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Problem Statement: aspenONE Process Explorer client opens with the following error message:
CheckXML(): Failed to parse: <!DOCTYPE HTML PUBLIC -//W3C//DTD HTML 4.01//ENhttp://www.w3.org/TR/html4/strict.dtd>
<HTML><HEAD><TITLE>Server Unavailabl | Solution: Make sure the AspenProcessDataAppPoolx64 is running in IIS. If it's not running, try to start it. If it's configured to run under a specific user account and the account password has been changed recently, reset the password on the account in IIS and try starting the app pool again.
Keywords: None
References: None |
Problem Statement: How do I enable on-demand PRT files for Aspen Process Controller FIR and MISO applications? | Solution: The entry DebugPrintCounter needs to be configured for FIR (DMCplus) and MISO (NonLinear) applications.
Note: The DebugPring entry does not have any effect on the Debug output for FIR or MISO based Aspen Process Controller –RTE- applications (only MIMO).
For Windows 2008 R2 64-bits and Windows 2012 the PRT file(s) can be found in:
C:\ProgramData\AspenTech\RTE\Vx.x\Clouds folder
For FIR is already available in the Controller Detail page.
For MISO, via PCWS / Configuration tab / Column Sets / APC / Category: General, APC column set to edit: Controller Detail (MISO), add DebugPrintCounter. Move Up to be sorted alphabetically. Apply the changes.
Keywords: Aspen Process Controller, PRT, debug, DebugPrintCounter, FIR, MISO
References: None |
Problem Statement: This Knowledge Base article provides steps to resolve the following error message received in Aspen Search when performing a Data Source Scan:
Scan Data Sources throws a timeout error : Failed to publish tag metadata to localhost ( Failed to send HTTP request ( The operation was timed out)) | Solution: The timeout error can be solved by incrfeasing the initial and maximum memory pool in Tomcat Java settings. Below are the configuration steps that resolve the issue:
1. Navigate to the Tomcat/bin folder, e.g., Program Files (x86)\Common Files\AspenTech Shared\Tomcat7.0.57\bin
2. Run tomcat7w.exe
3. Double default memory settings as follows: Initial Memory Pool -> 256, Maximum memory pool -> 512 (or higher)
4. Restart Tomcat Service
5. Publish the data source that previous experienced HTTP 500 errors from the Admin Tags tab on Aspen Search page.
Keywords: Failed to publish tag metadata to localhost
Failed to send HTTP request
The operation was timed out
References: None |
Problem Statement: This Knowledge Base article shows how to schedule the daily automatic database scans by Data Source. | Solution: It is not possible to schedule the daily automatic database scans by Data Source from the Manage Search Data Admin UI. However, this can be accomplished by creating an aspenONE Scheduler Job for each data source that should be scheduled:
1. On aspenONE Process Explorer server, go to Tomcat folder, c:\Program Files (x86)\Common Files\AspenTechShared\Tomcat7.0.57
2. Navigate to Tomcat Scheduler Jobs folder in appdata\scheduler\config\jobs
3. Copy NPEScanData to another folder, rename it, and copy the renamed folder back to scheduler\config\jobs
4. Restart Tomcat
5. Log into the Scheduler: http://localhost:8080/AspenCoreSearch/scheduler using Tomcat username and password (admin/admin is the default)
6. Go to the Job you created, expand it, open Primary Workflow
7. Change the AtProcessDataRest.dll method in the Data Source URL field from ScanAllLocalDataSources to ScanTagsByLocalDataSource/<datasource> where <datasource> is the name of the particular data source you want to scan
8. So, the format of the URL used in the Scheduler should look like this: http://localhost/ProcessData/AtProcessDataRest.dll/A1/ScanTagsByLocalDataSource/datasource
9. Close Primary Workflow and open Schedule
10. Schedule scan by clicking radio button to the left of Every and select 24 hours for a daily scan
11. Specify the Starting date and Time when Scan Schedule will begin
12. Scroll up and press Save
13. Data Source will be scheduled at the defined interval
14. Open the Manage Search Data Admin UI ( http://localhost/ProcessExplorer/WebControls/PBItemDetails.asp?admin=true ) after this scheduled time has been reached to see the log of the scan on the All tab
Please note that you were to do this backend configuration you should not ever configure any scheduled scans from the Admin UI as that would add automatic scans to these manually configured backend scans.
Keywords: None
References: None |
Problem Statement: What is the position of the impingement plate for an exchanger with a dome? | Solution: Aspen Shell and Tube Exchanger can help users design an exchanger with a dome and insert an impingement plate(round/square). The default position of the impingement plate is on the top of the tube bundle as shown below.
If users would like to change this position, they can first select Dome as the Nozzle/Impingement type at Input>Exchanger Geometry>Nozzle>Shell Side Nozzles and then go to Impingement tab to specify Impingement plate clearance to tube edge.
Giving this number will result in a more accurate RhoV2 for shell entrance.
Keywords: Position, Dome, Impingement Plate clearance to tube edge
References: None |
Problem Statement: Since Microsoft Visio gives users the ability to make custom graphics and symbols and copy them to a user's clipboard, can you create custom symbols in Microsoft Visio and use then in an aspenONE Process Explorer graphic? | Solution: AspenTech only supports symbols and graphics developed by AspenTech.
The symbols created by AspenTech can be found in the directory:
C:\Program Files (x86)\AspenTech\Web21GraphicStudio\Libraries\Basic
You can create graphics in .WMF format and import them into AspenOne Process Explorer.
Keywords: Visio
Custom symbols
References: None |
Problem Statement: In Aspen Shell and Tube Exchanger, the users can import a customized Aspen Properties file through Input | Property Data | Hot (Cold) Stream Compositions | Advanced Options. Normally, after importing the file, the corresponding stream should have the same properties as shown in the Aspen Properties file, e.g. specific enthalpy, viscosity, thermal conductivity, density, etc.
However, the users might see different properties values after importing a file that is using ELECNRTL or ENRTL-RK. | Solution: When an Aspen Properties file is used in EDR with ELECNRTL method, the mole fraction of the true component should be specified.
The users need to go to Input | Property Data | Hot (Cold) Stream Compositions | Compositions, and enter the true component composition, i.e. the electrolytes' mole fraction. Then, go to Hot (Cold) Stream Properties | Get Properties, the properties should now be the same as seen in the Aspen Properties file.
Keywords: Aspen Properties, ELECNRTL, ENRTL-RK, EDR, True components
References: None |
Problem Statement: The following error occurs when trying to add a comment to an aspenONE Process Explorer Event Plot: | Solution: This error occurs because aspenONE Process Explorer is attempting to historize a comment or annotation in a record that does not exist. This error occurs most frequently when there is no Aspen InfoPlus.21 database that contains the commenting record, Comments, which is defined by IP_CommentDef. To enable this feature, follow theSolutions in AspenTech KB article 143917.
Keywords: Comments
aspenONE Process Explorer
References: None |
Problem Statement: When modeling a Reflux condenser, where can I find the calculated flooding velocity? | Solution: The calculated flooding velocity will be reported in the Warning/Messages|Advisory Notes section under Advisory Note 1334
Keywords: Relux condenser, flooding velocity, Advisory Note
References: None |
Problem Statement: What is the aspenONE Credentials utility - also known as aspenONE Search Engine Configuration? | Solution: aspenONE Credentials is a utility that can be used to change the Tomcat and/or LDAP username and password everywhere on the server. When the Tomcat username or password changes, it will encrypt the new username and password in the required formats and update all the configuration files. It will also update the username and password for the SOLR Domain Security User. It updates the required HPT and aspenONE Process Explorer configuration files.
aspenONE Credentials can be started from the Windows tile interface or the Start Menu on the server.
Keywords: None
References: None |
Problem Statement: Since event plots source data from Aspen Production Record Manager, does Aspen Production Record Manager have to be configured in order to use aspenONE Process Explorer's Event Plots? | Solution: Event plots can source data in three ways:
1. Aspen Production Record Manager
2. Comments
3. Alarms
If Aspen Production Record Manager is not installed, event plots can still be used if they are use data from comments or alarms.
Keywords: Event Plots
Aspen Production Record Manager
References: None |
Problem Statement: External enhancements are designed for boiling and condensing applications. How can one model the external enhancements in the Aspen Shell & Tube Exchanger Program? | Solution: The program does not explicity model the external enhancement on the tubes. One can make allowance for it by explicity specifying the shellside heat transfer coefficient or by specifying a multiplier for the calculated coefficient. This can be found under Program Options / Thermal Analysis / Heat Transfer tab.
In addition, performance data can be supplied under Program Options / Methods-Correlations / Enhancement data tab. The data that can be supplied is Reynolds numbers, Colburn factors and friction factors for the shell side and tube side.
The program then will use this data to calculate pressure losses and heat transfer coefficients.
Keywords: external enhancement, tube enhancement
References: None |
Problem Statement: How do I prevent Input error 1124: The data input for separate cold liq/vap is unacceptable? | Solution: The Input error 1124 is coming due to the cold side's outlet nozzle specification. Aspen Shell & Tube Exchanger requires a kettle or knockback condenser to have separate nozzles for liquid and vapor outlet. You will get this error if you choose no for Use separate outlet nozzles for cold side liquid/vapor flows. The way to fix the error is as follows:
The detail path: Input || Exchanger Geometry || Nozzles || Shell Side Nozzles || choose Yes for Use separate outlet nozzles for cold side liquid/vapor flows.
Note: If you don't have a liquid product, choose yes and don't provide any dimension under liquid product. If there are default numbers, you need to take them off. You should only provide the vapor outlet nozzle dimensions in this case.
Keywords: ShellSide Nozzel, Input error 1124, Cold side liquid/vapor flow
References: None |
Problem Statement: From Input > Exchanger Geometry > Bundle Layout > Layout Parameters tab, the “Number of sealing strip pairs” can be entered. This | Solution: explains what they are and what the impact of using them are.Solution
If the baffle cut is in line with the nozzles, the need to provide entrance/exit areas by leaving out tube rows may result in excessive by-passing of the tube bundle. Sealing strips can be used to reduce bypassing of the shell side flow around the bundle between the shell inner diameter and the outer most tubes (outer tube limit, OTL).
Sealing strips consist of thin plates fitted into slots in the top and bottom of the baffles, and are normally fitted to seal the free area between the bundle and the shell. It is usual to speak of 'pairs' of sealing strips, each strip installed at the top of the bundle having an opposite one at the bottom.
In fixed tubesheet (L, M & N rear heads) and U tube exchangers, the clearance between the shell ID and the OTL is comparatively small. Therefore sealing strips are seldom needed for these types. For floating heads (S, T, P &W) the potential for bypassing greater and in these cases sealing strips are generally required.
In Aspen Shell and Tube Exchanger, sealing strips are always present (unless set at zero), and when omitted one pair of sealing strips is used for every 6 rows of tubes in crossflow.
If there are in-line pass partitions lanes, Shell & Tube will assume that these have corresponding extra sealing strips.
Sealing strips, can be seen from Results > Mechanical Summary > Setting Plan & Tubesheet Layout > Tubesheet Layout tab.
The inclusion of sealing strips helps increase the fraction of the total flow passing through the bundle and hence gives higher heat transfer coefficients, particularly for single phase flows. They also introduce a corresponding penalty in terms of pressure drop in the shellside stream.
Keywords: Leakage flows, bypass, flow fractions, flow splits
References: None |
Problem Statement: Getting Invalid Map (IP_AliasMap) when refer to an Alias tag on A1PE graphic. | Solution: This issue is due to the IP_AliasMap that gets specified in the Map portion under the Data tab in Properties due to the fact that it is an alias record. Please remove the map and specify <VALUE> in the Attribute portion as per below.
Save and republish the graphic. Clear the browser cache and check if the value is showing.
Keywords: Invalid map
IP_AliasMap
References: None |
Problem Statement: This Knowledge Base article provides steps to resolve the following issue:
Some Ad-hoc calculation are working in aspenONE Process Explorer while others are not.
Examples:
 =movingaverage({WIT-14005}, 00:01:00) does work
 =log10({WIT-14005}) does not work | Solution: Run the following command in the directory where the CalcBuiltinFunctions.dll file is located:
C:\Windows\Microsoft.NET\Framework64\v4.0.30319\regasm CalcBuiltinFunctions.dll /codebase /tlb:CalcBuiltinFunctions.tlb
Verify that you are able to trend in A1PE the Ad-hoc calculation that was failing before.
Example:
 =abs({WIT-14005})
Keywords: calculations
References: None |
Problem Statement: The message Unable to validate server response. Search Service responded with the following error HTTP Code: 512 appears while opening the search in a single event plot when trying to add a characteristic.
This may also appear with other aspenONE Process Explorer plotting options. | Solution: The error is associated with a lack of domain security configuration in the aspenONE Credentials tool. To correct this, close out of aspenONE Process Explorer and open the aspenONE Credentials tool by navigating to Start | All Programs | AspenTech | Aspen Manufacturing Suite | aspenONE Process Explorer | aspenONE Credentials.
To correct the issue, check Domain Security and specify the option to be either ON or OFF, but do not leave it blank. After closing this tool and re-opening aspenONE Process Explorer, the error should no longer be present.
Keywords: Unable to validate server response
Search service responded with the following error
HTTP Code: 512
aspenONE Credentials tool
References: None |
Problem Statement: How do you add internal fin tubes in the Aspen Shell & Tube Exchanger? | Solution: Internal Fin tubes are not very commonly used in general heat transfer application because cleaning of these tubes is extremely difficult. Direct modeling option of these tubes are not available in EDR however we have few workarounds available.
1. You can include these as Relative Roughness. That will help to predict accurate pressure drop.
2. Relative roughness will not increase the tube side heat transfer area. To adjust the excess heat transfer area you could reduce the fouling factor (may be no fouling factor at all). If you think even zero fouling-factor will not be enough. You could increase tube wall's conductivity.
Keywords: Internal Fin Tubes, Tube Roughness
References: None |
Problem Statement: After upgrading aspenONE Process Explorer, the search page does not load and the waiting “spinner” icon spins continuously. This was working correctly before the upgrade. | Solution: This is known behavior which can occur if you had not cleared the browser cache before returning to the upgraded aspenONE Process Explorer web site (URL). Instructions for clearing the cache should be provided by the web browser product.
Keywords: a1PE
Search for Everything
References: None |
Problem Statement: I can't seem to find the Aspen Assay Manager help file. There is no usual Help tab like in Aspen PIMS and Aspen Petroleum Scheduler. | Solution: All newly developed AspenTech software will have a question mark icon in the top right of the screen, just under the Close button. This is not what most PIMS and APS users have been used to over the years.
Another way of reaching the help file is by pressing F1
Help icon is also shown with a red arrow on the capture below:
Keywords: Aspen Assay Maanger
HELP file
F1
References: None |
Problem Statement: STI files are created by STX™ from AspenTech.
STX was the predecesor of Aspen Shell and Tube Exchanger. STX allowed users to design and rate shell and tube heat exchangers with methods based on open-literature. This | Solution: explains how to convert the .STI files into .EDR files using EDR V8.4.
Solution
In V8.4, the File Conversion Utility is not included in the Star Menu / Programs / AspenTech / Exchanger Design and Rating V8.4 folder.
Therefore, in order to convert the STI files, the following procedure has to be done.
The user will need to locate the utility in the installation folder C:\Program Files (x86)\AspenTech\Aspen Exchanger Design and Rating V8.4\XEQ and run the file “SaveAs EDR” as shown below.
STX creates various files with extensions: .STI, .STO, .HOT, .CLD.
In order to use the File Conversion Utility as mentioned in Knowledge BaseSolution 125142, the users need to have all those files saved in the same folder.
Then select STX as shown below and the source and destination of the file. Finally, the users need to click on convert and close the file converter utility.
Keywords: sti, file conversion utility
References: None |
Problem Statement: I have linked a Heat Exchanger in Aspen HYSYS to Aspen Exchange Design & Rating (EDR) through the Rigorous Shell and Tube Feature. The reported properties, however, for the streams in Aspen HYSYS are not identical to the liquid and vapor properties inside the EDR Overall Summary Form. How can I get a better match between the two programs? | Solution: There should be a close match between the values reported in HYSYS and EDR. To get a closer match between the properties, the user will have to match the estimated pressure drop in Aspen HYSYS to the pressure drop calculated in EDR. Through the Heat Exchanger|Rigourous Shell&Tube|Process input inside HYSYS the user can match the estimated pressure drop with the pressure drop reported inside the associated EDR file.
To further tighten the difference in property values between the two simulations, the user can increase the number of pressure levels inside the Property Ranges Form. Furthermore, the user can enter a temperature range that matches with that stream data inside the overall summary page inside EDR.
If the discrepancy between HYSYS and EDR is still too large please send the simulation through to [email protected].
Keywords: EDR, HYSYS, Rigourous Shell&Tube
References: None |
Problem Statement: The input and calculated values in the Nozzles page of the Exchanger geometry are not consistent. For example, when introducing a new Actual ID (inner diameter) for the same Actual OD (outer diameter), the value of the wall thickness is not updated. | Solution: If the user wants to introduce the internal ID and the thickness of a shell side nozzle in an existing bundle layout (Simulation/Rating mode), please follow these steps:
a. Go to Input/Exchanger Geometry/Bundle Layout
b. Choose the tab ‘Tube Layout’
c. Select the ‘Nozzles’ view from the drop-down menu.
d. Enter the ‘Internal Diameter’ and the ‘Wall thickness’ in the table below the schematic.
These values are the ones now appearing in the Input/Exchanger Geometry/Nozzles menu. If a Nominal Pipe Size is chosen, so that the actual outer diameter is different from the one calculated from the user input ID values, then a new outer diameter is calculated (as ID + 2* Wall thickness) and used instead.
This internal diameter will be used to calculate the Shell Nozzles area (as can be confirmed from the Results in Flow Analysis tab).
Keywords: Nozzles, Nominal, Pipe, Inner, Outer, Diameter, Wall thickness, Shell
References: None |
Problem Statement: How do I find vibration tubes in the Tubesheet Layout output? | Solution: To see vibration tubes in the Tubesheet Layout output, click the Vibration Tubes box above the diagram. A red V appears on the vibration tubes, and a table with further information on these tubes appears below the Layout. If there is a very large number of tubes in the layout, you need to zoom in to be able to see this. If there is a vibration or resonance risk, the tube is drawn as two displaced circles to give a visual indication of the problem. For vibration, the tubes are displaced horizontally, and for resonance, vertically. Four displaced tubes are drawn when both effects are present. The extent of the risk is also indicated in the table below the layout.
Each vibration tube has a number which allows you link it with the main Vibration and Resonance Analysis results. Numbers 1-8 are used for program-selected vibration tubes, and numbers 10-15 for user selected ones. Numbers 21-28 are used for program selected tubes in the second shellside flow half of an F-,G- or H-shell. Not every number will appear, because numbers define representative locations and are often specific to certain baffle orientations or types.
The program-selected vibration tubes are chosen to be representative of potential worst cases. You will see that they are concentrated in the baffle windows, where support for the tubes is less frequent, and near inlet and outlet nozzles, where flows are highest.
Keywords: tube layout, vibration
References: None |
Problem Statement: If installing aspenONE Process Explorer as a Workgroup machine you may get error Null | Solution: Edit file web.config found in c:\inetput\wwwroot\AspenTech\DispatchService\Metadata and look for keys LocalMetaDataService and LocalSearchServer. Remove any reference to .WORKGROUP so that the entries just include the system name.
Keywords: Null
References: Exception when trying to scan all data with url such as:
localhost/ProcessExplorer/webcontrols/pbitemdetails.asp?admin=true |
Problem Statement: This Knowledge Base article provides steps to resolve the following issue with aspenONE Process Explorer trend files:
a1PE trend links disappear from the Navigation Pane overnight even though the XML files are still in the web server. Moving the files out of the folder they are in and putting them back in resolves the issue temporarily for the day. The issue comes back the next day. | Solution: The issue is caused by a backup routine that runs at night and changes an attribute on the trend files. The Attribute A, which indicates that a file is ready for archiving, is changed overnight by a backup routine to N, which indicates that a file has been archived.
However, aspenONE Process Explorer does not support files that do not have the “A” attribute set and that's why they are not displayed in the Navigation Pane.
Here is how to check the attribute status on your trend XML files:
· Go to the location where your a1PE files ar saved, such as C:\inetpub\wwwroot\AspenTech\ProcessExplorer\Files\Public\
· Right click on one of the trend XML files and select Properties from the Context menu
· Switch to the Details tab and verify that the value for Attribute is “A”
· If not, then go to the General tab, click the Advanced button and tick the “File is ready for archiving” box
· Click OK all the way out to save your changes (see screen captures below)
· Go back to the Details tab to verify that the value for the Attribute is now A
· Next go to the Navigation Pane in aspenONE Process Explorer and notice that the link to the missing trend has re-appeared.
To resolve the issue permanently, the server backup routine must be modified to not change the file Attribute to N on the trend XML files or the folder where the files are save needs to be excluded from archiving.
Keywords: gone
removed
vanished
missing
References: None |
Problem Statement: This knowledge base article explains how to create a dynamic list for a custom definition record in aspenONE Process Explorer. Aspen InfoPlus.21 updates a dynamic list whenever a record in the list changes. This provides a convenient way to display a tabular display based on fields from the records. | Solution: Suppose we have a custom definition record named Cst_BasicRecDef defined as follows:
with the following records defined against Cst_BasicRecDef:
Follow these steps to create a dynamic list for Cst_BasicRecDef:
1. Create a new SummaryDef record and set values for fields SUMMARY_LINE_LENGTH and MAX_SUMMARY_LINES:
2. Create default base record for Cst_BasicRecDef. The naming convention for default base records is d-recname, where recname = definition record name without the trailing string Def. So the name of the default base record for Cst_BasicRecDef would be d-Cst_BasicRec.
3. Create a new SummaryLineDef record to format the lines displayed in the summary. Set the fields DEFAULT_BASE_RECORD to the name of the default base record, #SUMMARY_DESCS to the number of columns to display in the summary, and #SUMMARIES to 1.
1.s
4. In the #SUMMARIES repeat area add a reference to the SummaryDef record created on step 1:
5. In the SUMMARY_DESCS repeat area add the fields containing the data to display in the summary lines using the default base record name.
6. Return to the record created on step 1 and populate the SUMMARY_LINE repeat area with the list of the tag name to display on the dynamic list as well as the field to activate the refresh of the value. Use a query to populate this record, for this example:
7. Follow steps inSolution 142496 and use your custom SummaryDef record created on step 1 instead of IP_AlarmSummary to create a dynamic list published on aspenONE Process Explorer, the grid object configuration should have your custom records fields as follow:
8. Publish the graphic. The result in aspenONE Process Explorer will be displayed like this:
Keywords: Custom record
Dynamic list
aspenONE Process Explorer
SummaryDef
SummaryLineDef
References: None |
Problem Statement: Aspen Process Explorer graphics are created and viewed with the .atgraphic extension, but this extension is not readable by aspenONE Process Explorer. This | Solution: describes how the graphics can be converted, in bulk, into .json files that are readable by aspenONE Process Explorer. In this way, the graphics do not need to be redrawn or opened and converted one by one.Solution
First, collect all your .atgraphic files and place them into one folder. These graphics can be further organized into subfolders as desired. The organization of the files within the folders will also be the organization by which the graphics appear in the aspenONE Process Explorer application frame.
Next, open the Aspen Process Graphics Editor and select File | Publish Multiple to aspenONE Process Explorer... and browse for the root folder that contains all of your graphics. Once you highlight the name of the root folder, Press OK and confirm the source folder and the publish path.
Pressing OK will migrate all of the graphics to aspenONE Process Explorer.
Keywords: Migrate graphics
References: None |
Problem Statement: For Aspen InfoPlus.21 versions V8.8 and earlier, an .rld file from KB | Solution: 143917 can be used to load the necessary files to allow commenting to work in aspenONE Process Explorer V8.8.1 or later. Do I need to load this file onto all my Aspen InfoPlus.21 servers?Solution
For each aspenONE Process Explorer web server, there only needs to be one Aspen InfoPlus.21 server that contains the comment.rld file. This is because there are two fields in the history repeat area of the Comments tag called IP_CMT_REF_DS and IP_CMT_REF_TAG that associated each comment with a single tag from a single data source. Since this does not have to be the same data source that is storing this information, having comments enabled in only one of the data sources is sufficient.
Keywords: Comments
Multiple data sources
References: None |
Problem Statement: Getting Unable to validate server component when entering a tag name or searching for tags in aspenONE Process Explorer.
Unable to validate server component
When checking the aspenONE Process Explorer Admin program to scan the Aspen InfoPlus.21 tags user gets an error:
Search Engine Status: Not Running
A connection with the server could not be established (Error code 500 )
Upon investigation it was found that when calling the page http://<hostname>:8080/solr/#/, where <hostname> is the name of the aspenONE web server the page returns the following error:
http status 500Â - {msg=SolrCore 'collection1' is not available due to init failure ... | Solution: These symptoms indicate a problem with the deployment of the Apache Tomcat solr application which is used in aspenONE Process Explorer tag searches. To correct this perform the following steps on the aspenONE web server:
· Was the Java V 1.8.0_xx pre requisite installed?
· Was either the JAVA_HOME or JRE_HOME environment variable defined to point to either the JDK or JRE for Java V 1.8.0_xx?
· Is there more than one Tomcat version is installed and running, and leave only Java 8 running?
asoenONE.web server installation places a solr.war and AspenCoreSearch.war files in the C:\Program Files (x86)\Common Files\AspenTech Shared\Tomcat8.0.xx\webapps  folder; a Tomcat top-level folder. These should be approximately 28,362 and 67,179 KB, respectively.
If answer to above three steps is yes, then stop the Apache Tomcat Windows service and restart (SOLR will be redeployed on startup); a few minutes will be required for Apache Tomcat to fix the deployment
If the restart of the Apache Tomcat Windows service does not fix the problem, then stop Apache Tomcat Window service , delete the solr folder under C:\Program Files (x86)\Common Files\AspenTech Shared\Tomcat8.0.21\appdata folder and restart the Apache Tomcat Windows service.
If the above step didn’t fix the problem, then stop Apache Tomcat Window service , delete the solr and scheduler folders under the C:\Program Files (x86)\Common Files\AspenTech Shared\Tomcat8.0.21\appdata folder and restart the Apache Tomcat Windows service.
Note:
After completing the the last two steps, start the aspenONE Credentials utility and switch Domain Security OFF, as shown below:
Keywords: aspenONE Process Explorer,validate server component, connection, error 500
References: None |
Problem Statement: In the results for Vibration & Resonance Analysis in Aspen Shell and Tube Exchanger, what does the Logarithmic Decrement (LDec) mean in the results for Fluid Elastic Instability analysis? | Solution: The logarithmic decrement (δ) is related to the amplitude of successive oscillations of the tubes and it is used to calculate the damping ratio of the system. It is calculated from the following equation:
Where An and An+1 are the successive oscillation during vibration.
The fluid elastic instability is not a resonance but a threshold effect, so there is a critical cross-flow fluid velocity above which vibration occurs.
In Results | Thermal / Hydraulic Summary | Vibration & Resonance Analysis Fluid Elastic Instability (HTFS), the ratio of actual shellside flowrate to critical flowrate (W/Wc) is calculated according to different damping or LDec.
The logarithmic decrement is linked with damping ratio ξ. For example, the relation between the two, for a lightly damped system where ξ <<1 is:
For more information on Damping, please refer to the Aspen HTFS Handbook | Vibration | VP7: Damping on the HTFS Research network
Regarding the different damping values, please seeSolution 135347.
Keywords: Logarithmic Decrement (LDec), Fluid Elastic Instability (HTFS), Damping, Vibration & Resonance Analysis
References: None |
Problem Statement: In the design of heat exchangers, high heat transfer coefficients are normally required to give a compact design. This may lead to high cross flow velocities which are normally limited by the allowable pressure drop. However, in certain circumstances the onset of vibration may be the limiting factor.
Vibration damage may result from:
Joint failure: Vibration may cause the joint with the tube and tubesheet to fail, e.g., pulling tubes out of the tubesheet.
Fatigue: Repeated bending of the tubes that may also be enhanced by corrosion and erosion.
Fretting: Baffle holes are larger than the tube diameter to permit assembly of the exchanger. Thus the tubes are not rigidly fixed but are free to move at the baffle location and if the amplitude is sufficient they may strike the baffle. If the baffles are thin or made from a harder material than the tubes, then the tubes may be cut locally by the baffles and if this continues long enough may sever the tube wall. This is sometimes termed baffle damage.
Impact damage: If the amplitude of vibration is great, adjacent tubes will collide with one another or even with the shell. The collisions cause the tubes to wear thin and eventually split open. Tube collision damage produces a diamond-shaped wear areas on the tube surface normally at the mid span between adjacent baffles. This is sometimes called collision damage.
Vibration may be so severe that a plant item has to be replaced early in its life cycle and may also result in the plant being shut down and a loss of production. | Solution: In general, two approaches can be used to minimize vibration:
1. Reduce tube unsupported length - so increasing Natural Frequency
2. Reduce crossflow velocity - so reducing energy given to tube
Unfortunately these two requirements often conflict while the heat transfer and pressure drop specifications still need to be satisfied. Using Shell & Tube Exchanger (Tasc+) it is a simple matter to explore how changes to the heat exchanger design affect the vibration response.
To reduce the tube unsupported lengths, you could
Reduce baffle pitch
Reduce end lengths
Add Intermediate supports
Use No-tubes in window
Use Rod-baffles
To reduce the crossflow velocity, you could
? Increase baffle pitch
Increase bundle-shell clearance
Use double segmental baffles
Use a split-flow exchanger, such as a J shell
Use an axial flow exchanger
In general, if there is spare heat transfer and pressure drop capacity you could
? Reduce baffle pitch
Reduce end lengths
Change baffle type
Remove some tubes
If heat transfer and pressure drop are near their limits, you could
? Change shell type
Use a No-tubes in window design
Keywords: Avoid vibration, Remove vibration warning, Natural Frequency, Crossflow Velocity
References: None |
Problem Statement: What could be the reason that the Aspen Simulation Workbook (ASW) Scenario Table does not run or update when linked to Aspen Exchanger Design and Rating (EDR)? | Solution: The scenario table created in ASW may not run or update results if the EDR file is over-specified in terms of process data. By deleting the process data over specification, the Scenario Table should run and update the results accordingly.
For instance, provide three of the following specifications (Hot side flowrate, Cold side flowrate, heat load, inlet temperature, outlet temperature) in EDR.
Keywords: ASW, Scenario Table, EDR, Process Data
References: None |
Problem Statement: Duty on TEMA sheet is not matching with the duty specified in the input filed. | Solution: When Aspen Shell & Tube Exchanger (Tasc+) is run in Design or Rating/Checking mode, sometimes the duty value on the TEMA sheet may not match with the input data. This will happen in the case of an over specification, for example, in the Input | Process data page if mass flow rate, inlet/outlet temperatures, inlet/outlet vapor mass fractions and duty are specified for both hot and cold side streams, then the program will consider it as over specification. Minimum data input should satisfy the heat balance (Q = MCpDT_cold = MCpDT_hot) on both sides anything other input data is considered as over specification.
In the case of an over specification, the default adjusted parameter is heat load. Hence the duty on TEMA sheet may not match with the input data. User can fix the Heat Load and adjust other parameters such as outlet temperatures or inlet temperatures or Flow rate by selecting one of these options under Input | Problem Definition | Process Data | under the filed Adjust if over specified.
Keywords: Duty, TEMA sheet, over specification, Process Data
References: None |
Problem Statement: We have observed that there are circumstances that will cause the MSI installer to determine that it must re-install something that has been removed.
Though it has only been observed with Advanced Control software, it could conceivably apply to other products in the aspenONE suite.
A client deleted the example controllers in a Aspen SmartStep installation because he had no need for them. MSI detected that some of the files (that it had installed, of course) were missing and, without asking or notifying, proceeded to ?repair? the installation.
During the course of Repairing the installation, MSI determined that it was necessary to stop the ACO utility server, the running controllers/testers and delete the MPF regions. This same behaviour has occurred for the Aspen Inferential Qualities context.
Unfortunately, during the initial installation, the user was not prompted with the option to choose whether or not to install the example controllers. | Solution: There are twoSolutions/work-arounds for this behavior.
1. Quite simply, do not delete anything that the MSI has installed.
2. Disable the MSI from automatically starting an install on an online computer.
This is how to disable the msi from automatically starting an install on an online machine....The customer will need to re-enable the installer before installing Microsoft updates and Aspen Patches....
To set the option:
Go to the Start menu and select the ?Run? option.
In the box, type ?Gpedit.msc?
Under
Local Computer Policy -> Computer Configuration -> Administrative Templates -> Windows Components -> Windows Installer
There is an option there to ?Disable Windows Installer?
If this setting is set to Enabled then all MSI installations on the machine are disabled Patches/repairs and full installations using the MSI engine are also disabled. Remember you are ENABLING the feature to DISABLE the windows installer.
Attempting to install after setting this option will result in either a dialog that explains the installation has been disabled or in a log file entry that says te same thing.
If it is necessary to run the MSI installer, the ?Disable Windows Installer? option must again be ?disabled?. (and then re-enabled after the installation is complete)
Some examples of behavior you might see if you enable the Disable Windows Installer and at a later time after having forgotten about it, try to install or update.
Attempt to apply a patch will produce the following message in the patch log file:
MSI (s) (44:18): Rejecting product '{A5529C7D-C0A2-4F10-B505-1D0B5B6B94FF}': Msi is completely disabled.
Info 1625.This installation is forbidden by system policy. Contact your system administrator.
Using the update agent the patch will just say it failed to apply the patch.
Attempt to install a new product or if the msi tries to repair a file the following pop-up dialog will appear:
Keywords: MSI, install, acod_utility, server, run
References: None |
Problem Statement: Why does a thermosyphon reboiler exhibit two-phase flow instability behavior? How do I remove this flow instability warning? | Solution: Instabilities are common to both forced and natural circulation systems. Instabilities can cause operational problems in process heat transfer. Thus, it is important to classify mechanisms that can lead to unstable operational behavior of the thermosyphon. The following processes can lead to an unstable behavior for the thermosyphon.
Surging and Geysering Instability: Surging and geysering occur mainly because of liquid superheat. Surging occurs when boiling is initiated in the evaporator, but because of no uniformity in the temperature at the wall and bulk fluid temperature, the vapor being generated becomes trapped, eventually resulting in vapor expulsion as described by Bergles et al. (1981). This mechanism is not destructive, but can trigger other types of instability in the system. Geysering is a similar phenomenon that occurs when the heat flux is sufficiently high, and boiling is initiated at the bottom. In low pressure systems this results in a sudden increase in vapor generation due to the reduction in hydrostatic head, and usually causes an expulsion of vapor. The liquid then returns, the subcooled, nonboiling condition is restored, and the cycle starts over again. Geysering is also a naturally occurring phenomenon.
Thermosyphon Evaporator Instability: If the evaporator section of the thermosyphon system is not sufficiently long for vapor superheat, then instability could occur such that the fluid at the outlet of the evaporator experiences a static pressure decrease, leading to the onset of fluid condensation within the thermosyphon. Slight vapor superheat from the evaporator should reduce this concern.
General rules for avoiding instability (warning) in a thermosyphon:
1. Since instabilities are associated with two-phase effects, ensure that a significant fraction of the pressure drop around the loop occurs in the single phase region (i.e. inlet pipe network). It can be achieved by
· Placing valve in the inlet pipe. The inlet pressure loss can be increased by partly closing the valve.
· Decreasing diameter of inlet pipe etc.
2. Reduce the pressure loss at the exit from the boiler section as far as possible. It can be achieved by
· Minimizing the outlet restriction from the channel.
· Increasing pipe diameter.
· Avoiding valves or any other form of outlet restrictions etc.
Keywords: None
References: s:
Aspen HTFS Handbook: TP7: Instabilities in Two-Phase Flow
Aspen HTFS Handbook: TM16: Stability Assessment of Boiling Two-Phase Systems
Aspen HTFS Design Report: DR1: Vertical Thermosyphon Reboilers
Aspen HTFS Design Report: DR17: Instabilities in Two-Phase Flow Systems
Key Words
Exchange Design Rating, Aspen Shell & Tube Exchanger, Thermosyphon Reboiler, Flow Instability, Surging and Geysering instability |
Problem Statement: When TEMA sheet is exported from EDR to Excel using the default template and the EDR file is re-run or closed/re-opened, the spreadsheet is updated with the original values and any changes made are lost. How can I get rid of this problem? | Solution: The Excel file that is exported via EDR has code within it to maintain a link with Excel - this is by design.
If your intention is to edit Excel only and not have it linked to EDR in any way, the connection should be broken. To do so, you need to modify the code within the Excel file. Please find steps below:
1. Export your TEMA sheet to Excel using the Default Template.
2. Go to the Developer tab and click on Visual Basic to open the code behind. If the Developer tab is not active, go to File | Options | Customize Ribbon | Active checkbox next to Developer | click OK.
3. In modBJAC module, scroll down until you find a green comment that says ''Get BJAC objects''. Under function LoadBjacObjects() type Exit Sub - essentially this is going to immediately exit the function, which is responsible for setting up the Excel/EDR link.
4. After you finish, run the Code and save it. If you have the EDR file opened, close it and re-open it, because you have to re-initialize the application to apply the changes.
Note: Just keep in mind once this is done, the drag/drop will not work and Excel will not update when EDR is opened, changed, or run for this particular file.
Keywords: Excel link, export, EDR link
References: None |
Problem Statement: What does it mean 'Missing variable type' on an APC controller message (Event Viewer \ RTE)? | Solution: The ‘Missing variable Type’ entry is logged when a User Defined Entry has a change.
User: UserName requested entry at: VariableName/UserDefineEntry be changed to x.xxxx.
Missing variableType with UseEntryFormat for message format parameter #2.
Entry at :VariableName/UserDefineEntry changed from x.xxxx to x.xxxx.
Missing variableType with UseEntryFormat for message format parameter #1.
Missing variableType with UseEntryFormat for message format parameter #2.
The difference between a User-Defined-Entry log and an standard entry is that the second one fills the fields (ind, dep, gen) based on config files.
The RTE.message.config for the following:
<add name=AppLogFacility: Entry value changed event message
text=Entry at %VarType%:%VarName%/%EntryName% changed from {0} to {1}.
msgType=Operator, Engineer logEntryType=Information severity=None>
<param index=0 desc=Entry old value useEntryFormat=True/>
<param index=1 desc=Entry new value useEntryFormat=True/>
</add>
<add name=Node: User requested entry change
text=User: {0} requested entry at %VarType%:%VarName%/%EntryName% be changed to: {1}.
msgType=Operator, Engineer logEntryType=Information severity=None>
<param index=0 value=string desc=User name/>
<param index=1 desc=Entry value useEntryFormat=True/>
</add>
This behavior has been reported on CQ00499309 APC User Defined Entries messaging logs (missing variable type).
Keywords: Aspen Process Controller, RTE, messages, User Defined Entries
References: None |
Problem Statement: When a User-Defined parameter is added to a variable (under Edit Calculations section) in APC Builder, the default setting for a Logchange property is False. This is to prevent a message to be generated every time the parameter is changed. In rare instances, when a ccf file is imported into APC Builder, a user-defined parameter may show up with a Logchange property of True and the field is locked/grayed out (seemingly unchangeable) | Solution: Rather than select the LogChange and toggle the property which is grey out in this case, select the DefaultIOFlags line and delete the word LogChange.
Keywords: LogChange
User Define parameters
Calculations
APC Builder
References: None |
Problem Statement: After installing v7.2 CP4 for Aspen APC Web Server the Aspen APC Web Provider Data Service fails to start | Solution: Symptom: After installing v7.2 CP4 for Aspen APC Web Server the Aspen APC Web Provider Data Service fails to start
Cause: The original WebDataProviderSvc.exe.config file had been modified since the original v7.2 installation and so the patch config file was not applied.Solution Verify this is the case, by looking in the Application Event log for an error similar to the following:
Failed to start WebDataProvider service. System.ArgumentException: This collection already contains an address with scheme http. There can be at most one address per scheme in this collection. ?
If you see this event every time after starting the service, then you will need to edit the following file:
(on 32-bit platform) \Program Files\AspenTech\APC\Web Server\bin\WebDataProviderSvc.exe.config
(on 64-bit platform) \Program Files (x86)\AspenTech\APC\Web Server\bin\WebDataProviderSvc.exe.config
Delete the entire system.serviceModel section of the file, then restart the Aspen APC Web Provider Data Service:
<system.serviceModel>
?
</system.serviceModel>
NOTE: If on a 2008 server, you need to run Notepad.exe as administrator and navigate to the .config file to edit it.
Keywords:
References: None |
Problem Statement: How do I change the refresh rate in a graphic published to aspenONE Process Explorer or Aspen IP.21 Process Browser? | Solution: ThisSolution applies to Aspen Process Browser Graphics Studio V8.7 with Aspen MES Cumulative Patch 2 applied or any future version.
To change the refresh rate of a graphic.
1. Open the Project and Graphic in the Aspen Process Browser Graphics Studio.
2. R-click on white space in the graphic and select Properties.
3. Select the Actions tab, and there is a setting on the bottom right “Refresh in Seconds”.
4. Set “Refresh in Seconds to the desired value.
5. Save the graphic, Project, and publish the project.
Keywords:
References: None |
Problem Statement: aspenONE Process Explorer wass introduced the V8.5 release of Aspen Manufacturing products. | Solution: aspenONE Process Explorer is a web-based application, accessible on multiple web-enabled devices, for visualizing real-time and historical process data and you can access it the aspenONE web site:
To access aspenONE Process Explorer, type the following url in your browser:
http://<aspenONE>/ProcessExplorer/ANYHome.html#
where <aspenONE> is the name of the server where the aspenONE programs are installed.
Once you access the site you can refer the the online HELP feature for further information on the operation of the product.
Keywords: aspenONE, Process Explorer
References: None |
Problem Statement: XY charts can be used to see if there is a mathematical relationship between two different data points. This | Solution: outlines two ways to open a brand new XY plot in aspenONE Process ExplorerSolution
To open a new XY Trend, click the large + symbol on the top left section of the trend chart to open up a pop-up showing the various plot types. Select XY Chart from the Basic category. This will open a blank chart ready for XY data to be entered. Now, add at least two tags to the plot and the tags will be added to the plot, along with a linear regression equation for the all valid points within the current time span.
A user can also take an existing trend plot and by selecting the Plot Modes icon on the right side of the utility bar, and selecting the XY option. This will convert all the tags in the current plot and move them into an XY chart.
Using the various columns, a user can specify which tag is set as the x-axis and by selecting the regression equation, the Regression type can be edited to be Linear, Quadratic, Inverse, Logarithmic, Exponential or Power.
Keywords: XY Chart
aspenONE Process Explorer
References: None |
Problem Statement: Where is the aspenONE Workspace file stored and what is its name? | Solution: aspenONE Workspace is stored in the Private folder for each individual user. The name of the file is aspenONE.Workspace.
An example for user called 'Aspen':
C:\inetpub\wwwroot\AspenTech\ProcessExplorer\Files\Private\Aspen
Keywords: None
References: None |
Problem Statement: How is the latent heat of a stream calculated? It is not part of the physical property data that is entered using the direct input method. | Solution: The calculation of the latent heat by Aspen Shell & Tube Exchanger for example is based on the physical property data supplied.
For a single component, the latent heat is defined as the saturated enthalpy of the vapor minus the saturated enthalpy of the liquid at the same temperature.
For a mixture, the latent heat (if it can be defined) is the enthalpy of the vapour minus the enthalpy of the liquid at the same temperature, taking into account that the stream is not all vapor or liquid. In practice you need to do this over a finite (but small) temperature range so you need to subtract the sensible heat change for the liquid and vapor.
This method is very sensitive to inaccuracies/inconsistencies in the Temperature, enthalpy, quality (Thx) data and specific heats of the vapor and liquid and so is a very good method of identifying poor data. In most cases the latent heat at the inlet and outlet of the exchanger should be similar - poor data is usually signaled by sudden changes (or even negative calculated latent heats).
The equation for latent heat is derived from an energy balance where the duty supplied is used to heat both the liquid and vapor phases and vaporize the fluid. As an approximation the latent heat is found from:
Latent Heat = ( dh/dx ) - ( (1 - x)*Cpl + x*Cpg ) * dT/dx
where:
dT = small change in temperature
dh = change in enthalpy over dT
dx = change in quality over dT
x = average quality within temperature range
Cpl, Cpg = average specific heats of liquid & vapor within temperature range
The value for the latent heat is not allowed to exceed 3000 kJ/kg or drop below 20.9 kJ/kg, otherwise it is reset to the limit.
Keywords: Heat of vaporisation
References: None |
Problem Statement: Within the Aspen EDR programs, it is possible for users to create their own chemical properties databank for those fluids that are not found in any of the EDR databanks (B-JAC Databank, COM-Thermo or Aspen Properties).
The private databank can accommodate up to 400 different fluids, where details on how to enter the fluid properties are given in the on-line help under the Supplementary Programs and Databases | Private Chemical Databank.
There maybe a time when users wish to transfer this database to a different machine, where is the method described? | Solution: The databank is contained in three files;
D_IDPriv
D_FxPriv
D_VaPriv
These files will normally be in the folder where the program has been installed, e.g. 'C:\Program Files\AspenTech\Aspen Exchanger Design and Rating V7.2\Dat\PDA' and can be copied across.
However, the files could be located in a different folder if customized database files have been set. To check if customized folders are used go to the Tools | Program Settings | Files tab, where users can specify a folder to store the customized files. If a folder has been specified, then copy the above three files from this folder rather than those in the PDA folder.
Keywords: transfer private chemical properties data bank
References: None |
Problem Statement: In Aspen Shell & Tube Exchanger, on Results | Thermal / Hydraulic Summary | Flow Analysis | Flow Analysis tab the program reports ''Shell Entrance Flow Area'' and ''Shell Exit Flow Area'' values in the Rho*V2 analysis section. How are they calculated? | Solution: Shell entrance and exit flow area values are output on Results | Thermal / Hydraulic Summary | Flow Analysis | Flow Analysis tab. They are calculated according to the methods given by TEMA. From TEMA 9th Edition (2007), the flow area calculations are described in details in Section 10 ''RGP-RCB-4.62 SHELL OR BUNDLE ENTRANCE AND EXIT AREAS'' under sub-set ''RGP-RCB-4.621 AND 4.622 SHELL ENTRANCE OR EXIT AREA'' on pages 10-14 and 10-15; the corresponding figures can be found on page 10-17.
They are measured directly underneath inlet nozzles and above outlet nozzles. The calculation depends upon impingements plates being present or not, the diameter of the shell, the Outer Tube Limit (OTL), the nozzle diameter and clearance from the nozzle to the last row of tubes etc.
An equation is given in TEMA with explanations of nomenclatures. Approximations and some special considerations during the calculations are also stated at the beginning of this section in TEMA.
Keywords: Shell entrance, Shell exit, Flow area, Rho*V2 analysis, TEMA
References: None |
Problem Statement: As described in | Solution: 121775, users can transfer a heat exchanger case between Aspen Shell & Tube Exchanger and Aspen Shell & Tube Mechanical, by going to Run | Transfer, and selecting the desired program name.
However, this behavior will cause Aspen Shell & Tube Exchanger and Aspen Shell & Tube Mechanical programs to be opened at the same time. If the user has limited tokens that only permit one Aspen program (i.e. either Aspen Shell & Tube Exchanger or Aspen Shell & Tube Mechanical) to run at a time, users will see warning and/or error messages regarding the lack of license tokens (information about ''token sever'' can be found on page 98 in the ''Installation and
Keywords: Aspen Shell & Tube Exchanger, Aspen Shell & Tube Mechanical, Exchanger Data Transfer, License Error, Enough Tokens
References: Guide'' under the ''Documentation'' directory). The procedures below describe how the user can still transfer the data between these two programs. |
Problem Statement: How can I export Tasc+ or Acol+ Results data to Excel? | Solution: After running the calculations in Tasc+, the results can be exported to Excel. This can be done from the main menu File | Export to | Excel (there are two options available 1. using a default template 2. using a specified template).
During HTFS+ installation, several pre-built excel templates are copied to Dat\Template under the installation folder, usually C:\Program Files\AspenTech\Aspen HTFS+ 2006\Dat\Template. User can select one of the templates in this directory.
To create custom templates, a user can follow the instructions below:
1. First make a copy of the *Blank.xlt template located in the Aspen Tasc+..\DAT\ Template sub-directory and rename it to use as your template for the customized results form.
2. Open this new template in Excel. Enable the macros (set the security to Low).
3. Open the Tasc+ Case and go to Tools | Program Settings | Advanced (2006.5 Tasc+) or Files (2006 Tasc+) and set the drag and drop format to Caption, Value and Units of Measure.
4. Now by selecting various sections of the output results in HTFS+ you can drag and drop into your template.
5. You can change what information is moved from HTFS+ by clicking on the right hand mouse button and selecting Drag-Drop format. You can select to drag-drop the value or units of measure only or to drag-drop the Caption, value, and units.
6. Once your customized template is complete and saved, every time HTFS+ is run you can open your customized template to review the results from the run.
Keywords: Export, Excel, Template, Results.
References: None |
Problem Statement: How does Aspen Shell & Tube Exchanger consider flow distribution on X shells? Does the number of nozzles have an influence on shell side flow distribution? | Solution: As shown in the figure below, Aspen Shell & Tube Exchanger assumes the shell side flow path in an X-shell to be evenly distributed along the tube length axial of the exchanger as soon as the flow enters the inlet nozzle(s). The shell side flow will be pure cross flow along the direction perpendicular to the tube length and it will be gathering to the outlet nozzle(s).
Aspen Shell & Tube Exchanger assumes the shell side flow distribution and combination along the tube length axial have no contribution to either heat transfer or pressure drop in the exchanger. This means the number of shell side nozzles will only affect the flow rate hence velocity through each of the nozzles, and the pressure drops through shell side nozzles will be varied accordingly.
Keywords: X shell; flow distribution; nozzle
References: None |
Problem Statement: In Aspen Shell & Tube Exchanger on Results | Thermal / Hydraulic Summary | Performance | Overall Performance tab both shellside and tubeside Inlet/Outlet Pressures are reported. On Results | Calculation Details | Analysis along Shell/Tube | Interval Analysis tab, local pressure values along the shell/tube are also reported at intervals. However, users will find the very first and very last local pressure values on Interval Analysis tab are different than the Inlet/Outlet Pressure values on Overall Performance tab.
This | Solution: explains why.
Solution
The Shell/Tube side Inlet/Outlet pressures on the Overall Performance tab are based on the very end points of the whole process, i.e. the ''Shellside Inlet Pressure'' is the shellside flow pressure at the entrance to the inlet nozzle(s), and the ''Shellside Outlet Pressure'' is the shellside flow pressure at the exit to the outlet nozzle(s).
On Interval Analysis along Shell/Tube tab, the pressure variation is shown that take into account the frictional, acceleration and gravitational components.
The first pressure in the tube is the tubeside inlet pressure minus losses due to the tubeside inlet nozzle(s) and corresponding header. The last pressure is the tubeside outlet pressure plus the losses due to the tubeside outlet nozzle(s) and corresponding header.
For shellside, the first pressure inside the shell is the shellside inlet pressure minus losses due to the shellside inlet nozzle(s). The last pressure inside the shell is the shellside outlet pressure plus losses due to the shellside outlet nozzle(s).
This means the pressure discrepancies between the two tabs are actually the pressure changes through inlet/outlet nozzles, and (only for tubeside) losses in the headers.
Keywords: Inlet/Outlet operating pressure, Pressure discrepancy, Overall Performance, Interval Analysis, Pressure drop (change) through inlet/outlet nozzles
References: None |
Problem Statement: If ''User specified properties'' are used in the Aspen Exchanger Design & Rating (EDR) software, users must manually type in their own property data at up to 24 temperature points and 5 pressure levels. However, sometimes the specific enthalpy values may not be always readily available. This | Solution: describes how to calculate the enthalpy changes (specific enthalpies) from other property data.Solution
FromSolution 119148, the specific enthalpy can be back-calculated as below.
dh = Latent Heat * dx + [(1-x) * Cpl + x * Cpg] * dT
where:
dh = change in enthalpy
dT = small change in temperature
dx = change in quality (or mass fraction)
x = average quality within temperature range
Cpl, Cpg = average specific heat capacity of liquid & vapor within temperature range
Latent Heat = latent heat of vaporization
For the thermal calculations in EDR, the ''enthalpy change'' for each temperature interval is important. Once the ''enthalpy changes'' are determined, the ''Specific enthalpy'' can be determined, by setting the specific enthalpy at the first temperature point as zero, and subsequent specific enthalpies at other temperature points will be the ''sum of enthalpy change''.
To summarize, there are four methods calculating enthalpy change.
For mixtures changing phase, dh = Latent Heat * dx + [(1-x) * Cpl + x * Cpg] * dT, where term ''[(1-x) * Cpl + x * Cpg] * dT'' is the sensible heat required to heat/cool the mixture between the dew and bubble points.
For a pure component changing phase, dh = Latent Heat * dx. This is because for a pure component the dew point and bubble point are identical (dT = 0), the term of sensible heat ''[(1-x) * Cpl + x * Cpg] * dT'' is Zero.
For a single phase process, dh = Cpl * dT for single liquid stream, and dh = Cgl * dT for single vapour stream. This is because without phase changes, there is no latent heat duty. The users should note that the gas-phase specific heat capacity values (Cpg) may change significantly with pressure.
Users need to be very careful if they choose to specify the properties under multiple pressure levels, because a common reference point must be used when entering specific enthalpy. For this reason, if heat loads are used then data at only one pressure level can be supplied.
The duty for the heat exchanger is found from the mass flowrate times the enthalpy change.
Keywords: Enthalpy change, Specific enthalpy, Heat load, Heat duty, Heat release curve, User specified properties.
References: None |
Problem Statement: The data published from any of the applications such as Aspen Operations Reconciliation Accounting, Aspen PIMS or Aspen Petroleum Scheduler can be processed within the Aspen Reporting Framework GUI and stored in the Aspen Reporting Framework database. This data within the Aspen Reporting Framework database can subsequently be viewed in the OLAP cube using the Microsoft SQL Server Business Intelligence Development Studio (BIDS). | Solution: The following procedure gives you detailed steps on how to connect to the Aspen Reporting Framework database to view the data in the OLAP cube within BIDS.
? Open the Microsoft SQL Server Business Intelligence Development Studio (BIDS) from
Start | Programs | Microsoft SQL Server 2005 | SQL Server Business Intelligence Development Studio
? In the Microsoft SQL Server Business Intelligence Development Studio (BIDS) GUI click on the
File | Open | Analysis Services Database
This opens up a new dialog box 'Connect to Database' shown in the image below.
? Check on Connect to existing database and type in the Server name where your SQL Server Analysis Services are running. Choose the Aspen Reporting Framework database to connect to from the drop down in the Database field and click OK. This creates database connection from Microsoft SQL Server Business Intelligence Development Studio (BIDS) to the Aspen Reporting Framework Database.
Once this connection is established go to theSolution Explorer, Expand the Cubes and double click on the Supply Chain Cube which opens up a window showing all the pre-defined measures that were defined like Inventory, Supply, consumption, demand, KPI's etc. Drag drop any specific measures to see the data in Microsoft SQL Server Business Intelligence Development Studio (BIDS) that was published into Aspen Reporting Framework database.
Keywords: None
References: None |
Problem Statement: This knowledge base article demonstrates a step by step procedure which outlines how to configure one of the 3rd party client applications i.e. Microsoft Excel to visualize the data from an already existing Aspen Reporting Framework database. | Solution: Go to Microsoft Excel and click on Data | 'PivotTable and PivotChart Report' which opens up a PivotTable and PivotChart Wizard. In that wizard select External data source as an option and click Next.
? Click on Get Data which opens up a new Choose Data Source dialog box and in there go to the OLAP Cubes tab, select <New Data Source> and click OK. This again opens up a new dialog to Create New Data source.
Under the Create New Data Source dialog give a name for the data source that you want to create then select Microsoft OLEDB Provider for Analysis Services 9.0. for the option 'Select an OLAP provider for the database you want to access' field. After this click the Connect button.
? Clicking Connect opens an other dialog box Multidimensional Connection 9.0 where you specify the Analysis Server to be used. Select Analysis Server and provide the name of the SQL server where SQL server Analysis Services are running and give the User name and Password of the account you login with. Click Next.
? In the next dialog box select the Aspen Reporting Framework database you want to connect to and click Finish.
? Clicking Finish takes you back to the create data source dialog box but now you can see the cube name under the 'Select the Cube that contains the data you want' field as you see in the SQL Server Business Intelligence Development Studio. To save the User ID and password for this data source check 'Save User Id and Password in the data source definition'. Click OK.
? Clicking ok creates a new data source and it takes you back to the Choose Data Source dialog. Select the new data source created and click OK which directs to the PivotTable and PivotChart wizard dialog box. Once you click Next again go to step 3 to see the location where it will start the report. Click the Finish button completes the configuration and opens a spreadsheet with the Pivot Table Field List using which we can drag drop the fields to see the data from the Aspen Reporting Framework as shown in the last image.
Keywords: Excel
Reporting Framework
References: None |
Problem Statement: For the physical properties in the Exchanger Design and Rating (EDR) suite of programs there are a number of ways that the data may be entered;
· Use one of the databanks like Aspen Properties, COMThermo or B-JAC to select from a range of components to define a single component for the stream of a mixture (multiple components).
· User specified properties, where you input the physical properties of the stream yourself, either directly, or by copying them from a spreadsheet.
With the user specified option, there is a choice to be made when entering the property data, to determine the duty. The options are to use specific enthalpy or heat loads. | Solution: Property points at various temperatures which encompass the operating temperatures of the exchanger are entered.
User Specified properties
If the stream is liquid or vapour only, then the properties like density, specific heat capacity, and thermal conductivity must be entered. It is not necessary to enter the specific enthalpy as this can be determined from the specific heat capacity times the temperature change, but if it is specified, then it will be used to determine the duty of the stream.
For a two-phase stream, then both the liquid and vapour properties must be specified, together with the specific enthalpy.
It is possible to enter data at up to five different pressure levels and recommended to use multiple levels for applications involving changes of phase or gas only since the pressure change through an exchanger can significantly impact the properties and heat release curves for these applications. Data at two pressures are adequate for most exchangers.
User specified properties using heat loads
With this option the cumulative heat load is used to determine the duty of the stream. A reference mass flowrate for the specified heat load is entered, where the entered heat load is divided by the reference flowrate to determine the change in specific enthalpy.
However, with the cumulative heat load, it is only possible to enter data at one pressure level (as the Add/Delete Set buttons are greyed out). This is by design as users do not always take care in ensuring that heat loads at different pressure levels have the same base reference point, as they would do when entering specific enthalpies or if these were calculated by one of the databanks.
Keywords: User specified properties, heat load, heat duty, cumulative heat load
References: None |
Problem Statement: How to send all controller messages to DCS? | Solution: ThisSolution applies only for controllers deployed under the RTE platform (APC Builder, DMC3Builder)
I. On Aspen Info Plus.21 Administrator start by creating a new IP_TextDef record that will hold the messages from controller event. Use the same name of the controller and add something like “_msg� or “_events� at the end.
a) Open Aspen Info Plus.21 Administrator.
b) Search for IP_TextDef under Definition Records node.
c) Right click over it and select New record defined by IP_TextDef
d) Write a record name using the controller name and adding something like “_msg� or “_event� to the name:
II. Create a new SQLplus query that will write the events vales into this record and saved it into IP.21 database:
a) Open new query window in SQLplus.
b) Copy the next query code and paste it into SQLplus:
Local Controller;
Controller = 'COL5X3DMC3APC'; --Change this for your controller name
Macro ControllerEvents = 'COL5X3DMC3APC_MSG'; --Change this for IP_TextDef to save events messages
DECLARE LOCAL TEMPORARY TABLE
MODULE.TEMP(MyTime CHAR(25), MyDescription CHAR(250));
INSERT INTO MODULE.TEMP
select AW_StartTime, AW_Description
from AWEvents
where aw_application = Controller
and AW_H_TIME_1 > &ControllerEvents.IP_INPUT_TIME
order by AW_H_Time_1 desc;
Select * from Module.Temp;
local MyValue string;
for(select MyTime, MyDescription from Module.Temp) do
MyValue = (MyTime ||' '|| MyDescription);
update &ControllerEvents set IP_INPUT_VALUE = MyValue;
end
c) Change the query code to make it work for your controller tags. Change the variable Controller for the name of the controller and change ControllerEvetns for name of the tag created on previous steps.
d) Go to the Record / Save menu and save this query as a CompQueryDef record, select a proper name for it:
III. Configure the previously created query to make it work under a specific schedule.
a) Open Infoplus.21 Administrator and look for CompQueryDef records:
b) Set the value for #Schedule_Times to 1:
c) Double click on #Schedule_Times field.
d) Define a time interval to run this query and a start time for it:
e) Verify that the query is working by looking at the Last_Executed field:
IV. Verify that messages are been collected into the record created on step I.
Keywords: Controller messages, DCS, RTE, DMC3
References: None |
Problem Statement: Where can I find the Aspen Process Controller - Collect files? | Solution: Go to :\ProgramData\AspenTech\RTE\Vx.x\Clouds\Online\DataCollection folder where *.INFO and *.DATA file are listed* (besides the DataCollection.config file).
* The path is for a Windows 2008 64-bits Server. If other OS is used follow the equivalent path.
The file names are associated to the *.INFO creation timestamp, e.g. YYYYMMDD_######_0000##.data
The *.INFO file stores information like tag name, IO server, IO tag, sample period, etc.
The *.DATA file stores the collection, it’s encrypted.
Note: Do NOT modify manually these files.
Keywords: Aspen Process Controller, APC, RTE, Collect
References: None |
Problem Statement: In Aspen Shell & Tube Exchanger when using the “find flow” option for a thermosiphon, the flowrate through the exchanger is calculated from a pressure drop balance around the piping circuit and the heat exchanger. When the program runs, a check is made on the thermosiphon flow rate to see if the flowrate is stable or constant, where unstable flows may cause vibration, system control problems or affect the local heat transfer coefficients.
Aspen Shell and Tube Exchanger looks at two types of flow instability
· Excursive or Ledinegg instability
· Oscillatory or density wave instability both in the entire circuit and parallel channels
The method for the stability analysis is presented below. | Solution: The method used is described in the HTFS Handbook Sheet TM16 “Stability Assessment of Boiling Two-Phase Systems” that can be found from the Aspen HTFS Research Network at http://htfs.aspentech.com/resnet.asp However, this report is enclosed, where it is a graphical method, whereby the x and y co-ordinates are evaluated and then checked on a graph to determine if the operating point is stable or not.
There are two locations where it is reported if the flow is stable or not;
· Results | Thermal / Hydraulic Summary | Flow Analysis | Thermosiphon and Kettles tab
· Results | Thermal / Hydraulic Summary | Pressure Drop | Thermosiphon Piping tab
In addition, if the flow is unstable, then there maybe Operation warnings 1604 or 1606.
Operation warning 1604 gives an indication of the x and y co-ordinates and the graph parameter that can then be used to check from the appropriate Figure number in TM16 how close the operating point is to the transition boundaries. It should be noted that the boundary lines between the regions, have a level of uncertainty, so checks should be made to ensure that the operating point is away from a boundary.
For Operation warning 1606, if the calculated x or y co-ordinate is beyond the range in the appropriate Figure, then the graphs are not extrapolated so the last point is used to determine the stability.
Keywords: Operation warning 1604, 1606, Excursive, Ledinegg, Oscillatory, Density Wave, Flow Instability
References: None |
Problem Statement: How are different Databanks selected based on the default databanks and the Property Method? How are the databanks effected by changing or deleting Property Methods?
For example:
Start with a blank Simulation.
Go to Tools-Options and select ENRTL-RK and HENRY as your only Binary Databanks.
Go to Properties and select NRTL as your property Method.
Go to Parameters-Binary Interaction-Henry and select the Databank Tab. Aspen has only the HENRY databank listed. Why isn't the ENRTL-RK databank listed? | Solution: The logic for many databanks is based on the vapor phase equation of state model name and the liquid phase activity coefficient model name for the property method.
The list of Selected databanks is determined by:
1 - The list of databanks specified as searchable on the Tools/Options/Component data tab
2 - The property method selected
Only the databanks that support a given property method will be used. For example, the VLE-RK databank is designed for activity-coefficient property methods that use the Redlich-Kwong (RK) equation of state for the vapor phase and the following activity coefficient models: NRTL, Wilson, UNIQUAC. Therefore, when the NRTL-RK property method is chosen, the Databank tab for the NRTL-1 binary interaction parameter form will show the databank VLE-RK as the Selected databank. The databank ENRTL-RK is keyed on the property method ELECNRTL or its variations (ENRTL-HG). If one of these property methods is selected, the ENRTL-RK databank will be selected on the databank tab.
Note that the databank is NOT automatically updated when the property method is changed. For example, if NRTL-RK is already chosen, the default databank is set to VLE-RK. However, if the method was subsequently changed to NRTL-HOC on the Properties/Specifications, the NRTL-1 parameters form is unable to automatically update to VLE-HOC. The user will need to manually select the VLE-HOC data on the NRTL-1 form.
Keywords: eos
gamma
References: None |
Problem Statement: In the Aspen Hydraulics Dynamic sub-flowsheet, why is there a temperature drop across swage while the material is expanding? | Solution: In Aspen HYSYS Dynamics, temperatures are reported at the pipe cell centers, that is, the temperature at half the axial distance of the pipe cell. Therefore, you don't see what is happening at the swage interface (actual zero pipe distance). If you look at the first cell of the pipe segment after the swage then the temperature is a higher value. Please note that this value also incorporates the heat loss of moving through half of a pipe cell.
Keywords: Hydraulics, pipe, expansion. swage, temperature decrease
References: None |
Problem Statement: Why am I not able to delete or select case in the Recap of Design page? | Solution: Go to Application Options, and Set the Storage for Recap of Designs to “Full Recovery”. Then rerun the case file.
Check the status under Recap case fully recoverable. Only the case which has “Yes” status will be able to be deleted or selected.
Keywords: Recap of design, delete, select case
References: None |
Problem Statement: Best Practices for pigging analysis in Aspen Hydraulics. | Solution: Please find below some recommendations while performing a pigging analysis in Aspen Hydraulics subflowsheet.
· Dynamic Solver
Pigging can only be performed with Regular Dynamic solver for Aspen Hydraulics. Dynamic3p and the Compositional solvers are not supported for this analysis.
· Integration parameters
Although time-step size is very case dependent, usually pigging analysis can be performed with larger time-steps (The range could be between 1 second and 1 minute).
NOTE: Remember Hydraulic solver has its own control of Time Step of integration, it can be found in the Dynamic tab of the Hydraulic subflowsheet window.
· Model Selection
Four options available, keep your selection consistent with your case. High performance pigging model is recommended when having two phase flow, then the pig will move with the average of the vapor and liquid velocities.
Â
· Initialization
Make sure your Hydraulic subflowsheet runs correctly before attempting to launch the pig, wrong initial values for the Hydraulic case could result in failure when running the pig analysis. For more information, refer to KB 142387 where you can find Best Practices for Hydraulics subflowsheet.
· Launching time
Preferably use an Event Scheduler to launch the pig at a specific time of your simulation. Launching the pig manually can result in different profiles and convergence issues as time of release implies different initial conditions for the pig. Instructions on how to use this tool for pigging can be found under “Aspen Hydraulics Sub-Flowsheet Window� in Aspen HYSYS Help File.
· Cell size
Try to keep similar cell lengths for the different pipe segments. Avoid large changes (>~10X) in cell size between pipes. For example, a pipe with 0.1m cells connected to a pipe with 100m cells will often cause instabilities or convergence failures.
· Complexity of the model
Keep your pipe configuration with only the necessary elements, not all details need to be modeled for Pigging analysis. Modeling the case as simple as possible while correctly representing the key parts should improve the convergence and solving time of the case.
· Topology and hold up review
When observing issues with the pig, review the pipe segment where the pig is failing.
Is there a large amount of liquid? Is there a large elevation change in that segment?
This can give you clues on what the problem is; increasing the number of cells or reviewing the pressure drop are some options that could be considered.
Keywords: HYSYS, Dynamics, Aspen Hydraulics, Pigging, Integrator, Time Step
References: None |
Problem Statement: When trying to load a composite file using the composite_manage DOS application, a message like the following pops out in the command prompt: Unable to find lock position: no error | Solution: The error “Unable to find the lock position: no error” for an Aspen product typically indicates that the user needs to run the applications using the “Run as Administrator” feature in Windows. Note that in Windows server 20xX, a user with Administrator rights/privileges does not necessarily equal a local system Administrator. Therefore, even if we are logged in using an account that has administrator privileges, it is still need to right-click the application we wish to run and use the “Run as Administrator” feature.
In this case, right click Command Prompt and using the “Run as Administrator” option and with this, it will be possible to use the Composite_manage command to load a controller.
In order to saving the trouble of having to right-click and “Run as Administrator” every single time, it is possible to set the applications to always Run as Administrator by right-clicking the icon for the application (in this case Command Prompt), move on to the Compatibility tab and towards the bottom of the window, there is the “Run this program as an Administrator” check-box. Make sure this is enabled.
Keywords: Composite, composite_manage, controller, DOS command
References: None |
Problem Statement: AspenONE Process Explorer has a basic plot option for manual data entry which allows you to manually update the value of a tag in the Aspen InfoPlus.21 database. | Solution: The option to select Manual Data Entry cannot be disabled; however, if a user does not have write access to a particular tag, then the Aspen InfoPlus.21 database security prevents the update.
Keywords: Manual Data Entry
security
References: None |
Problem Statement: Got CIMIO_ACG10S_Excess Tagss, Too Many Tags in Record error. | Solution: Aspen Cim-IO for Yokogawa ACS10S has following limitation.
Read: 32 tags at a time
Write: 8 tags at a time
So, IO_#TAGS of Get and Put transfers should be limited as follows.
Get Transfer : 32 maximum
Put Transfer : 8 maximum
And, LISTSZ of DMCplus controller should be set to 8.
Keywords: CIMIO_ACG10S_Excess Tags
Too Many Tags in Record
ACG10S
LISTSZ
References: None |
Problem Statement: Why does the CCFswitcher stop and start the Composite process? Is that necessary to make sure the aliasing is correctly rebuilt? Or is there another reason (besides taking into account changes in the INI file)? Does the online composite process use the SSG and MAP files or are they only generated for debugging?
I also noticed that the SSG file contains the SSG's without the effect of the GMULT. Are the GMULTs taken into account in every composite run and read from the Context every cycle (to make sure you use the correct SSG)? | Solution: ALIDWN can be read from the DCS. Below is an example. You need to make sure it is declared at CH(60). The Composite reads the new mapping on the fly and does not require a restart to use the new mapping. DCS logic can swap the ASC string.
.ALIDWN001~~~READ~~~CH(60)~~~FMX C2FUELPV FC121SP~~~::F01_ALIAS.Alias_1:ASC:
.ALIDWN002~~~READ~~~CH(60)~~~FMX C2COTPV TC109SP~~~::F01_ALIAS.Alias_2:ASC:
.ALIDWN003~~~READ~~~CH(60)~~~FMX C2COTPV TC110SP~~~::F01_ALIAS.Alias_3:ASC:
.ALIDWN004~~~READ~~~CH(60)~~~FMX C2COTPV TC111SP~~~::F01_ALIAS.Alias_4:ASC:
.ALIDWN005~~~READ~~~CH(60)~~~FMX C2COTPV TC112SP~~~::F01_ALIAS.Alias_5:ASC:
To check if it is working, you can set the debug level to a very high value in the INI file (greater than or equal to 10). In the Composite log files, you will be able see the current steady state gains being used by the Composite. By checking these gains, you can also check if the dynamic aliases are being used as expected (by seeing if there are non-zero gains between the corresponding inputs and outputs). The controller PRT files will also show the future feedforward moves.
The SSG and MAP file are generated for debugging purposes only.
GMULTs are taken into account in every Composite run and read from the controller contexts.
The CCF switcher stops and restarts the Composite in case the user has changed the configuration in the CCF by adding/removing variables in the model (by adding a new CV for example). The Composite does not handle those kind of configuration changes well and it is better to stop and restart the program. It is not necessary to stop/restart the Composite when only the dynamic aliasing is modified.
Keywords: SSG, Map, clp, dmcplus,
References: None |
Problem Statement: Aspen DMCplus Composite Critical Status on the Aspen Production Control Web Server (PCWS) display does not match the critical settings in .ini file. | Solution: The composite ini file is not loaded online and is therefore not maintained in the online shared memory. The critical status setting in the ini file is not considered when calculating the critical status to be displayed on the PCWS web page.
The composite critical indicator displayed in PCWS is different from the one in the composite ini file. The status of a controller is displayed as composite critical if one of more of the variables involved in the controller are marked as critical for composite operation (CRIDEP/CRIIND = 2). When a controller is loaded online, PCWS scans the CRIDEP and CRIIND for the variables in the controller and accordingly calculates the composite critical status for the controller.
The above is only true for controller deployed through the legacy DMCplus (ACO Base) platform. For controller deployed through the APC Builder (RTE) platform, the composite application is also loaded in the shared memory and therefore the composite critical status for the participating controllers is displayed based on critical status setting for the controller in the composite application.
Keywords: Composite critical status
References: None |
Problem Statement: When the heat flux to a surface is increased, a point is reached where the contact between the liquid and the heated surface is lost. At this point, the heat transfer coefficient is greatly reduced and the surface temperature rapidly increases. This point is called the “critical heat flux”, CHF, which not only refers to the value of the heat flux but the phenomenon.
The mechanisms of critical heat flux have been classified into two groups, depending upon the quality range.
Low quality (subcooled) region
If CHF occurs in the low quality, then it may have certain characteristics that resemble pool boiling CHF.
Near wall bubble crowding and vapour blanketing: A bubble boundary layer may build up on the wall of the heated surface which eventually becomes sufficiently thick to prevent liquid from reaching the surface.
Local overheating at nucleation sites: Micro-layer evaporation may occur underneath the growing bubble, which at sufficiently high heat fluxes may prevent the surface from being re-wetted when the bubble departs.
Vapour clots or slug formation: Vapour clots or slugs may approach so close to the wall, that the liquid film on the tube wall may be evaporated, leaving the wall temperature high enough to prevent re-wetting.
CHF at high qualities
CHF at high qualities is associated with convective boiling in annular flow, where the liquid film on the tube wall approaches zero. The thinning of the liquid film occurs due to liquid evaporation and entrainment, but is counter-acted by droplet deposition.
Beyond the CHF point, liquid droplets are dispersed in the vapour core, with the region commonly called the “liquid deficient region” or “post-dryout”. Here the heat transfer rates are low due to the poor heat transfer characteristics of the vapour phase. | Solution: An indication of how close the process is operating to the critical heat flux, can be found from Results | Thermal / Hydraulic Summary | Heat Transfer | MTD & Flux tab, from the “Highest ratio, actual/critical flux.
Care should be taken in interpreting the table as the critical heat flux (at highest ratio) may not necessarily occur at the highest actual flux reported.
If the critical heat flux is exceeded, then there will be an Advisory 1530 warning, indicating that the critical heat flux was exceeded between a quality range and at one quality point give the calculated heat flux and the calculated flux and state that post dryout calculations have been applied in the region where the critical heat flux is exceeded.
If required, from Input | Program Options | Methods/Correlations | Vaporization tab, post dryout calculations can be turned off from the “Post dryout heat transfer determined” input, where if set normal boiling coefficients will be calculated in the region beyond the point of dryout.
In general, post dryout should be avoided, especially at low qualities and the process conditions changed if possible. When dryout occurs, there is an uncertainty in the determining the critical heat flux and the location where it occurs in the exchanger. This can have a significant impact on the performance due to the low heat transfer coefficients in the dryout region.
Keywords: Liquid deficient region, post dryout, critical heat flux
References: None |
Problem Statement: Which TCP ports does aspenONE Process Explorer (A1PE) need in order to work successfully? | Solution: A port needs to be opened between the end user system and the machine which is serving the aspenONE Process Explorer. This will typically be port 80 unless the default settings have been changed in Internet Information Server (IIS).
Keywords: ports, configuration
References: None |
Problem Statement: Formula to copy a value from exported TEMA to another sheet does not work (shows the formula only or #VALUE! error). | Solution: Change the default worksheet name from Tasc+ to Tasc. The + sign (or any special character) in the worksheet name causes problem. The plus sign will be removed from the worksheet name in a later version of Shell&Tube.
Keywords: TEMA, worksheet, exported, formula, #VALUE, excel
References: None |
Problem Statement: How to specify the geometry of the Multitube Hairpin Exchanger | Solution: Multitube Hairpin Exchanger will contain two shells. So when specifying the geometry specify the information relevant to single shell.
Number of Tubes: Specify double the number of U-tubes or total number of tube holes in the tubesheet of one shell.
Tube length: Specify the total effective length of tube in one shell i.e. From front end of front tubesheet to start of U-Bend (Specify the straight tube length).
Baffles: Number of baffles in a single shell.
Shells in Series or Parallel: One Multitube Hairpin heat exchanger contains two shells.
For example if you have 4 shells in series or parallel you need to specify them as 2 exchangers in series or parallel accordingly.
Keywords: Hairpin Multitube exchanger, U-Tubes
References: None |
Problem Statement: The liquid heat capacity for solvents other than water can be significantly off with ELECNRTL. Can solvent liquid heat capacities be improved by using the saturated liquid reference state for enthalpy with ELECNRTL? | Solution: The saturated liquid enthalpy reference is not compatible with ELECNRTL calculations. Consider a system with Water, Acetic Acid and Sodium Hydroxide. Acetic Acid and Sodium Hydroxide react to form water, sodium ion and acetate ion. Databank values for ions are dependent on the pure component reference state. Adjusting the reference state of solvent components such as acetic acid would change the effective heat of reaction of reactions containing the solvents. Therefore, the saturated liquid reference state is not supported for use with ELECNRTL.
There are two potential methods for improving the liquid heat capacity of solvents with ELECNRTL. Neither has been evaluated for specific systems of interest by AspenTech at this time. After any regressions described in step 1 or step 2, it is the reponsibility of the user to verify that system VLE, liquid enthalpies (including implied heats of reaction), and heat capacities are suitable for his/her simulation.
In general the heat of vaporization parameters (for either the Watson equation or DIPPR equation) were fit with heat of vaporization data from the boiling point to the critical point . Generally, they provide good results for the heat of vaporization at the expense of liquid heat capacity. It may be possible to refit DHVLWT or DHVLDP parameters from both heat of vaporization data and liquid heat capacity over a narrower temperature range of interest to get a better fit of liquid heat capacity without sacrificing too much accuracy in heat of vaporization. If possible, DHVLWT or DHVLDP parameters should be regressed so that the heat of vaporization at 25 C does not change. For the Watson equation this can be done by setting DHVLWT/1 to the heat of vaporization at 25 C, and setting DHVLWT/2 to 298.15 K.
Although Henry's Law was not intended for solvents, it may be suitable to declare a solvent as a Henry's Law component, if there is an abundance of data for regression and analysis. Note that use of this method precludes use of the solvent as a pure component in the liquid phase.
For any solvent assigned as a Henry's Law component, the user would need to determine the following through regression:
Henry parameters for this solvent in all other solvents (especially water). [Regressed from VLE]
NRTL parameters between this solvent and other solvents (especially water). [Regressed from VLE]
CPAQ0 parameters for the solvent [Regressed for aSolution of 99.9 % solvent, 0.1 % water]
DHAQFM for the solvent. [Set such that the heat of vaporization is correct]
DGAQFM for the solvent [If it participates in equilibrium reactions with K-STOIC parameters, such that the extent of reaction is correct.]
Keywords:
References: None |
Problem Statement: Why are fouling resistances not taken into account for hydraulic calculations in my heat exchanger? | Solution: In heat exchanger design, it is expected to get a higher pressure drop and higher velocity when fouling conditions increase. When I specify fouling resistances in my heat exchanger, these are not affecting hydraulics results, such as pressure drop or velocity. The fouling resistance specified in the Process Data section of the heat exchanger is only considered for the heat transfer coefficient calculation, which is why no changes are observed in pressure drop and velocity.
However, it is possible to additionally specify either a fouling layer thickness for both hot and cold side, or the fouling thermal conductivity.This can be done in Input | Program Options | Thermal Analysis | Fouling tab:
If two of these three variables are specified (fouling factor, layer thickness, fouling thermal conductivity), the third one will be calculated by EDR, and the program will have enough information to include fouling conditions in both thermal and hydraulic calculations.
Keywords: Fouling factor, fouling resistance, pressure drop, velocity, layer thickness, fouling thermal conductivity
References: None |
Problem Statement: Aspen Plus version 10.2 through version 12.1 allowed users to export an input file with graphics. This feature does not appear to be available in version 2004 and later. | Solution: This option was changed to allow the export of an input file (.inp) where the graphics information is now exported to the Aspen Plus embedded object file (.apmbd). When opening an .inp file in the GUI, the flowsheet graphics will be loaded if an .apmbd file is present in the directory.
The export to an input file with graphics was creating some extremely bloated input files which resulted in increased time and memory on the engine to process them.
In V7.2, the Input File with Graphics file export type has been renamed more accurately Input and Graphics Data File. This format stores the flowsheet graphics and embedded objects in a separate .apmbd file which must be stored together with the .inp file. The older Input File with Graphics format is once again available. This format stores flowsheet graphics as comments in the .inp file, and does not retain embedded objects.
Note: Input and Graphics Data Files may not restore the graphics correctly when used in client-server environments. To ensure the graphics restore correctly in this environment, save the file as a Backup (*.bkp) file on an Aspen Plus installation with the server running locally.
Keywords: save files
References: None |
Problem Statement: A flowsheet runs perfectly when specified as a 3-phase (vapor-liquid-liquid) system; however, there are errors when it`s specified as a 2 phase system in Aspen Plus. The system is expected to be a 2-phase (vapor-liquid) system, and the results indicate that no 2nd liquid phase exists. Why would this occur? | Solution: This problem can occur when the Water Solubility Method (SOLU-WATER) is 0 (K-value of water calculated from water-solubility correlation with vapor fugacity of water calculated by free-water phase property method) even though Free-Water is not used.
The Water Solubility method (SOLU-WATER) normally only associated with Free-Water calculations is also used for non-free-water calculations in certain cases. When SOLU-WATER=0, the fugaticity coeficient of water in the vapor phase is computed using the free-water property method for 2-phase flashes even when free-water=NO.
TheSolution is to change the Water Solubility Method to something other than zero.
In summary, regarding the use of SOLU-WATER=0:
The SOLU-WATER keyword is always ignored when NPHASE=3.
When NPHASE is not 3, SOLU-WATER=0 will force the vapor phase fugacity of water to be computed using the free-water option set irrespective of FREE-WATER specification.
Hence, when SOLU-WATER=0, it is reasonable for the Flash
to give different results when NPHASE=2 and NPHASE=3.
Keywords: liquid-liquid
solu-water=0
SOLU-WATER
Free water
FreeWater
References: None |
Problem Statement: There is a mass imbalance in a block. Why would this occur? | Solution: Some types of specifications such as pseudoproduct streams, stream manipulator blocks, and heat duty or work load specifications without a heat or work stream may cause imbalances.
Each unit operation model in Aspen Plus has a Results form with a Balance sheet that displays a summary of material and energy balances around the block. These balances represent the total of all inlet and outlet material and energy streams around the block. Normally these balances are closed, but in these situations a block may show a difference in the balances:
If a block has a heat duty or work load specified or calculated, without a corresponding heat or work stream, that duty or load is not included in the balance, and an imbalance in the amount of the duty or load will result. To avoid this, either specify the duty or load as an inlet heat or work stream, or attach an outlet heat or work stream to the block to carry the duty specified or calculated in the block.
Stream manipulators like Mult, Dupl, and Selector by their nature do not preserve material and energy balances.
Pseudoproduct streams, which represent copies of internal column flows, will result in imbalances equal to the total pseudoproduct stream flow.
Incorrect specifications for stoichiometry, yield fraction, or user kinetic rates may result in imbalances.
Flows changed by Calculator, Transfer, and Balance blocks may result in imbalances.
In some cases where a block could not converge, or if convergence tolerances have been set very loose, the balances may not be satisfied.
Keywords:
References: None |
Problem Statement: When creating a dashboard displaying multiple aspenONE Process Explorer trends, some windows may be analytics plots that consume two tokens, but some screens may just be normal Trend Plots that do not consume any additional tokens. This may cause confusion as to how many tokens this dashboard will consume. | Solution: The dashboard will consume tokens equal to the largest token consume of any of those screens. This means that it will consume two tokens if any of the screens are displaying an analytics plot, but if no analytics plots are displayed, then the dashboard will not consume any additional tokens.
Keywords: dashboard
tokens
References: None |
Problem Statement: How do I select custom start and end dates in an aspenONE Process Explorer Trend Plot? | Solution: The aspenONE Process Explorer trend plot functions similarly to a trend plot from classic Process Explorer, except the interface looks different. This may lead to confusion as to where certain tools lie.
In an aspenONE Process Explorer trend plot, the time line lies just below the chart area. The gray box denotes the time span that is actually shown. This box can be dragged or resized as desired to change the time span of the plot. The clock icon on the right side of the time line toggles the plot in and out of real-time mode, with a green clock indicating that it is in real-time mode. the calendar icon on the left side of the plot can be used to manually specify exact time spans. The gray bar to the left of the calendar enables the replay option. Towards the top left of the chart, there is a + icon that will expand to give the options of custom zoom, reset zoom, half the time span, or double the time span. The time span can also be customized with the predetermined spans underneath the time line bar.
Keywords: Timeline control
References: None |
Problem Statement: For a boiling stream, you can specify the use of a heat transfer coefficient based on a boiling curve which you may supply. A boiling curve can be applicable when nucleate boiling dominates and convective boiling is small.
A boiling curve gives the relationship between the heat flux and driving wall to stream temperature difference, where it is usually in the form:
Heat flux is proportional to temperature difference raised to some power greater than unity
To define such a curve, users should supply one value of temperature difference, the corresponding heat flux, and power (exponent) to which the temperature difference is raised. Using this information, the program can calculate the heat flux that applies at any other temperature difference. This information can be entered in the Input | Program Options | Methods/Correlations | Vaporization tab.
Heat transfer coefficients are equal to heat flux divided by temperature difference, and so are readily determined using a boiling curve. | Solution: Described below is the form of the boiling curves that may be entered.
The corrections to the boiling curve can be set where there are a number of options:
· No corrections - Use as given, with no corrections for mixture effects or convective boiling. This option should only be used when there is a good match between the conditions in your exchanger and those to which the boiling curve relates.
· Mixture + convection - Apply HTFS mixture corrections and convective boiling terms. Mixture corrections and convective effects may permit useful results to be obtained when the match is less good.
· Boiling curve not used
Boiling curves are normally very specific to particular fluids, tube surfaces and operating pressures. They generally apply to pure fluids in nucleate / pool boiling situations, where flow effects (other than those induced by rising bubbles) are secondary. The heat flux should relate to the heating surface; it should be based on tube OD for shell side boiling, or tube ID for tube side boiling.
You can specify that boiling heat transfer is based on a boiling curve you provide. You need to specify three parameters to define the curve:
·
Keywords: Pool boiling, nucleate boiling
References: heat flux ( Qr )
· Reference delta-T ( dTr )
· Boiling curve exponent ( n )
Aspen Shell and Tube Exchanger will use the following relation to determine the heat flux Q corresponding to a temperature difference dT between the boiling fluid and the wall
Q = Qr ( dT / dTr ) n
If you have a boiling curve expressed as
Q = A ( dT ) n
Set dTr (reference temperature difference) to 1.0 (deg C or deg F as appropriate)
Set Qr (reference heat flux) to A
Set the boiling exponent n
If you have an expression for heat transfer coefficient with a dT exponent such as
α = B ( dT ) m
Set dTr (reference temperature difference) to 1.0 (deg C or deg F as appropriate)
Set Qr (reference heat flux) to B
Set the boiling exponent n to m+1 |
Problem Statement: Why does the superheating/condensing transition region produce spikes in heat transfer coefficient? | Solution: For a pure fluid (single component), when the condensation begins, the only resistance to heat transfer is an initial thin film. The heat transfer coefficient in this case is very high. Technically the film thickness begins at zero, so the coefficient starts with a very high value. The coefficient then falls rapidly to normal value as film thickness increases with condensation. This explains the spikes in the heat transfer coefficients without wet-wall de-superheating or superheating. The sharp peaks in coefficients have a relatively small effect. The peaks in most cases are less noticeable when the fluid is a multicomponent mixture.
In reality, condensation begins as soon as the wall temperature is below the dew point. This is wet-wall de-superheating. This gives a much larger coefficient than the dry wall (gas only) coefficient, but does not begin with a spike, because the resistance to heat transfer not only the liquid film but also the gas, since that part of the gas condenses must first be cooled to the dew point.
Keywords: Heat transfer coefficient, Superheating, De-superheating, Condensation
References: None |
Problem Statement: Why is the calculated vapor outlet temperature by Aspen Shell and Tube Exchanger lower than the displayed bubble point? How is the bubble point calculated? | Solution: In some cases, you may see a vapor outlet temperature lower than the displayed bubble point in the TEMA sheet as shown in the screenshot below:
Bubble and dew points are calculated at the inlet pressure. Hence, the bubble point 267.08 F shown in the screenshot represents the inlet stream bubble point. The inlet stream will be evaporated in the heat exchanger so that the stream temperature goes up. Because of the pressure drop, the outlet stream bubble point should be lower than the bubble/dew point reported.
Keywords: Bubble Point, TEMA sheet, Vapor Outlet Temperature
References: None |
Problem Statement: What combination of series and parallel configuration are allowed in Aspen Tasc+? Is it possible to use different sizes or types of exchangers in one file for a series / parallel combination ? | Solution: Aspen Aspen Tasc+ does allow combinations of both series and parallel heat exchangers in a given file subject to the constraints indicated below:
1.) For parallel exchangers, feed streams are equally divided among each parallel path, with all exchangers being of identical size, type and configuration.
2.) There must be an equal number of exchangers in series in each parallel path.
If a feed stream is not equally divided into parallel paths or if there are different sizes, types or configurations of exchangers, the heat exchanger network must be modeled using multiple files that each satisfy the restrictions indicated above.
Keywords: series, parallel, Tasc+, TASC, Hetran, B-Jac
References: None |
Problem Statement: How do I transfer the program settings from the old version to a new version? | Solution: This can be achieved by running the Version Control Utility (BJACVC.exe) from either Start | All Programs | Aspen Tech | Exchanger Design and Rating V7.1 or the window explorer. Using the window explorer, navigate to local drive where you have installed the software | Program Files | Aspen Tech | Aspen Exchanger Design and Rating V7.1 | XEQ (C:\Program Files\AspenTech\Aspen Exchanger Design and Rating V7.1\XEQ) folder then search for a file called BJACVC.exe and open it.
Once the Version Control utility's view is open, go to Program Settings tab.
In the Select a source and a target version below field, highlight the version of Aspen Exchanger Design and Rating that has the program settings and select it as a source by clicking on Source button then highlight the new version of Aspen Exchanger Design and Rating where these program settings go to and click on Target button.
Finally click on the Apply button at the bottom to move the settings.
Keywords: program settings, version control
References: None |
Problem Statement: How to model a bayonet type heat exchanger in Aspen Exchanger Design and Rating (EDR) | Solution: The bayonet type exchanger (also called Stab-in exchanger) is not directly handled by EDR. However, it may be possible to mimic such an exchanger by using AXU, BXU, AKU or BKU TEMA types with the Thermosiphon application (Input | Problem Definition | Application Options).
Please note the following items:
TEMA K shell is always a horizontal shell. If the shell is vertical and the cold stream is on the shellside, the hydraulic results might be different, which means the user needs to improvise with the pressure drop spec or pressure drop expectation. Then an X-shell should be used rather than a K-shell. If the cold stream is on the tube side for horizontal orientation, it can still be modeled using the above geometries. For a vertical tubeside thermosiphon in U-tubes, there might be difficulties with pressure specifications along the piping loops.
If a large pressure drop is not expected on the column inflow or outflow, the recommended approach would be to use a very large nozzle diameter (or even select ignore pressure drop through nozzle option). This can be specified on the Nozzles form (Input | Exchanger Geometry | Nozzles).
For Baffle type, use the Unbaffled option since there are no baffles in this part of the column. (Input | Exchanger Geometry | Baffles/Support)
If a K-shell is used, specify the Kettle diameter as that of the column and specify the Shell diameter as that of the bundle.
Keywords: Bayonet type exchanger, Stab-in exchanger.
References: None |
Problem Statement: When building the search index for aspenONE Process Explorer the following error message is logged:
Failed to get tag metadata for tags on: DATASOURCE ( All tags are invalid)
The message occurs despite the number of tags to publish being a non-zero number.
This is occurring when using either the Tag Name or By Wildcard (*) scan filter options: | Solution: The cause of the error is likely to be that the tags that meet the scan filter do not in fact have an associated map record. For example, assuming a custom tag called MYTAG is specified in the search scan filter and the tag's definition record does not have an associated map record, the following log can be expected:
Scan to publish tags by wildcard started .... Publishing to localhost
Retrieving requested tags from data source: DATASOURCE ...
Done retrieving requested tags from datasource: DATASOURCE
Number of tags to publish: 1
Getting metadata for retrieved tags...
Getting the datasource (DATASOURCE) tag count...
Done getting the datasource (DATASOURCE) tag count...
Getting tags security info...
Done getting tags security info...
Retrieving tags metadata...
Done retrieving tags metadata...
Failed to get tag metadata for tags on: DATASOURCE ( All tags are invalid)
Failed to scan tags by wildcard
Scan to publish tags by local ProcessData data source ended
Note, MYTAG would not appear in the Tag Browser either for the same reason. It is necessary to create and configure a record defined by AtMapDef,please refer to Knowledge BaseSolution 105326 to resolve both these problems.
Keywords: Admin
Missing
Item Details
Manage Tags
References: None |
Problem Statement: Data stored in an Aspen Reporting Framework (ARF) database can be viewed within a cube in Microsoft Business Intelligence Development Studio utilizing the Microsoft SQL Server Analysis Services. In turn this data can be viewed from any of the client machine to generate reports with different hierarchies defined in Aspen Operations Domain Model (ODM) by using third party applications. This knowledge base article outlines different applications that can be used to visualize the data and where can you may find some information on how to use them. | Solution: The different client applications that can be used to create reports are:
? Microsoft Excel:
Please refer the following knowledge base article for a detailed procedure on how to use Microsoft Excel to retrieve the data from the Aspen Reporting Framework database to generate reports
127625: How can I visualize the data from Aspen Reporting Framework using Microsoft Excel?
? Microsoft Performance Point:
Following is the link to get the performance point materials from the web
http://www.microsoft.com/business/performancepoint/
? Microsoft SQL Server Reporting Services (SSRS):
For information on how to create reports using SSRS please refer the following link
http://msdn.microsoft.com/en-us/library/ms170246(SQL.90).aspx
Keywords: Third party applications
ARF
Excel
References: None |
Problem Statement: Register EDR components when the program starts up option doesn't work correctly on Vista Operating System as it needs to run the executable files(.exe) with Administrative privileges.
Note: This happens when multiple version of EDR components is installed in the same machine. | Solution: To solve the problem uncheck the Register EDR components when the program starts up option from the Tools | Program settings | Advanced tab for all the versions of EDR or you can run the EDR (Bjacwin.exe) by selecting Run as administrator
Keywords: Runtime error 430, Vista, Administrator
References: None |
Problem Statement: Is it possible to use CHEMISTRY without using the ELECNRTL property method? | Solution: It is possible to use CHEMISTRY without ionic species with other activity coefficient property methods; however, the true component approach should be used. There is no route for the conversion of apparent to true components (XTRUE) built into other property methods. To use another property method with the apparent approach, start with the ELECNRTL property method and change the gamma activity coefficient model. This is the methodology used for the formaldehyde data package. 3-phase (vapor-liquid-liquid) calculations and CHEMISTRY are not allowed with the true component approach; hence, ELECNRTL or a modified ELECNRTL property method must be used.
Keywords: VLL
References: None |
Problem Statement: How can I choose a designed exchanger geometry from the optimization path? | Solution: Select one of the exchangers from the items and press the Select button. Note that the exchanger with the minimum cost or area is already select by the program and appears in the bottom of the table. After selecting the exchanger, go to Run on the main menu and click on ?Update the Geometry?.
Keywords: exchanger, geometry, optimization path
References: None |
Problem Statement: What are the properties returned by a CAPE OPEN package created by Aspen Plus 12.1? | Solution: Constant Properties:
casRegistryNumber
iupacName
chemicalFormula
structureFormula
molecularWeight
CriticalTemperature
CriticalPressure
criticalVolume
criticalCompressibilityFactor
criticalDensity
acentricFactor
dipoleMoment
parachor
gyrationRadius
associationParameter
diffusionVolume
diffusionCoefficient
vanderwaalsVolume
vanderwaalsArea
energyLennardJones
lengthLennardJones
normalBoilingPoint
heatOfVaporizationAtNormalBoilingPoint normalFreezingPoint
heatOfFusionAtNormalFreezingPoint
liquidDensityAt25C
liquidVolumeAt25C
idealGasGibbsFreeEnergyOfFormationAt25C idealGasEnthalpyOfFormationAt25C
standardFormationEnthalpySolid
standardFormationEnthalpyLiquid
standardFormationEnthalpyGas
standardFreeFormationEnthalpySolid
StandardFreeFormationEnthalpyLiquid
standardFreeFormationEnthalpyGas
standardEntropySolid
standardEntropyLiquid
standardEntropyGas
Calculated properties:
fugacityCoefficient
enthalpy
entropy
gibbsFreeEnergy
gibbsFreeEnergy.Dtemperature
gibbsFreeEnergy.Dpressure
gibbsFreeEnergy.Dmolfraction
gibbsFreeEnergy.Dmoles
volume
volume.Dtemperature
volume.Dpressure
volume.Dmolfraction
volume.Dmoles
diffusionCoefficient
diffusionCoefficient.Dtemperature
diffusionCoefficient.Dmolfraction
diffusionCoefficient.Dmoles
viscosity
thermalConductivity
thermalConductivity.Dtemperature
thermalConductivity.Dmolfraction
thermalConductivity.Dmoles
surfaceTension
surfaceTension.Dtemperature
surfaceTension.Dmolfraction
surfaceTension.Dmoles
heatCapacity
viscosity.Dtemperature
viscosity.Dpressure
viscosity.Dmolfraction
viscosity.Dmoles
enthalpy.Dtemperature
enthalpy.Dpressure
enthalpy.Dmolfraction
enthalpy.Dmoles
entropy.Dtemperature
entropy.Dpressure
entropy.Dmolfraction
entropy.Dmoles
fugacityCoefficient.Dtemperature
fugacityCoefficient.Dpressure
fugacityCoefficient.Dmolfraction
fugacityCoefficient.Dmoles
activityCoefficient
solubilityIndex
pH
vaporPressure
molecularWeight
normalBoilingPoint
density
Flash types:
TP
PVF
PH
PS
TVF
TH
TS
Keywords:
References: None |
Problem Statement: Can values for the infinite dilution activity coefficient (GAMINF) be reported by Aspen Plus and if not how can it be calculated? | Solution: Infinite dilution means such a large dilution so that when you add more solvent there is no change in concentration.
The concept of infinite dilution is used to study how substances are dissolved in solvents. Infinite dilution is an extrapolation method that tests aSolution's properties to see if they originate from the solute.
The infinite dilution activity coefficients characterize the behaviour of the solute molecule when it is only surrounded by solvent molecules and there are no interactions between solute–solute molecules
Very often (but not always) the maximum value of the activity coefficient occurs at the infinite dilution value, which is the limit of the activity coefficient as the concentration of the solute tends towards zero
Thus, to take into account of non-ideality in liquidSolution use is made of activity coefficients. Depending on the types of components present in the streams in the flowsheet, a variety of activity coefficients maybe used (refer toSolution 102289 and 105428 for more information)
The following activity coefficients are available in Aspen Plus:
GAMMA is the symmetrically normalized activity coefficient used for for all components (include charged species like electrolytes).
GAMINF is the infinite dilution activity coefficient
GAMUS is the unsymmetrically normalized activity coefficient i.e., in contrast to the definition of the symmetrically normalized activity coefficient (GAMMA), GAMUS approaches unity as the corresponding mole fraction approaches zero. GAMUS is computed from GAMMA divided by the infinite dilution activity coefficient (GAMINF):
GAMINF can’t be reported in Aspen Plus but it can be calculated from the following equation:
GAMUS = GAMMA/GAMINF
In which GAMUS and GAMMA can be retrieved from the property database for the selected components.
Keywords: GAMUS, GAMMA, GAMINF
References: None |
Problem Statement: This knowledge base article explains how to change the update frequency of a plot in apenONE Process Explorer [a1PE]. | Solution: To change the update frequency of a plot in apenONE Process Explorer [a1PE]
1. Open the plot and select settings.
2. The update frequency setting is under the Timeline.
3. Set Update Frequency to the desired value.
4. Save the plot.
Keywords:
References: None |
Problem Statement: This Knowledge Base article provides steps to resolve the following aspenONE Search issues:
1. The search page does not load and the waiting “spinner” icon spins continuously.
2. The following error appears in the Process Data logs located at C:\Programdata\AspenTech\DiagnosticLogs\ProcessData:
http://<your_server_name>/aspenONE/aspenONESearch.svc/: Access is denied.
Access is denied.
: Access is denied. | Solution: The issue can be resolved by granting the Users group access permissions to the AspenTech folder in IIS at the following location
C:\inetpub\wwwroot\AspenTech
The Users group should be granted the following permissions:
· Read & Execute
· List Folder Contents
· Read
Keywords: None
References: None |
Problem Statement: How do I input a helical fin type in Aspen Shell & Tube Exchanger | Solution: The shell type for the heat exchanger must first be set to an X shell that can be set from Input > Exchanger Geometry > Geometry Summary > Geometry tab
Now from the Input > Exchanger Geometry > Tubes > Tubes tab, for the Tube type, “Other (radial fins) can be selected.
From the Fins tab, the type of radial fin and geometry can be entered.
The G-finned tubes are formed from metal strip that is tension wound into helical groove in the base tube. The sides of the grooves are then peened over to produce a firm mechanical bond. This is a high conductivity fin tube for high temperature applications up to 450°C.
Keywords: Helical fin, G-finned tubes, Other Fin Data
References: None |
Problem Statement: This Knowledge Base article shows how to integrate any object, such as a waterfall diagram, in an IP.21 Process Browser graphic and then display it in aspenONE Process Explorer (A1PE). | Solution: Graphic Studio has a new frame object that allows HTML inline frames to be embedded within a graphic page and a URL specified for that frame.
So any page, including the trend control, can now also be placed in a graphic using the frame object and entering the URL for it prior to publishing to a1PE.
For details on specifying the URL, see Aspen KB article “Using the aspenONE Process Explorer Trend Plot on a URL referenced as KB # 144975.
Keywords: None
References: None |
Problem Statement: How do you ensure a good distribution of the shell side fluid in an X type shell? | Solution: There are several things you can do to ensure better distribution of the shell side fluid in an X shell.
1. Use multiple inlet and outlet nozzles: The default is one inlet and one outlet nozzles. You can specify multiple inlet and outlet nozzles. You can specify the distance from one to the other.
2. Use Supports: Tube supports will compartmentalize the shell. If you use one inlet and one outlet nozzles for each of these compartments. The will act like smaller X shells individually, which can make sure pure cross flow.
3. For Gas stream: Inlet nozzles at the top and outlet nozzles at the bottom: The default location of inlet is at the bottom and outlet at the top. If you have gas in the shell side, if you put the inlet nozzle(s) at the top and outlet nozzle(s) at the bottom, there is less chance of direct channeling from inlet to outlet. Thus it may help in better distribution.
The following picture shows the interface where you specify multiple nozzles, nozzle location, distance etc.
Keywords: Xshell, Nozzels, Fluid Distribution, Shell Fluid
References: None |
Problem Statement: What is the difference between the Number of U-tubes on TEMA sheet and the total number of U-tubes in the U-Bend Schedule? | Solution: U-bend Schedule number of U-tubes is based on the Tube Number (layout) and the Number of U-tubes on the TEMA sheet is based on number of tubes specified by user Tube Number (Calcs.).
The Tube Number (layout) is the total number of tubes estimated by the program and Tube Number (Calcs.) is the total number of tubes specified by the user on the Geometry summary (Input/Exchanger Geometry) inputs.
These values can be viewed in the Settings Plan & Tubesheet Layout results as shown below.
TEMA sheet value = Tube Number (Calcs.)/2
Total number of U-tubes on U-bend schedule = Tube Number (layout)/2
Keywords: U-tubes,U-bend schedule,Tube Number (layout),Tube Number (Calcs.)
References: None |
Problem Statement: Where can I specify the weir height for a Kettle Reboiler? | Solution: The users can enter the height of the weir above the top of the bundle for a kettle reboiler. This can be specified in the Heat Transfer form via Input | Program Options | Thermal Analysis. A screenshot of this form is shown below.
The default weir height is zero that is the top of the weir is level with the top of the outer tube limit circle of the bundle.
The height of the weir is taken as defining the head of liquid providing the driving force for re-circulation within a kettle reboiler.
Keywords: Kettle Reboiler, Weir Height
References: None |
Problem Statement: Why is the effective surface area per shell not changing when the No tubes in Window option is selected? | Solution: Heat Transfer Area per Shell is calculated by PI(3.14) * tube OD * tube Length * Number of Tubes Per shell.
For the overall area you would have to multiply this number by the Number of Shells in Series and Number of Shells in Parallel.
If a tube count is specified in the exchanger geometry Aspen Shell & Tube Exchanger will calculate the area based on the specified value. For the no tubes in window option this input value has to be removed as Aspen Shell & Tube Exchanger will calculate the new number of tubes that fit in the shell.
In the below figure remove the specified 170 number of tubes while using the No tubes in Window option to get the correct heat transfer area.
Keywords: no tubes in window, area, TEMA sheet, effective, tube count
References: None |
Problem Statement: Why are the tubes in the Tubesheet Layout in grey color? Normally they are white. | Solution: If you right-click the Tubesheet Layout diagram, a context menu appears with printing and drawing options, such as drawing tubes as crosses rather than circles. If the Display Details option is unselected then the tubes will appear in grey color. To make them as while color select Display Details option.
Keywords: tubes, grey, color, white, tubesheet, drawing
References: None |
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