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Problem Statement: How do I force the simulation to solve from within my Extension Unit Operation? | Solution: Add a new sub procedure named VariableChanged to the unit operation extension class module. This procedure will be called whenever a variable in the extension is changed. An InternalVariableWrapper object is passed to it as an argument. This object is used to identify the name of the variable and take an appropriate action, such as triggering a solve. For example,
Public Sub VariableChanged(ByVal VariableName As InternalVariableWrapper)
If VariableName.Tag = NAME Then hyContainer.TriggerSolver
End Sub
If the Tag property of the VarableName object is equal to NAME then the hyContainer object uses the TriggerSolve method to triggers a solve. NAME is the name of the enumeration widget (or any other widget) in the EDF file. NOTE: hyContainer is an object referenced to the Container object which is made in the Function Initialize section of the class module.
For example,
Public Function Initialize(ByVal Container As Object, ByVal IsRecalling As Boolean) As Long
Initialize = extnCurrentVersion
Set hyContainer = Container
End Function
Keywords: extension, force solve, VariableChanged
References: None |
Problem Statement: How is the Heat Transfer Area per Shell value calculated? | Solution: The area is calculated per shell branch. If you have two parallel branches of four shells in series, the area displayed in HYSYS corresponds to the shells in series. For the overall area you would have to mulitply this number by the number of parrallel branches you have.
Keywords: Heat Exchanger, Heat Transfer Area
References: None |
Problem Statement: Can I access PFD Objects via Automation? | Solution: HYSYS exposes all the objects on the PFD (streams, operations, labels, tables ...) via Automation. All the manipulations that are possible within the interface (movement, rotation, mirroring, hiding, unhiding ...) can be accomplished through code.
The key object types are
PFD- The HYSYS PFD
PFDItems - A collection of objects on a PFD (can be limited to all streams, ops, visible items ...)
PFDItem - An individual object on the PFD
The attached simple piece of code Excel VBA code links to the active PFD of the main flowsheet of the currently open HYSYS case.
Sub PFDTest()
'HYSYS Type Library reference required
Dim hyApp As HYSYS.Application
Dim hyFlowSht As HYSYS.Flowsheet
Dim hyCase As HYSYS.SimulationCase
Dim hyPfd As HYSYS.PFD
Dim hyPfditems As HYSYS.PFDItems
Dim hyPfditem As HYSYS.PFDItem
Dim hyBD As HYSYS.BackDoor
Dim RowOff As Integer
'Link to objects
Set hyApp = GetObject(, HYSYS.Application)
Set hyCase = hyApp.ActiveDocument
Set hyFlowSht = hyCase.Flowsheet
Set hyPfd = hyFlowSht.PFDs.ActivePFD
Set hyPfditems = hyPfd.Items(pfdOperation, pfdVisible)
'Enums: PFDItemType_enum - Sets whether to access streams/ops, labels, workbook tables etc...
' PFDItemVisibility_enum - Whether item is visible or hidden on the PFD
'List all objects
RowOff = 0
For Each hyPfditem In hyPfditems
Range(A1).Offset(RowOff, 0).Value = hyPfditem.Name
RowOff = RowOff + 1
Next 'hyPfditem
'Make sure the PFD is showing - if this is not done the following two code sections will fail
'(SeeSolution 112359 for full details of this workaround)
Set hyBD = hyFlowSht
hyBD.SendBackDoorMessage CreatePFDAndView
'Play with object position (N.B. HYSYS won't move something if it will overlap with another object)
Set hyPfditem = hyPfditems.Item(0)
hyPfditem.XPosition = hyPfditem.XPosition + 100
'Hide an object - this time the named operation E-100
Set hyPfditem = hyPfditems.Item(E-100)
hyPfditem.Hidden = True
'This hides the object and causes the PFD to redraw
End Sub
An individual HYSYS PFD is accessed via the PFDs collection of the HYSYS flowsheet object. Here all the PFDs defined for each flowsheet (via the PFD ... Add a PFD menu option) can be found. The ActivePFD property gives an object for the currently active PFD.
The most important line in the code above is the line
Set hyPfditems = hyPfd.Items(pfdOperation, pfdVisible)
In this case this obtains a collection of all the visible operation objects. The Items collection takes two enums: PFDItemType_enum and PFDItemVisibility_enum, these can have the following values:
PFDItemType_enum: pfdAll, pfdObject, pfdOperation, pfdOperationLabel, pfdOperationTable, pfdStreamLine, pfdTextAnnotation, pfdWorkSheetTable PFDItemVisibility_enum: pfdHidden, pfdVisible, pfdVisibleandHidden
By supplying different enum values different collections of PFD objects can be obtained.
Once a PFDItem object is obtained then it can be manipulated through it's properties (e.g. XPosition, YPosition, Hidden) and methods (MirrorBy and RotateBy). However this will only work if the HYSYS PFD is open. SeeSolution ID# 112359 for full details.
For an Excel example file that creates a sketch copy of the current HYSYS PFD on the Excel spreadsheet seeSolution ID# 112355.
Keywords: Automation, PFD, PFDItems, PFDItem
References: None |
Problem Statement: What does the Pump acting as a Turbine checkbox do in Aspen HYSYS? | Solution: When this box is checked, Aspen HYSYS changes how it handles the energy and efficiency equations for the pump operation. This box should be checked when you use the pump to extract energy from a liquid by decreasing its pressure. As opposed to the more traditional use of the pump operation, which is to add energy to a liquid to increase its pressure. This checkbox only effects the operation of the pump while you are in dynamics.
The turbine is the same as the normal pump except that the pump equations are changed as follows:
1. The first equation uses 100/efficiency instead of efficiency/100 in the following pump equation:
flow *(-deltaP) - density *efficiency / 100.0 *power = 0.0
2. Also in:
sign *g *density *Head - deltaP = 0
sign is +1 for a pump and -1 for a pump acting as a turbine.
A simulation case is enclosed to illustrate a pump acting as a turbine. The case was built in Aspen HYSYS v3.2 (S110716.hsc)
Keywords: Steady state, Dynamics
References: None |
Problem Statement: Can I check for <empty> values using a HYSYS spreadsheet? | Solution: Internally HYSYS represents any value which is <empty> as -32767. The HYSYS @if function can be used to check for this value. This has the syntax @if(Logical Test, Value if True, Value if False)
For example if cell A1 contained an imported value, then the following formula would test whether this value is <empty> or not. If it is then a 1 is returned, otherwise a 0 is returned.
=@if(A1=-32767,1,0)
Keywords: <empty>, Spreadsheet, -32767, @if
References: None |
Problem Statement: What is the meaning of error message 'Depressuring - Dynamics-1 is unable to calculate because Separator Vessel is not complete. Please solve the sub-flowsheet completely first and then press the Calculate button.'? | Solution: When this error message is received, return to the Main flowsheet. To return to the main flowsheet environment press the upward pointing green arrow button in the main button bar until Case (Main) appears at the top right of the HYSYS window, or go to Simulation ... Main Properties and press the 'Main Environment' button on the 'Simulation Case' window that appears.
In HYSYS 3.1+, this error message has been clarified to read 'Depressuring - Dynamics-1 is unable to calculate. Please return to Main flowsheet and do calculation again.'
Keywords: Dynamic Depressuring, Sub Flowsheet Environment
References: None |
Problem Statement: Is it possible to override the default values for pure component properties of library components in HYSYS? | Solution: Yes. Starting from HYSYS version 3.0, users are able to edit/modify the properties of traditional HYSYS library components, as well as hypothetical components. Please note that Electrolyte component properties are specified by OLI Systems and therefore not user-modifiable.
You can edit/modify component properties on three different levels by using the Edit Property button.
Component level - Double click on any component or right click and select View in the Component List View in the Basis Environment. Select the Edit Properties button.
Fluid Package level - Select the Edit Properties button on the Fluid Package view in the Basis Environment.
Stream level - Select a stream which is not a product stream. Select the Edit Properties button on the Composition page, in the Simulation Environment.
Keywords: Edit properties, pure compoent properties
References: None |
Problem Statement: How do I include a Diesel (CAS 68334-30-5) component in a simulation? | Solution: Even though Diesel can be found with CAS number 68334-30-5, Diesel is not one specific chemical component but a mixture of components which are separated into ranges by their boiling point. That's why it is not found in the databank as It cannot have specific properties like molecular weight etc.
In case, user have average value of properties of diesel, he may create a hypothetical component for diesel.
Keywords: diesel, hypothetical, fuel
References: None |
Problem Statement: Unexplained DLLs and TGZ files are created when opening simulation files. Example of files appear are:
lsprst7.dll, lsprst7.tgz, tmpPrst.tgz, sysprs7.dll, sysprs7.tgz | Solution: Installed version of SLM Client tools is not capable of handling Window 7 security requirements. To resolve the issue Uninstall SLM Client tools 7.3 then install SLM Client tools 8.4 from Aspen Engineering DVD 1 for 32 bit systems
Un-install SLM Client tools 7.3
Click on Start | All Programs | AspenTech | Uninstall AspenTech Software
Select SLM Tools --ver. V7.3 and then click Uninstall and then click Install
Install SLM Tools 8.4
Insert Aspen Engineering DVD 1 for 32 bit systems
Select Administration Tab, Select SLM Tools 8.4 and then click
Keywords: lsprst7.dll, lsprst7.tgz, tmpPrst.tgz, sysprs7.dll, sysprs7.tgz
References: None |
Problem Statement: How can someone rotate or flip a stream or a unit operation to improve the aesthetics of the PFD? | Solution: There are a few ways to do this:
The user can just do right click on the stream or unit operation and select the Transform menu. Then select the desired option, i.e. rotate the icon or mirror about X or Y axis.
Another alternative would be to use one of the shortcuts available within HYSYS.
Depending on the key you select from the keyboard, the user will see an action on the stream or unit operation selected, i.e.:
1, 2, 3 : rotate each item clockwise 90, 180, 270 degrees
X, Y : mirror each item about its x or y axis
For a full list of these shortcuts or hot keys please refer toSolution 109052
Keywords: Shortcut
Hot key
Rotate
Mirror
References: None |
Problem Statement: Are the velocities reported in the HYSYS pipe segment Actual or Superficial velocities? | Solution: The phase velocities reported in the HYSYS pipe segment are the Superficial velocities.
[This data can be accessed from the Performance Tab by pressing the View Profile Button.]
They are calculated using:
Phase Velocity = Phase Volumetric Flow / Pipe Area
In order to calculate the phase actual velocity the area occupied by the phase must be used rather than the total area. The fraction of the total area can be derived from the Liquid Holdup. (The ratio of the volume of a pipe segment occupied by liquid to the volume of the pipe segment)
Liquid Area Fraction = Liquid Holdup
Vapour Area Fraction = 1 - Liquid Holdup
Hence
Vapour Velocity = Vapour Volumetric Flow / [(1 - Liquid Holdup) x Pipe Area] Liquid Velocity = Liquid Volumetric Flow / [Liquid Holdup x Pipe Area]
This is illustrated in the enclosed HYSYS 2..4.1 case.
Keywords: Pipe Segment, Velocity, Actual, Superficial, Holdup
References: None |
Problem Statement: Can I change the font size of X & Y-axis labels in Strip Chart? | Solution: You cannot change font size directly in Strip Chart by selecting Graph Control.
Procedure:
Tools/Preferences/Resources/Fonts
Please select Selecting Custom Font tab afterwards select size.
Afterwards come back to Stripchat & look at X-Axis and Y-Axis labels.
Keywords: Stripchart, fontsize, graph control, labels
References: None |
Problem Statement: HYSYS warns me that my Heat Exchanger has a Ft Correction Too Low - what does it mean? | Solution: The Ft factor (LMTD Correction Factor) is related to the shell & tube configuration (shell/tube passes). As a practical economic consideration, it is seldom that a configuration should be chosen where Ft is less than about 0.8. HYSYS generates a warning if the Ft factor for a given heat exchanger is below 0.8. The heat exchanger will be solved/rated anyway (results available), so it is only a warning that this might not be the best configuration. The warning can generally be eliminated when more shells are added to the design.
Keywords:
References: None |
Problem Statement: Is it possible to display a user variable in the Workbook? | Solution: Beginning with V7.2, it is possible to display User Variables in the Workbook. The procedure to add a User Variable is the same as adding other variables, as described below:
1. With the Workbook window active use the Workbook | Setup menu option
2. Press the Add button in the Variables group to bring up the Variable Navigator
3. Choose the 'User Variables' variable, and then in the 'Variable Specifics' list, choose the User Variable of interest as shown below:
Keywords: Workbook, User Variable, Display
References: None |
Problem Statement: The 3-phase separator horizontal vessel correlation considered fixed nozzle location for Aspen HYSYS V7.3 and older versions. See KB | Solution: 132364. This has been enhanced in Aspen HYSYS V7.3.1.Solution
In Aspen HYSYS V7.3.1, the feed nozzle location has an impact on gas-liquid carrryover when the Horizontal Vessel correlation is used, just as works in the case of ProSeparator correlation.
In addition, a check is performed to ensure the feed nozzle location is reasonable (greater 0 and less than gas product nozzle location) and a proper status flag is issued when violated.
Keywords: Horizontal correlation, feed nozzle
References: None |
Problem Statement: Why do I get high CPU usage for REXECD.exe on a client machine? | Solution: This issue occurs when Hysys or Basic Engineering products are installed on a client machine using the 'Server' option. This can cause the system to be slow or have performance issues. To work around this turn the Windows Service off and\or disable it.
- In Windows 2003/XP - Go to Start | (Settings) | Control Panel | Administrative Tools | Services. Look for REXECD. Right-click and select Stop.
- In Windows 2008/Win 7 - Go to Start | (Settings) | Control Panel | System and Security | Administrative Tools | Services. Look for REXECD. Right-click and select Stop.
You may also want to disable the service by Right Clicking and selecting Properties and under Startup Type change to 'Disabled'
Note: You may need Administrator access or your company IT to assist.
Keywords: REXECD
CPU
References: None |
Problem Statement: Is there an easy way to tell which streams have which dynamic specs? | Solution: Yes, this can be done by changing the colour scheme of the PFD.
In Aspen HYSYS v3.0.1 and below:
The Dynamic specs colour scheme is not present by default so you will have to add it. To add it, follow the instructions in the viewlet below. To view the viewlet, unzip the file to folder on your hard disk and double click on the file Colour_Schemes.html.
In Aspen HYSYS v3.1 and above:
The Dynamic specs colour scheme may be selected from the Default Colour Scheme drop-down menu located at the top right corner of the Main PFD. Select Dynamic P/F Specs.
Keywords: Colour Scheme
References: None |
Problem Statement: I have some unit operations in my Aspen Hysys subflowsheet, but they don't show up in the project component map preview list | Solution: When using Activated Economics feature inside Aspen Hysys, all unit operations are mapped to Aspen Process Economic Analyzer (APEA) process equipment, in order that they may be sized and costed. This is done automatically by APEA, when the user selects the 'mapping' function in the Economics toolbar of the Aspen Hysys simulation.
However, if the unit operation is inside a column or Aspen Hysys subflowsheet, APEA may not automatically map it to a project component. Additionally, if the column has been customized to include extra vessels or side operations such as a pump around , APEA might not identify these as simulator items and will instead map the Aspen Hysys column to a default Tower configuration available in the APEA process equipment library.
In order to ensure that a complete equipment list is created from flowsheet simulator items, the user can do the following:
1) Unit operations which are inside the subflowsheet should be brought into the parent/main flowsheet. This can be done by selecting the required unit operations, right-click the selection\cut-paste object\move to owner flowsheet
2) If there are column side operations and modifications that haven't been represented, then create duplicate unit operations of these items in the main flowsheet and proceed with your costing
Keywords: Activated Economics, simulator items, mapping, economic evaluation.
References: None |
Problem Statement: Why is the Heat Duty reported by the Heat Exchanger in Aspen HYSYS not corresponding to Q = mCpdT? | Solution: The heat duty of a heat exchanger operation in Aspen HYSYS is calculated based on the enthalpy difference between the feed and product streams. Heat capacity Cp is not used since its value is not constant during heat transfer processes. Hence the formula Q=mCpdT is not used, instead duty is calculated as:
Heat Duty = Heat Flow out (Molar enthalpy * Molar Flow) - Heat Flow in (Molar enthalpy * Molar Flow)
Keywords: Heat Exchanger, Heat Duty, Enthalpy Difference, Heat capacity
References: None |
Problem Statement: Can I set Component Splitter TBP Cut points by Automation? | Solution: Attached below is some example VBA code to illustrate how to do this. You may have noticed that the component splitter does not have an entry in the HYSYS object library - it has not yet been wrapped for simple access via OLE so there is no easy way to access it's properties. However it is possible to access all it's properties via Backdoor methods. These use the internal HYSYS variable labels (or monikers) to refer to particular properties.
The example is set up to link to a component splitter called X-100 with 4 product streams. Attached is a case with such a splitter (saved in HYSYS 3.0.1 format).
Public Sub SetSplitCutPoints()
' Description: Set the TBP cut points for a Component Splitter
' The component splitter is not yet wrapped for OLE hence need to use a Backdoor variable 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
'Declare Variables
Keywords: None
References: None |
Problem Statement: How do I get or set the Std Ideal Liquid Volume Flow of a stream? | Solution: [In previous HYSYS versions this property appeared on the Worksheet ... Conditions tab as Liquid Volume Flow]
The appropriate property of the ProcessStream object is IdealLiquidVolumeFlow the following code sample illustrates this
Public Sub LiqVolFlow()
'Declare Variables
Keywords: None
References: None |
Problem Statement: How do I print tray by tray properties plots? | Solution: You can print tray by tray properties in graphical format at a time for that particular column.
In order to get best view please make below settings:
1. Using the attached file, double click on the Depropanizer column then go to the Performance tab and select Plots/Tray by Tray properties.
2. Select Temperature and then click on View Graph, then right click on it. Choose Graph Control then select the Title tab and then double click on Font Tab (A symbol).
By default the font size is large, so reduce the font size for better view when you print the graph.
Please follow same procedure for other tray by tray properties.
Procedure to print only tray by tray properties in Graphical format
Double click on Depropanizer column then right click on column title header then select Print Datasheet
Please uncheck all other options from Available Datablocks, except Tray Plots then click on Preview button.
You will be able to see the Depropanizer column tray by tray properties plots as per attached PDF file.
Keywords: Tray properties graphs, plots, column profile plots;
References: None |
Problem Statement: How is the total heat transfer area calculated by detailed heat loss model in Dynamic - Depressuring utility? | Solution: The contribution of the metal wall to the heat losses is only taken into account if Detailed is selected as Heat Loss Model in the Heat Flux page. The total heat transfer area for Detailed heat loss model is sum of cylindrical area, top head area and bottom head area.
Total Heat Transfer Area = Cylindrical Area + Top Head Area + Bottom Head Area
Keywords: Heat transfer area, dynamic depressuring, detailed heat loss
References: None |
Problem Statement: What is the best way to rigorously model a column with a thermosyphon in which 2 liquid phases could be encountered? | Solution: In current versions, HYSYS enables the selection of a thermosyphon reboiler instead of a kettle for a given column. However, the process diagram used for modeling of the thermosyphon is not supported by all theSolution algorithms, the Sparse Continuation Solver being one of the limitations.
When you expect your column to show a liquid phase split at some point of the column, the recommended algorithm to solve the column is the Sparse Continuation Solver. In this case, the reboiler would need to be solved outside of the column subflowsheet.
Attached is a sample of how to do this.
Keywords: Water, hydrocarbons split, Thermosyphon reboiler
References: None |
Problem Statement: Streams connecting two consecutive stages can be exported to main flowsheet from column property view | Flowsheet | Internal Streams | Add command. For other interior streams, a user can follow the technique described below to export the stream to main flowsheet. | Solution: In thisSolution, we present a general applicable scheme to export an internal stream from column subflowsheet to main flowsheet.
It is always possible to replace a material stream with one stream to a TEE (with two outlets) and one stream from the TEE. As long as the other outlet of the TEE has a negligible flowrate, the overall results after replacing the original material stream will be the same. The stream with negligible flowrate from the TEE becomes a product stream and can be mapped to a stream on the main flowsheet. This stream carries correct compositions and state variables, but a negligible flowrate.
Another observation is that in HYSYS a stream allows for negative flowrate. If the stream with negligible flowrate is sent to a TEE with two outlets. The two outlets can have same flowrate with opposite signs.
Based on the two observations, we derive a scheme with two main parts to bring an internal stream in subflowsheet to main flowsheet, 1) get the correct compositions and state variables to main flowsheet; and 2) get the correct flowrate to main flowsheet. Using the attached example, we can describe the steps to set this scheme. In the example, the bottom of the column has a customized configuration. The stream from unit Reboiler back to the column, Boilup, is to be exported to main flowsheet.
1. Solve the column using Solving Method ModifiedHYSIM Inside-Out,
2. In column subflowsheet, replace the stream with stream 2, TEE-100, stream Boilup (original) and Exp To Main,
3. In main flowsheet, activate the split ratio for stream Boilup as column spec, and enter a value of 0.999,
4. Solve the column again,
5. Map the interior stream Exp To Main to Imp From Sub on main flowsheet,
6. Add a TEE and a SET on main flowsheet,
7. Connect Imp From Sub to the inlet of TEE-100 on main flowsheet,
8. Open SET unit, and map the flowrate from Boilup in subflowsheet to stream Copy of Boilup in main flowsheet,
In stream Copy of Boilup, we have correct compositions, state variables and total flowrate. The TEE added to main flowsheet gives us one degree of freedom to set the correct flowrate. The other outlet of the TEE added to main flowsheet will have a negative flowrate.
Keywords: export, stream, subflowsheet
References: None |
Problem Statement: Why can?t I rate a valve in HYSYS? Is this option included in Steady State? | Solution: On earlier releases, HYSYS did not include the option to rate the valves in steady state (i.e. define C1, Cv or K and opening percentage and calculate pressure drop), but starting with V7.3 this option is included.
The following scenarios are supported:
a. Mass Flow and P2 (downstream) are known, P1 could be calculated;
b. Mass Flow and P1 (upstream) are known, P2 could be calculated;
c. P1 and P2 (downstream) are known, Mass Flow could be calculated;
d. P1 and Delta P are known, Mass Flow and P2 could be calculated;
e. P2 and Delta P are known, Mass Flow and P1 could be calculated;
The checkbox ?Use sizing methods to calculate Delta P? in the Design tab > Parameters need to be checked to enable this calculation option.
Keywords: Rating, control, valve, steady, state
References: None |
Problem Statement: How does one view process utility consumption in Aspen HYSYS? | Solution: The Aspen HYSYS Process Utility Manager lets you define and apply utility tags to material and energy streams, to designate them for calculation of energy and utility consumption and costs.
User can view overall Utility consumption data per utility tag, or User can view data for each utility at the stream level.
1. Click the Flowsheet | Flowsheet Summary menu option.
2. Click the Utility Consumption tab (Drag to expand the dialog to the right if necessary).
When the Overall Summary radio button is selected, the overall consumption of each utility type is listed.
Use the Stream Level Summary radio button to view the flowsheet utility data at the stream level. For each utility selected in the Utilities column, the stream associated with the utility and the returned values are displayed.
Keywords: utilities, process utilities, utility consumption
References: None |
Problem Statement: Validation of water content in natural gas calculations by Peng-Robinson property method in Aspen HYSYS . | Solution: Predictions of water content in natural gas by Peng-Robinson property method are very good. Results are validated against GPSA and experimental data.
Results are compared against
1. Experimental data from Olds, Sage and Lacey, Phase Equilibria in Hydrocarbon Systems. Composition of Dew-Point Gas in Methane-Water System, Ind. Eng. Chem. 34, 1223-1227 (1942) and
2. GPSA charts Figure 20-4. The values are read from the chart.
The figure below shows the comparison.
Keywords: Water content, natural gas, validation
References: None |
Problem Statement: How does one use the Electrolyte NRTL model in Aspen HYSYS? | Solution: 1). From Simulation Basis Manager Components/Databank select Aspen Properties then add only molecular species.
2). Create a Fluid Package then select Aspen Properties then select Property Package as Electrolyte NRTL.
3) Click on the Electrolyte Wizard button.
4). In the ensuing window, include the water dissociation reaction
5). Select the components that are involved in the ionic system and click the button Get Reactions. Uncheck any reactions which you think not relevant to your case, then click on OK
The remainer of the simulation can then be created as with any non-electrolyte property model.
Keywords: Aspen Properties, ElecNRTL etc
References: None |
Problem Statement: How can I export a HYSYS workbook to Excel? | Solution: You have a number of options here. The simplest one would be to use the Text To File option. This saves the data from the workbook in a comma delimited ascii text file which can then be opened and formatted in Excel. To do this, open the workbook and select File - Print from the main toolbar. When the print dialog appears, select the Text To File checkbox and then press the print button. You will then be prompted to name the file. The file will be given a .txt extension and can then be imported in Excel. (when opening the file in Excel you must specify All Files (.) or Text Files (*.txt) in order to see this file) Another option would be to use OLE to perform this task for you. This option can sometimes be a better idea since it allows you to set the formatting and only import the information you are interested in examining. There are a number of downloadable examples in the Macros and Extensions section of this website.
Sample OLE option: The Workbook Dump. Open your HYSYS case, open WorkbookDump.xls file, click on the Dump Workbook button. Each time the Stream Data changes in HYSYS, you will have to update the Excel workbook (ie. again click on Dump Workbook).
Keywords: workbook, datasheet, print, options, OLE, automation, Excel
References: None |
Problem Statement: In MASSBAL, you could define streams as Chemical, VLE, Fluid, Food, or Pulp. What stream definition is supported in the MASSBAL subflowsheet in HYSYS? | Solution: MASSBAL has many different possible stream definitions (e.g. Chemical, VLE, Fluid, Food, Pulp). However, the only one used in HYSYS will be the VLE stream type. Thus, in order for MASSBAL to use HYSYS to perform its thermodynamic calculations, callback functions have been set up. We have callback functions to deal with flashes, property calculations of individual components and streams.
Keywords: MASSBAL, stream definition, VLE
References: None |
Problem Statement: Why do old Dynamic Depressuring utility cases return different results when loaded in Aspen HYSYS V7.3 CP1 (or newer)? | Solution: Some changes have been implemented in Aspen HYSYS V7.3 with CP1 and within the Aspen HYSYS dynamic depressuring utility. When the inlet stream is pure vapor (V/F =1), the liquid level will not be allowed to be specified and will be defaulted to zero.
In earlier versions, Aspen HYSYS allowed the specification of the liquid level even if the inlet stream had a vapor fraction of 1. Now, for consistency purposes, this cannot happen since the attached feed stream defines the entire vessel initial conditions previous to blowdown. As a result, the liquid level is now assigned as 0. This may generate different results with respect to older Aspen HYSYS versions.
In the case of a feed stream at supercritical conditions, the inlet stream's vapor fraction displayed may be 1. The liquid level would then be defaulted to zero.
However, when dealing with feed streams at supercritical conditions, if the user wants a vessel full of liquid instead, manipulating the Dense Phase Tuning factor is an option.
Keywords: Dynamic depressuring utility, pure vapor, liquid level
References: None |
Problem Statement: How do I tell HYSYS to use the steam tables property package (NBS or ASME) when I have other components besides water in my case? | Solution: The heat exchanger operation allows the shell and tube sides to be solved using 2 different property packages. To tell the shell side to use NBS (or ASME), you must create two Fluid Packages and a sub-flowsheet and in the Basis Environment associate the subflowsheet to use the steam table property package.
Steps to create such a case from scratch:
In the Basis Environment, create a Fluid package for your Main Case. We'll assume Peng Robinson and the HYSYS default name Basis-1. Add your components.
Create a Fluid Package using NBS or ASME and add water as the component. We'll call this Basis-2.
Go to the Simulation Environment and add a Flowsheet to your case. Choose the Start with Blank Flowsheet option. Close the window.
Go back to the Basis Environment and on the Simulation Basis Manager Window, Fluid Packages tab, use the drop down menu and associate Flow-1(your subflowsheet) to use Basis-2.
Go back to the simulation environment and add a heat exchanger to your case.
On the Design Connections page, use the dropdown menu under Shell side Flowsheet and choose Flow-1. Close the window.
Go into the subflowsheet (double click on it) and press the Enter SubFlowsheet button.
Create your steam streams in the subflowsheet. One for the Shell feed stream, one for the shell product stream. You only have to specify the composition of one stream. Set the conditions (T and P) if you know them.
Go back to the Main environment (press the arrow icon at the top of the window to exit to Main).
On the design connections page, use the drop down menu's to choose the shell in and shell out streams.
Keywords: subflowsheet, heat exchanger, steam tables, ASME, NBS, components, two fluid packages
References: None |
Problem Statement: How does Aspen HYSYS depressuring perform with respect to the experiment and the BLOWDOWN simulator? | Solution: The Aspen HYSYS Depressuring Utility predictions are validated against experimental data reported in the literature for three experiments originally intended to test the capabilities of the BLOWDOWN? simulator [1]. The experiments were carried out in an order that reflects an increasing degree of difficulty: the first and simplest one simulates a gas phase, pure component case; the second one a three component case with extremely small amount of liquid condensing during the experiment; the third one is the most challenging, since it is in supercritical conditions at initial time and large amounts of liquid undergo condensation.
After recent improvements (the Dense Phase Tuning factor) only available in version V7.2 and on or in version V7.3 (the Venkatarathnam-Oellrich method), it becomes clear that the depressuring utility in Aspen HYSYS successfully predicts the experimental results.
The detailed discussion is in the attached folder ?Depressuring Validation? with test cases that reproduce the experimental setups. This document also emphasizes the need of small recycle efficiencies in the simulation of blowdown vessels and gives suggestions on how to assess the simulation results when very small liquid accumulations result.
Keywords: HYSYS Dynamics, depressuring utility, recycle efficiency, dense phase tuning factor, phase identification
References: s
[1] Haque, M.A., Richardson, S.M., Saville, G., Chamberlain, G., and Shirvill, L., Blowdown of Pressure Vessels, II. Experimental Validation of Computer Model and Case Studies, Trans I. Chem. E., Vol. 70, Part B, February 1992, pp. 10-17 |
Problem Statement: What are the definitions of the pressure types for the Aspen HYSYS Dynamics PSV valve? | Solution: Set pressure is when valve starts to open. The inlet static pressure rises above the set pressure of the safety valve, the disc will begin to lift its seat. let say the set pressure is 10 bars. If the inlet pressure is higher than 10 bars then the valve starts to open.
Full open pressure is when the valve is fully opened. The allowable overpressure depends on the standards being followed and the particular application. For compressible fluid, this is normally between 3% and 10%, and for liquids between 10% and 25%. It could be Full Open Pressure = (100+x)*Set pressure.
Closing pressure is when the valve starts to close. Once normal operating conditions have been restored, the valve is required to close again. The closing pressure is slightly lower than set pressure. For example, 9.8 bars if set pressure is 10 bars.
Reseating pressure is when the valve is fully closed. It is usually specified as a percentage of the set pressure as well. For compressible fluids, the blowdown is usually less than 10%, and for liquids, it can be up to 20%.
Figure 1. Relationship between pressure and lift for a typical safety valve (from spiraxsarco.com)
Keywords: Set pressure, Full open pressure, Reseating pressure, closing pressure
References: None |
Problem Statement: What is new for the Component Splitter in Aspen HYSYS? | Solution: The new Component Splitter is still based on the material balance on each component, but the theory has been extended to handle the two split types Fraction in Products and Flow in Products. In addition splits can be specified on bottom stream as well and splits for overhead can be calculated.
Theory:
The Component Splitter satisfies the material balance of each component:
Where = molar flow of the ith component in the feed
= molar flow of the ith component in the overhead
= molar flow of the ith component in the bottom
Depending on the split type, the molar flows going to the overheads and bottom are calculated as
? FeedFrac to Products
Where xi =?FeedFrac to Products?, fraction of component i going to each overhead
? Fraction in Products
Where
= Fraction in Products, fraction of the ith component in each overhead,
= Fraction in Products, fraction of component in bottom,
= molar flow of the overhead
= molar flow of the bottom
Flow in Products
ai = Flow in Products, molar flow of the ith component in each overhead
bi = Flow in Products molar flow of the ith component in the bottom
Keywords: Component Splitter
References: None |
Problem Statement: How do I get around the problem of products not being at equilibrium conditions? | Solution: The use of tray efficiency is the main reason for products not being at equilibrium. If the draw tray is set to 100% efficiency, its products will be in equilibrium with each other.
In columns with large number of of trays (~10 or more actual trays), this approach will not affect the accuracy of the model, since a drop in the efficiency in the rest of the trays can account for the increased efficiency of the draw trays.
In cases where the number of trays in the column are significantly low (less than 5 actual trays), setting the draw trays to 100% efficiency will have a greater impact on the column results compared to reality which might not be accepted in some situations. In these cases, we need to rely on more detailed modeling technique that mimics what happens in reality such as accounting for internals (mist eliminators) to prevent liquid carryover. This can be modeled with a separator in HYSYS.
Keywords: columns, towers, efficiencies
References: None |
Problem Statement: How are the compressor (and expander) Isentropic and Polytropic exponents calculated? | Solution: The Isentropic Exponent (k), and Polytropic Exponent (n) are calculated by the Hysys compressor as follows:
k = log (Pout / Pin) / log (density-out ideal / density in)
n = log (Pout / Pin) / log (density-out actual / density in)
Where in and out signify the inlet and outlet streams, and P is the stream pressure. The ideal outlet density is that obtained if the compression is performed isentropically.
Note that in general these are not equal to Gamma the ratio of specific heats. (Cp/Cv)
The Polytropic efficiency and head are then derived from these numbers.
For more details see Section 5.1.1, page 5-6 of the Steady State Modeling paper manual (same section in Hysys 2.2 pdf manual).
The calculation of these figures is illustrated in the attached file:
Keywords: Compressor, Expander, Isentropic exponent, Polytropic exponent, n, k, Gamma, Cp/Cv
References: None |
Problem Statement: In Aspen Hsysy V7.2 and V7.3 Installation guide, only Multiflash V3.8 is supported. But the latest version of Multiflash is currently V4.0. Is the latest version V4.0 is applicable to HYSYS V7.2 and V7.3? | Solution: The Hysys Multiflash interface automatically takes are of the Multiflash version, provided that Multiflash install creates the correct registry key. The key we are looking for are:
HKCU\Software\Infochem\Multiflash\COMTHERMO
Or
HKLM\Software\Infochem\Multiflash\COMTHERMO
Starting with version 4.0 the key is automatically created if the Hysys Upstream support is checked in the custom installation option. Note that the user MUST select this option during installation of Multiflash 4.0.
In addition, you need to make sure that the customer has one of the following upstream licenses:
SLM_RN_PML_HYSYSUPSTRM or SLM_RN_PML_HYSUPSTRM_R3
The old upstream license: SLM_HYSYS_Upstream does NOT work any more in V7.2
Keywords: Multiflash Version, Hysys upstream, installation key
References: None |
Problem Statement: How can I achieve a ''PFD1 to PFD2 cross PFD feeder connector? If I want to use a product stream of an existing PFD as the feeder stream of a new PFD, and the two PFDs are linked through this ''across PFD stream''? | Solution: You can add a new PFD first.
Do not clone from the existing PFD.
Then delete any stream you want to link from the existing PFD, and re-add it again.
You will see the newly created PFD will contain this stream as well. And this stream is synchronized among all the PFDs.
Now you can start adding the downstream operations of this 'feeder stream in the new PFD.
Keywords: Stream feeder, across PFDs, synchronizing PFDs
References: None |
Problem Statement: How is Mass Flow converted into the Std. Gas Flow [STD_m3/h] variable reported in the ‘Properties’ page of any stream in Aspen HYSYS? | Solution: The Std. Gas Flow is calculated from the specified or calculated mass flow, according to the Ideal Gas law at standard conditions (1 atm, 15 deg. C):
IdealDens = p0 Mw / (R T0)
where,
p0 – pressure at standard conditions (Pa)
Mw – gas molecular weight (kg/kmol)
R – ideal gas constant (8.314 J/mol/K)
T0 – temperature at standard conditions (K)
For a particular standard pressure and temperature, the mass density is only a function of the molecular weight. You can create a user variable to display this property for each stream or you can use the spreadsheet block in HYSYS to perform this calculation. In the file attached, a user property ‘IdealDens’ was defined in the Properties environment, where F2= p0 / (R T0)=1/23.644 kmol/m3 (based on previous standard conditions). This is used in all streams of the flowsheet.
Keywords: Mass Flow, Std. Gas Flow, Standard conditions, Density, Ideal
References: None |
Problem Statement: Pressure assignment in a mixer is either ‘Equalize all’ or ‘Set Outlet to Lowest Inlet’. Thus, the pressure of the mixed stream is either the lowest of all inlets, or all streams have the same pressure. The user may wish to mix a lower pressure stream to others at higher pressure, and have the outlet pressure equal to the highest value. | Solution: Instead of using a Mixer, the user should use the Balance operation of ‘Component mole and heat flow’ and assign the desired pressure value to all streams connected.
Keywords: Balance, Mixer, Pressure
References: None |
Problem Statement: Why the component specification in the column changes after modification of the component list? | Solution: When a component specification is added in the column, the component is taken from the array index in the component list. The column specification then uses this index. If the component list is re-ordered or a component is deleted from the list or a new component added in the list then the component in the original index will be replaced with a different component. This may result in a different component being used in the column component specification. The column may not converge with incorrect specification or give unreasonable results.
It is recommended to check the column specifications following any modification in the component list to make sure that the specifications have links to the correct components.
Keywords: Column Modelling, Component Specification.
References: None |
Problem Statement: How do I restrict what values the user can enter into a User Variable? | Solution: For example, how do I prevent negative lengths?
The VariableChanging procedure allows the programmer to check what value the user is entering and if necessary to reject it using the AllowThisChange property.
The following example illustrates the use of this procedure.
Sub VariableChanging()
If ActiveVariableWrapper.NewRealValue <= 0 Then
'NewRealValue is always in HYSYS internal units (C, kPa, m, Flow/s etc...)
AllowThisChange = False
MsgBox Diameter must be positive,,Error Checking
End If
End Sub
Keywords: User Variable, NewRealValue, VariableChanging, AllowThisChange
References: None |
Problem Statement: Can I use DIPA with the Amine Package in HYSYS 3.0.1? | Solution: Yes, as with previous versions, DIPA is a supported component in the Amines package. With HYSYS 3.0.1, you need to be careful about how you select this component. Simply typing DIPA in the match cell will lead you to select DIPropylAmine, which is not a supported component. Typing DIsoPAmine instead will select the right component.
Keywords: DIPA Amine
References: None |
Problem Statement: Why is the Energy Analysis button greyed out in Aspen HYSYS? | Solution: Starting from V8.0, Aspen HYSYS users are able to see activated Energy Analysis button showing above the PFD flowsheet, which facilitates the data extraction from HYSYS to Aspen Energy Analyzer.
However, sometimes this button is greyed out. When this happens, please check the following on the Navigation Pane:
1. HYSYS simulation is fully converged: no unsolved streams and unit operations are in the flowsheet.
2. Remove unsolved Stream Analysis.
3. Remove unsolved Equipment Design utilities.
Keywords: integration, interface, unavailable
References: None |
Problem Statement: How is the K factor in the Pipe Segment calculated in Aspen HYSYS v2.4.1 and above? | Solution: In versions of Aspen HYSYS older than version 2.4.1 (recently released version), the pressure drop through the fitting was calculated as delP = 1/2*rho**K*V^2. The K factor was also referred to as the Velocity Head factor. The values for the K factor used in the database for HYSYS version before 2.4.1 were based on a table in Perry's Chemical Engineer's handbook. Exact editions of the handbook are unknown for values originally referenced, but below are the references for the 5th and 7th editions:
Perry's Chemical Engineers Handbook; 7th Ed., Table 6-4 Additional Frictional Loss for Turbulent Flow Through Fittings and Valves.
Perry's Chemical Engineers Handbook; 5th Ed., Table 5-19
Changes have been made to the pipe segment for version 2.4.1 which brings the fittings database in line with the method used in the Crane reference. Located below is an excerpt from an email from one of our developers explaining the changes. Also, the new fittings database contains the references for each fitting, most of which now derive from the Crane reference.
Fittings Pressure Loss Method
The standard fittings pressure loss method has been extended to allow the option of an additional term. The equation used is
K = A + B * fT
Where
A
= constant, also known as VH (velocity head) factor
B
= constant, also known as FT factor
fT
= the fully turbulent friction factor
Note that in Aspen HYSYS, the fittings will have a non-zero value for either A (VH Factor) OR B (FT Factor) but not both. For example, if you select a 90 degree bend (4 ID) in a Pipe Segment, Aspen HYSYS gives a FT Factor of 14 for it (based on Crane page A-29) and a VH Factor of zero. Using the equation for K above:
K = B * fT = 14fT
And thus K is equal to the Crane K Factor for the 90 degree bend.
The fittings pressure loss constant K is then used to obtain the pressure drop across the fitting from the equation..
delta P= K (rho * v^2)/2
Where
deltaP
= pressure drop, Pa
rho
= density, kg / m3
v
= velocity, m/s
Calculation of the fully turbulent friction factor fT needed in the method requires knowledge of the relative roughness of the fitting. This is calculated from user entered values for roughness and fitting diameter. The pipe segment's standard friction factor equation (Churchill) is then called repeatedly with the calculated relative roughness at increasing Reynolds numbers until the limiting value of friction factor is found.
Keywords: K factor, Pipe Segment
References: None |
Problem Statement: What does the Take Partial Steps option do in the recycle logical operation? | Solution: The option of Take Partial Steps will pass/update information as it is available. Not using the Take Partial Steps should only pass information / update the recycle once the full feed stream is solved.
If this option is used on the recycle it will solve every time even if the the attached feed stream is not fully solved.
Keywords: Take Partial Steps, Recycle
References: None |
Problem Statement: Does the HYSYS.INI file stop HYSYS from looking for other keys if it finds that the licenses are taken up on that keyserver? | Solution: Not necessarily. HYSYS will search within sub-nets. If there are two keys of the correct family code in the sub-net, HYSYS will contact the one with the IP address in the HYSYS.INI first, but it will still look for another key it if finds this first key's licenses are in use. If it finds one within the sub-net then HYSYS will open up. If there are no other keys, you'll get the error message No more users are allowed on this Network security key...
Keywords: HYSYS.ini, keyserver, licenses, pre-SLM
References: None |
Problem Statement: Can I set Tee splits via Automation? | Solution: Yes, the attached VBA code example will set the split fraction for the first outlet stream of a Tee called 'TEE-100' on the main flowsheet of the currently open case. The code is set up to be run from VBA (e.g. in Excel) but also includes the line necessary to link to the active case in the HYSYS Macro Language Editor.
Sub Main()
'Description: Simple example of linking to a Tee and setting split fractions
'In Excel VBA Requires HYSYS type library to be set under Tools ...
Keywords: None
References: s
'Declare Variables |
Problem Statement: Why are some objects in my PFD shown in gray, even though the flowsheet appears to be solved? | Solution: The objects have been selected for sizing (right click on PFD icon and choose Select For Sizing) This relates to an old HYSYS feature that has been superseded by the integration of Aspen Economic Analyzer.
Selecting an object for sizing will not affect the simulation results in any way, however it does limit the effectiveness of the PFD color scheme. To disable this feature, select the affected objects on the PFD and right click. Choose Remove Selection For Sizing.
Keywords: Grey, PFD, Objects, Unit Op, Stream, Sizing
References: None |
Problem Statement: How do I use the TBP Cut Point page of the Component Splitter? | Solution: The modification is to allow the user to specify compositions of the product streams by giving the TBP Cut Point between the streams, assuming sharp separation at the cut point.
So, what should the user specify and how should it work?
Should be able to specify the initial TBP Cut Point on Feed (ICP) for each product except the overhead. Values should be in ascending order and are temperatures. Consecutive streams can have the same ICP value, implying the second or subsequent stream has zero flow.
Pure components distribute according to their NBP. Let's illustrate by example. Suppose we have three products with TBP Cut points defined as:
overhead (-273.15)
middle 25 C
heavy 60 C
Any pure component with an NBP <= 25 C goes to overhead.
Any pure component with an NBP >
25 C
& <=
60
C goes to middle
Any pure component with an NBP >
60 C
goes
to
heavy
Split fractions are hence always 1 or 0.
Hypo components are treated as a continuum and distribute according to their final boiling point. To calculate these, sort the hypos into ascending NBP order. With the sorted order then:
for last hypo, FBPlast = NBPlast + (NBPlast - NBPlast-1) else
FBPi = (NBPi + NBPi+1)/2
Hypos then distribute according to where the cut point lies. Each hypo is regarded as having a boiling range defined by the final boiling point of the previous component to the final boiling point of the current component. Each product stream also has a boiling range - from its initial TBP cut point to the initial TBP cut point of the next stream. Assuming we start from absolute zero, let the stream cut range be denoted by TBPi to TBPf. Hence, working up in temperatures:
for component i
if FBPi <= TBPf then
split of i to current prod = 1
else if ( FBPi > TBPf && TBPi < FBPi-1) // cut point falls within a hypo
split = (TBPf - FBPi-1) / (FBPi - FBPi-1)
else // entire cut lies within a hypo
split = (TBPf - TBPi) / (FBPi - TBPi)
once all of a component has been allocated, it obviously can be allocated to the next stream.
The only other wrinkle is what is the initial boiling point of the first hypo? (ie assuming zero-based, FBP-1). If there are no lighter boiling pure components, take absolute zero (-273.15). Otherwise take the maximum of the nearest lighter pure and (FBP0-(FBP1-FBP0)).
The feature should work on any stream, although its intended for streams with hypos.
Keywords: component splitter, hypos, TBP
References: None |
Problem Statement: How may I count streams and operations in a HYSYS case? | Solution: The attached MS Excel sheet calculates the number of objects in the HYSYS active case. It prints the results in a text file with the same name as the case (with the extension .txt), and breaks the counted objects down by object type. It also prints the date and time in the file as well as the case name and path.
Keywords: HYSYS, streams, operations, count, excel
References: None |
Problem Statement: How do I get HYSYS and STX (ACX) linked or how do I export HYSYS data to STX (ACX) and vice versa? | Solution: If you are installing HYSYS and/or STX for the first time on your desktop then it is best to register the STXHYSYS.dll file within HYSYS in order to get the two programs linked. This is assuming that both HYSYS and STX were installed successfully, an STX key is on the desktop (or a STX network license available) and a HYSYS key (and license file for HYSYS 2.3 and higher) is on the desktop (HYSYS network license is available).
Steps:
Start up HYSYS.
Go to the Tools menu and choose Preferences
Go to the Extensions tab. You'll want to register the file called STXHYSYS.dll
Press the button Register an Extension.
A window will pop up asking you for a file. Surf on your computer for the STXHYSYS.dll file. The default directory will be something like C:\HTC\STX 3.5.
Once located, click on this file and press OK.
You should receive a message stating the Registration has been successful. If you also receive a warning that no .edf file was found then follow the 6 steps below.
If you have recently upgraded your version of STX and/or HYSYS, the easiest way to re-establish the link between STX and HYSYS (or ACX) is to open up STX standalone and import a HYSYS exchanger. These steps are assuming that both HYSYS and STX were installed successfully, an STX key is on the desktop (or a STX network license available) and a HYSYS key and license file if required is on the desktop (or a HYSYS network license is available). License files are required for HYSYS 2.3 and higher.
Upon linking the program you should be able to open HYSYS and choose the STX Rating solver on the Design Parameters page of your heat exchanger. The View Design button will show you the calculation details in STX.
Steps:
Start up STX. HYSYS does not need to be opened.
Go to the Edit menu and Choose import HYSYS exchanger.
A window will pop up asking for a HYSYS case. Surf through and find a HYSYS case with an exchanger in it. A good case is the sample HYSYS case G-2. The default directory for the samples is C:\Program Files\AEA Technology\HYSYS\Samples. If you are running HYSYS 2.3 the default directory will be C:\Program Files\Hyprotech\HYSYS\Samples.
A window will come up with a list of the exchangers in the case. Choose one and ensure that the process data is there. The link has been automatically re-established with this step.
Close STX, no need to save the case.
To test that the link works: open HYSYS, open your case with the exchangers using theSolution method STX Rating. On the Design Parameters tab press the button View Design. HYSYS should open STX in the background with your process data in the exchanger.
Keywords: install, STX, HYSYS, ACX, link, edf, dll, register, extension, export, exchanger, rating
References: None |
Problem Statement: If I include the outer Heat Transfer Coefficient, why is the calculated overall Heat Transfer Coefficient smaller than if I exclude the outer Heat Transfer Coefficient? | Solution: The reason you are seeing such a big difference in the overall Heat Transfer Coefficient when you do not check the Include outer HTC checkbox is because HYSYS has no knowledge about the outer Heat Transfer Coefficient, so a fixed internal default value for the outer Heat Transfer Coefficient is used that has nothing to do with specified outer conditions. In this case this value is much larger than the value that is calculated when the Include outer HTC checkbox is active.
The total heat transfer coefficient is calculated as the reciprocal of the total resistance.
The total resistance is defined as: Rtot = Rfilm + Rsurr + Rinsul
The total HTC is calculated by: combinedU0 = 1 / (Rtot diameter 1000)
When the Include outer HTC checkbox is deactivated, Rsurr is given a default value of 0. So the total Heat Transfer Coefficient is relatively large. This situation is equivalent to the case when the Include outer HTC checkbox is activated and the air velocity is set to a large number, say 1.0e+8. On the other hand, when the Include outer HTC checkbox is active and the air velocity is zero, then a fixed value of 1.0e+38 is given to Rsurr causing the total HTC to be very small.
Keywords: Pipe Segment, HTC, outer HTC, Heat Transfer Coefficient
References: None |
Problem Statement: Head loss under downcomer is too large란 애러메시지는 무엇을 뜻하는가? | Solution: 이 메시지는 downcomer head loss값이 너무 크다는 뜻이다. 결과값은 Tray Sizing Utility를 실행한 후, Performance | Trayed | Trayed Results | Downcomer 에서 DC Head Loss에서 볼 수 있다. Head Loss계산에 영향을 주는 주요 요소로는 Downcomer Clearance이다. 이 메시지를 제거하려면, Design | Tray Internals | Downcomer Clearance(기본값 1.500)을 메시지가 없어질때까지 줄이면 된다.
Please find theSolution 124197 for the original English version.
Keywords: head, loss, downcomer, warning, error, tray, sizing, utility, KR-
References: None |
Problem Statement: How to model Hydrotreater bed in Aspen HYSYS Petroleum Refining | Solution: The Hydrocracker within RefSYS can be used to model either a hydrocracker or a hydrotreater. From a modeling standpoint, the only difference between the two is that the cracking and ring-opening rates for a hydrotreater are much lower than they are for a hydrocracker. Typically, a hydrocracker will have a few hydrotreating beds which are primarily for removing sulfur and nitrogen along with some saturation and a few cracking beds which will mainly be for saturation, ring-opening, ring dealkylation and paraffin cracking. The cracking beds can also remove sulfur and nitrogen, but typically most of that will have already been removed.
The point is the same reactions happen in both hydrotreating and hydrocracking, just at different rates, so it is straightforward to use the hydrocracker in RefSYS to model a hydrotreater. As a matter of fact, the Aspen Plus Hydrotreater uses the exact same flowsheet as the Aspen Plus Hydrocracker, it just has the kinetics tuned to a different point. The exact same thing can be done with the RefSYS hydrocracker. In addition, RefSYS also has a unit operation called HBED which can be used to model either a single hydrotreater or a hydrocracker bed.
Note:Sample templates are located in the Template folder under the Aspen HYSYS installation root directory (C:\Program Files (x86)\AspenTech\Aspen HYSYS V7.3\Template)
Keywords: Hydrotreater
References: None |
Problem Statement: In a dynamic model I have a spreadsheet that changes the composition of a feed stream, but the composition keeps flipping between the old and new values. What is happening? | Solution: Every feed stream has a Feeder Block, which is a holder for composition and conditions of the stream. This is used to make sure the stream composition and conditions are recovered after a case of flow reversal, where the stream acts as a product stream and gets its conditions and composition from the downstream operation.
In the case of changing the stream composition from a spreadsheet, Aspen HYSYS flips the composition back to the one in the feeder block the next time step. So the best way to do this is to export the values to the feeder block rather than to the stream itself. (Feeder blocks can be accessed from the Dynamics Tab of a feed stream, and can be exported to a spreadsheet cell).
The enclosed case (S109024.hsc) illustrates thisSolution.
Keywords: Spreadsheet, Feeder Block
References: None |
Problem Statement: What is a 'Forget' Pass? | Solution: HYSYS unit operations can calculate product variables based on feed variables, feed variables based on product variables, or a combination of the two. This can lead to very complicated interdependency between the variables in a flowsheet. When a variable is changed, HYSYS must first forget all of the variables that were calculated based on the original value, and then re-calculate based on the new value. If the values are not forgotten, an attempt to calculate a new value will be misinterpreted by HYSYS as an inconsistency.
To illustrate this, assume that the temperature of the inlet stream to a unit operation is changed from 40C to 41C. The following sequence occurs: The stream will forget its temperature, as well as any variables it calculated based on temperature (e.g. vapour fraction, density); The unit operation will get an Execute pass, with IsForgetting = True. If the unit operation asks its inlet stream for any of the forgotten variables, it will receive <empty> (which can be an E_FAIL error, or the value -32767); The unit operation will be unable to calculate any of the variables it had calculated based on the inlet stream's forgotten variables. HYSYS will cause these variables to be forgotten as well. Their owners (e.g. the unit operation's outlet stream) will then receive a similar Execute. When the Forget pass has propagated through the flowsheet, the inlet stream will recalculate using the new temperature value. An Execute pass - with IsForgetting = False - will propagate through the flowsheet.
Keywords: Calculate Passes, Forget, IsForgetting, Execute
References: None |
Problem Statement: What does the error message 7 mean? No Dongle. Make sure that the hard lock is attached to the parallel port or that the hardlock server is up and running. Check the connection and select retry to continue.. How do I get rid of it? | Solution: If you are trying to open a HYSYS case that contains heat exchangers that have been rated or designed by STX, HYSYS will try to set up the STX-HYSYS link. You need both the HYSYS and the STX keys. The STX key is not being found and this is the reason why you get the error message. If you want to work with the case with the STX data still in it, you need the STX key. If you want to work with the case and don't care if the data is from STX or not, you can open the case by pressing ABORT. Then, go into the exchanger that is on STX rating and change theSolution method to End Point or Weighted. Save the case. At this point, you will need to shut down HYSYS and open it back up again. Otherwise, STX will continue to look for the key and continue to present the error message.
Keywords: error message, stx, no dongle, stx rating, stx-hysys link
References: None |
Problem Statement: Can MASSBAL solve backwards? Do all feed streams in MASSBAL have to be specified? | Solution: Solving Backwards:
One of the constraints of MASSBAL using VLE streams is that ALL source streams have to be specified. This means all source streams in the MASSBAL flowsheet have to be fully specified (Phase Rule has to be satisfied for each stream) as well. Specifications can be (judiciously) made elsewhere in the flowsheet.
Keywords: MASSBAL, specified feed, degrees of freedom
References: None |
Problem Statement: How are the K factors in the fittings.db file used? | Solution: The fittings K factor is not proportional to flow i.e. there is no account taken of friction - for fittings it is usually acceptable to have a zero length.
However, future plans include a fitting database where the k factor term would take into account the flow of the fluid, and this is being addressed by a new Hydraulics add on module to HYSYS - where detailed fluid flow options are available in SS and dynamics.
Some additional points:
As mentioned previously the Hysys fixed K factor is only valid to model fittings in which friction is not the main mechanism for the pressure loss. Thus the calculation is not very good for fittings such as bends. For some valves / restrictions in which acceleration/deceleration is the major contributor to the friction loss calculations then the approach used by HYSYS is correct.
To use HYSYS and take into account friction (e.g. for large pipe diameters, concrete pipe) then you will have to overwrite the K values with the derived value from Crane (in the fittings.db database). It is true that since the K factor is a function of Ft then it must also be a function of diameter. e.g.. You would calculate the fully turbulent friction factor for the pipe material and pipe size then calculate from K = 30 * Ft or whatever the constant is.
Keywords: K factor
fittings
pipe
Hydraulics
References: None |
Problem Statement: What is XML? | Solution: XML is the official acronym for the Extensible Markup Language. XML is a language that uses contextual tags to describe data so that other applications and tools can correctly read the data and do interesting things with it. Now, XML is more than just a markup language, as it has become synonymous with a family of technologies that can be leveraged to build highly extensible and interoperable softwareSolutions.
A significant R&D effort has gone into the development of an XML technology infrastructure in HYSYS 3.0. An XML Data Schema has been defined so that every object and piece of data in HYSYS can be represented in an XML format. Many new tools have also been developed to take advantage of this novel data format and are evident in several of the new capabilities in HYSYS 3.0.
The HYSYS XML reader that takes the place of the old Print...Specsheet...Flowsheet is the most obvious use of the XML technology. This is a new tool that allows the user to view and printout the case data in a highly readable format. You can choose to view all the case data including the Basis information or just the user specifications.
Other capabilities are also made possible through the use of XML technologies. For Instance, a HYSYS case can now be stored as an XML file giving an alternative to the traditional binary .hsc file. XML is the means of data transfer used by the new Case Linking and Collaboration capabilities. Finally, the Custom Stream Properties uses XML to store the user defined sets of properties that they wish to have displayed.
Keywords: XML
References: None |
Problem Statement: Can HYSYS calculate exergy? | Solution: HYSYS does not include exergy flow in its default calculations. However, you can use the flexible customization capability of HYSYS to incorporate exergy calculations into your flowsheet.
What HYSYS provides are the values of enthalpy and entropy at the specified states for pure substances or mixtures. Since the calculation of exergy requires the specified reference state for each substance or mixture involved, it is up to you to define those crucial reference states for your system, find the corresponding values of enthalpy and entropy at those states, and then calculate exergy values based on its definition.
Properties like exergy lend themselves to being user variables.
Attached is a user variable (exergy.huv) which can act as proof of concept.
To calculate the exergy for each stream, the user var creates a duplicate fluid, and flashes it at the reference T & P. Then it uses: Exergy = (H - Href) - Tref(S - Sref)
Of course this isn't entirely correct, but if you have a more accurate way to calculate exergy, feel free to edit the user var.
To add this user variable to your case, save the attached .huv file to your hard drive. Then, from within HYSYS, select: Simulation | Import and Export User Variables
Press the Select button to browse for the file, and press OK once you have found it. Select the variable in the User Variables list and Press the Import button. The Exergy User Variable should be added to all streams in your case by default. It can be viewed by opening the stream property view and looking on the User Variables tab.
Note that you will have to force a recalculation of the flowsheet (all of the exergy values in the streams will be <empty> until you do this).
IMPORTANT NOTE: THIS EXAMPLE IS PROVIDED PURELY AS A PROOF OF CONCEPT. TO IMPLEMENT AN EXERGY CALCULATION FOR YOUR SYSTEM, THIS EXAMPLE WOULD PROPERLY BE USED SOLELY AS A STARTING POINT.
Sub PostExecute()
On Error GoTo EarlyGrave
Tref = 25.0
Pref = 101.325
Set refFluid = ActiveObject.DuplicateFluid
isOK = refFluid.TPFlash(Tref, Pref)
If Not isOK = fsFlashOK GoTo EarlyGrave
H = ActiveObject.MassEnthalpyValue
H0 = refFluid.MassEnthalpyValue
S = ActiveObject.MassEntropyValue
S0 = refFluid.MassEntropyValue
m = ActiveObject.MassFlowValue
Exergy = (H- H0) - (Tref + 273.15) * (S - S0)
ActiveVariableWrapper.Variable.Value = m * Exergy
Exit Sub
EarlyGrave:
ActiveVariableWrapper.Variable.Erase
End Sub
Keywords: exergy analysis, availability, user variable
References: None |
Problem Statement: How to use Shell & Tube Exchanger Design/Rating Utilities to get results from Aspen Shell & Tube Exchanger in Aspen HYSYS? | Solution: 1. Go to: Tools | Utilities | Shell & Tube Exchanger Design/Rating Utilities
2. Select the Heat Exchanger available on the simulation
3. Click in EDR Results.
Keywords: EDR, Shell & Tube Exchanger, Aspen Hysys, results
References: None |
Problem Statement: If I feed a 3 phase stream to a 2 phase separator, which liquid does the liquid product stream represent ? What about in Dynamics? | Solution: In steady state HYSYS will mix the two liquid phases back together and send them off the vessel through the liquid product stream.
In dynamics, HYSYS always separates the phases and add each phase to its corresponding holdup. Then it will decide which phase is the heavy liquid, and calculates the interface levels. These interface levels together with the liquid product nozzle location and diameter decides the composition of the product stream.
Keywords: Separator, 3 phase, 2 phase
References: None |
Problem Statement: How does the compressor extrapolating in negative zone: of performance curves calculated and take care of surge control valve? | Solution: Extrapolating in negative flow zone:
1. Aspen HYSYS does NOT apply any special methods based on the head values in negative zone, we apply either linear or quadratic extrapolating standards available based on user selection and this option is also applicable in negative head zones
2. Aspen HYSYS performs a quadratic fit on a set of numbers passed to it and extrapolate a Y value given an x. Equation form ---> y = A*x^2 + B*x + C
3. When multiple curves at different speeds are provided (for example three curves for 9000 RPM, 11000 RPM and 13000 RPM), and given 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, Head For 9000; 11000 RPM, Head For 11000; and 13000 RPM, Head For 13000),
4. 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.
5. 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.
6. It is not recommended to let the flow go very far into negative zone as it may not give you accurate compressor performance predictions after it fails to extrapolate properly.
However, sometimes it is needed to study the surge control valve size limitation. If you are doing such modeling, make sure to review following.
7. The specified inertia and friction loss parameters set for this machine are accurate data.
8. Knowing that Aspen HYSYS limitation in extrapolating in negative head zone, try to avoid going in that region by properly sizing the anti surge Valve (ASV). So that even at low speed, you get positive flow from the compressor.
9. The negative flow at positive speed will be from extrapolating of the compressor curves after the trip. This can be seen by the fact that, after the trip, the operating point is way off to the left of the compressor curves in what would be the surge flow region.
10. The situation is also complicated by the fact that the Use Surge Curve option (on the Rating\Flow Limits page of the compressor) introduces flow instabilities into the simulation in an attempt to mimic surge behavior when the flow is below the surge limit.
11. However, these disturbances usually result in problems getting the Pressure-Flow solver to converge and we would recommend deactivating this option. Deactivating this will not really affect the simulation because the anti surge controller works from its own Surge, control and backup lines (in terms of the A and B parameters).
12. Given that the problems arise from the fact the compressor is moving into surge flow, concentrate on the anti-surge valve (ASV).
a. If the ASV valve is not big enough (this can be seen because the compressor still enters surge even without an anti-surge controller if the ASV is fully opened manually before tripping the compressor).
b. Even with a larger valve, the anti-surge controller (ASC) is not taking appropriate action, particularly at low speed. This is perhaps not surprising given that the Surge line in the anti-surge controller is fitted against the operating speed conditions. You can also observe that the ASC surge line does not fit the true surge line very well. Therefore you need to fit a new ASC Surge line (A and B parameters) to the surge data (extrapolated to zero flow) to better handle the low speed conditions we encounter during the trip.
c. The friction loss and inertia settings could also be too small resulting in the speed not falling quickly enough.
d. Also try to disabled the Surge line in the compressor itself for the reasons mentioned above.
Finally make above changes, so that the case runs without any problems and does not show the negative flows at positive speed.
Keywords: Dynamic, compressor, curve, stonewall, surge, performance, extrapolation, negative
References: None |
Problem Statement: Why does the Aspen HYSYS Pipe Segment unit operation fail to solve when pressure is specified at outlet and temperature is specified at inlet? | Solution: The Aspen HYSYS pipe segment is designed to only handle situations where the boundary conditions are specified on the same side of the pipe. It was not designed to perform a calculation where the pressure is specified at the outlet and the energy (temperature) is specified at the inlet.
In simple cases (no or minimal heat transfer), then the pipe can often solve with these types of conditions. However, in a case like this, where there is a lot of heat transfer and the pipe is long, then the pipe will likely have difficulty solving. In a case where the boundary conditions are specified as proposed, then the Aspen Hydraulics subflowsheet should be used. The Aspen Hydraulics solver is designed to handle these types of boundary conditions (pressure at the outlet, temp and mass flow at the inlet.)
If you want the Aspen HYSYS pipe segment to solve with the outlet pressure specified, then the temperature specification should also be moved to the outlet.
Keywords: pipe segment,
References: None |
Problem Statement: What are the Shell Baffle Types Hysys uses for Rating of Heat Exchangers | Solution: Shell Baffle type can be set on the Rating tab ... Sizing page ... Shell radio button of the Heat Exchanger property window.
Single, Double and Triple
These are the standard segmented baffle types as illustrated in the TEMA standards (8th Ed, p 31) or Perry (7th Ed, p 11-42)
Grid
These could equally be called rod type baffles. They consist of alternating horizontal and vertical sets of parallel rods (See attached file). These allow axial flow, and are mainly intended to support the tubes. They provide some heat transfer enhancement effect due to the turbulence generated.
Keywords: Exchanger, Shell Baffle Types, Single, Double, Triple, Grid
References: None |
Problem Statement: Can I size a three-phase separator in HYSYS? | Solution: The Vessel Sizing utility does not currently support three-phase separator sizing. While in HYSYS Version 2.4.1 and up you can select a three-phase separator as the object for the Vessel Sizing utility, the calculations will be based only on the Vapour and Light Liquid flows, and will not take the Heavy Liquid (aqueous) phase into account. Therefore while the utility will provide results, these results are based only on the Vapour and Light Liquid phases and do not correctly represent the sizing of a three-phase separator.
Keywords: size, three-phase separator
References: None |
Problem Statement: What is the difference between the GCEOS PR package and the standard PR package? | Solution: GCEOS model is used to define and implement your own generalized cubic equation of state including mixing rules and volume translation. When you select PR option from within the GCEOS it reduces to the PR EOS. This is the Standard PR, not HYSYS PR. The main difference between standard PR and HYSYS PR is the alpha function used (HYSYS PR uses a modified alpha function when acentric factor is greater than 0.49). It is recommended to use Hysys PR or PRSV property package, rather than using GCEOS and modifying this to PR. HYSYS PR is more advanced and continuously improved over the years e.g. binary coefficients.
Keywords: GCEOS, HYSYS PR, Standard PR
References: None |
Problem Statement: How can I simulate a heterogeneous catalytic reaction in a PFR? | Solution: A heterogeneous catalytic reaction can be simulated in a PFR. The following document oulines some of the steps as well as some of the terms used in this operation.
Keywords: PFR, Catalytic, Void Fraction
References: None |
Problem Statement: What is Weep Velocity? | Solution: On a tray if the gas rate is too low, much of the liquid may rain down through the openings of the tray (weeping), thus failing to obtain the benefit of complete flow over the tray. The gas velocity at which the weeping starts to occur is defined as weep velocity.
Keywords:
References: None |
Problem Statement: How to model a Decanter in Aspen HYSYS? | Solution: Decanters are used to separate liquids where there is a sufficient difference in density between the liquids for the droplets to settle readily. Decanters are essentially tanks which give sufficient residence time for the droplets of the dispersed phase to rise (or settle) to the interface between the phases and coalesce. In an operating decanter there will be three distinct zones or bands: clear heavy liquid; separating dispersed liquid (the dispersion zone); and clear light liquid.
An example is illustrated in the C-3.hsc case file in the HYSYS Samples folder (C:\Program Files (x86)\AspenTech\Aspen HYSYS V8.0\Samples) .
The example file C-3.hsc uses two different fluid packages, VLE-Basis and LLE-Basis. The Fluid package VLE-Basis has NRTL-Ideal as property method and Water, Ethanol and Benzene as components. This basis uses the default binary interaction parameters and are good for predicting LLE. Thus if you flash a stream using this basis, it reports two liquid phases when encountered.
Where as the LLE-Basis Fluid Package uses the same property method and components, but the binary coefficients are estimated using UNIFAC-LLE method (based on the group contribution methods). This basis is only used with the sub-flowsheet 'DECANT', where you have a decanter to predict more accurate separation between the two liquid phases. Entire simulation, except the Sub-flowsheet, uses the VLE-Basis.
Keywords: Decanter
References: None |
Problem Statement: How do I input my assay data from ASTM D2892 to Aspen HYSYS? | Solution: There is no direct way to input your ASTM D2892 to Aspen HYSYS. The recommendation for these kind of assays is to input them as TBP.
TBP distillations are performed in columns with 15 to 100 theoretical plates at relatively high reflux ratios (i.e., 5 or greater). The high degree of fractionation in these distillations gives accurate component distributions for mixtures.
ASTM D2892 is Standard Test Method for Distillation of Crude Petroleum (15-Theoretical Plate Column) so you can use the 'TBP' option in Hysys to characterize your crude.
Keywords: D2892, TBP
References: None |
Problem Statement: If I change a property in my hypothetical group (MW, NBP, density) will the changes also be made on the component list? | Solution: Yes, the changes will also be made on the component list.
You just have to go Simulation Basis Manager > Hypotheticals > View the Hypothetical Group then change the properties you want and then if you don?t know the rest of them don?t forget to click on Estimate Unknown Properties.
You will also be able to see these changes in the Simulation Basis Manger> Components> Hypothetical, and then double click on the desired group and the properties should be the same as the ones you changed.
For more information about adding hypotheticals, please refer toSolution 109353.
Keywords: Hypothetical Properties, component list
References: None |
Problem Statement: 怎样将两个PFD通过一个Feeder连接起来？比如，用户要将第一个PFD的产品物流链接到第二个PFD作为其进料，从而两个PFD通过这条物流连接到一起。 | Solution: 你需要先加入一个新的PFD。
不要从已有的PFD克隆。
然后从已有的那个PFD上删除掉你要连接的那条物流，然后再将这条物流加回去。
你会在新的PFD里面看到这条物流。这条物流和之前PDF里的删除又加回的物流是同步实时链接的。
现在你可以在新的PFD里面以这条物流作为进料进行下游的所有操作的模型建立与模拟。
Keywords: Chinese-
References: None |
Problem Statement: Is the Cp/Cv in stream properties view the Rigorous Cp/Cv in Relief Valve? Similarly, the Cp/(Cp-R)in the properties view is Semi-Ideal Cp/Cv in Relief Valve | Solution: Yes, Rigorous Cp/Cv in RV corresponds to Cp/Cv in the stream. Semi-Ideal Cp/Cv means Cp/(Cp-R) in stream.
Relief Valve View:
Stream Properties View:
Keywords: Cp/Cv, Relief Valve, rating
References: None |
Problem Statement: How to assign the split ratio for Aspen HYSYS Tee in C# | Solution: Aspen HYSYS automation objects may be different between Visual basics and C#. Sometime you could not find the exact objects as VB. For example, you may find there is not TeeOp.Splits.Variables in C# as in VB.
In the case, you may use backdoor variables.
Here is example how to use backdoor variables and specify the tee split ratio:
HYSYS.Operations hyOps;
HYSYS.TeeOp hyTee;
hyOps = hyFlwsht.get_Operations(TeeOp);
int aNumb = hyOps.get_index(TEE-100);
hyTee = (HYSYS.TeeOp)hyOps[aNumb];
HYSYS.BackDoor hybd;
hybd = (HYSYS.BackDoor) hyTee;
HYSYS.InternalRealVariable oRatio = (HYSYS.InternalRealVariable) hybd.get_BackDoorVariable(:Ratio.500.0).Variable;
if (oRatio.CanModify == true)
{
oRatio.Erase();
oRatio.SetValue(0.3,);
}
Keywords:
References: None |
Problem Statement: What Hotkeys / Keyboard Shortcuts are available in HYSYS? | Solution: File
<Ctrl> + N : Create New case
<Ctrl> + O : Open Case
<Ctrl> + S : Save Case
<Ctrl> + <Shift> + S : Save Case
<Ctrl> + Z : Close Current Case
<Alt> + <F4> : Exit HYSYS
Simulation
<Ctrl> + B : Go to Basis Manager
<Ctrl> + L : Leave Current Environment (Return to Previous)
<Ctrl> + M : Main Properties
<F5> : Access Optimiser
<F7> : Toggle Steady Sate / Dyn Modes
<F8> : Toggle Solver Active / Solver Holding
<Ctrl> + I : Open Integrator Properties Window
<F9> : Start / Stop Integrator
<Ctrl> + <Break> : Stop Calculations
Flowsheet
<F11> : Add Material Stream
<F12> : Add Operation
<F3> : Access Object Navigator
<F4> : Show / Hide Object Palette
<Ctrl> + K : Access current stream composition view when in workbook
Tools
<Ctrl> + W : Access Workbook
<Ctrl> + P : Access PFDs
<Ctrl> + U : Access Utilities
<Ctrl> + R : Access Reports
<Ctrl> + D : Access Databook
<Ctrl> + F : Access Controller Faceplates
<Ctrl> + Y : Access Dynamics Assistant
<F1> : Access Help
Column
<Ctrl> + T : Access Column runner when in Col Sub Flowsheet environment <Ctrl> + <Break> : Stop Column Solver
Window
<Ctrl> + <F4> : Close Active Window
<Shift> + <F4> : Tile Windows
<Ctrl> + <Tab> or <Ctrl> + <F6> : Switch the view to the next open window in the current workspace
<Ctrl> + <Shift> + <Tab> or <Ctrl> + <Shift> + <F6> : Switch the view to the previous open window in the current workspace
Editing / General
<F2> : Access Edit Bar
<F10> or <Alt> : Access Pull Down menus (Then use highlighted letter to choose a menu item)
<Ctrl> + <Shift> + N : Go to next page tab
<Ctrl> + <Shift> + P : Go to previous page tab
<Ctrl> + X : Cut
<Ctrl> + C : Copy
<Ctrl> + V : Paste
Change PFD extents:
<Page Up> : Zoom in small amount
<Page Down> : Zoom out small amount
<Shift> + Page Up : Zoom in large amount
<Shift> + Page Down: Zoom out large amount
<Home> : Zoom to show entire PFD area if nothing selected, or just selected items Z : Show previous PFD area
C (or '.') : Centre on mouse cursor
Arrow key : Move PFD area small amount
<Shift> + Arrow key : Move PFD area large amount
Adjust selected item(s) on PFD:
S : Select first object; select next object (in PFD's internal order of all visible objects) <Shift> + S : Select previous object
D : De-select all selected objects
Arrow key : Move item(s) small amount, if no collision occurs <Shift> + Arrow key : Move item(s) large amount, if no collision occurs <Delete>: Delete associated 'engineering' object(s)
<Home> : Zoom PFD to show selected object(s)
V or E : Open property view of object
1, 2, 3 : Rotate each item clockwise 90, 180, 270 degrees
X, Y : Mirror each item about its x or y axis
L : Select labels; de-select objects
N : Return item(s) to 'normal' orientation
Change PFD Material stream Label variable:
<Shift> + N : toggle between stream names and last variable shown <Shift> + T : Temperature
<Shift> + P : Pressure
<Shift> + M : Mass Flow
<Shift> + F : Molar Flow
<Shift> + O: display stream elevations
Miscellaneous PFD:
<Ctrl> : Enter 'Attach' mode from Move/Size mode
<Esc> : Abandon Swap Connections' or 'straighten' or 'manual route' mode <Delete> (while in 'manual route' mode) : Delete 'manual route' F : Enter Swap Connections' mode
Keywords: Hotkeys, Keyboard Shortcuts
References: None |
Problem Statement: Can I access the Cold Properties Utility via Automation? | Solution: Yes, the attached Excel spreadsheet includes code to access all the results from a specified cold properties utility or to link to the cold properties utility linked to a specified stream. It also includes similar functionality to the example inSolution #112356 which adds a critical properties utility to all streams in the case and reports results from them.
The spreadsheet includes 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: Cold Property, RVP, TVP, RON
References: None |
Problem Statement: If the heat of combustion is missing for a library component in Aspen HYSYS, can I supply a new value that will be used throughout the associated simulation? | Solution: Aspen HYSYS does not provide the heat of combustion for all library components. For some, such as H2S, the heat of combustion is 'Empty'. As a result, certain stream properties that are based on the heat of combustion (i.e. Higher Heating Value) will display a value of 'Empty' in the Workbook. To eliminate this problem, a user defined value can be added to the pure component directly without the need for creating a hypo component or using a spread sheet to manually do the calculations.
To do this:
- Enter the Basis Environment, and view the component list.
- From the Component List view, double click on the component that is missing the Heat of Combustion (this will open the property view).
- On 'Point' tab, press 'Edit Property' button
- On 'Editing Properties for component?' screen, select 'Heat of Combustion' from the list to display the property value on the right side of the screen
- Edit the property and enter the desired value. The 'Reset selected property for all users of this component' button will be highlighted. Press this button.
- You will be prompted with the message 'This will clear any local change for selected property for all users of component *** - Continue?'
- Select 'Yes' to use the new value in all stream property calculations.
Please note that this procedure does not work in HYSYS version 3.2 if a component property value is 'Empty'. It does, however, work for all versions from Aspen HYSYS 2004 and up.
Keywords: Heat of Combustion
References: None |
Problem Statement: How do I reveal hidden objects in the PFD? | Solution: You can reveal hidden objects in two ways.
1) Open the PFD menu and select Show Hidden Objects.
2) Right-click on the PFD background and select Reveal Hidden Objects.
In either case, the Show Hidden Objects view will appear and you can select which Hidden Objects you want revealed. The view contains a Filter so make sure the appropriate radio button is selected for the object you are searching. Select the object of interest in the list on the left and click the OK button.
Keywords: hide, object inspect
References: None |
Problem Statement: What criteria does Aspen HYSYS use to term a liquid phase as an aqueous phase? | Solution: Aspen HYSYS uses the following criteria to term a liquid phase as an aqueous phase (dissolved in water):
If the mole fraction of water is either more than 0.5 or more than the combined mole fractions of all the hydrocarbon components in a liquid phase, then Aspen HYSYS terms that liquid phase as an aqueous phase.
Note 1: Prior to V7.1, however there was a flaw that the presence of other non-hydrocarbon compounds were not considered (CO2, NH3, alcohols, amines, etc.). In V7.1 we made a change that will affect the phase for stream.
For example if a stream has 90% (mole) of TEG and rest water, it used to be identified as aqueous phase prior to V7.1. But when you add a new stream in V7.1 and later, then the stream with 90% TEG will be identified as liquid phase.
Note 2: If you have an old case file created in version prior to V7.1, the stream phase will not be updated until it reflashes (Temperature may be changed to reflash the stream). So stream with 90% TEG will be identified as aqueous phase stream in V7.1 and later as well. The phase will be updated for new stream or for stream where some values updates so that flash calculation is triggered to be solved again.
Keywords: aqueous, liquid
References: None |
Problem Statement: How compressor curve is calculated for various speed when user specify Head \ efficiency in only one speed? | Solution: As a compressor or expander slows down or speeds up, its head versus its discharge characteristics change. When only a single curve is specified and the specified compressor speed is different from the single user-defined curve speed, the calculations of the head and efficiency based on the characteristics curve are different from V7.1 and V7.2.
In V7.1 and early versions, the head and efficiency are calculated just using the single available curve even if the speed is different from the current compressor speed. The interpolation using Spline method for flow value within the curve flow range and least square fit for extrapolation.
From V7.2 and later versions, HYSYS internally creates a new characteristic curve on the fly, based on the Fan curves, to predict the head and efficiency at the specified speed. The speed of the FanLawCurve is set to be the current speed and the curve points are converted from the original active curve based on the Fan Law.
The efficiency curve is converted as this:
Qi = Q0 Ni/N0
Effi = Eff0
Where
Q0 is the base curve's flow rate
Qi is the new fan law curve's flow rate
Eff0 is the base curve's Efficiency
Effi is the new fan law curve's Efficiency
N0 is the base curve's speed
Ni is the new speed for the fan law curve
Based on this, the efficiency curve will be shifted by a factor of Ni/N0 in the Horizontal-Axis. That is the difference seen in the plot above.
Please note that this internally generated Fan Law curve is not shown on the user interface.
Keywords: Fan Law, compressor curve
References: None |
Problem Statement: Why can't I Disable a user variable? | Solution: I want to disable a user variable on a particular stream / operation, but the enable checkbox is greyed...
This means the user variable has been set to be automatically enabled on all streams or operations. In order to turn this off go to the Attributes tab on the User Variable editing window of the User Variable. (If no tabs are visible, click the downward pointing green arrow at the top right hand corner of the window) Now change the Activation radio button to User Enable. This will allow you to manually enable / disable user variables.
Keywords: User Variables, User Enabled, Activation
References: None |
Problem Statement: Does Aspen HYSYS calculate the specific gravity relative to air for a stream? | Solution: To display the specific gravity of a stream, one can use the session preferences to change the units of the mass density to SG_H2O60api or SG_H2O60nbs. Note, however, that both available units use the density of water measured at 60F as the reference state.
In order to determine the specific gravity relative to air, one must create a PFD table for the desired process stream as described below:
1. Right-click on the stream icon on the PFD and select Show Table
2. Right click on the newly created table and select View Properties
3. Click the Add Variables button
4. Find Specific Gravity rel Air in the list and press OK
Note that the variable Specific Gravity rel Air is the specific gravity of an ideal gas phase relative to air (i.e MW / Mair, where MW = gas molecular weight and Mair = 28.96443 g/mole). As a consequence, this variable does not change with stream conditions.
If you need to determine if the gas is heavier or lighter than air at stream conditions, then you will need to use the Aspen HYSYS spreadsheet, as described below:
1. Import the Mass Density of the gas stream at the desired temperature and pressure
2. Create a second stream with the same process conditions but set the composition as air
3. Import the Mass Density of this air stream into the spreadsheet then divide the two density values to obtain the density relative to air
Keywords: specific, gravity, air, gas
References: None |
Problem Statement: When having a file (Aspen Plus or Aspen HYSYS) in which the user has set up many relief valves under the Safety Analysis environment, it can sometimes take a long time for the file to open. The lengthy reload time is because all calculations are being re-run upon entry into the safety environment. | Solution: To prevent this issue try to save the file from the simulation environment, instead of the safety environment, so then the recalculation on load would be bypassed, which would significantly improve the load time. However, please notice that it will still recalculate upon entering the safety environment.
Keywords: Time on loading, safety analysis, relief valves.
References: None |
Problem Statement: In HYSYS, if you use the Heat Exchanger | Design | Parameters | Heat Exchanger Model | Exchanger Design (End Point), what equations are used to find the heat transfer correction factor? | Solution: See the attached document which contains the equations used to calculate the Ft factor. The equations in the document are from the book, Process Heat Transfer, G.F. Hewitt, G.L. Shires, and T.R. Bott, 1994, CRC Press, Boca Raton FL.
Keywords: Ft
References: None |
Problem Statement: When running a heat exchanger in Aspen HYSYS, does the Exchanger Design (Weighted) model include the Ft correction factor? | Solution: While the Exchanger Design (End Point) model calculates an overall Ft correction factor, the Exchanger Design (Weighted) model splits the heat exchanger into zones of equal enthalpy (i.e. dP/dH, dP/dA, etc.). The UA is then calculated for each zone and the overall UA corresponds to the UA sums for each of the individual zones. Since the problem is solved in terms of zones, the Ft correction factor is not incorporated in the algorithm. As a consequence, the weighted model is independent of the geometry of the exchanger (i.e. it doesn't account for configuration, number of tube passes, etc.).
Keywords: Ft, correction, factor, end point, weighted, HEX, heat, exchanger
References: None |
Problem Statement: Aspen Engineering Product installation will not continue after displaying the initial page or two. Error 1327, Invalid H:\ drive is given as the reason. | Solution: To properly complete installation, the user account should have administrative privileges and the user should be able to access the file system and registry without any restriction. Please verify that there is no protection program or network policy preventing the creation or usage of temporary folders. If so, this policy should be disabled and the user account modified before continuing with the installation.
Keywords: invalid H:\ drive, error 1327, 1327, error
References: None |
Problem Statement: What is component mapping and why is it used? | Solution: Component mapping is used at the interface of two different property packages. The maps tell HYSYS how to transfer the compositions from one property package to another. Composition values for individual components from one fluid package can be mapped to a different component in an alternate fluid package.
Two previously defined fluid packages are required to perform a component mapping which is defined as a collection. One fluid package becomes the target component set and the other becomes the source component set. Mapping is performed using a matrix of source and target components. Mapping can be performed on a mole, mass or liquid volume basis.
For more information on mapping, please refer to Section 6.2 of the Simulation Basis Guide.
Keywords: Component, mapping, stream cutter, property package
References: None |
Problem Statement: How doI add the stream compositions in the Summary Grid inside HYSYS so I can Export to excel. | Solution: You can copy and paste the Composition from material streams to the Summary Grid but you might need to do the copy and paste Twice in order to work.
Follow this procedure:
1. First from the Ribbon / Home tab / Summaries select the Model Summary.
2. Once you open the summary grid you will see your process stream with this default information.
3. To transfer the information you need to open any stream, select the Composition, right click on them, select Copy.
4. Click paste on the summary Grid Icon. .
5. If you see this warning:
“Can’t find variables on the clipboard�
Then repeat the copy and paste and the error will go away.
Once you do that I will recognize the composition and you won’t have more problems with transfer this information.
Keywords: Summary, grid, copy, paste, composition.
References: None |
Problem Statement: Unable to locate Aspen HYSYS Amines and Aspen HYSYS Crude on any of AspenOne 2006 DVDs. | Solution: Aspen HYSYS and all engineering related products can be found on the aspenOne 2006 DVD #6. Since Aspen HYSYS Amines and Aspen HYSYS Crude are layered products, installing Aspen HYSYS will automatically load the Aspen HYSYS Amines and Aspen HYSYS Crude modules. These options can then be activated at run time based on the available licenses.
Keywords: HYSYS Amines, HYSYS Crude, Amines, Crude
References: None |
Problem Statement: How to Calculate Volumetric flow rate along pipeline? | Solution: To get overall volumetric flow rate along pipe, please follow the steps below.
Step1: Select performance tab in pipe segment view window as attached screen shot (Figure 1)
Step 2: Click on view profile in right hand corner of the window. The profile along the pipe length appears as Figure 2. Here, you will be able to see Elevation, pressure, heat transferred, liquid superficial velocity , vapor superficial velocity along the pipe length.
Step3: As there is no volumetric flow shown in profile- you have to manually calculate total volumetric flow using either Excel or the spreadsheet in Aspen HYSYS. First, based on inner pipe diameter- you have to calculate pipe x-sectional area.
Step 4: Then get individual (liquid/vapor) volumetric flow rate by multiplying area with corresponding superficial velocity. You can import superficial velocity by copying velocity data from view profile window and paste it to spreadsheet.
Step 5: Add liquid and vapor volume flow rate to get total volume flow rate.
Please find the enclosed Word document with the screen shot and the created Aspen HYSYS file (version 3.2).
Keywords: Pipe Segment, Volumetric Flow Rate
References: None |
Problem Statement: How to change from molar fraction to mass flow in the composition tab of the workbook. | Solution: 1. Open your workbook and select the compositions tab, after that right click and select Setup:
A
2. When the next window appears, please click delete all the variables since we will need to add those variables in mass flow. Then click in Add and select the variable Master Component Mass Flow and select AllA then click OK:
at the end it will look like the following:
Keywords: Workbook, compositions tab, setup
References: None |
Problem Statement: Can I specify aromatic wt% for my oil when I only have ASTM D86 data for the assay? | Solution: A simple answer to this question is NO. You can add aromatics information in the Aspen HYSYS Oil Manager only if you have chromatographic data. Other assay types, such as ASTM D86 and ASTM D1160 do not have separate analyses for paraffinic, naphthenic and aromatic compounds, according to API procedures.
However, you can consider a work-around if you have both ASTM D86 data and the weight percentage of aromatics. What you can do is to use the Aspen HYSYS Oil Manager to input your ASTM D86 data and use the Hypothetical Manager to create a single hypo component to represent the collection of the aromatic compounds, assuming that you can come up with some reasonable estimates for its basic properties, such as Normal Boiling Point, and Ideal Liquid density, etc. Then mix your oil stream generated by Oil Manager with a stream containing only the aromatic hypo you created in the Simulation Environment. By specifying the mass flow rates for these two streams, you will be able to have the mixture stream with a wt% for aromatics which matches your data.
Please validate your results while using this work-around for a simulation and make sure that the ASTM D86 data you have was measured with the aromatic contents already being taken out.
Keywords: D86, wt%, mass fraction, weight percent, aromatics, D86, aromatic contents
References: None |
Problem Statement: Can I export database properties from Aspen HYSYS without opening Aspen Exchange Design Rating (EDR)? | Solution: Yes, it is possible to export database properties from Aspen HYSYS without opening Aspen Exchange Design Rating (EDR)? By using this approach, users can avoid consuming additional licenses by having for Aspen HYSYS and EDR both open at the same time. In order to accomplish this task, follow these steps:
1. Open HYSYS and use the Aspen Properties within HYSYS functionality to export the database properties.
2. Close HYSYS and then open EDR to import the database properties.
For more information on the Aspen HYSYS Export feature, please see KB 132493.
Keywords: Aspen Database Properties, Export/Import, HYSYS, EDR, License error, and Aspen Engineering
References: None |
Problem Statement: How do I print a large PFD in several sections so it is still legible? | Solution: There is no a direct way in Aspen HYSYS to print in sections, but there is a workaround. Please go to PFD tab and click in Add PDF. Click in clone the existing one and then in each of the cloned PFD you can hide as many objects as you want and then print it. For example, if this is the main simulation:
Then you clone it. After that you need to hide the object you don't want to see. To do that, you just have to select them and right click, choose Hide. You have to adjust the size of the objects, you may make them look bigger with zoom. Then you can print that PFD and the objects will look bigger.
In this moment, you will be able to print the sections you may need, and they will be pretty legible.
There are other methods of doing this, printing the entire PFD on a large size paper, or exporting to other software and print it from there. For more information please refer to the nextSolution 121496
Keywords: print, PFD, simulation legible
References: None |
Problem Statement: Multiple effect evaporators are separation processes widely used in chemical industries. The objective of evaporation is to concentrate a | Solution: consisting of non-volatile solute and a volatile solvent (usually water). Evaporation is conducted by vaporizing a portion of the solvent to produce a concentratedSolution. In a multiple effect system, connections are made so that vapor from one effect serves as the heating medium for the next, resulting in energy savings. There is no such an evaporation effect operation in Hysys. Moreover, evaporators are commonly used to concentrate inorganicSolutions as NaOH, NaCl and etc.
Solution
An evaporator effect can be modelled in Hysys using a heat exchanger and a separator. InorganicSolutions can be modelled using the OLI fluid package, where the boiling point rise effect is rigorously calculated. The flowsheeting capabilities of Hysys allow the simulation of the entire evaporation system. In the sample case, it can be found a 2 effect evaporator that concentrates an aqeousSolution containing NaOH and NaCl. Using the Adjust logic operation and a spreadsheet, it is possible to calculate the required amount of steam to concentrate theSolution until a specified percentage of solids in the product stream is obtained.
Keywords: Evaporation, electrolytes, multiple effect.
References: None |
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