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Problem Statement: Can I model valve hysteresis when using a Relief Valve in the Dynamic Depressuring Utility? | Solution: The Dynamic Depressuring Utility can model depressuring through a relief valve by selecting Relief for the Vapour Flow Equation on the Design\Valve Parameters page of the Dynamic Depressuring Utility.
When a Relief valve is selected the user is able to specify the Relief valve Set Pressure and Full Open Pressure. To model relief valve hysteresis requires also the specification of the Relief Valve Closing Pressure and Reseating Pressure. These options are not available directly from the Dynamic Depressuring Utility but can be specified as follows:
From the Tools\PFDs menu at the top of HYSYS select the Depressuring subflowsheet and click the View button. Note that this subflowsheet is created automatically by HYSYS when the Depressuring Utility is run, and therefore is not available until the utility has been run at least once.
Double-click on the VapourReliefValve.
On the Dynamics\Specs page, check the option Enable Valve Hysterysis. Two new fields will appear allowing you to specify the Closing Pressure and Reseat Pressure.
Close the PFD for the Depressuring subflowsheet.
Once this is done the Dynamic Depressuring Utility will then use the specified Relief valve Set Pressure, Full Open Pressure, Closing Pressure and Reseat Pressure and therefore provide a realistic model of the relief valve hysteresis.
For future versions of HYSYS the Closing Pressure and Reseat Pressure will be made available directly from the Dynamic Depressuring Utility. The misspelling of Hysterysis on the Relief Valve Dynamics\Specs page will also be corrected!
Keywords: Hysteresis, Closing, Reseat, PSV, Relief Valve, Depressuring
References: None |
Problem Statement: You have been asked by business users to find a list of users logged into Collaborative forecasting tool. Upon analysis there were two tables found (CF_LOGIN_AUDIT & CF_LOGIN_SESSION) which captures the login details of users. CF_LOGIN_AUDIT does not captures admin login where as CF_LOGIN_Session captures it. What is captured in these 2 tables? | Solution: CF_LOGIN_AUDIT tables captures the windows authenticated users log off information (we use this table for internal business processing). The CF_LOGIN_SESSION table captures login details of user(s). The admin user information is not captured in any of the above mentioned tables.
Keywords: None
References: None |
Problem Statement: Automation example - Access to LNG Exchanger results data | Solution: The attached Excel spreadsheet illustrates how to obtain LNG results data via OLE Automation (including the UA values for each side using a Backdoor method).
For example code illustrating access to LNG Exchanger curve data (including Hot Composite Curve) see KnowledgebaseSolution #112509.
Saved with a HYSYS 3.2 Type Library reference - For troubleshooting advice on common HYSYS / OLE Automation errors see KnowledgebaseSolution #112361.
Note
The Knowledge Base examples are provided for academic purposes only and as such are not subject to the quality and support procedures of officially released AspenTech products. Users are strongly encouraged to check performance and results carefully and, by downloading, agree to assume all risk related to the use these examples. We invite any feedback through the normal support channel at [email protected].
Keywords: LNG, Side, UA
References: None |
Problem Statement: Every time I load in a case in HYSYS 3.1 or higher, I get a message box asking Would you like to see a standard property set for all streams in addition to those properties already being displayed?. What does this mean, and how can I get rid of this message so that I don't have to answer the same question over and over? | Solution: The message that you are seeing when you open a case in HYSYS 3.1 or higher is asking if you would like HYSYS to display all of the stream properties included in the Standard property set, or if you would rather keep any property sets that you may have created yourself.
Choosing 'Yes' will overwrite any existing custom property sets and display all Standard properties, while choosing 'No' will retain your custom property set. You can see what the Standard property set looks like by going to the Properties page, clicking on the Append New Correlation button (the bright green cross) and expanding the Standard group in the list that appears.
The message is appearing because both the Activate Standard Property Correlations and Confirm Before Adding if Active Correlations are Present boxes under Tools | Preferences | Simulation | Options are checked. The first option is telling HYSYS to apply the Standard property set to all streams in the case. The second option ensures that before doing so HYSYS first checks to see if the loaded case already has a property set applied to the streams.
If you are already using the Standard property set it will not make a difference whether you answer 'Yes' or 'No' to the question. You can avoid having this message pop up by unchecking the Activate Standard Property Correlations box. Note that if you do not have the Activate Standard Property Correlations box checked and you load a case into HYSYS that was created in a version earlier than version 3.1, the Properties page will be blank and you will need to activate this checkbox to see the stream properties.
You could also choose to uncheck the Confirm Before Adding if Active Correlations are Present box; however doing so means that HYSYS will automatically apply the Standard Property Correlations to all of the streams in your case, without warning you that it is about to overwrite existing property sets.
Keywords: standard property, correlations, options
References: None |
Problem Statement: What is the best approach to build and converge a complex column? | Solution: Generally speaking, it is very difficult to set up a whole complex column and converge it to specifications. There are two approaches with which Hyprotech Technical Support has had success.
METHOD 1 - BUILD A SIMPLE COLUMN AND INCREMENTALLY ADD SIDE OPERATIONS
The first approach is to take a step-by-step approach, starting with a simpler column which can first be converged and then incrementally built on:
If possible, start with one of the column templates, such as the Distillation Column (with Condenser and Reboiler).
Converge the column using easier specs such as reflux ratio and draw rate. Often, converging a column using a flow rate specification and allowing the heat balance the flexibility to float during theSolution phase is easier, to start with. (So for initial convergence where two specs are required, a reflux ratio and product flow would be preferable to, say, a product flow and temperature spec).
Once the column is converged (even to different specs than you ultimately want), it becomes easier to add side operations. Make sure that the column is converged with each addition of a side operation! First, add pumparounds as they are easier to converge than side strippers and use easier specs such as rate and duty. Then add side strippers and side rectifiers. (Supposing you have a crude tower where you wish to add a reboiled Diesel side stripper. You may wish to add the pumparound and side stripper at the same time, so that the pumparound can remove the required amount of heat to balance that added by the side stripper).
When adding a refluxed side rectifier, you add two degrees of freedom. A suggested starting point for these specs is to specify a low draw rate to that rectifier and a low product rate from the rectifier. Once the column has converged, you can begin to increase these flow rates up slowly.
Add other flow specs such as side liquid draws, liquid and vapour flows from a tray etc.
Once the column is converged with all the side operations and draws, the real fun begins!
You can then add the specs you want and trade them for the ones you don't want. For example, you can define a cut point spec for a given product and activate it while deactivating another related spec (such as a product draw) initially used to converge the column. Another example would be to trade a pumparound duty spec for a temperature difference spec.
Remember, it is always a lot easier to start with a converged column! You may find it useful to start with a looser specification which can easily be attained, and change its value incrementally from a converged case until you reach the desired specification.
METHOD 2 - ADD ALL EQUIPMENT AT ONCE AND CHOOSE YOUR SPECS TO GIVE THE SOLVER FLEXIBILITY
Often the above approach works well for complex columns and non-ideal systems. Another approach which works in certain cases is to build all equipment before trying to solve the column.
It is recommended that a careful analysis of the specs chosen be performed, so that they give theSolution algorithm a lot of flexibility. It is important to always try to avoid conflicting specs. (For example, in a generic distillation column, you would not specify both reboiler duty and overhead product flow rate, as these are closely linked.)
The approach of building the column in its entirety on the first attempt has often been successful in the simulation of crude towers. Of course, no two columns are the same, and these are simply suggestions. Here are some tips if you are interested in applying this approach to a crude tower.
For each pumparound, use 2 specs (Flow & delta T, or Flow & Duty, for example)
For each side stripper, use a product specification - a suggestion is either a cutpoint or product flow rate
Add a trim duty in the flash zone
Use overflash flow (liquid flow from the stage above the flash zone) as a specification
Consider the use of a reflux ratio or top tray T
Try to leave the top and bottom flow rates of the column to be calculated by the solver
The most important factors in this approach are that the specs are distributed to give the solver flexibility, and that the consistency/quality of the numbers chosen for specifications is good. When this is the case, Hyprotech Support has seen successful in using this method.
Keywords: approach, method, methodology, converge, complex, column, crude, custom, step-by-step
References: None |
Problem Statement: How do I obtain the coefficient of thermal expansion? / Example User Variable | Solution: The derivative properties, such as the coefficient of thermal expansion, and Joule-Thomson coefficient are not readily available in HYSYS. However, it is relatively easy to calculate their values. The attached HYSYS 3.0.1 case illustrates how to calculate the coefficient of thermal expansion.
The coefficient of thermal expansion (Alpha) is defined as:
Alpha = - 1/ rho * d(rho)/dT @ constant P
where rho is the mass density, T Is the temperature, and P is the pressure
[Ref Perry 7th Ed P2-128 or http://scienceworld.wolfram.com/physics/ThermalExpansionCoefficient.html]
In the attached example case this is calculated using a numerical approximation to the partial derivative obtained by temperature pertubation. A dummy cooler (Delta Temperature = 0.1C, pressure drop = 0 bar) is used to perturb the temperature slightly and then the coefficient is calculated using a spreadsheet.
Also included in the attached case is a user variable that calculates the same property. (Worksheet ... User Variables page of the stream) Find also an huv file that will allow this user variable to be imported into any other case. (SeeSolution #109210 for details on how to import the huv file.)
[SeeSolution #109856 for a user variable that calculates the Joule-Thomson coefficient using a similar method.]
Keywords: coefficient of thermal expansion, User Variable
References: None |
Problem Statement: How can I find a volumetric heating value using Aspen HYSYS? | Solution: The lower and higher heating values reported in Aspen HYSYS are on a mass or mole basis, these can obviously be converted to a volume basis by multiplying by the appropriate density. However, the gas lower and higher heating value property correlations in Aspen HYSYS are already reported on a volume basis. These can be added to a stream by going to the Worksheet ... Properties page, using the green cross button in the 'Property Correlation Controls' group, navigating to the Gas section of the tree and applying the heating value properties. These properties are calculated according to the ISO 6976:1995 standard. See the Simulation Tools \ Correlation Manager \ Gas Properties Correlations section of the User Guide manual for more details.
Keywords: Volumetric Heating Value, Property Correlation, ISO 6976:1995
References: None |
Problem Statement: Is there any reason to justify Beggs and Brill as the default correlation for the pressure drop estimation of a pipe segment? | Solution: The Beggs and Brill correlation is able to predict the liquid holdup and pressure drop that occur during two-phase flow in pipes at all angles and at several flow conditions. For more information please refer to the classical paper by Beggs and Brill: Journal of Petroleum Technology, May 1973, P607-617.
Keywords: pipe, segment, angle, pressure, drop, correlation, two-phase, flow
References: None |
Problem Statement: What is the discharge coefficient for an orifice/venturi/valve and how is it defined? | Solution: Please see the attached Word document.
Keywords: discharge coefficient, orifice, valve, venturi
References: None |
Problem Statement: When I click on the Manage Overrides tab in Collaborative Forecasting I just get a blank screen. | Solution: Check to see if you have logged in as an Administrator. The Admin role does not have privileges to manage overrides.
Keywords: CF
References: None |
Problem Statement: I am unable to move icons in the PFD, whenever I move the cursor over an icon small squares appear on the icon. | Solution: You are in Attach mode in the PFD. Select the button in the upper left hand corner of the PFD (i.e., the Move/Attach button) to leave that mode
Keywords:
References: None |
Problem Statement: Dynamic Simulation Across Project and Facility Lifecycles | Solution: Process simulation models are essential components of the basic toolkit of process design teams. Traditionally, these simulations are static models, and sometimes, substantial engineering design margins are required to compensate for their limited abilities. Specialised dynamic modeling was developed to investigate specific non steady-state scenarios, thereby reducing design uncertainties. Today, increasing computing speed and software that is more advanced constantly extend the application of simulations to project elements that were out of practical reach until recently. Dynamic simulation of an entire process can now be used not only in the design of a facility throughout several project phases, but also beyond into the facilities operation and development lifecycle. A major Australian-based gas processing facility design project has embraced dynamic modeling to design, test and confirm the functionality of the new process and to provide a development and review tool for operating procedures. Case studies are examined and numerous benefits described. Further potential applications of lifecycle dynamic simulation are envisaged as the concept becomes increasingly accepted as a fundamental process design activity.
View the attached pdf file for the complete paper.
Keywords: hysys, dynamic, simulation, across, project, facility, lifecycle, reeves, james
References: None |
Problem Statement: I get Run-Time Error 1607 during the installation of my application. What do I do? | Solution: This issue occurs on some systems depending on the system configuration and privileges set for the user. Listed below are some common causes of this error message:
The user does not have administrative privileges on the machine. This pertains to Windows NT, 2000, or XP machines.
The ALLUSERS property is not set appropriately for the IsScript.msi file. This is only true for the Installation of Express 3.54 itself. Express 3.54 setup is based on InstallScript, leading to this error message.
Permissions are not set appropriately on the Installer folder in the Windows folder.
An older version of InstallShield Express 3.x is installed on the machine, and the older version fails to uninstall properly. This usually happens when upgrading Express from an older version to a newer one.
Multiple instances of files Msiexec.exe or IDriver.exe may be running in the memory.
Windows Installer Service may not be properly installed or configured on the machine.
The setup is trying to remove a file that is locked on the machine. This issue generally occurs when setup is being removed using the Remove option of the Add Remove Programs applet on Windows XP, 2000, or ME.
Solution
Listed below are some suggestions that may help eliminate this error message. You may need to try all or some in order to work around the error message.
Make sure that you have admin privileges to run the setup on the machine. To run InstallShield Express 3.5 SP4 setup, users need full admin privileges on Windows NT, 2000, and XP machines.
Download and run IsScript.msi. (Attached to thisSolution as IsScript.zip). This file internally sets the ALLUSERS property, which is known to fix the issue in some cases. After downloading the attached file, replace the IsScript.msi shipped with InstallShield Express 3.5 SP4 setup with this updated version. The file IsScript.msi can be found in the same path as InstallShield Express 3.5 SP4 Setup.exe.
Make sure that the Installer folder in the Windows directory on the machine is not read only. The path to the installer folder is typically C:\Winnt\Installer on Windows NT, 2000, and XP machines and C:\Windows\Installer on Windows 9x and Me machines. Right-click on the Installer folder and make sure that it is not read only. On some machines, the installer folder may be hidden. Before searching for this folder in the above path, make sure to show hidden files and folders in the Windows Explorer options.
You may want to manually uninstall any previous version of InstallShield Express 3.x from the machine before installing the new version. If the uninstallation fails, use MsiCleanUp utility to uninstall the old product. You can download MsiCleanUp from MSDN at Q238413 OFF2000: Windows Installer CleanUp Utility.
Launch the Task Manager to see if multiple instances of Msiexec.exe or IDriver.exe are running on the machine. You can launch the Task Manager by pressing Ctrl+Alt+Delete. You should have at least one instance of these files running as these engine files drive the setup. However, if you see more than one instance of Msiexec.exe or IDriver.exe, it could be the cause of the issue. If this is the case, reboot the machine and run the setup again.
Run the file InstmsiA.exe on Windows 9x or Me or InstmsiW.exe on Windows NT, 2000, or XP to install and configure the Windows Installer Service on the machine. These files can be found in the same path as Setup.exe for the InstallShield Express 3.5 SP4 setup. If the issue persists, then register the file Msiexec.exe manually on the machine. To do this, run the following command-line option in the Start > Run command or command prompt of the operating system:
Windows NT, 2000: C:\Winnt\System32\Msiexec.exe /REGSERVER
Windows 9x, Me or XP: C:\Windows\System\Msiexec.exe /REGSERVER
If your setup is trying to uninstall a file that is in use, the Windows Installer Service throws the File In Use Dialog. However, when you attempt to uninstall the setup via the Remove option of the Add/Remove Programs applet (ARP), the windows Installer setup runs the uninstallation in a basic User Interface mode, which does not display the File In Use Dialog, simply displaying Error 1607. As a workaround, you may want to disable the ARP Remove option in the setup. This forces users to uninstall via the Change option of ARP, which will notify the user a file being in use. To disable Remove option from ARP, open your project in Express and:
Click on Organize Your Setup > General Information.
Look for the Disable Remove Button Attribute and set it to Yes.
For more informatoin on this error, refer to the following website: http://support.installshield.com/error_central/
Keywords: Error 1607; Installation Error
References: None |
Problem Statement: While running a user variable, how do I bring up a dialog box to collect input data the first time and only the first time a unit is created.
How do I conditionally bring up a user dialog in user code? | Solution: In order to bring up an input box while code is running, you need to provide some code in the user variable code that creates a user input window. Here are some steps that needs to be followed.
1. Bring up the property interface for the unit-operation or object where you want to attach the user variable
2. Click on the user variable page
3. Create a user variable
4. On the macro editor, name the variable, check the method (for example: PostExecute method) and click in the middle of the code generated.
5. Click on Edit User Dialog button (Right most button on the Macro Editor tool bar)
6. In the dialog editor, drag a text box widget and a OK button onto the dialog area and close/save it
7. Add following code to the end of the sub routine
Dim Val As Double
Val = ActiveVariableWrapper.Variable.Value
If Val = 0 Then
Dialog dlg
ActiveVariableWrapper.Variable.SetValue dlg.TextBox1
Else
End If
8. Now set the Activation attribute of the variable to be automatic (to activate the user variable in other unit-operation), click on Apply default value and type in default as 0
Now whenever such a unit is added into flow sheet and you begin to fill in data for the unit, it will bring up the dialog asking for a value to be assigned to the user variable.
Modellers can easily adapt the code to take care of other variables for initialization purposes.
More details please see attached WinWrap Basic help file and the sample case file where one could add streams to test how it reacts to user inputs.
Keywords: User dialog, data initialization, user code, WinWrap Basic, conditional dialog, user variable
References: None |
Problem Statement: How to hide all stream labels on the PFD? - Automation example | Solution: The VBA code in the attached Excel spreadsheet allows the user to select a flowsheet within the currently open HYSYS case and attempts to hide all of the stream labels in the currently active PFD for that flowsheet.
Each of the PFDItem type objects that make up the PFD (i.e. stream and operation icons and their labels) has a Hidden property which can be set to True to hide the item. Currently there is no direct way to know which icon object each of the label objects belongs to. Hence the attached code checks the distance of each label from all the stream icons and decides based on some user configurable rules. In order to understand and modify these rules, users should review the Constants section in the notes for the HideFSPFDLabels() procedure in the VBA code before using this example. To see this section press Alt+F11, go to the modHideLabels module in the Project tree and scroll to the relevant part of the code.
For troubleshooting advice on common HYSYS / OLE Automation errors seeSolution #112361.
Note
The Knowledge Base examples are provided for academic purposes only and as such are not subject to the quality and support procedures of officially released AspenTech products. Users are strongly encouraged to check performance and results carefully and, by downloading, agree to assume all risk related to the use these examples. We invite any feedback through the normal support channel at [email protected].
Keywords: Automation Hide PFD Stream Labels
References: None |
Problem Statement: How can I set Separator Dimensions via OLE Automation? | Solution: Since the separator dimensions properties are not available within the HYSYS type library (they are not yet 'wrapped' for standard Automation access), it is necessary to use a 'Backdoor' method. This uses the internal variable name (or 'Moniker') to directly access the values. The code below illustrates how to do this.
To use the code below open up HYSYS with any case that contains a separator, paste the code into the VBA editor in Excel, set the code to reference the separator name, make a reference to the HYSYS type library (Tools ...
Keywords: None
References: s menu option in the VBA editor) and run the procedure.
Sub SetSeparatorDimensions()
'
'Description: Set Dimensions of separator
'
'Declare Variables |
Problem Statement: How do I add a Property Correlation to my Stream Table or Workbook? | Solution: Any of the possible Property Correlations (i.e. those on the Worksheet ... Properties page of the stream - e.g. Water Dew Point, Wobbe Index (both HYSYS 3.1+), RVP (3.2+), Refinery properties (REFSYS)) can be displayed on a Stream Table or on the Workbook by using the following procedures:
Stream Table
Double click on the Stream Table on the PFD
Use the Add Variable button to bring up the Variable Navigator
Choose the 'Calculator' variable, and then in the 'Variable Specifics' list choose the property
A stream table can be displayed for a stream by right clicking on the stream PFD icon and choosing 'Show Table' from the pop-up menu that appears. (SeeSolution 112190 for more details)
Workbook
With the Workbook window active use the Workbook ... Setup menu option
Press the Add button in the Variables group to bring up the Variable Navigator
Choose the 'Calculator' variable, and then in the 'Variable Specifics' list choose the property
For more details about property correlations see Section 11.18 of the HYSYS User Guide manual / Section 3.1.1 of the Operations Guide manual.(for both the HYSYS 3.1 and 3.2 documentation).
Keywords: PFD Stream Table, Workbook, Property Correlation
References: None |
Problem Statement: Does Collaborative Forecasting support derived attributes dependent from multiple base attributes, as well as in Aspen Collaborative Demand Manager? | Solution: Any attributes in Aspen Collaborative Demand Manager that are derived from the base attributes in ELEMENT can be used in Aspen Collaborative Forecasting. For example if we have in Aspen Collaborative Demand Manager a derived attribute dependent on LOC and PRO can be managed in Aspen Collaborative Forecasting.
Aspen Collaborative Forecasting does not differentiate between base attributes and derived attributes.
Keywords: Attributes
Derived attributes
Base attributes
References: None |
Problem Statement: The streams coming out of my column are not arranged properly on the PFD (i.e. the bottoms stream looks like it is coming from the middle of the column). How can I change their placement? | Solution: Changing the column configuration after the streams are connected to the column will sometimes cause the streams to become misplaced.
To force the streams to their proper positions, changing the column icon sometimes helps. To do this, right click on the column and choose Change Icon. Change to any other icon and then change back to the original one, or if you see an icon that suits your configuration better (e.g. a column icon with no reboiler if you have no reboiler) then use that icon instead.
If this does not work, try breaking the connection and attach the stream using the Attach mode on the PFD. Attach mode can be toggled on and off using the appropriate button on the top left hand corner of the PFD window.
Keywords: column, PFD, stream location, column icon, connectivity
References: None |
Problem Statement: How do you clear out an Aspen Collaborative Forecasting (CF) database and rebuild from scratch? | Solution: Note: This is a 'last resort' option as it wipes out all current user Ids and security subroles. Users will also have to recreate any custom reports they had previously
* Recreate CF database schema for :
- Open a CMD window and navigate to the cf_integ folder for the envelope/environment that you want to recreate:
- From the command window run the following two commands:
setenv
create_schema_shell
The system should take a while to process create_schema_shell. That script completely wipes out the existing database content and regenerates based on the files most recently published from DM
- When the command is finished, check the create_schema log in the cf_integ_logs folder to make sure there are no exceptions or errors.
* Restart the associated CF service on the CF server
Once complete, you will need to recreate the user subroles (security) and user Ids in the instance. The users will have to recreate any custom reports they had previously.
Keywords: None
References: None |
Problem Statement: What is the Reset Perts flag? | Solution: Use of the Reset Perts flag will reset the perturbations before proceeding with the perturbation of the subsequent variable. Use of this flag may help to reduce the noise in the Jacobian matrix.
Keywords: Reset perts, perturbations, optimizer
References: None |
Problem Statement: What can I do to speed up convergence of my optimization problem? | Solution: Fine tuning an optimization case for optimal performance will require a thorough understanding of cause and effect of the process variables in your model, and an understanding of how the optimizer and its tuning parameters work. There is no answer to this question that will perfectly address all cases, however, experience shows that there are a few places to look.
In general, to evaluate the potential to gain speed in convergence, three things you you will need to consider are the following:
Optimizer tuning - How aggressively you can tune the optimizer will affect the number of iterations the optimizer takes to converge. This will be a factor of the the linearity of the model, the optimizer's fit of the model, and the noise in the model.
Flowsheet modeling - The optimizer will solve the case to completion several times during each optimizer iteration. The time taken for the flowsheet to converge on eachSolution pass will be important.
Miscellaneous computational overhead.
Let us look at some basic items which should be considered during the optimization problem.
Number of iterations the optimizer takes to converge
This is a very difficult and case specific problem to solve. Several factors must be taken into consideration. To determine how aggressively you can tune the optimizer, you should understand the answer to the following fundamental questions:
How linear is the problem around the operating point? How good is the optimizer's fit of the model around the operating point?
if using the RTO optimizer, check the diagnostic file for the Goodness of Fit - this should ideally be close to 1
Is there any noise contribution to the Jacobian which can be avoided?
tightenSolution tolerances for unit operations such as recycles, columns, and heat exchangers by a couple of degrees of magnitude if possible
Note that there may be a tradeoff when tightening tolerances. The downside is that for the flowsheet itself to solve, tighter tolerances may cost some computational time. The potential potential upside is that the corresponding decrease in noise, improve the fit, and allow the optimizer to make larger steps on the way to the optimum. The optimal modeling approach will consider this tradeoff.
Are the perturbation sizes appropriate for the problem being solved?
for example, make sure that the optimizer is not trying to adjust a flowrate by 1 mol/h when the perturbation size used to calculate the gradient is 10 mol/h.
How large is the base search step and maximum step size for the optimizer?
if the problem is very linear and goodness of fit is close to 1, consider increasing step sizes
Time taken for the flowsheet to converge on eachSolution pass
Again, this is a very case specific problem to solve. However, one item to consider is the logical operations such as the adjust and the recycle operation which require several flowsheet passes to converge.
Are there adjust operations whose functionality can be transferred to the optimizer?
an adjust has a manipulated variable, a constraint and a tolerance which can easily be added to the optimization problem. To do this automatically, check the Optimizer Controlled checkbox on the Adjust operation.
Are there recycles whose composition does not change? Consider whether it is possible to move their functionality to the optimizer. For example, consider a steam steam recycle with inlet stream 1 and outlet stream 2. Would you be able to add it to the optimizer taking the following steps?
ignore the recycle
add the flow rate and temperature of 2 as optimizer manipulated variables
calculate the difference in flow rate between 1 and 2 in a spreadsheet cell
calculate the difference in temperature between 1 and 2 in a spreadsheet cell
import the spreadsheet cells containing the differences as constraints. Create an equality constraint by setting the minimum and maximum value for the constraints to zero.
Miscellaneous computational overhead
There are not very many places where miscellaneous computational overhead is encountered. However, one place where HYSYS continually updates information which can slightly reduceSolution time is in the updating of the Status Window.
Adjust Status Window Properties - this will result in a small, but noticeable percentage improvement At the bottom of HYSYS, you will see two panes - the Status Window on the left hand side and the Trace Window on the right hand side. During the course of theSolution, the status window will update, containing optional information pertaining to the status of the variables associated with each operation (ex. before the flowsheet has calculated, you may see Stream 126 - Temperature - Not solved). You can eliminate the computational time required to populate the status window this by setting the minimum severity for information displayed to Error. This can be configured by object inspecting (right-clicking) the Status Window or accessed from Tools | Preferences.
Keywords: optimizer, speed, tips and tricks
References: None |
Problem Statement: When user login to Collaborative Forecasting application, they get the error message insufficient client license, contact CF administrator. | Solution: When user exits Collaborative Forecasting application, please always use application logoff/logout link.
The CF application license works in a following way:
1. When you need to exit CF web client, DON?T just kill the browser, instead, click on Logoff. Then the client license seat is released.
2. If you kill the browser, there is an internal time to timeout the session before the license is released i.e. default it is 60 minutes.
Keywords: CF Error
Logoff
Login
Insufficient client license
CF administrator
References: None |
Problem Statement: Extension unit operations are present in my model, but they don't appear on the PFD. How can I get them back? | Solution: Extension operations (eg Saturate and Gas Properties) sometimes vanish from the PFD. This seems to occurs when the file is opened on a PC without the extension installed, then saved. Once the file gets saved on this PC, the extension vanishes from the PFD.
They are still present in the model and work as expected (assuming the extension is installed on the PC being used).
To get them back on the PFD:
Open up the PFD.
From the main HYSYS menu, select PFD + Add a PFD, make sure the Clone from Existing PFD box is checked, then click OK.
This will create a new PFD identical to the existing one, but the extensions will reappear.
Click on the tab (probably PFD 1) at the bottom of the original PFD, then right click and select Delete this PFD.
Keywords: PFD, Extension Unit Operations, icon
References: None |
Problem Statement: In a Japanese system, when trying to enter overrides, after clicking the Submit button, the following error appears: Failure of submitting the quantity override. Please consult the controller. | Solution: This error is due to the fact that the Internet Explorer language setting for the Collaborative Forecasting user is different from English. It must be reset to English. To do this, open Internet Explorer, go to the menu Tools | Internet Options, select the General tab, click the Languages button under Appearance and make sure that English is selected.
Keywords: Error
CF overrides
IE
Foreign languages
References: None |
Problem Statement: How does the MASSBAL solver compare to the normal HYSYS Solver? | Solution: HYSYS solves using a sequential modular solver. Unit operations must have specific degrees of freedom satisfied (specified) in order for the unit operation to solve.
MASSBAL uses a simultaneous solver. In MASSBAL, a completely specified problem requires that there be no degrees of freedom remaining for the flowsheet. However, the specifications are not restricted on a unit by unit basis. They can be specified anywhere in the flowsheet.
Keywords: MASSBAL, solver, sequential modular, open equation, degrees of freedom
References: None |
Problem Statement: Why does the forecast only show through June 2013 in Aspen Collaborative Forecasting? | Solution: This is caused when the weblogic server is hanging on a thread and not accepting any more new requests at that juncture. To resolve the problem, restart the weblogic service.
Keywords: None
References: None |
Problem Statement: Calculation of Integral and Differential Condensation Curves in HYSYS | Solution: [Based on HTFS Handbook Datasheet CP13 Vapour Liquid Equilibrium in Condensers]
Integral Condensation
To calculate an integral condensation curve the bulk vapour phase at any point is considered to be in equilibrium with all of the previously formed bulk condensate.
To calculate such a curve in HYSYS there are two approaches. Either a property table utility is used to vary the temperature between the dew point and the bubble point at a given pressure, or a series of coolers is used to drop the stream temperature by a small temperature decrement. In either case the total mass enthalpy of the system is recorded and then subtracted from the mass enthalpy at the dew point to give a heat released value.
[In the attached case both approaches to calculate the Integral condensation curve for a 50% molar mixture of n-Butane and n-Pentane are used. See Property Table utility 'Property Table Integral Condensation' and spreadsheet 'Integral Condensation Results (Prop Table)' and also spreadsheet 'Integral Condensation Results (Flowsheet)'. The temperature difference across each Cooler is set by a Set operation. The spreadsheet 'Set Delta Ts Integral' sets the offset in each of the Sets.]
Differential Condensation
For differential condensation the bulk vapour at any point is considered to be in equilibrium only with the newly formed condensate. Any previously formed condensate is not considered to take any part in the vapour/liquid equilibrium.
To calculate such a curve in HYSYS a series of condensation steps is used. At each step the vapour from the previous step is cooled to a given small temperature decrement below the local dew point. The liquid that condenses is then mixed with the liquids from previous stages which has also been cooled to the same temperature.
The heat released is calculated by finding the total 'mass enthalpy' at each stage. This is calculated by adding together the total heat flows of the vapour and combined liquids at each stage and dividing by the total mass flow.
Since the vapour phase becomes richer in the more volatile components, the equilibrium temperature tends to fall more rapidly than for integral condensation.
[In the attached case see spreadsheet 'Differential Condensation Results' and spreadsheet 'Set Delta Ts' which is used to set the delta temperature at each stage. The attached case requires the virtual stream extension to be registered (see KnowledgebaseSolution #110889. Also included is an Excel spreadsheet that includes a plot of both the integral and differential condensation curves.]
Keywords: Integral, Differential, Condensation Curve, Condenser
References: None |
Problem Statement: Can I use Automation to flash a Fluid object to a different pressure with a specified polytropic Efficiency? | Solution: Unfortunately using OLE Automation to flash a Fluid with a given polytropic efficiency is not straightforward. It is best done by guessing an outlet temperature, calculating the polytropic efficiency and then iterating on the temperature until the required efficiency is achieved. The code below illustrates this.
This code assumes a polytropic compression. In order to calculate a polytropic expansion it will need some modifications since the equations for adiabatic and polytropic efficiency change slightly (See Section 6.1.1 of the HYSYS operations guide manual), and the iterative scheme will need some modifications to the way it brackets the requiredSolution. The code can also be fairly easily modified to calculate a compression or expansion with a given adiabatic efficiency.
To use the code below open up HYSYS with the 'G-2.hsc' sample case, paste the code into the VBA editor in Excel, make a reference to the HYSYS type library (Tools ...
Keywords: None
References: s menu option in the VBA editor), and run the CalcPolytropicEffContainer() procedure.
Sub CalcPolytropicEffContainer()
'
'Description: Example container for FlashToGivenPolytropicEff() function
'
' Eg run this macro from Excel VBA to call the FlashToGivenPolytropicEff() function
'
' Incident 593726 and |
Problem Statement: How can I saturate a gas stream with water in HYSYS? | Solution: There are two methods to saturate a gas stream with water in HYSYS. The first method is to do it manually: Create a water stream and use a Mixer Unit Operation to mix the water and gas streams. The product from the Mixer goes into a 3-phase Separator. You can then use the Adjust Logical Operation to adjust the water going into the Mixer to give the desired water coming out of the liquid product stream of the Separator (typically a small excess amount of water out of the Separator).
The second method is to use the sample macro and extension SATURATE, which is a free example downloaded from our website. Refer toSolution ID# 110073. Your gas or two-phase (vapour and hydrocarbon liquid) stream can be fed directly into this Unit Operation Extension, resulting in a saturated gas stream. In this case, you will not have the option to chose the amount of water added to the stream, HYSYS will simply saturate it.
Keywords: saturate, separator
References: None |
Problem Statement: Common OLE error codes which occasionally pop up in HYSYS | Solution: Here are a few of the common OLE error codes that pop up occasionally in HYSYS:
Hex Decimal
Code
Meaning
0x00000000 0
S_OK
All''s well. This is returned if the OLE call is successful.
0x80004005 -2147467259 E_FAIL Generic error. Returned if you try to access an item past the end of a collection, if you ask for an <empty> value, etc. Also seen if an extension unit operation has an unhandled E_FAIL error in the code it runs when it is added (the Initialize procedure).
0x80004001
-2147467263
E_NOTIMPL Not implemented. The method exists, but doesn''t do anything. Extensions sometimes return this to HYSYS.
0x80070057
-2147024809
E_INVALIDARG Invalid argument. Something you passed in to the method is not understood. (e.g. A Variant is not properly dimensioned.)
0x80070005
-2147024891
E_ACCESSDENIED Access denied. Usually this means you are attempting to access a Basis method while in the Build environment, etc.
0x80040154 E_CLASSNOTREG The extension was not registered properly. You could try re-registering the extension or looking in the system registry to make sure the entries were written into the registry.
You may see other errors; they are probably from another source (VB, an extension, etc.).
Keywords: Error Codes
References: None |
Problem Statement: You are going to deploy the CF permanent fix to your production environment.Before applying you would like to have some rollback instructions in the eventualities of no options left other than rollback the CF patch. | Solution: Before applying patches you should back up of CF.ear and CF.JAR files. Once the Patch is applied it will overwrite existing resources with new ones. You should also make a backup copy of both the CF_integ folder and your CF database to ensure nothing bad happens.
Keywords: None
References: None |
Problem Statement: Are there any tips and tricks for converging refinery crude columns? | Solution: Below are a few tips for converging refinery crude columns:
Observe the oil distribution chart in the Oil Manager. If the oil characterization for the stream was not done within the HYSYS case, you can re-engineer the TBP curve based on the Boiling Point Curves utility so that you can then view the oil distribution chart.
The oil distribution chart (in terms of volume) allows you to see the production limit for each product stream. With the oil distribution chart and the feed flowrate, you can roughly work out the proportion of flow for each product stream; these values can then be used as initial column specifications.
Converge the side operations in a few steps. E.g. Start with Gas Oil pumparounds & Gas Oil side strippers, run and converge the column; then add Diesel pumparounds & Diesel side strippers, run and converge the column; then add Kerosene pumparounds & Kerosene side strippers, run and converge the column.
Do not use the 'Reset' button, because the history ofSolutions helps you get to the nextSolution. It may or may not converge again after pressing 'Reset'.
Start by using variables that make for easier column convergence when used as active specifications. You should have few problems getting a converged column completed with all the side operations if you start with easy specifications. Flow specs for product streams and duty specs for pumparounds are easy specs; the reflux ratio is another possibility.
Once you have a converged column, slowly trade the easy specification variables for difficult specification variables:
e.g. Start with duty specs, then trade for temperature specs. To guarantee convergence, it is important to trade the 'corresponding' specs E.g. Duty for Diesel_Cooler replaced with Diesel_return_temperature spec.
e.g. Start with product flow specs, then trade for cut point specs. To guarantee convergence, it is important to trade the 'corresponding' product flow and product quality specs. E.g. Kerosene product rate replaced with Kerosene cut point spec.
Before making a problematic specification active it is a good idea to first observe its current calculated value. Observe the calculated values for a few specified values of the corresponding easy spec variable, so that you can get a feel for the upper and lower bounds for your difficult spec. If the spec value you intend to use differs a great deal from this bound, it gives you some indication that your intended specification may not be achievable with the current column conditions.
If you find that a new specification is not achievable, consider adjusting other specifications to achieve the desired target spec. For example if you want to specify a higher flow rate for the diesel product, you may want to specify a lower flow rate for the kerosene product. You can extend this idea to the more difficult specs, e.g. you can adjust cut point & RVP spec values for one stream relative to other specifications.
Save your HYSYS case after each convergence so that in case you made a wrong choice in specs or spec values, you can reload the saved converged case quickly.
Keywords: Column, column convergence, crude distillation
References: None |
Problem Statement: The vapour fraction reported on the stream conditions sheet is different from that reported on the stream properties sheet. What is the difference between the phase fractions reported on these screens? | Solution: Phase fractions reported on the stream conditions form are mole based while that displayed by default on the stream properties form are Std Vol based.
Keywords: vapor, standard volume
References: None |
Problem Statement: What process is used to inform the SLM Server that a license token can be released? Will the SLM Server periodically check if a session is still valid? Or is there another process in place? | Solution: There is one underlying library in the CF web application end which sends notifications and receive acknowledgements to and from the SLM server if that particular client license token is released.
Keywords: None
References: None |
Problem Statement: You would like to install Weblogic 10 with Collaborative Forecasting (CF) version 2006.5. Is this version included with the CF install? | Solution: Yes. The CF installation does include Weblogic 10 as well as the BEA licensing required to run the Weblogic server.
Keywords: Weblogic
CF
2006.5
10
References: None |
Problem Statement: Can I add Triolein to my component list in Aspen HYSYS? | Solution: In Aspen HYSYS 2006.5 and higher versions, Triolein is included in the Aspen HYSYS component library to facilitate the modeling of the bio-diesel processes. Triolein, (C17H33COO)3C3H5, is a triglyceride that is frequently used to represent the reactant oil.
Keywords: triolein, bio, diesel, biodiesel, triglyceride
References: None |
Problem Statement: In V7.1, you encountered this error when attempting to upload override file.
Error Message: The system was not able to create an override from the uploaded file. Please check that the file is valid and try again. | Solution: There may be multiple reasons as to why the file doesn't upload. ThisSolution attempts to provide some guide to resolving common issues. At the end of each suggestedSolution, do try if it works by attempting to (a) invoke the webservice at the IIS host; and (b) file upload through the CF website from the client machine.
1. Ensure that you have a proper Overrides Excel file created.
The suggested steps to create an Override Excel file are:
- Click <Download> in 'Create Overrides Value' page.
- A dialog box pops up with options of <Save> or <Open>.
- Click on the <Open> button. An MS Excel file will open and shows the Overrides xls.
- In Excel, click <Save As> and save the file in xls format.
Try to upload the xls again.
2. Ensure that your ms2jservice is reachable at your server and client Internet Explorer.
At your IIS server machine, you should not encounter HTTP error by going to the URL Error! Hyperlink reference not valid..
Similarly, you should not get any HTTP errors from your client machine.
3. Verify ms2jservice configuration at the IIS server.
Ensure that you have ASP.NET 2.0 installed and allowed in IIS.
Ensure that ms2jservice is using ASP.NET 2.0 and above.
If you do not have ASP.NET v2.0.50727 registered here, you can download and install MS .NET Framework 2.0. If you do have .NET Framework 2.0 install, you can redo registration by:
- Open a command window.
- Change directory to %SYSTEMROOT%\Microsoft.NET\Framework\v2.0.50727\
- Run aspnet_regiis.exe -i
- Restart your IIS.
** V7.1 does not support Win2003 or Win2008 64bits OS. Ms2jservice uses MS Jet 4.0 provider that is natively 32bits. Therefore, if ms2jservice is configured to use ASP.NET 2.0 64bits, it will not run properly. From web resources, you can enable .NET 2.0 (or higher) web application in 32-bit mode in IIS 6.0 on a 64bit server:
o cscript.exe C:\Inetpub\wwwroot\AspenTech\ms2jservice\IISConfig\adsutil.vbs SET W3SVC/AppPools/Enable32BitAppOnWin64 1
o %SYSTEMROOT%\Microsoft.NET\Framework\v2.0.50727\aspnet_regiis.exe -i
o Restart your IIS.
Verify the permissions.
- Authentication method should not use 'Anonymous' Logon.
- Use 'AspenAppPool'.
AspenAppPool's identify is configured to use predefined 'Local System' account.
** A recorded incident had a following error message ?Unexpected error. The Microsoft Jet database engine cannot open the file 'xxx.xls'. It is already opened exclusively by another user, or you need permission to view its data.? The ms2jservice was configured to use 'DefaultAppPool' (configured to use predefined Local Service account). It was resolved by using the 'AspenAppPool'.
4. Check your CF properties.ini and proxy.properties files.
Both files are required and should have correct information.
In the properties.ini file (located at c:\bea\user_projects\domains\xxx\rc folder), change:
- IIS_HOST = <Actual Host Name>
In the proxy.properties file (located at c:\bea\user_projects\domains\xxx\rc folder), enter the correct information:
- PROXY_LOGIN = <domain\\windows> ** this must be a valid windows login id **
- PROXY_PW = <actual password>
- ENC = N
5. Check your MS Jet 4.0 provider at the IIS server.
If you run invoke Ms2jservice/readFile2String with this error message ?System.InvalidOperationException: The 'Microsoft.Jet.OLEDB.4.0' provider is not registered on the local machine?, then your IIS machine may not have Jet 4.0 correctly installed. Most OS installation will have Jet 4.0 provider installed and there is no need to install MS Excel on your IIS server machine. If this driver is installed, you will find the following files in %SYSTEMROOT%\system32 folder:
- Msjetoledb40.dll
- Msjet40.dll
- Mswstr10.dll
- Msjter40.dll
- Msjint40.dll
Alternatively, you may create the a script and run it using cscript.exe.
--- sample vbs script to verify Jet 4.0 provider ---
Dim connectionString
Dim cn
set cn = createobject(ADODB.Connection)
connectionstring =Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\Temp\Test.xls;Extended Properties=Excel 8.0;HDR=NO;IMEX=1
on error resume next
cn.open connectionstring
if err.number <> 0 then
msgbox err.description
else
msgbox Ok
end if
set cn = nothing
--- end of sample ---
If none of the above helps, please contact Aspentech Technical Support, submit the weblogic log and cf.log files.
Keywords:
References: None |
Problem Statement: I can't see any information in my extensions after importing the data from an XML case I created. | Solution: You can not use the XML feature with extensions or user unit operations in HYSYS. This is because the code needed for using XML is not included within the extensions/user unit operations, therefore HYSYS does not know how to read this information.
Keywords: XML; Extensions; User Unit Operations
References: None |
Problem Statement: Why do we need JAVASYSPRIV permission for CFUSER when we configure the Aspen Collaborative Forecasting database in the Oracle environment? | Solution: We need to configure JAVASYSPRIV permission for CFUSER only if we setup server side triggers
You don't need this security permission setup if you are using client side triggers.
Keywords: JAVASYSPRIV
CFUSER
Server side triggers
References: None |
Problem Statement: Visualizing Mass Higher Heating Value in stream properties in Aspen HYSYS | Solution: Higher Heating Value can be added to stream properties by performing following steps.
1. Double click on the stream and go to Worksheet | Properties
2. Then click 'append new correlation' button (green plus button)
3. From the available stream correlations, expand the Gas correlations.
4. Under Gas correlations select Higher Heating Value and click apply button.
5. Higher Heating Value is added to stream properties at the bottom of the list.
Now this Higher Heating Value is a gas property and is reported based on volume (i.e., volume specific energy, units MJ/m3 or BTU/ft3). But if you want to access Mass Higher Heating Value, it can be accessed via 'variable navigator' only.
It can be added to all streams via Aspen HYSYS workbook or it can be added to stream PFD tables. To add it to Workbook please follow the steps below.
1. Go to Tools | Workbooks | select Case (Main) and click view
2. Then from the main menu go to Workbook | Set up
3. Select Material Streams to add it material stream properties and click 'Add' under variables.
4. From the available variables select Mass Higher Heating Value and click OK.
5. Mass Higher Heating Value will be added to material stream properties in workbook.
To add it to stream PFD table
1. Right mouse click on the stream and select 'Show Table' to add PFD table.
2. Then double click on PFD table and click Add Variable button.
3. From the available variable list select Mass Higher Heating Value and click OK.
4. Mass Higher Heating Value will be added to PFD table.
Mass Higher Heating Value is not listed in stream standard property correlations and it can only be accessed via variable navigator using above methods.
Keywords: Higher Heating Value, Mass Higher Heating Value, Stream Properties.
References: None |
Problem Statement: Where are the sample files located? Can I get brief description about the sample files? | Solution: When installed, the samples should be located at: C:\Program Files \ AspenTech \ Aspen HYSYS (version such as 2006) \ Samples.
Note that the sample files for HYSYS version 3.2 and Aspen HYSYS 2006 have been attached to thisSolution. A brief description of each case is provided below:
ammonia.hsc
Ammonia Synthesis Loop
Highlights: demonstrates OLE links; external optimizer
C-1.hsc
Azeoptropic Column
Highlights: Steady State and Dynamic modelling; Data Recorder
C-2.hsc
Ethanol Plant
Highlights: Steady State modelling; distillation column with side draws; Specifications and efficiencies to a column
C-3.hsc
Ethanol Dehydration
Highlights: Steady State modelling; Decanter Sub-Flowsheet with LLE Thermo
C-4.hsc
Synthesis Gas Prodution
Highlights: Steady State modelling; Reaction Manager
comploop.hsc
Compressor Loop
Highlights: Dynamic simulation
debutdyn.hsc
Debutanizer dynamics (rigorous ovhd)
Highlights: Dynamic simulation; Distillation column using more detail than just the condenser module
dyncrude3.hsc
Dynamic Crude Column
Highlights: Dynamic equivalent of the R-1.hsc crude column simulation
DynDep-1.hsc
Pressure Vessel
Highlights: Compare the dynamic depressuring utility against a reference case
G-1.hsc
Acid Gas Sweetining with DEA
Highlights: Steady State Modelling; Amine Tower simulation; Set Operation and Spreadsheet.
G-2.hsc
Natural Gas Dehydration with TEG
Highlights: Steady State modelling; H2O Dew Point Calculation
G-3.hsc
Deep Cut Turbo-Expander Plant
Highlights: Steady State modelling; Sub-Flowsheets
gstr-dy.hsc
Propylene Glycol Production
Highlights: Dynamic simulation
gstr-ss.hsc
Propylene Glycol Production
Highlights: Steady State modelling
hxlcmod.hsc
Shell and tube heat exchanger
Highlights: Shell liquid level controlled
network.hsc
Water Distribution Network
Highlights: Dynamic simulation
P-1.hsc
Propylene/Propane Splitter
Highlights: Steady State modelling; Multi-Tower Column Sub-Flowsheet
R-1.hsc
Atmospheric Crude Tower
Highlights: Steady State modelling; Oil Characterization
R-2.hsc
Sour Water Stripper
Highlights: Steady State modelling; Sour Thermo Options; Case study
R-3.hsc
Dynamics of a Partial Condenser
Highlights: Dynamic modelling; Data Recorder; Feed Forward Control
The below mentioned sample files are described in detail in the Aspen HYSYS Tutorials and Applications guide. These tutorials start in Steady State mode and end in Dynamic mode.
TUTOR1.hsc / dyntut1.hsc
Sweet gas refrigeration plant
Highlights: Gas Processing Tutorials
TUTOR2.hsc / dyntut2.hsc
Crude oil processing facility
Highlights: Refining Tutorials
TUTOR3.hsc / dyntut3.hsc
Propylene Glycol production process
Highlights: Chemical Tutorials
Note: Some of above samples need optional licenses, as indicated below:
C-1.hsc, comploop.hsc, debutdyn.hsc, dyncrude3.hsc, DynDep-1.hsc, dyntut1.hsc, dyntut2.hsc, dyntut3.hsc, gstr-dy.hsc, hxlcmod.hsc and R-3.hsc all need an Aspen HYSYS Dynamics license.
G-1.hsc needs an Aspen HYSYS Amines license.
R-1.hsc, R-2.hsc and R-3.hsc all need an Aspen HYSYS Crude license.
Keywords: samples, examples, simulation, description, location, license
References: None |
Problem Statement: How can I use Automation to programmatically set Equation of State Options (e.g. Enthalpy Method, HYSYS vs. standard PR, or Liquid Density options) and Fluid Package options (e.g. Stability Test Method)? | Solution: The code below illustrates how to use VBA to set the following options on a Peng Robinson fluid package:
Enthalpy Method
Peng Robinson Options (HYSYS vs. Standard)
Use EOS Density checkbox
Smooth Liquid Density checkbox
Stability Test method (can be used on any kind of non COM Thermo fluid package)
The HYSYS type library currently only includes a property to set the Enthalpy Method option. The other properties must be set using a Backdoor method. Backdoor methods allow access to features not yet wrapped for access by normal OLE Automation methods.
To use this example, copy and paste the code below into the Excel VBA Editor.
See alsoSolution #109180 for details of how to create a Fluid Package via Automation.
Sub ChangeFluPkgOptions()
'
'Description: Example of how to set additional PR property package options:
' - HYSYS vs Standard PR
' - Use EOS Density and Smooth Liquid Density Checkboxes
' - Stability Test method
'
' Uses a Backdoor method
'
' NB Backdoor methods are only recommended when there is no other alternative, the internal
' HYSYS monikers may not remain constant between versions so care should be exercised when upgrading
'
' This code tested in HYSYS Versions 3.1 and 3.2
'
'Declare Variables
Keywords: None
References: None |
Problem Statement: Is it possible to generate an input summary using Aspen HYSYS? | Solution: New in Aspen HYSYS 2006.5, an Input Summary was added to the HYSYS Flowsheet Summary form (i.e. select Flowsheet | Flowsheet Summary | Input Summary from the HYSYS main menu). Alternatively, the Input Summary can be generated by selecting Simulation | View XML from the main menu, and then activating the Input Summary button.
The Input Summary form provides a break down of all the user supplied values in the HYSYS flowsheet (i.e. this summary does not include any unit operation default values or values calculated by HYSYS when solving the flowsheet).
Keywords: input, summary, file, XML, flowsheet
References: None |
Problem Statement: After changing the password for the IIS service account user, Upload of overrides are failing in Aspen Collaborative Forecasting (CF). How is this corrected? | Solution: You should review the IIS log files first. Most likely you will see multiple 401 error messages in the logs, IIS log file clearly indicates that domain\\user name, password combination in proxy.properties file not valid (Error 401 means unauthorized login failed). You then need to perform the following actions to make Offline Override functionality to work in CF.
In proxy.properties file client needs to re-fill the following entries:
PROXY_PW=valid password
PROXY_LOGIN= domain\\user name (Make sure that you are using proper domain name followed by two backward slashes and user name)
ENC=N
After making the above change client needs to stop IIS and re-start IIS first and stop and re-start Weblogic as next in sequence.
Note: user should be an administrator and have sufficient privileges with domain account; once user performs Offline Overrides after the above changes; next sub-sequent logins; user information would be validated against caching.
Keywords: None
References: None |
Problem Statement: Is the Tacite pressure drop correlation still available in Aspen HYSYS? I can no longer find in among the list of pressure drop correlations in the pipe segment. | Solution: As of Aspen HYSYS 2006, the Tacite Hydrodynamic Module is no longer available in the pipe segment operation. When loading older cases that contain this correlation, the following error message may appear:
After acknowledging the above warning, the simulation case will load without further incident, but will use the Beggs and Brill correlation in place of the Tacite Hydrodynamic Module.
Note that when loading cases that contain more than one instance of the Tacite pressure drop correlation, a separate warning message will appear for each. In these situations, it may be preferable to activate the Send further recall error messages to the trace window checkbox (shown above) in order to avoid acknowledging each error individually.
Keywords: wax, deposition, pipe, segment, ProFES
References: None |
Problem Statement: Server Error when the Create Override functionality is filtered by Legal entity and Business unit in the Collaborative Forecasting | Solution: Reason for the error, Collaborative Forecasting offline loading may take a long time if the file is large or data volume is high. The default transaction timeout in Weblogic server is 30 seconds and it is recommended to change this to 90 seconds or more.
To do this please follow the below Procedure
1. Login to Weblogic Administration tool:
http://<yourHost>:<yourPort>/console
Login/password is as what you saved when you created the domain. This has nothing to do with CF.
2. In the admin page, on the left navigation panel, click: services ->JTA, and the transaction timeout is shown as follows:
Change the value in seconds and Apply. This setting is saved persistently, after that you need to restart the Collaborative Forecasting web application using Windows service.
Keywords: Server Error
Transaction timeout
JTA
Create override
Collaborative Forecasting
Weblogic
References: None |
Problem Statement: Data Chart failing to display when user clicks Display Chart(s) icon. | Solution: Make sure you select the check box in the Chart column before you select the Display Chart(s) icon.
Failure to select the check box will result in an error.
Keywords: Collaborative Forecasting
Chart
References: None |
Problem Statement: This knowledge base article describes the steps to install bridge libraries into SCM. | Solution: 1. Open the case into which you will install the Bridge Libraries.
2. From the Navigation Pane, click Modeling | Tools | Library Manager.
3. In the SCM Ribbon, do one of the following:
Under the Home tab, click Properties or
Under Data tab, click Properties.
The Properties Panel opens.
Note: Review which Libraries are already linked, as this will let you know which Bridge Libraries to install.
4. Install the Bridge Library corresponding to the SCM Application.
For example, install DMB_VX-Y into Demand Manager.
5. In File Explorer, locate the file and paste its file path, including the file name, into the Properties
Panel’s Add/Upgrade Libraries section.
6. Click Add/Upgrade.
7. In the Properties Panel’s Library Status section, click the newly added library in the Linked Library
list to select it. A single available feature should appear in the list below the Linked Library list.
8. Select that feature, and then click Re/Install.
9. Install the Shared Library Bridge (SHB_VX-Y.CAS).
Each feature corresponds to a library. For example, the General Methods Feature corresponds with
the General Methods Library.
10. In the Properties Panel, do the following:
Select the features that correspond with the libraries noted in step 4.
Check the version number of the feature.
If any selected feature has a version number in which the final six digits are all 0 (ex. X.Y.000.000),
deselect that feature.
Because no fixes have been made against that feature, it isn’t necessary to install it.
Note: An error message will appear at the end of your installation if you try to install these features.
However, because nothing is being installed from these features, you can ignore the error message.
11. Click Re/Install to reinstall the selected features.
Keywords: None
References: None |
Problem Statement: This knowledge base article gives an overview of Macros in SCM. | Solution: What is a Macro?
A macro in SCM is a user defined procedure that contains a set of instructions to perform a particular task. It comprises of a series of commands. Any SCM command can be executed from a macro, however there are certain SCM commands that can be used only in macros.
How to write a Macro:
1. Create a new set.
2. Type the desired commands in a sequence. Enter each command on a separate line.
The Description of the macro definition set should contain the commands to be executed.
3. The code of the macro definition set can contain optional labels as below:
DO
GOTO
EOF
ON ERROR
4. Save the set.
Note: Use only upper case letters in a Macro and write one macro per set. It is also recommended that you use letter M when you name a Macro set.
How to run a Macro:
A Macro can be run from the command line,
Syntax:
<macroname
How are Macros executed?
Aspen SCM executes the commands in a Macro sequentially until the END command is reached. Macros are very useful when you want to perform repetitive tasks and execute commands in a sequential manner. However since SCM interprets each line of a macro every time it is being run, processing certain large and complex loops can be slow.
Keywords: None
References: None |
Problem Statement: When making a copy of process stream, how does using a Balance operation differ from using the Define from Other Stream button (found near the bottom of the stream property view)? | Solution: Both Balance operation and the Define from Other Stream feature can be used to create a copy of a stream. The primary difference between the methods is that the Balance unit operation provides a continuous link, whereas the Define from Other Stream feature transfers stream information only once. Thus if original stream is updated, the Balance operation will ensure that it updates the copied stream automatically. Conversely, the Define from Other Stream facility creates the copy of stream, but does NOT update the copied stream automatically.
Key words
balance, copy, define, stream
Keywords: None
References: None |
Problem Statement: What are the differences between the SRK and PR equations of state in HYSYS? | Solution: The SRK equation of state in HYSYS has not been modified in any way and therefore remains much like the original text book model.
On the other hand, the original PR correlation has been extensively enhanced for HYSYS based on literature and experimental data.
You can find more information on the specific differences between SRK and PR in Appendix A of the Simulation Basis Manual (see Technical Library/Documentation).
Keywords: SRK, PR, EOS, property package, method, model, selection, selecting, chosing, choice, difference.
References: None |
Problem Statement: What are the correlations used to calculate flooding in the Tray Sizing Utility? | Solution: For Packed columns, the flooding equations used are either Robbins or SLE, and come from the following references:
Improve Pressure Drop Prediction with a New Correlation, Lanny A. Robbins, Chem. Eng. Progress, May 1991, pp. 87-91.
SLE, as summarized in Equilibrium Staged Separations, Philip C. Wankat, Elsevier, New York, NY, 1988, pp. 420 - 425.
For Trayed columns, the flooding equations depend on the type of tray selected: bubble cap, valve or sieve tray, and come from the following references:
Bubble tray methods come from Design of Equilibrium Stage Processes by Bufford D. Smith, published by Wiley & Sons.
Sieve tray methods are from Mass Transfer Operations by Robert Treybal.
Valve tray methods are from the Glitsch, Koch and Nutter tray design manuals.
Refer to Section 14.16 in the Aspen HYSYS 2004 Operations Guide for more information.
Keywords: design, column
References: None |
Problem Statement: If you have two Aspen Collaborative Demand Manager models is it possible to use one instance of Aspen Collaborative Forecasting for the two? | Solution: We do support multiple Aspen Collaborative Demand Manager models sharing a single Aspen Collaborative Forecasting instance, which is called Multi-Business unit support (see section 11 configuring Multiple Business Units in the Aspen Collaborative Forecasting Implementation Guide). Please also note that you must have the same configuration being sent to Aspen Collaborative Forecasting (i.e. attributes, time periods, etc?) as you do in the Aspen Collaborative Demand Manager environment.
Keywords: None
References: None |
Problem Statement: There are a number of heat transfer fluids and refrigerants available in the Aspen HYSYS pure compound database, such as THEOL-59, and Refrig-22. Please refer to | Solution: #108968 for the whole list of these compounds.
When comparing the Aspen HYSYS predicted property values for these compounds with vendor data, for properties such as liquid density, viscosity, thermal conductivity and heat capacity, users often notice some discrepancies. This should not be a surprise, since the properties reported in Aspen HYSYS are generated from general thermodynamic models. These models should be able to represent the general behavior of those specialty fluids. However, it is not realistic to expect the model predicted results to exactly match the real data from the vendor.
Solution
The good news is that if you do have vendor data, you can take advantage of the Tabular feature in Aspen HYSYS to accurately model the properties of these specialty fluids. Aspen HYSYS provides you with the flexibility of using your (or your vendor's) valuable data to overwrite the model predicted property values.
You can access the Tabular feature from the Tabular tab page of the Fluid Package view in the Basis Environment, as shown in the attached image file. Here are the steps to follow:
1. On the Tabular page, check the box to Enable Tabular Properties.
2. Press the + sign beside Options on the left-hand side of the view to expand the list.
3. Select All Properties under Options and then check the boxes beside the properties you have data for, such as Density (L) for Liquid Density, Viscosity (L) for Liquid Viscosity, and Thermal Conductivity (L) for liquid Thermal Conductivity. Please note that you can only pick two of three enthalpy related properties, due to thermodynamic consistency concerns. Among the three enthalpy related properties, we suggest that you use Liquid Heat Capacity and Latent Heat (Heat of Vaporization).
4. Press the + sign beside Information on the left-hand side of the window.
5. Highlight a property for data input (please refer to the second image file attached).
6. Press the button Cmp. Prop. Detail button at the right-bottom corner to bring up the detailed view for that specific property.
7. Select the Table tab page where you will enter all your data for that property. Please make sure to select the right units (for temperature and for the property) BEFORE entering your data. HYSYS will not convert the data if you change the units afterwards.
8. Press the Regress button once you complete your data entry.
9. Save your HYSYS file.
10. Repeat steps 5 to 9 until you cover all the properties for which you wish to enter data.
11. Save your HYSYS file again.
12. Press Ctrl-L to leave the Basis Environment and go back to the Simulation Environment.
For more information on using the tabular package, please refer toSolution #108893.
Keywords: thermal fluid, Tabular, physical properties, heat transfer fluid, refrigerant, THEOL, Refrig, tabular
References: None |
Problem Statement: Is Aspen Collaborative Forecasting v2006.6 supported on Internet Explorer 7.0/8.0? | Solution: QE not tested Collaborative Forecasting v2006.6 with Internet Explorer 7.0/8.0, AspenTech cannot ensure the quality for the products that we didn't tested thoroughly.
We have tested Collaborative Forecasting v2006.6 with Internet Explorer 6.0; AspenTech recommends using Microsoft Internet Explorer 6.0
Keywords: Collaborative Forecasting
Internet Explorer
Microsoft
Support
IE7.0
IE8.0
References: None |
Problem Statement: Common Errors that can occur when linking Excel to Aspen HYSYS via OLE Automation / VBA, and how to resolve them. | Solution: Type Mismatch, Method or Data Member not found, Compile Error ... Object Library Feature not supported or RPC errors
When linking Excel to Aspen HYSYS, the HYSYS type library must be correctly referenced to allow VBA to access Aspen HYSYS. These errors are often caused when the type library reference is to the wrong Aspen HYSYS version. They can be solved by re-referencing the HYSYS type library. The procedure to do this is as follows:
Close Aspen HYSYS and Excel
Open the version of Aspen HYSYS that is to be used
Open the spreadsheet in Excel
Go to the VBA editor. (Tools ... Macro ... Visual Basic Editor menu option, or press Alt + F11)
In the VBA editor go to Tools ...
Keywords: Automation, Type Library, Type Mismatch, Macro Security
References: s
If HYSYS #.# Type Library (where #.# is the version of Aspen HYSYS being used - see note below) is checked, uncheck it and press OK, then go to Tools ... References again
Find HYSYS #.# Type Library in the list, check it, press OK and close the VBA editor.
Note the #.# in the Type Library name does not always correspond to the version of Aspen HYSYS being used, however it will always be located in the directory of the relevant Aspen HYSYS version.
None of the macros work, pressing buttons to trigger macros does nothing [This is accompanied by a warning message about the macro security level setting]
This occurs either because the macro security level in Excel is set to high, or you chose to disable the macros in the Excel file when you opened it. The macro security setting must be at most medium and macros must be enabled when opening the file.
To change the macro security setting in Excel go to Tools ... Macro ... Security and make the setting Medium. Whenever an Excel file with macros is opened you will then get the choice whether you want the macros to be able to run.
This does not apply to Excel versions prior to 2000 as they do not have a macro security option. |
Problem Statement: Do I have to add a comment on every override in Aspen Collaborative Forecasting? | Solution: Ovd_comment_mandat=true in the property.ini file is set by default. Thus, you must ALWAYS add a comment for any override. You can change this to false, but this goes against best practice and is not advised.
Keywords: None
References: None |
Problem Statement: How do I model solids in dynamics? | Solution: Solids cannot be directly modelled dynamically in HYSYS. The work-around is to create (a hypothetical) or use a component with a high boiling point as the solid. Attached is a HYSYS 2.2 simulation case and an MS Word document that outlines how this can be achieved for a dynamic solid-drying process.
Keywords: solids, dynamics, drying
References: None |
Problem Statement: What additional roles (ex: ASP .NET), need to be added to IIS in order for CFasp and MS2JService to work?
This knowledge base article describes which role services must be installed on IIS prior to installing Aspen Collaborative Forecasting (CF).
Here is the complete list of role services available in the IIS Add Roles Wizard in Windows Server 2008. The image below shows the boxes that are checked by default.
A | Solution: Please make sure these two are added when installing this role:
.NET Extensibility
A
Check IIS 6 Management Compatibility
A
Please also be sure you have installed already .NET 3.5.1
Keywords: Aspen CF, IIS, .NET
References: None |
Problem Statement: What are the conditions for Normal Boiling Point (NBP) and Ideal Liquid Density for Aspen HYSYS library components and Hypos? | Solution: For Aspen HYSYS library components and Hypos:
NBP is the Boiling point at 1 atm.
The conditions for the Ideal Liquid Density are somewhat more complicated. (This information comes from Section A.6.2 Page A-67 to A-69 of the HYSYS 2004.1 Simulation Basis manual. This refers to the database of library components, but also applies to any hypos you create). There are three possible cases:
Case 1 - For any component that is a liquid at 60F and 1 atm, the database contains the density of the component at 60F and 1 atm.
Case 2 - For any component that can be liquefied at 60F and pressures greater than 1 atm, the database contains the density of the component at 60F and the Saturation Pressure.
Case 3 - For any component that is non-condensable at 60F under any pressure, i.e. 60F is greater than the critical temperature of the component, the database contains GPA tabular values of the equivalent liquid density. These densities were experimentally determined by measuring the displacement of hydrocarbon liquids by dissolved non-condensable components.
Keywords: NBP, Ideal Liquid Density, Hypothetical Component, Library Compoent
References: None |
Problem Statement: By default, every 15 minutes, HYSYS will automatically save the simulation file in use. Sometimes, you would like to recover this file and wonder where it is located. | Solution: The location of the autosave HYSYS file is displayed in the trace window at the bottom of your HYSYS desktop, as shown in the attached image file. For example, on this specific computer where its user's name is lwang, this file can be located at C:\Documents and Settings\lwang\Local Settings\Temp.. It has an extension of .ahc.
For HYSYS to recognize this file, all you need to do is to change the extension of the file name from .ahc to .hsc.
In the case of HYSYS crashing, the last saved file can be recovered when you reload HYSYS. Just make sure that you select the file you would like to recover and press OK button to confirm it.
Keywords: autosave, auto-saved file, recovery, archive, crash
References: None |
Problem Statement: Pipelines often do not remain at the same buried depth, so how does the Aspen HYSYS pipe segment calculate the heat transfer? | Solution: The buried depth that you enter in the heat transfer section of the pipe segment is the depth of the pipe, assuming that the pipe is parallel to the ground. That is, even if your pipe changes depth relative to the surface of the ground, the heat transfer calculation will always use the same value as the buried depth. This means that if you have a rising and falling pipeline, you may need to enter it as several pipe segment unit operations in order to approximate the correct depth for heat transfer calculations.
Buried depth is defined exactly as the depth of cover to the centre line of a horizontal pipe that runs parallel to the ground level.
In addition, when you have a buried pipe in Aspen HYSYS, you are required to input an 'Ambient Temperature'. For a buried pipe you must enter the temperature at ground level above the pipe. This is described in section 5.2.3 of the Operations Guide (OpsGuide.pdf) on the HYSYS documentation CD (also available from our support website at http://support.aspentech.com by following the Documentation link under Technical Library on the left hand side). See alsoSolution #115454.
Keywords: pipe segment, heat transfer, buried depth, pipeline
References: None |
Problem Statement: What is the difference between how dependent property curves and independent property curves are treated in the HYSYS Oil Manager? | Solution: In the HYSYS Oil Manager, it is possible to define physical property curves (density, MW and viscosity) as dependent or independent, in reference to distillation data. For a dependent property curve, a common set of assay fractions is used for both the distillation and physical property curves. For an independent property curve, a common set of assay fractions is not used for both the distillation and physical property curves.
The physical property curves (density, MW and viscosity) in the Oil Manager are average values for the given range, and hence are midpoint values. Distillation data reports the temperature when the last drop of liquid boils off for a given assay range; therefore distillation is an endpoint property. Since all dependent input property curves are reported on the same endpoint basis as the distillation curve, they are converted by HYSYS to a midpoint basis.
Independent property curves are not altered by HYSYS in any manner before being used in the characterization, since they are already defined on a midpoint basis. This typically means that the user has to calculate the midpoint of the fraction before inputting the values in HYSYS. Attached is an Excel spreadsheet demonstrating the manual calculations required before inputting an independent density curve, as an example.
You may view the density curve generated by HYSYS in the Blend Property View (Composite Plot tab) - this can help to analyze the density shifting to midpoint values.
Note that there is an existing wishlist item logged in our tracking database requesting the same treatment for the independent curves as for dependent ones, as the latter corresponds to the usual format of data obtained from the laboratory.
Keywords: property curve, density, MW, molecular weight, viscosity, dependent, independent, lab, distillation, cut, average, midpoint, fraction, correction.
References: None |
Problem Statement: How can I access an un-wrapped variable without using a Backdoor object? | Solution: Many 'un-wrapped' variables - those that can only be accessed directly in code by using a Backdoor variable approach (see the cross-referencedSolutions above) - can be accessed indirectly via Automation by importing the variable into a spreadsheet cell and then using Automation to read or modify the value of the cell. This can be more straight forward than a backdoor variable method, since it does not require any knowledge of the HYSYS 'moniker' (an internal variable name) for the variable being accessed.
To import a variable into a spreadsheet cell, use one of the following methods:
a. Use the 'Add Import' button on the Connections tab, then navigate to the required variable, and choose the cell into which to import.
b. Right click on a cell on the Spreadsheet tab and use the 'Import Variable' option, then navigate to the required variable.
c. Right click drag and drop the variable from the place it appears in Aspen HYSYS onto the spreadsheet cell.
Option c) is particularly useful for any Aspen HYSYS variables which do not appear in the variable navigator used in options a) and b).
To access the spreadsheet operation via Automation see Knowledge BaseSolutions 109201 and 110044.
Keywords: Backdoor, un-wrapped, variable
References: None |
Problem Statement: Real Separator User Guide: How to model carry over in separators? | Solution: Please see the attached pdf document.
Keywords: Real Separator, Carryover modeling
References: None |
Problem Statement: Why is HYSYS predicting a temperature increase across a valve? | Solution: When a fluid has a negative Joule-Thomson (J-T) coefficient, all equation of state (EOS) models will predict a temperature rise corresponding to a given pressure drop. An article on this subject has been attached to thisSolution (Working with Fluids that Warm Upon Expansion by J. Carroll, Chemical Engineering, September 1999). While the J-T coefficient of a fluid is defined as the partial derivative of temperature with respect to pressure at constant enthalpy, many gas mixtures exhibit a characteristic wherein the slope of the V-T curve changes sign at some specific point. Since the slope of this curve is proportional to the J-T coefficient, this change in sign signifies the point at which the gas changes from cooling to heating upon expansion. As an example, the temperature of hydrogen will increase during expansion at normal pressures, while most light hydrocarbons will cool on expansion. At very high pressures, however, many hydrocarbon gases will heat up during expansion.
A HYSYS case has been attached to thisSolution wherein a user variable has been added to a stream in order to calculate its J-T coefficient.
Specific to TEG Systems:
Based on past comments from industry, it has been observed that HYSYS will correctly predict the increase in temperature across a valve for TEG systems. However, the feedback that we have received indicates that HYSYS will over-predict the temperature rise, which is typically around 1-2 degree Celsius. One possible explanation for this phenomenon is that the excess liquid volume predicted in the high-pressure inlet stream causes the enthalpy calculation to be less accurate, thus affecting the temperature downstream. This is an inherent limitation of EOS models, which tend to be very good at predicting vapour phase properties, but are less accurate for the liquid phase. Unfortunately, there is no experimental data available to quantify the extent of the temperature deviation in HYSYS resulting from the negative J-T effect.
If the predicted outlet temperature is the primary process concern, the GCEOS property model is recommended due to its incorporation of volume translation principles. This model allows for the specification of volume translation parameters that will ultimately correct the over-prediction of the temperature rise. It is important to remember that by deferring to the GCEOS model, the simulation will lose the advantage yielded by the optimized TEG/H2O interaction parameters used in PR. The PR-LK enthalpy model can also be considered because the flexibility of the combined model allows for the use of the PR model for VLE calculation, and the Lee-Kesler equation for the calculation of enthalpy and entropy.
It is important to emphasize that PR correctly predicts the mass and heat transfer characteristics of a TEG dehydration unit. This information is typically more useful for design calculations than accurately predicting the extent of the J-T effect. Knowing that the actual temperature increase will not be as high as predicted in HYSYS, a dummy cooler can be installed downstream of the valve to lower the stream temperature by a few degrees.
Keywords: Joule-Thompson, Joule-Thomson, JT, J-T, Valve, Increase, Temperature, Expansion, Warm, Negative, Coefficient, Effect, TEG, C6H14O4, Triethylene Glycol, User Variable, Dehydration.
References: None |
Problem Statement: What version of OLGAS is being used in HYSYS? | Solution: OLGAS 2000 is incorporated into HYSYS v3.1 and up. HYSYS versions previous to 3.1 used the OLGAS v1.1 correlation.
Keywords: OLGAS, HYSYS, Pipe, Correlations
References: None |
Problem Statement: Why can I not enter my D86 assay in mass percent? | Solution: Aspen HYSYS accepts TBP and Chromatographic analyses in any one of the three standard bases; however, due to the form of the API Data Book conversion curves, EFV, ASTM D86 and ASTM D1160 distillations must be supplied on a liquid volume basis and ASTM D2887 distillations must be entered on a mass basis.
Keywords: assay, enter, basis, bases, D86, EFV, ASTM, D1160, TBP, D2887, chromatographic
References: None |
Problem Statement: When do the Data Sets in the Update Log on the home page of Collaborative Forecasting update and what triggers their update? | Solution: The All Sets Published columns update when the create_schema.cmd is executed or when the database (Converting CF database from prior version to current version) is upgraded.
The Data Sets Re-Published columns updates after:
1. Published is selected from the Publish Collab Forecast screen.
2. Re-publish is selected and then intra_repub u1 (here u1 means business unit one u1,u2,u3...un) is executed from the command line.
3. After you accept or reject an override in DM then Re-publish on Process CF Override screens, this column also updates.
The Selected Records Refreshed columns update when the create_schema.cmd is executed or when the database (Converting CF database from prior version to current version) is upgraded.
Keywords: Collaborative Forecasting
Main Screen
References: None |
Problem Statement: Prior to HYSYS v3.1, the variables shown in the variable navigator (e.g. when importing/exporting in the Spreadsheet, when selecting a Target Variable for the Adjust etc.) was not in any particular order. Consequently, the list of components displayed for a component variable (e.g. Comp Mass Frac) was in the same order as defined in the Basis Environment. | Solution: In HYSYS v3.1, a defect was fixed so that the variables shown in the variable navigator are alphabetised. Consequently, this also means that all the lists are alphabetised, including the component list.
Keywords: Components, List, Alphabetised, Order, Sort, Variable, Navigator, Variable Specifics.
References: None |
Problem Statement: Why when using the ENRTL-RK property method, DHVL calculated for water does not change when the corresponding submodel is modified (THRSWT/4 ) | Solution: This is actually an expected behavior that is determined by an option code of one of the models used in ENRTL-RK, in this case the model to compute DHL (DHLELC). ENRTL-RK is implemented so that for a non-water solvent, DHVL is calculated using the DIPPR submodel by default. The user can switch to another equation by setting THRSWT/4 to a different value, say 0 for the Watson model. However, this does not apply to Water since the steam table is used by default. That's why DHVL is not affected for Water.
If you want Water to be treated like any other solvent, you can change the option code 1 for the model DHLELC from 0 (default using the steam table) to 1. This will allow DHVL to pick up the model from THRSWT/4 for Water accordingly.
Attached to thisSolution there is an example, DHVL-Water_AspenTech.bkp, in which we show how to create a custom property method based on ENRTL-RK and change the option code 1 from 0 to 1 for DHLELC. Now DHVL will be changed for Water when we switch from the DIPPR model to the Watson model.
Keywords: ENRTL-RK, DHVL, Water
References: None |
Problem Statement: Why does a controller go to unstable when setting its parameters from a spreadsheet?
This problem appears usually when trying to configure an adaptive controller, i.e. a controller in which tuning parameters are a function of current conditions. | Solution: Note: This problem is fixed in V2006.5 and V7.1. Refer to theSolution id: 127899 and 128112.
The source of the problem is the fact that the export takes place all the time during the simulation even if the new value exported is the same. In other words, the simple fact of exporting a new parameter to the controller produces a disturbance, indeed, when the controller parameters are changed, the controller will be initialized. Continues resetting the parameter will cause the oscillation if the CV is not lined out.
Using the parameter scheduling it is possible to avoid resetting the PID parameters when the new parameters set and hence to cure instability problems.
The point is to reconfigure the controller to have scheduled gain but set the lower range limit at 99.99998%, the upper range limit at 99.99999%, and select the Low Range on the scheduling parameters from the drop down menu. This means the controller is always in the Low Range, and scheduling parameters can be considered as the usual tuning parameters.
Then a calculated gain (or any other control parameter) in an external spreadsheet can be exported to the Low Range gain in the scheduling parameters. This way the PID controller does not reinitialise every time the scheduling gain is changed by the spreadsheet.
Keywords: Adaptive controller, gain scheduling.
References: None |
Problem Statement: How can I take a side draw from a tray and set out to a stage below? For a better understanding of the procedure, this | Solution: document presents an example on how to take all the liquid from tray 6 and set out to the tray 7 in an Atmospheric Crude Tower.Solution Add a new specification into the Column. You must select the Column Liquid Flow spec. In the Stage option you will select the tray you want to take the side draw. As Spec Value a very low value would be defined. In the Column Environment go to the Column editor and select the Side Draws page located in the Design tab. Select the Liquid option. Create a new stream with the tray number corresponding to the side draw. The go to the Connections page and add the new stream already created associated with the set out tray. Return to the Main Subflowsheet and be sure the degrees of freedom in the Column are equal to zero. Set the active specs. Finally run the column.
Keywords: column, tower, tray, specification, liquid
References: None |
Problem Statement: -----------------
I'd like to be able to change the (dynamic) vessel heat loss model based on a spreadsheet cell value. | Solution: --------
Refer to attached model, and inspect the user variable code associated with the vessel. Code changes the heat loss model depending on the value in spreadsheet cell B1.
Note: These examples are provided for academic purposes only and as such are not subject to the quality and support procedures of officially released AspenTech products. Users are strongly encouraged to check performance and results carefully and, by downloading, agree to assume all risk related to the use these examples. We invite any feedback through the normal support channel at [email protected].
Keywords: --------
Heat Loss Model
References: None |
Problem Statement: How is the flow rate calculated from the pressure drop in a valve in Dynamics? | Solution: The attached document describes the equations that are used to relate the flow rate through a valve in Aspen HYSYS Dynamics to the pressure drop. This document describes the general equations, the valve and pipe k value calculations and gives details of the pipe friction factor methods Assume Complete Turbulence and Full-range Churchill.
Keywords: valve, pipe, k value, friction factor, dynamics
References: None |
Problem Statement: What does the Inlet droplet d95 distribution parameter, in the Horizontal Vessel Carry Over Correlation method, represent? | Solution: The Inlet drop distribution parameter represents the size of the inlet liquid droplets. This value is then used to determine the size of the droplets of water in oil and the size of the droplets of oil in water using the following method.
First the amount of water that is in the stream is determined from;
Water% = WaterFlow / (OilFlow + WaterFlow)
If water is the continuous phase then;
Water in Oil = Inlet Droplet * (WaterDensity / OilDensity)^0.6 Oil in Water = Inlet Droplet
If water is not the continuous phase then;
Water in Oil = Inlet Droplet
Oil in Water = Inlet Droplet* (OilDensity / WaterDensity)^0.6
Keywords: Inlet droplet, d95, Real Separator
References: None |
Problem Statement: Collaborative Forecasting patch- is there any back-out process or logic if the patch fails after installing? | Solution: There is no rollback script. The following files are replaced with existing files for CF 7.1 CP9 patch.
C:\CFBea\user_projects\domains\AspenCF\applications\cf.ear 11/9/2010
C:\CF\cf_integ\lib\cf.jar 11/9/2010
C:\Inetpub\wwwroot\AspenTech\CFasp\Bin\CFAspxLib.dll 3/19/2010
C:\Inetpub\wwwroot\AspenTech\ms2jservice\Bin\CFAspxLib.dll 3/19/2010
C:\CFBea\user_projects\domains\AspenCF\rc\proxy.properties 1/21/2010
C:\Inetpub\wwwroot\AspenTech\CFasp\cf.aspx.cs 3/9/2010
Caution: in proxy.properties existing entries overrides with empty values; after applying patch replace new proxy.properties file with existing file(backup file).
These files should be backed up and in the case of a problem, restored.
Keywords: None
References: None |
Problem Statement: Why is there an inconsistent pressure trend when using Beggs & Brill correlation in PIPESYS? | Solution: For saturated gas at different temperature and pressure conditions, user may gets inconsistent pressure drop trend if the Beggs & Brill correlation is used for pressure loss calculation in PIPESYS.
In this condition, Neotech's recommendation is to use OLGAS or the default method (Oliemans) for pressure drop calculation inside PIPESYS model.
Keywords: PIPESYS, Pressure drop correlation, Saturated gas.
References: None |
Problem Statement: What is the difference between the To AWD and From AWD buttons found on the Auto Water Draw window (opened via the column view)? | Solution: The Auto Water Draws (AWD) option allows for the automatic addition and removal of total aqueous phase draws from each stage depending on the conditions in the converged column. When the AWD configuration is turned on, the To AWD and From AWD buttons are used to manipulate this feature, as described below:
TO AWD: If this button is on, Aspen HYSYS will convert all existing water draws to auto water draws
FROM AWD: If this button is on, it will convert all auto water draws to regular water draws.
Keywords: AWD, auto, water draw, column
References: None |
Problem Statement: Why are there two phases shown in the stream's property view when the stream is at its Bubble Point/Dew Point? | Solution: When the stream is at its Bubble Point/Dew Point the second phase is always displayed, however the flowrate of this phase will be zero. The second phase is displayed because the stream is right at the boundary of the liquid-vapour region. When the stream is above the Bubble Point or below the Dew Point then only one phase will appear since the stream is now completely in one phase.
Keywords: Bubble Point, Dew Point, Flash, Stream Property View
References: None |
Problem Statement: Is it possible to get the V7.1 cf.ear file and deploy it at your site without upgrading any other components or would the whole thing not work? | Solution: You cannot simply deploy the CF.ear file without converting Demand Manager and CF integration manager to the V7.1 level. To support CF it is expected DM and CF should be at same level. The upgrade path must be followed for other components also (DM, CF integration manager) which are defined in the documentation.
Keywords: None
References: None |
Problem Statement: As Hysys calculates cetane index using a proprietary method, how do I calculate cetane index using ASTM D 4737 - 96a method? | Solution: Cetane index calculation in Hysys is performed using a proprietary method. If you are interested in calculating cetane index using ASTM D4737 - 96a method, follow the steps below:
Download the attached CetaneIndex.huv file and save it.
Open your Hysys case and go to Simulation menu and click on submenu Import and Export User Variables.
Click on Select File button. Select the file CetaneIndex.huv (downloaded in step 1).
Select both the user variables(both at once or one by one) under User Variables in Export File and click Import. Then click OK.
Goto Flowsheet menu and activate the flowsheet user variable FlwCetaneIndex by clicking on the green tick button and then checking the checkbox below it. To see the code, double click on the flowsheet user variable.
Activate the stream user variable CetaneIndex in the streams for which you want to calculate cetane index (in the same way as in Step 5). To see the code, double click on the stream user variable. The stream user variable page is accessed by:
Hysys 3.0.1 - current - stream property view --> Worksheet tab --> User variables page. Hysys 2.4.1 - 2.4.2 - stream property view --> User Variables tab.
Force the flowsheet to calculate.
Cetane Index will be calculated for all the streams for which the stream user variable was activated. An example Hysys 3.1 case CetaneIndexCalculation.hsc is also attached.
Note:
For details about how this user variable works, please seeSolution # 109215.
Users are advised to refer to the ASTM D4737 - 96a standard for details of this method and the risks associated with its use.
These examples are provided for academic purposes only and as such are not subject to the quality and support procedures of officially released heritage Hyprotech products. Users are strongly encouraged to check performance and results carefully and, by downloading, agree to assume all risk related to the use these examples. We invite any feedback through the normal support channel at [email protected].
Keywords: Cetane Index, stream user variable, flowsheet user variable, cold property utility, ASTM D4737 - 96a
References: None |
Problem Statement: What are the possible flow regimes reported by the Slug Tool and how are they calculated? | Solution: The Slug Tool in HYSYS is used to predict slug properties for horizontal and inclined two-phase flows in the Pipe Segment. The Slug Tool is accessed from the Pipe Segment Properties View on the Performance\Slug Options and Performance\Slug Results pages.
The Slug Tool works by finding travelling waveSolutions of the one-dimensional averaged mass and momentum equations which are then analysed to obtain the slug flow properties. The approach is based on a stability analysis whereby stratified flow is tested for instablility to small disturbances and then analysed in the unstable region to determine if slug flow is possible. If large amplitude waves can bridge the pipe then slug flow is deemed possible. For high gas flowrates when the flow is unstable and slug flow is not deemed possible, the flow regime is interpreted as annular flow. For high liquid flowrates when the flow is unstable and slug flow is not deemed possible, the flow regime is interpreted as bubble flow.
Therefore, based on this analysis, one of the following flow regimes will be reported on the Pipe Segment Performance\Slug Results page in the Status column:
Single phase - no slug flow possible
Stable 2 phase - stable stratified two-phase flow, no slug flow deemed possible
Slug flow
Annular flow - no slug flow deemed possible
Bubble flow - no slug flow deemed possible
A full discussion of the approach is given in the paper:
Watson, M., The Modelling of Slug Flow Properties., 10th International Conference Multiphase '01, Cannes, France, 13-15 June 2001.
which can be downloaded fromSolution ID 112332.
See alsoSolution ID 112331 What is the difference between slug translational velocity and the liquid velocity in the slug?Solution ID 112332 How are slug flow properties calculated in the HYSYS pipe segment?
Keywords: pipe segment, slug tool, slugging
References: None |
Problem Statement: After converging a column, running the column again from a different starting point or after it is reset results in the column converging to slightly different | Solution: s. The range of theSolutions can be up to 10% of the variable of interest. How can I ensure that the column converges to a consistentSolution?Solution
This may occur when the Modified HYSIM Inside-Out Solver has been selected. It is usually observed when a heat duty is the variable of interest in the column. This problem can easily be avoided by providing reasonable values for specifications used as estimates.
However, in the absence of good estimates, the Heat/Spec Error Tolerance for the column should be tightened. This can be accessed as one of the Solving Options, which can be found on the Solver page of the Parameters tab in the Column Window. This should be sufficient to make the column to converge on oneSolution, regardless of its starting point.
However, this may not always work, especially when there are Recycle operations in the simulation. As a result the Sensitivities of the Recycle operations need to be tightened as well. Depending on the nature of the column, the Equilibrium Error Tolerance (also one of the Solving Options) may also need to be tightened; however there should be general caution, as tightening tolerances significantly increases computational time.
Keywords: column, convergence, Modified HYSIM Inside-Out
References: None |
Problem Statement: Sometimes there is a difference in the order of the components as they have been added to the simulation to what is being displayed on the workbook. This is due to a hidden Master Component List in the code. In older versions, on the Basis Environment | Components tab, there used to be a default component list called Master Component List. Any component added to the user component list is added to Master Component list and if the order in the user component list is changed, this does not necessarily changes the order in the Master Component list.
Starting with V7.0 this master component list is hidden in the code to accommodate the Aspen Properties component list and user has lost the flexibility of modifying the components order or changing the anything in Master component list. Now, if the user wants to add the composition (Master component composition) to the workbook, there is a possibility of disorder in component list. | Solution: The best way to handle this in current versions is to Add the Phase Component Mole Fraction and then select the Overall Phase and select the All radio button. This will include the components in the current fluid package used for the stream and only the associated components. More importantly they will be displayed in the same order as your component list.
Keywords: Phase comp molar fraction, Master componet list, Composition, Order components
References: None |
Problem Statement: Why is the Hydrate Formation utility is not available for all property packages? | Solution: The hydrate models incorporated into Aspen HYSYS are based on the work done by Ng and Robinson. Parameters for these hydrate models were developed with the use of the Peng Robinson equation of state. It is therefore not appropriate to use these models with other property packages as the hydrate formation results may be unreliable.
Keywords: PR, hydrate, PR-Twu, utility
References: None |
Problem Statement: In the tray sizing utility, tray flooding results table, what does the term flood capacity refer to? | Solution: The flood capacity is an empirical value calculated by a formula that includes tray spacing, vapor density and foaming factor. It is used to calculate the percent flooding according to the formula below:
%FLOOD = (VLOAD + GPM * FPL/13000)/(AA*CAF)
VLOAD = vapour loading (ACFM)
GPM = liquid phase flow rate (GPM)
FPL= flow path length (in)
AA = active area (ft2)
CAF = flood capacity factor (figure attached).
Keywords: tray sizing, flood capacity, flooding
References: None |
Problem Statement: 1) How does the compressor in Aspen HYSYS interpolate amongst performance curves?
2) How does Aspen HYSYS extrapolate compressor curves to stonewall (for Dynamics)
3) How does Aspen HYSYS interpolate the performance curves amongst different Inlet Guide Vane (IGV) angles (for Dynamics)? | Solution: 1) When multiple curves at different speeds are provided (for example three curves for 9000 RPM, 11000 RPM and 13000 RPM), and given the flow, F, the first step is to calculate the Head and Efficiency for the given flow (for each of the three curves) using a Cubic Spline Method.
With the resulting three pairs of data (9000 RPM, HeadFor9000; 11000 RPM, HeadFor11000; and 13000 RPM, HeadFor13000), the next step is to find out the HeadForSpecified for the speed specified (10000 RPM for example), again using the Cubic Spline Method.
The same procedure is used to find out the Efficiency at the specified Speed.
If you input multiple curves into the compressor and then run the compressor at a speed below the lowest curve (i.e. lowest speed), the method used in Aspen HYSYS includes a limited functionality of extrapolation when the point lies outside of the data. Note that extrapolation is generally not very accurate, all depending on the degree of curve non-linearity.
2) To extrapolate compressor curves to stonewall, Aspen HYSYS always fits the head vs. flow (and efficiency vs. flow) curve to the analytical equation defined in the Aspen HYSYS documentation (Aspen HYSYS documentation suite, Operations Guide, section 9.1.1). The fit is weighted so that the points entered by the user around the current operating point will be given highest weight. When operating beyond the last points entered, Aspen HYSYS uses the curve fit from the last fitting (i.e. the extrapolation is not linear). Note that stonewall applies to Dynamics only.
3) If Inlet Guide Vane (IGV) curves are supplied, the compressor will, based upon the current IGV position, linearly interpolate between the closest two entered Head vs. Flow and Efficiency vs. Flow curves to arrive at two new curves. These two curves are then analytically fit as they normally would be (as if no curve collections were entered) and are used as two of the equations supplied to the Pressure-Flow solver. If you are operating exactly at an IGV position corresponding to one of your entered curve collections, then that curve collection alone will be used and you should operate right on one of those curves (if you do not have variable speed and you are operating at the one design speed of your one curve of the collection, then you will be right on that curve someplace). No extrapolation is done beyond the highest or lowest IGV curve collection used. Note that IGV applies only for dynamic simulation.
This is the same approach if you use MW curve collections. The approach is empirical and solely relies on user / manufacturers input data.
See alsoSolution 117509 for an example of a compressor with IGV curves.
Keywords: Dynamic, compressor, curve, stonewall, surge, performance
References: None |
Problem Statement: You are attempting to load a subroles.txt file into Collaborative Forecasting and all subroles cannot be loaded into CF, receiving Oracle error : '1000 ORA-01000: maximum open cursors exceeded. | Solution: This problem is due to the number of open cursors not being set correctly. The Open_Cursor setting in SQL needs to a number greater than the number of subroles to be uploaded into CF.
There are two possibleSolutions to this, depending on how the DBA there has Oracle set up.
If you are using spfile they need to use the following bellow commands to increase the no of cursors parameter in oracle DB to avoid ora-1000 error while loading sub roles into Oracle DB.
SQL> show parameter cursors
NAME TYPE VALUE
Keywords: None
References: None |
Problem Statement: In the Aspen HYSYS components database, the following sulphur components can be found: S_Rhombic, S_Monoclinic, S_Amorphous, S_Liq_150, S_Liq_190, S_Liq_280 and S_Vapour. What is the difference between them? Which one should I use in my simulation? | Solution: Monoclinic, amorphous and rhombic: those are defined as solid components and therefore they are NOT included in any vapor liquid equilibria calculations. There are some differences in the heat of formation of these different crystalline forms of sulfur.
S_Liq_150, S_Liq_190 and S_Liq_280: the viscosity of liquid sulfur shows a bizarre behaviour. It is not possible to reproduce such a behaviour using Hysys correlations. See attached excel file where Hysys results and the values calculated using the correlations obtained from DIPPR are compared. Therefore, when you want to model liquid sulfur, you should use the following components at the following ranges: Component T range (oC) S_Liq_150 < 170 S_Liq_190 170 to 190 (see the maximum value at 190oC) S_Liq_280 > 190
S_Vapour: sulfur also shows an odd behaviour when enthalpies are analyzed. It is not possible to calculate the enthalpy of both liquid and vapor sulfur using the traditional fluid packages. For that reason, a different component should be used when if calculations on the vapor phase are needed.
Keywords: Thermodynamic, viscosity, sulfur, sulphur, component
References: None |
Problem Statement: When you try to open the Aspen Utilities Planner (AUP), the program displays the error message below:
***WARNING MESSAGE: No Compatible version of Aspen Properties installed. The Aspen Properties GUI will not be available*** | Solution: This error message, as it shows, is related to an incompatibility issue between the AUP version and the Aspen Properties package version selected to be used in such program. In order to select the appropriate Aspen Properties package, the Aspen Properties Version Selector has to be used. Go to Start | All Programs | Aspentech | Process Modelling VX.X | Aspen Utilities Planner | Aspen Properties Version Selector, and select the appropriate version. See attached screen below as an example:
Keywords: Error message, Compatibility issue, Aspen Utilities Planner, Aspen Property package.
References: None |
Problem Statement: Time periods on the Create Override: Options screen are selected for certain dates (Example: Jun 09 to Dec 09) but when viewing the Create Override: Values screen all periods are open for overrides.
Time periods for override displayed are Jun 07 to Dec 09 | Solution: Set the DEFAULT_TIME_FENCE_OPEN statement in the property.ini file (C:\bea\user_projects\domains\aspencf\rc\property.ini) to one of the following:
True (DEFAULT_TIME_FENCE_OPEN = true) - all periods are open.
False ( DEFAULT_TIME_FENCE_OPEN = false) - allows updates within the time fence specified in Create Override: Option screen.
You must restart the WebLogic server for the changes to take affect.
Keywords: TIME FENCE
Collaborative Forecasting
Create Override
References: None |
Problem Statement: I've added additional components to the Master Component List but they don't appear in my simulation. | Solution: The Master Component List contains every component that has been added to all component lists in a Aspen HYSYS case. However, since the Master Component List is not associated with any Fluid Packages, components which are added to the Master Component List will not appear in the simulation because a simulation requires a Fluid Package and an associated Component List.
To add more components to your existing simulation or existing Fluid Package, you'll need to add the components to the Component List which is associated to the Fluid Package which is being used by the simulation.
NOTE: Although adding a component to the Master Component List will not add the component to the simulation, deleting a component from the Master Component List will remove the component from the simulation and any Component List(s) that were using said component.
Keywords: component, master, list, add, appear, show up, simulation
References: None |
Problem Statement: How can I export utility summary to Excel? | Solution: The utility summary can be viewed under Flowsheet Summary| Utility Summary tab. However there is no option to export to Excel in the Flowsheet Summary page.
Other than copy and paste, the workaround is to create a Report first, then export the results to excel.
Following are the steps:
1. Create a Report by going to Tools| Report Manager.
2. Click on Create when the Report Manager pops up. Then click on Insert Datasheet.
3. Select ?Other? radio button under the Filter option. Then select the only object, ?Main Properties?.
On the right hand side, you will see ?Utility Balance?. Check that and finish up by clicking Add button. Refer to screenshot shown below.
4. Once done, look at the Report builder. Select the Datasheet and check Text to File, Delimited. Then click on Preview button.
5. Once the report text is open, click on Print to File.
6. Select the location where you want to save the file. Under Save as type, select ?All Files (*.*), and give an extension ?.csv? after the File name.
Keywords: Utility summary, Export Excel
References: None |
Problem Statement: How do I access the Relief Valve through automation? | Solution: Currently in HYSYS the Relief Valve unit operation is not wrapped and therefore the VB objects are not available in the HYSYS type library. However, you can access the relief valve via Backdoor variables, by knowing the HYSYS internal labels (called Monikers) for the various properties.
The attached example gets data from the Relief Valve using BackDoor variables. To run the example, have HYSYS open and load the attached HYSYS case. Open Excel, the attached Excel case and enable the Macros.
Note that Backdoor methods are only recommended when there is no other alternative, the internal HYSYS monikers may not remain constant between versions so care should be exercised when upgrading. This example has been saved with a HYSYS 3.2 Type Library reference and tested with HYSYS 3.2, 3.4 and 2004.
For troubleshooting advice on common HYSYS / OLE Automation errors see KnowledgebaseSolution #112361.
Keywords: Relief Valve, OLE, VBA, automation, backdoor, PSV
References: None |
Problem Statement: When attempting to upgrade Aspen Collaborative Forecasting (CF) it fails using cf integration manager.
Evidently it is looking for C:\Data\CF\cVX_integ\dm\control\bean_sheet.txt and can't find the file. After checking the folder location the file does not exist. | Solution: Bean_sheet.txt is generated through CF 7.1 media under C:\CF \cf_integ\dm\control folder; it is not generated through java code base.
When cf_integ folder (cvx_integ) is replaced when the new V 7.1 cf_integ folder part of upgrade process it is expected Bean_sheet.txt file to exist under C:\CF \cf_integ\dm\control folder before initiating database upgrade process. This is the reason your upgrade process fails. TheSolution to this problem is for you to make sure that bean_sheet.txt exists under C:\CF \cf_integ\dm\control folder and re-initiate upgrade process again.
Keywords: None
References: None |
Problem Statement: How is pressure correction applied while calculating liquid density using COSTALD in HYSYS? | Solution: Cheuh and Prausnitz (Cheuh, P. L., and J. M. Prausnitz: AIChE J., 13: 1099 (1967); 115: 471 (1969)) method is used to correct the density of a compressed liquid in HYSYS. The following equation is used:
V = Vs (1+b)^(1/9)
where
b = f (Trm, Vm*, P, Psat, Tcm)
Tcm = critical temperature of mixture
Vm* = characteristic volume of mixture
Trm = reduced temperature of mixture
Also, if the pressure is less than the saturation pressure, b = 0 and therefore, V = Vs, i.e. no pressure correction is applied.
At a given temperature, HYSYS calculates the saturation pressure based on pure component ideal saturation pressure. Therefore, it is not the same as true bubble point pressure and can be termed as the ideal saturation pressure.
This leads to the flattening of the density - pressure curve between true bubble point pressure (calculated rigorously using flash calculations) and the ideal saturation pressure calculated by HYSYS as described above. The difference between the two pressures can be quite significant at higher temperatures.
For example, if you look at the property table utility in the attached HYSYS 3.2 case, the density - pressure curve (T = -30 deg C) is flat between 78.27 bar (true bubble point) and 130 bar (ideal saturation pressure calculated by HYSYS). This is because HYSYS does not apply any pressure correction in calculating the liquid density below the ideal saturation pressure. If you reduce the temperature, the flat portion of the curve will become smaller and at some point it will disappear. This is probably because as the temperature is reduced liquid becomes more ideal and so the difference between the ideal saturation pressure and true bubble point becomes smaller.
Keywords: COSTALD density, pressure correction, density
References: None |
Problem Statement: How to model line heaters in Aspen HYSYS? | Solution: You can use the Pipe Segment operation in Aspen HYSYS to model the line heater. Please read the attached article that explains how to model the line heaters.
Keywords: line, heater, pipe, segment
References: None |
Problem Statement: Rules of Dynamic Simulation | Solution: Through my experience in using HYSYS Dynamics and interacting with other users, I realized that there are many ways to do the same thing, and it is a matter of preference as to which way to go. One thing is common between the ways though; you need to fully understand the implications of your ways and how they affect your model. The attached article presents 10 rules for dynamic simulation that I follow at all times and never ignore. Sometimes, I choose to deviate from a few of them for some purposes, but I always keep them in mind. I believe following these rules will keep you out of trouble as you start your dynamic simulation experience, and will eventually lead you to your own set of rules as you become more experienced.
Keywords: hysys, dynamic, simulation, rules, integrator, solver, spec, mohamed, abouelhassan, boundary, sump
References: None |
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