen InfoPlus.21 uses records defined against FieldNameDef and FieldLongNameDef to create data field names for Aspen InfoPlus.21 records. The only difference between data field names defined against FieldNameDef and FieldLongNameDef is the maximum length of the data field names defined against them. Data f... |
Problem Statement: How can I delete a file set to recover disk space without first stopping Aspen InfoPlus.21? | Solution: Aspen Technology strongly recommends stopping Aspen InfoPlus.21 before deleting the contents of file sets (arc.dat, arc.key, and arc.byte); however you can following these steps if it is not possible to stop Aspen InfoPlus.21.
1. Open the Aspen InfoPlus.21 Administrator and stop the repository with the file... |
Problem Statement: TSK_DBCLOCK hangs at 50% during startup, then quits. Error messages found in TSK_DBCLOCK are:
h21_arck_local failed with ret = -1040
CreateFile failed
The problem appears to be related to the history filesets. For V7.1 and later, a new utility exists that attempts to validate the path to each fil... | Solution: In this case customer had run h21chgpaths.exe to change the UNC path for all the filesets in config.dat. Since the directory structure was unchanged on the new server, the change of nodename in config.dat seemed to be enough. However in addition to the fileset locations, config.dat also specifies the reposito... |
Problem Statement: When using standard IP_AnalogDef records, normal behavior is that values written to the IP_INPUT_VALUE field will propagate to the IP_VALUE field, and then be written to history. You might see a situation where the values updating in IP_INPUT_VALUE do not propagate to IP_VALUE. | Solution: One possible cause of this behavior is that compression is activated for the record. If this is not the case then there could be a problem with the IP_BoxcarSlope record. The IP_BoxcarSlope record must be configured for data to propagate from IP_INPUT_VALUE to IP_VALUE even though compression is not being use... |
Problem Statement: This knowledge base article explains how to remove duplicate tasks from the Aspen InfoPlus.21 Manager defined task list. | Solution: Duplicate tasks can appear in the Aspen InfoPlus.21 Manager task list when there is more than one task registered in the registry with the same order number. Try to remove the extra task using the 'Remove' button. If that does not work go to the following location in the registry:
32 bit systems :-
HKEY_LOC... |
Problem Statement: The example for INSOCCS in the manual is for inserting new occurrences into history. The following example shows how to do this for a non history occurrence such as ENG-UNITS. | Solution: NOTES: modify the #define for ARRSZ for the number of occurrences to insert, INSERT_AT for the occurrence number to begin inserting, the recid variable for ENG-UNITS on your system and the description array values for the actual units to write.
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#inclu... |
Problem Statement: Users who develop large custom applications which rely on Aspen Batch.21 data prefer to use the fastest method of data retrieval possible to optimize performance in their custom applications. This knowledge base article describes which method of data retrieval is faster. | Solution: Assuming the user interacts with the Aspen Batch.21 API and the web service identically the performance will be faster in the Aspen Batch.21 API as the web service is just an extremely thin wrapper around the API datasource's XML method. If the web service is used, the application will see the performance imp... |
Problem Statement: What are Static-cell Constant or Static-cell volume used for ebulliometry data? | Solution: The Static-cell constant should be used when TPZ data type is used.
The Static-cell volume is used when TPF data type is used.
The value of static-cell constant or volume should be found in the user manual of the differential static-cell apparatus used for generating those TPZ/TPF data. This type of apparatus... |
Problem Statement: ?e`a电脑???L?{???s?????{Aspen Hysys软??时?C??么设?u?z?E???{?H | Solution: Aspen Hysys软???A?E调?pExcel automation work???I拟`S关?I?H?o?B ?v?Y电脑????时?A`????D?{???s?????{Aspen Hysys?C??么?K须??设?u?z?E???{?B???A?Iscript?????Y专门?p为???e?z?E???{?I?B
1. ??载RegHYSYS72.txt?????B
2. ?u??RegHYSYS72.tex?I扩?W??为RegHYSYS72.bat.
3. `o击该?????C?o???i删???????e?IAspen Hysys???{??时???ev7.2... |
Problem Statement: Does an Aspen Plus compound (.apwz) file contain an .apw file or a .bkp (backukp) file? | Solution: The compound (.apwz) file can contain either a .apw or .bkp file. It is selected on the File | Options | Files page. The default is .apw.
Keywords:
References: None |
Problem Statement: When should the water solubility option be changed? | Solution: Water Solubility method should be left at the default value of 3 except when modeling water-hydrocarbon systems where two liquid phases form and the aqueous phase is almost pure water, and is modeled using the Vapor-Liquid-Free Water or Liquid-Free Water valid phases options.
In V7.3.2 and higher, an inform... |
Problem Statement: Running a simple steam turbine calculation works fine with STEAMNBS, but fails with IAPWS-95 producing the following error message:
***SEVERE ERROR
CANNOT FIND TEMP FOR ISENTROPIC COMPRESSOR/TURBINE.
ERROR IN ENTROPY = -0.11711E+07 | Solution: When using a COMPR model as a Turbine and IAPWS95. If the conditions are above the supercritical region, the IAPWS95 will return single density for both so called vapor and liquid phases. With the same density Aspen Plus will return same fugacity for both phases, thus the simulation does not converge properly... |
Problem Statement: This Knowledge Base article answers the following question:
Does any AspenTech software product (IP.21, AtOMS, Advisor?) support /3GB memory switch as described in the Microsoft article: Memory Support and Windows Operating Systems
(link to the article provided below)
http://www.microsoft.com/whdc/... | Solution: Neither Aspen InfoPlus.21 (IP.21), nor any other AspenTech software product supports /3G memory switch technology as described in the above MS KB article. However, there really isn't a need as even the largest Aspen Advisor and Aspen AtOMS models do not come close to using the address space available under 32... |
Problem Statement: 当安装或者升级的时候点击Install会出现如下错误 | Solution: 1:
停止安装并确认如下事项：
1. 当安装的时候需要有本地管理员权限。
2. 本地Administrators组要对C:\WINDOWS\Installer文件夹有完全控制权限
如果无法看到此文件夹要在文件夹选项中取消对隐藏受保护的操作系统文件(推荐)的选择和选择显示所有文件和文件夹
3. 重新进行安装Solution 2:
1. 此问题也会发生在把系统语言设置为挪威语[Norwegian (Bokmal)]的时候. 默认语言选择US-English会正常进行安装。
更多有关此问题的信息可以查看http://consumer.installshield.com(可供用户查看常见错误的网站)中的Error -16... |
Problem Statement: 설치 혹은 업그레이드할때 아래와 같은 오류 발생: | Solution: 1:
설치작업을 중지하고 아래와 같은 내용 확인:
1. 설치작업을 관리자 권한으로 진행하는지 확인.
2. Administrators그룹은 C:\WINDOWS\Installer 폴더에 완전권한이 있어야 합니다.
만약 이 폴더를 볼수 없으면 폴더 옵션에서 보호된 운영 체제 파일 숨기기(권장)를 선택 안함 및 시스템 폴더 내용 표시
3. 설치 다시 시작.Solution 2:
1. 본 오류는 언어를 노르웨어[Norwegian (Bokmal)]로 선택했을때도 발생합니다. 디폴트로 언어를 US-English 로 변경하면 문제가 해결됩니다.
상세한 내용은 사이트... |
Problem Statement: Does the repository TSK_DHIS_AGGR have to have its settings (number of file sets, tuning parameters, etc.) match those of any other repository (for example, TSK_DHIS)? | Solution: This repository does NOT need to match the settings of TSK_DHIS (if it exists) or any other repository. They work independently.
Additional details about TSK_DHIS_AGGR, which is a repository used for the Stored Best Fit functionality introduced beginning in Aspen InfoPlus.21 V7.3.02, can be found inSolutions ... |
Problem Statement: Default options provided on IP.21 database for IP_VALUE_FORMAT fields used on IP_DiscreteDef, IP_AnalogDef or other type of records cannot be the suitable to use for some cases, this | Solution: provides explanation and guide on how to add new options on the list available for this field.Solution
List of options in IP_VALUE_FORMAT is defined by Selector records found in IP.21 database, this kind of records works as enumerated options binding an integer number with a string value; It is possible to fi... |
Problem Statement: After deleting / Removing a repository in the InfoPlus.21 administrator the Health Monitor is run and still shows the removed Repository. | Solution: This issue will occur when you delete a repository but have not stopped and started Infoplus21. InfoPlus21 whenever a Repository is added or removed has to be restarted in order for the snapshot to take effect.
To restart InfoPlus you will need to stop Ip21 from the Manager or Administrator
Keywords: Healt... |
Problem Statement: When trying to upgrade a snapshot using the Aspen InfoPlus.21 Database Upgrade Wizard, the upgrade process fails instantly with the following message:
Error in loading InfoPlus.21 snapshot.
The error terminates the upgrade process. | Solution: The snapshot in question is actually the base model snapshot. When selecting the Typical upgrade option this snapshot (named InfoPlus21DB.snp) can be found in the \AspenTech\InfoPlus.21\db21\etc folder. Make sure the snapshot exists and that file permissions allow you to read the file.
Keywords: UpgradeWizard... |
Problem Statement: When I try to import heat exchanger information from Aspen Plus into EDR I cannot import it and Aspen Plus is showing me the following error:
Also when I click the Size Shell&Tube button in Blocks| <block_name>| Setup folder, specification tab in Aspen Plus. Aspen Plus shows the error below: | Solution: This error appears when the Aspen Plus bkp file contains a dot “.” In the file name; for example xxxx.xxx.bkp. This is a common practice when you have installed several versions of Aspen Plus in the same machine and you want to include the version in which the file was created in in the file name; for example... |
Problem Statement: What properties are used with a free-water or dirty-water method that contains only water? | Solution: When you use the free-water or dirty-water calculation method, if a stream contains only water, all properties for the stream are calculated using the free-water method as if it was the main property method.
Keywords: None
References: None |
Problem Statement: What type of centrifuge is recommended for separating solid particles from thick suspension of coarse and semi-coarse particles (80-100 micron) in liquid? | Solution: A pusher type centrifuge can be used for separation of coarse solid particles from suspension. The centrifuge combines both centrifugation and filtration operation. A perforated drum is used as rotor for drainage of liquid. Inside the drum the separation of liquid and solids takes place. The product is transp... |
Problem Statement: When importing a file that uses OLI into a simulation, there is an error about the Chemistry.
****EXECUTION ERROR WHILE PERFORMING INITIAL ENTHALPY CALCULATIONS FOR
STREAM: NAOH
Error: A chemistry model is required to use the
OLI property option, but none was found. | Solution: OLI needs to have the database .dbs file in the working directory which is generally the directory where the simulation file is located. When importing from a file in another directory, you need to manually copy the .dbs file into the working directory.
Keywords: None
References: None |
Problem Statement: In Aspen Plus version 7.3 and earlier, you were able to place the model blocks in the simulation and adjust their sizes by selecting Resize Icon from the right mouse button. How is this done in version 8.6? I have a distillation column with a large number of side streams leaving and entering the co... | Solution: In V8.4, Resize Icon was removed from the drop-down list. Click and drag the handles on the corner of the selected block to resize the icon.
Keywords: None
References: None |
Problem Statement: When using the ‘Assistant – Property method selection’ from Methods | Specifications | Global (Tab) or from the Home (Ribbon) | Tools, and clicking on the ‘Next’ button, one can select between two options: Specify component type or Specify process type. However, there are some cases where those optio... | Solution: In order to avoid this, one has to change the security level under Windows Internet Options to ‘Default’. If changing to this level does not help, change it to ‘Low’.
This allows the assistant to get access without restrictions to the Aspen Plus Online Help. See screenshot below.
Keywords: Property Method Ass... |
Problem Statement: When trying to restore a database such as the legacy databanks in APLDB to the Aspen Properties Enterprise Database (APED), I get the message:
Error occurred while trying to restore the database from this file. [SQL-DMO]This cache contains no result sets, or the current result set contains no rows. | Solution: You need to check which account is being used to run SQLExpress. This can be checked in the Control Panels, Administrative Tools, Services. Do a right mouse click on the SQLExpress service, Properties and check the Log On account.
The error will occur if the account used does not have read permission in the f... |
Problem Statement: When running a model with calculator in Aspen Plus V7.2 with Excel 2010, the error message VBTableData object cannot be created is dispatched in the Control panel. What can be done to eliminate the error message. | Solution: The problem is that Aspen Plus V7.2 does not work with MS Excel 2010. There is currently no plan to address this issue for V7.2.
The alternatives are
1. Run V7.2 with Excel 2007or 2003.
2. Move the user calculation currently in Excel to use Fortran.
Keywords: calculator, Excel 2010, User2
References: ... |
Problem Statement: How to retrieve the vapor flow profile from Pres Relief calculations? | Solution: How to report the vapor flow in the property profiles from the Pres Relief calculations?
Those values are not reported directly in the results form from the Pres Relief tool in Flowsheeting options. However, there is another way to extract those results from Aspen Plus.
The Pres Relief tool calculates the pre... |
Problem Statement: In the new Aspen Plus User Interface from V7.3.2 and higher, after I open a new tab, older tabs disappear. How do I find tabs that have disappeared when new ones are created? Are they automatically closed when too many tabs are opened? | Solution: Using Workbook mode in V7.3 and earlier, the size of the tabs was automatically reduced as more tabs were created. In V7.3.2 and higher, the size of the tabs remains the same and new tabs will push the oldest tabs off the screen. At the right of the tabs, there is an icon that can be used to see a list of all... |
Problem Statement: What are the appropriate steps to take when the following error shows up on the control panel?
* WARNING IN PHYSICAL PROPERTY SYSTEM
NRTL BINARY PARAMETERS FOR ALL COMPONENT PAIRS ARE ZERO,
YOUR RESULTS MAY NOT BE ACCURATE. PLEASE REVIEW AND PROVIDE BINARY
PARAMETERS AS APPROPRIATE. | Solution: This error means that your NRTL parameters are all zero so you should look at them to see if that can be rectified.
Without the NRTL parameters, the case will be modeled as ideal. This will not happen if you have values filled into the NRTL parameters table. You can achieve this going to Tools | Retrieve Para... |
Problem Statement: In some models built in V7.1 or earlier versions, D2887 assays are entered. When the models are opened in V7.2 or later versions, the viscosity calculated for the streams with D2887 assay can be significantly higher. What has caused this discrepancy between versions? | Solution: There are many ways to generate distillation curve for a crude. The most accurate way is TBP curve (true boiling point curve). In Aspen Plus, only the TBP curve is used for generating the pseudo components. These pseudo components and their properties are used in simulation model to represent the crude feed a... |
Problem Statement: How to find the usability improvements in a newer version of Aspen Plus? | Solution: There is an easy way to quickly see the usability improvements added to Aspen Plus.
1. Open an Aspen Plus file and click on help menu icon (on the top right hand corner in the window below).
2. Click “What’s new in Aspen Plus V8.8�, if you are interested to know about the usability improvements ... |
Problem Statement: My simulation crashed and created a .dmp file. Can I send this to AspenTech without my .bkp file? | Solution: The .bkp file and the steps to reproduce the crash are all that is needed for development to investigate the problem. The .dmp (dump) file is not useful by itself; however, the .dmp file is sometimes helpful in diagnosing a non-reproducible crash when we have the .bkp file also. If a .log file is created, tha... |
Problem Statement: When the user specifies the parameter value of SRKWF manually for a component, under Methods | Parameters | Pure Components | New (Scalar):
This value does not seem to be updated when clicking on the Retrieve Parameters button and the result value of SRKWF remains still as 0, and confirm checking the... | Solution: User input will not affect the retrieved results shown on the form. User input will be included in the generated input file and therefore, it will be used in the simulation. In this case, the generated input file will include the following lines:
PROP-DATA PURE-1
...
PROP-LIST SRKWF
PVAL CIS-2-01 3E+4... |
Problem Statement: How to change the concentration basis for the reaction rate equation? | Solution: It is possible to select the concentration basis of a reaction. The concentration basis determines which form of the power law expression will be used. See the help for more information.
The steps for changing the concentration basis are as follows:
1. Go to the particular reaction set, for wh... |
Problem Statement: When the user tries to regress an equilibrium reaction’s constants, these constants cannot be regressed via Regression mode under the Properties Environment in Aspen Plus or Aspen Properties. | Solution: Instead of using Regression mode under the Properties Environment in Aspen Plus or Aspen Properties, use the ‘Data Fit’ option in the regular simulation mode under Simulation Environment | Model Analysis Tools | Data Fit, in order to adjust the chemistry A, B, C, D values for the equilibrium constant.
Keyword... |
Problem Statement: I can’t find a certain compound in Aspen Plus databanks, but it is available in the online NIST website: What can I do? | Solution: NIST TRC is a third party pure component databank that we make available for users to broaden our own resources. Aspen Plus includes a built-in version of the NIST databank that it is updated in each Aspen Plus release. You can add it by selecting the NISTVXX NIST-TCR under Properties / Specifications / Enter... |
Problem Statement: What are typical conveyance values in dense phase for pipes in solids conveying? | Solution: In order to use the dense phase conveying in Aspen Plus the throughput will generally be larger than 5 ton/h and have a pressure drop as high as 1–6 bar.
This method of conveyance is adopted to reduce gas requirements and to avoid wear of the conduit and abrasion of the product conveyed. The load ratio “μ” ca... |
Problem Statement: My exact packing is not available in the pack rating or sizing for Aspen Plus. What should I do? | Solution: The user can use user-defined packing in Aspen Plus, but not in HYSYS. In Aspen Plus, select USER as the Packing Type. Then the user needs to enter the packing parameters. The user can only do this under Sizing and Rating | Packing Sizing or Packing Rating:
Sample Steps for Pack Rating:
1. Navigate to ... |
Problem Statement: Aspen Plus Automation with C#: How to create a new reference to Aspen Plus COM starting object? | Solution: The following lines of code illustrate how to create a new instance of the starting COM object in Aspen Plus, the one that will give access to the rest of interfaces that it implements.
For a new document:
Type aspenPlusType = Type.GetTypeFromProgID(Apwn.Document);
IHapp aspenPlus = Activator.CreateInstance(a... |
Problem Statement: Version 7.1 of Aspen InfoPlus.21(IP.21) introduced a new feature called the IP.21 Configuration Tool Add-In.
It allows a user to retrieve and update current records and add new records from Excel Spreadsheets
The first step is after selecting the choice from the Aspen drop-down menu would be to click... | Solution: Part of the installation of this new feature is to load a file called 'excel.exe.config' into the same directory as excel.exe.
This file contains information to tell Excel which version of the .NET framework (v2.0.50727) has been installed.
This is important for the IP21 Tag Configuration because the IP21 Tag... |
Problem Statement: What kind of pressure drop correlations are used when vendors' packings are used in Pack Rating calculations? How does one check that the appropriate correlations are being used? | Solution: When performing a Pack Rating calculations in Aspen Plus, the pressure drop correlation used automatically default to vendor correlations if nothing is specified in the Design/Pdrop input form, Pressure drop calculation method field.
A list of the available correlations from vendor is found in the online Help... |
Problem Statement: How can I correctly release Aspen Plus COM object in VB.NET and C# (close Aspen Plus process) | Solution: VBA (old vb6 engine) and .NET are very different in the way they handle COM (managed vs unmanaged runtime environment). In VB.NET or C#, unlike VBA, the following code won't release the interface pointers on the COM object, so Aspen Plus process won't shut down:
myAP.Visible = False
myAP = Nothing
They will b... |
Problem Statement: Aspen Shell & Tube Exchanger can be linked to Aspen Plus to allow users to design, check/rate and simulate heat exchangers within their simulation. The method to link is described in the | Solution: #130470 “Design heat exchangers for chemical processes using Aspen Shell & Tube Exchanger and Aspen Plus”.
When this method is used, sometimes it may be noticed that the outlet temperature specification supplied to Aspen Plus may be slightly different to the outlet temperature given in the Results of the Shel... |
Problem Statement: Can I adjust the flooding factor for the flood calculation to predict flood for the actual diameters that have been obtained from plant data?
As an example it is known, from plant data, that flooding occurs for a 3m diameter column and it is required to carry out simulations using the Radfrac model ... | Solution: When carrying out a tray rating study the flooding calculation method can be selected from a drop down menu, in the Tray Rating | Setup | Design / Pdrop sheet, as shown in the screen shot.
For trays the Fair correlation uses the following correlation:
The Fair72 correlation is an improvement of the correlatio... |
Problem Statement: What does the warning message Fluid velocity is out of range to calculate Flow Regime� mean in Aspen Plus?
*WARNING
FLUID VELOCITY IS OUT OF RANGE TO CALCULATE FLOW REGIME
GAS SUPERFICIAL VELOCITY MUST BE BETWEENÂ 0.05 AND 500 M/S
LIQUID SUPERFICIAL VELOCITY MUST BE BETWEENÂ 0.005 AND 50 M/S | Solution: The correlation used to determine flow regime for pipe results has limits of applicability based on superficial liquid and vapor velocity. Since V7.2, when the liquid and/or vapor superficial velocities are outside the ranges of applicability of the Taitel/Dukler correlation used to calculate the result, flow... |
Problem Statement: I added two new assays into an old simulation which already have assays and generation objects.
When I try to select either of these two assays to be the composition of a feed stream (old or
newly created ) the assays do not show up listed on Streams Input folders, though previously created
assays sh... | Solution: When a model contains Assays, Generation objects, which defines unique set of pseudo components
to be generated for a given set of selected assays, user have to define additional Generation objects
and associate them with the new assays before the new assays can be selected on the Stream/ Input
folders. That ... |
Problem Statement: If I want to conduct a typical calcination reaction within the RGibbs model in Aspen Plus, I do not get the required temperature that is typically reported for the reaction listed below:
Reaction: CaCO3=CaO+CO2
I do not understand why this is the case. The observed temperature is usually lower than t... | Solution: It is a known issue that calcination takes place at specific conditions and if the temperature is too low, the reaction can’t take place. But when the user’s model has H2O present in the process the reaction conditions can change. H2O present in the gas will cause a smaller partial pressure for CO2, which i... |
Problem Statement: Radfrac경우, V8.0부터 Property method을 변경하거나 선택하기 위해 사용되는 block options form이 더 이상 지원되지 않는다. | Solution: Block options form은 Radfrac이외의 모든 block에는 기존처럼 이용가능하다.
Radfrac경우, 다음 경로에서 block option form을 확인 할 수 있다
Radfrac |Specifications folder| block options
Please findSolution 136908 for the original English version.
Key Words
RateSep
Keywords: None
References: None |
Problem Statement: When calculating the heat capacity (Cp) of water with various property methosd, we found that the heat capacity calculated using IAPWS is extremely large around critical point.
The Cp using IAPWS is 1501 cal/gm-K at 218.3 atm Cp using STEAMNBS is 1380 cal/gm-K at 218.1 atm.
Are these reliable res... | Solution: The heat capacity (Cp) of a substance is infinity at the critical point; therefore, the large values observed with different property methods are expected.
Keywords: results, heat capacity, limits, range
References: None |
Problem Statement: When performing flash calculations involving certain solid components, the calculation may get hung up at a certain point, unable to converge.
In other types of calculations, apparently anomalous jumps in enthalpy may be observed for solid components at certain temperatures.
For example, for Olivine ... | Solution: For many components, especially in the INORGANIC databank, multiple versions are available which represent the individual solid forms, as well as a single component which represents the entire range. Commonly, the parameters CPSXP1, CPSXP2, etc. are provided to specify enthalpy for the combined component. You... |
Problem Statement: I would like to set the operating pressure of Radfrac from a calculator block. I cannot decide which variable I should refer to in the calculator block? There are PRES, PRES-STAGE1, PRES-STAGE2 etc. I am not sure which one I should choose as output variable for the calculator | Solution: If you use the variable name as described below (stage-pres) (see screen shot and the attached example file) then you should be able to specify the pressure for any stage in the column. Note the field ID1 refers to the stage number.
The calculated pressure can be verified on the TPFQ tab in the Profile form f... |
Problem Statement: I am getting an error in the Control Panel for a design specification:
MANIPULATED PARAMETER NOT CHANGING. PROBABLE CAUSE:
EITHER TOL-SPEC TOO SMALL OR XTOL TOO LARGE.
Depending on specifications, this may be accompanied by:
THE CONVERGENCE LOOP WILL BE EVALUATED ONCE MORE.
What are TOL-SP... | Solution: The error message indicates that the variable specified in the design specification changes very rapidly with respect to the manipulated variable near the target value. This results in the design specification taking smaller and smaller steps. It converges, in the sense of reaching a near-constant value, but ... |
Problem Statement: I have an RBatch reactor in the simulation and it is specified with continuous feed for a certain period. After running the simulation, the following error message is displayed:
**Â Â ERROR IN THE BLOCK PARAGRAPH WHICH BEGINS ON LINE 266
     BLOCK NAME: B1   MODEL NAME: RBATCH    SKW... | Solution: To solve this problem follow the instructions below:
1. Export the simulation file as an input file. To do it go to File | Export | Export a document | Select input file *.inp.
2. Open the input file in the Notepad application.
3. Check continuous feed time: you may see that there are some units s... |
Problem Statement: In V7.3.2, the menus and toolbars have been replaced with a ribbon interface. The File menu still contains the familiar commands for opening and saving files. Other commands have been relocated onto a set of ribbon tabs, with the most frequently used commands together on the Home tab. I am used to th... | Solution: In the help there is a map of the old commands in V7.3 and earlier to the new commands in the ribbon.
To find it, simply, go to the Getting Started tab of the ribbon and click on Ribbon Mapping. This links to the Help Contents | What's New in Aspen Plus V7.3.2 | Mapping Commands to the Ribbon topic.
This list... |
Problem Statement: When using a RBATCH reactor and you try to export an input file with a continuous feed input from a previous Aspen Plus version, for example V7.3 the following error message is shown in the control panel: | Solution: The issue when you try to export an input file with a continuous feed input from a previous A+ version is related to an invalid set of units in that previous version, located under RBATCH (model name) | Setup | Continuous Feeds | ‘Specify flow vs time profile’. On the new GUI (Graphical User Interface), there... |
Problem Statement: My HEATX heat exchanger is bypassed. The error is
Block: BOILER Model: HEATX
** ERROR WHILE GENERATING RESULTS FOR UNIT OPERATIONS BLOCK: BOILER
(MODEL: HEATX)
COLD STREAM IS HOTTER THAN HOT STREAM
BLOCK BYPASSED | Solution: The problem in this file is that the cold stream was connected to the hot stream port of the HEATX rather than the cold stream port.
To solve this problem, the connections need to be reversed by disconnecting and reconnecting them to the correct port. If you hover over the port on the block, a pop-up help box... |
Problem Statement: When using a Heat exchanger in countercurrent and using the Hot/Cold outlet temperature approach I am observing convergence problems. | Solution: If the heat exchanger is in countercurrent and you use the Hot/Cold outlet temperature specification, the simulator is going to have a hard time estimating the possible results, particularly during initial iterations, which could cause convergence problems for the block.
This is because this specification is ... |
Problem Statement: When opening a newer file in an older version, all of the databanks are missing | Solution: With the most recent patches, it is possible to open newer version such as V8.4 in V8.2, V8.0, or even V7.3. You will get a message about the file being created in a newer version. New features will, of course, be lost.
The problem is that if you used the Aspen Properties Enterprise Database (APED), the pro... |
Problem Statement: I am unable to run economic evaluation in Aspen Plus V7.3.2.
I run Aspen v7.3.2 model, then activate Economics. After finishing mapping, the icons remain grey out (Figure 1) and can't see results of economic analysis or proceed any further. I have installed Economic Evaluation V7.3 on machine.
Fi... | Solution: This happens because Economic Evaluation V7.3.2 suite is not installed on machine. Economics Evaluation suite version should match the Aspen Plus version in order to have this functionality to work.
Install economics Evaluation V7.3.2 on machine and you will be able to complete economic analysis in Aspen
Plus... |
Problem Statement: Is a chemical reaction involving no-nconventional components allowed in an RGIBBS reactor? | Solution: The only physical properties that are calculated for nonconventional components are enthalpy and density. As quoted in the Getting Started manual, the RGIBBS reactor models chemical equilibrium by minimizing Gibbs Free energy. The Gibbs free energy of nonconventional components are not calculated.
Therefore, ... |
Problem Statement: How to calculate additional properties for streams within hierarchy blocks. | Solution: In some cases it is necessary to calculate additional properties for streams only inside Hierarchy blocks.
There are two options to do that:
1. Â Open Blocks| Hierarchy_block_name| Setup| Report Option folder| Stream sheet and add additional Property Sets which include properties to report, as shown in th... |
Problem Statement: What does the following error mean and what can I do to solve it when working with RCSTR, FPlug or RBatch?
* WARNING REACTION RATE IS GREATER THAN ZERO FOR REACTION (X) BUT REACTANT X IS NOT PRESENT. POSSIBLE CAUSE: ZEROTH ORDER REACTANT NOT PRESENT
** ERROR M-BAL LOOP DID NOT CONVERGE | Solution: This error commonly occurs when the driving force term for the kinetic reaction has not been defined (the exponents for the rate equation have not been entered, see picture below). In this case a zeroth order is assumed for all reactants. This means that the reaction will continue even when one of the reactan... |
Problem Statement: When using an Aspen HYSYS property method such as HYSPR in Aspen Plus, the density predicted for water is too way high. | Solution: When using the HYSYS property methods such as HYSPR or HYSSRK, it is recommended that the HYSYS property databank be selected first.
For a case of a pure water stream at 300 psia, there is almost a 25% difference between either HYSPR or HYSSRK and the Steam Tables (STEAMNBS) if HYSYS is not selected as th... |
Problem Statement: Which correlations are used in the HCJ1BOIE enthalpy model for NC Solids? What does the option code allow to select? | Solution: The HCJ1BOIE enthalpy model can be selected from the Property environment, Methods | NC Props sheet. When selecting HCJ1BOIE, as shown in the image below, there is only one option code that one needs to specify. This option code refers to the Heat capacity correlation. The 2 codes that can be specified are:
... |
Problem Statement: After deleting a component, I cannot run because many property parameter forms are now incomplete. | Solution: After deleting a component, parameter data for that component is also deleted. When retrieved parameter data is deleted some forms or columns could be left empty. Aspen Plus does not delete the forms automatically to make sure that it does not inadvertently delete any data.
If you go to “Clean Parameters” fro... |
Problem Statement: Is there any way to get AspenPlus to calculate and set automatically the required amount of air that is needed for stoichiometric combustion? | Solution: A simpleSolution is to use a DesignSpec and to vary the oxygen inlet until combustion is complete.
As an example suppose we have carbon and hydrogen being fed into a Gibbs reactor and it is required to calculate the stoichiometric oxygen requirement for combustion of inlet carbon and hydrogen into carbon diox... |
Problem Statement: I am migrating my V7.1 models to V7.3. The files that I ran in 7.1 gave results that I expected, but the same files in V7.3 gave strange and substantially different results, even while keeping the same V7.1 databases. I am suspicious that the problem may somehow be associated with some of my componen... | Solution: This is a compatibility issue resulting from the way Aspen Plus V7.3 handles solid type components compared with versions V7.2 and earlier.
This is documented on Aspen Plus/ Help/ What?s new in Aspen Plus V7.3 (Figure 1)
Figure 1. Aspen Plus/ Help/ What?s new in Aspen Plus V7.3
In V7.3, components marked ... |
Problem Statement: Is it possible to have a component be both a salt and an apparent component that dissociates using electrolyte chemistry? | Solution: It was possible in earlier versions to one component be both a salt and an apparent component though it was not recommended. Now, in V7.3 and later, two components should always be specified since components with a type of solid are calculated using solid property parameter models. The salt should be specifie... |
Problem Statement: When specifying that the solid substream for a RPlug reactor is at a different temperature, do you need a user kinetic subroutine? If so why? Can you give some guidance as to how to use this feature? | Solution: In V8.6 and earlier, if you specify the substreams are at different temperatures, you must supply a user kinetic subroutine. This subroutine must calculate FLUXM and FLUXS, the rates of components transferred between substreams, in order for Aspen Plus to properly calculate the enthalpy of each substream (acc... |
Problem Statement: I received an Aspen Plus simulation with a custom table. The names of the variables in the custom table do not indicate how to find them in the simulation. How can I identify the path of this variables to its unit operation? | Solution: If you right click in one of the headings of the custom table, a contextual menu will be shown, see image below:
Select the option choose columns:
You will be able to add the variable name and the path as a column to the custom table.
This way you will be able to see easily the path to the variable and locate... |
Problem Statement: Where can I find Unit-set option for results in new Aspen Plus V7.3.2 GUI?. I could not find the Output Results unit option in V7.3.2, but here is a screenshot of the old version: | Solution: You still select the global units of measure on the Setup | Specifications | Global sheet.
It can also be selected on the Units section of the Home ribbon.
The difference is that there is only one global unit set now rather than Input and Output units.
In V7.3 and earlier:
Units of measure were set at t... |
Problem Statement: Which flooding calculation method is used by Aspen Plus by default in a RadFrac block when none is specified by the user for tray sizing? | Solution: By default when the user does not specify any method for flooding calculations in a RadFrac model for tray sizing:
Aspen Plus uses Glitsch calculation method as default. This can be checked under the ‘Report’ which can be generated from the simulation environment Home (ribbon) | Summary (group) | Report. With... |
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