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Problem Statement: What are preliminary typical values for PID Tuning parameters (Kc, Ti, and Td) in HYSYS Dynamics? | Solution: The suggested preliminary values for Kc, Ti, Td are listed in the table below. These values might be used as a starting point to tune the PID.
Key Words
PID
Tuning parameters
Preliminary typical values
Keywords: None
References: None |
Problem Statement: How can the Convergence Monitor help? | Solution: The Convergence Monitor helps diagnose issues in convergence and solver performance. Users can use the Convergence Monitor tab of the Flowsheet Summary form to monitor convergence of your HYSYS simulation. Users can access this tool by clicking the View Convergence shortcut button in the lower left corner of the HYSYS frame.
It includes a Convergence Plot, where you can view how variables change over successive iterations for the selected Recycles and Adjusts to help you assess flowsheet convergence.
Keywords: Convergence Monitor, Flowsheet summary
References: None |
Problem Statement: How does negative additive concentrations impact the objective function or profit in MBO? | Solution: In MBO, the total additive variable is multiplied in the objective function times the cost of the additive. This total additive variable is required to be greater than or equal to zero. This variable cannot go negative, therefore there can be no “profit” from using negative additive concentrations.
The additive concentration is allowed to go negative, but if it does, the total additive is bound to zero. That’s why there could be no positive effect in the objective function from negative concentration of additive.
Keywords: None
References: None |
Problem Statement: How to troubleshoot error Failed to validate the | Solution: ID in PrSolutinoID table. Please run the model again and generate the report.
Solution
If by following the next steps you observe the error Failed to validate theSolutionID in PrSolutinoID table. Please run the model again and generate the report.
Open Volume Sample Model, turn AO on and run 2 cases the results will be as follow:
This issue might be caused by a conflict between MSMPI and Cisco AnyConnect VPN client. The issue seems to be related to a DNS suffix issue, and could be resolved by following the steps below:
To upgrade to MSMPI v10:
https://www.microsoft.com/en-us/download/details.aspx?id=57467
1. Stop PIMS
2. Download the MSMPISETUP.exe from the link above
3. Run MSMPISETUP.exe and click yes to upgrade and then follow the instructions
4. After the installation is complete, go to Services(you can use the windows search bar near the Start menu to look for it) and restart the MsMpiLaunchSvc in the services.
We also recommend checking on the following KB Article that has additional suggestions to troubleshoot this issue:
https://esupport.aspentech.com/S_Article?id=000070114
Keywords: None
References: None |
Problem Statement: How do I fix this error message “ CALCULATED PSD DOES NOT FIT INTO THE DEFINED MESH” ? | Solution: The following error occurs in any solid operation, often one where a distribution function is used to specify the outlet PSD, such as Granulator:
** ERROR WHILE EXECUTING UNIT OPERATIONS BLOCK: <id> (MODEL: <name>)
(DISPRP.13)
CALCULATED PSD DOES NOT FIT INTO THE DEFINED MESH.
THE PSD FRACTIONS DO NOT SUM UP TO UNITY (0).
Root cause for the message is too few intervals in the particle size distribution (PSD) mesh (Simulation Environment/ Setup/Solids/PSD Mesh). This can occur because there are particles of sizes outside the range of the PSD mesh, or because the mesh is too coarse to accurately represent the distribution.
First, check that there are not particles finer or coarser than the limits of the PSD for the outlet stream of the block with the error. If necessary, extend the mesh to include those sizes.
If that is not the issue, try adding more intervals within the same size range. When a normal distribution function is used, the PSD intervals near D50 should be smaller than the standard deviation of the distribution.
Keywords: Screen, crystallizer, agglomerator
References: None |
Problem Statement: What does this control panel message “SUBSTREAMS ARE AT DIFFERENT TEMPERATURES.
THERMODYNAMIC EQUILIBRIUM WILL BE ASSUMED FOR FURTHER CALCULATIONS” mean? | Solution: It is possible to specify in the Stream input a different temperature for the Solid substreams (CI Solid and NC Solid) than for the Mixed substream. However, not all blocks can handle this difference. Pressure must be the same for all substreams present in a stream.
If the block cannot handle the difference in temperature, there will be a message similar to the following:
Block: <id> Model: <solid unit operation name>
INFORMATION
SUBSTREAMS ARE AT DIFFERENT TEMPERATURES.
THERMODYNAMIC EQUILIBRIUM WILL BE ASSUMED FOR FURTHER CALCULATIONS.
INLET STREAMS WILL BE PQ-FLASHED.
The above control panel message may occur for CFFilter, CFuge, Classifier, Crusher, Cyclone, ESP, FabFl, Filter, FluidBed, Granulator, HyCyc, Pipe, Pipeline, Screen, or VScrub. Most of the new solids features added in V8.0 or later do not support inlet streams where the substreams are at different temperatures.
No action is required, but be aware that when this message appears, the inlet temperature of the stream is recalculated before the stream enters the unit operation. The calculation is the equivalent of inserting a Heater block before the solid model with specified pressure drop 0 and duty 0.
Keywords: Sub-streams, solids troubleshooting
References: None |
Problem Statement: How can I know which licenses are being used by the simulation case? | Solution: You can review the licenses that are being used by the simulation in File | About | Licensing Information. This window will show the name of the licenses that are being currently used, their expiration date and their location.
Keywords: Licenses, used, licensing, tokens
References: None |
Problem Statement: I can’t find the Aspen Plus calculator toolbar in 64-bit Excel | Solution: In Aspen Plus V10 and earlier versions, 64-bit Office is not supported. You need to install 32-bit Excel on your machine, then the add-ins (including the calculator toolbar) will be available.
Aspen Plus V11 is now a 64-bit program. Therefore, both 64-bit Office and 32-bit Office are supported.
For more details about the platform support and computer infrastructure information to use of AspenTech software, please check this link on our support website:
https://www.aspentech.com/platform-support
Key Words
32-bit
64-bit
Excel add-in
Calculator toolbar
Keywords: None
References: None |
Problem Statement: After ACCE running complete, you may face typesetting issue on .ccp item report shown as below, item report row/column are not aligned as linear line but twist, then how to recover it back to normal alignment shown. | Solution: ACCE item report is a mono faced/typeset report. You can change the Ff back to Courier New/Regular/8.
Then .ccp item report will recover to normal typesetting as below shown.
Keywords: ACCE, .ccp item report, Typesetting
References: None |
Problem Statement: Best practices and guidelines for setting IO Flags for User Defined Entries in DMC3Builder.
Starting at V10, specific IO Flags (IsConstant and IsPublished) have been changed. The main change is that the AWRITE configuration does not longer need IsConstant IOFlag as TRUE. Keeping the old configuration (V9 and before) will result in the following error on Web interface:
The entry bound to parameter 'X' is a constant and is not allowed to be changed | Solution: Engineers can add user defined entries to a DMC3 controller. These entries can be used to augment the interaction between the controller and DCS, and they can be used as input or output or scratch pad variables for User Calculations.
All entries, including user-defined entries, have a set of properties that govern how the APC Web Viewer and the DMC3 Controller present and interact with those entries. One of these properties is IO Flags, which is explained in detail in this KB article.
**Note: The IO Flags for all built-in parameters (measurement, setpoint, limits, etc.) are automatically set by the engine and cannot be changed by the user.
About the IO Flags
The IO Flags control whether the entry value is read from or written to an IO Tag mapped to that entry. Each entry in an DMC3 controller has some combination of IO Flags set, or possibly no IO Flags set.
The IO Flags also control whether value change operator messages are displayed when the entry value changes. Additionally, they also control whether the changes to the entry value are historized in the online application history of the controller.
How reads happen in an DMC3 controller
Any entry mapped to an IO Tag will be read at the start of the cycle if and only if that entry has the IsInput IO Flag set to TRUE.
How writes happen in an DMC3 controller
In almost all cases an entry mapped to an IO Tag will be written to the DCS if and only if its value changes – unless it has the IsReadOnly IO Flag set.
It is possible to force an unchanged value to write every cycle, but only if the IsPublished IO Flag is marked TRUE (see IsConstant and IsPublish in the next section).
The IO Flags and their meaning
IsConnectedDCSRead
This flag is automatically set or reset at runtime. A value of TRUE for this flag indicates that the entry is connected to an IO Source tag for reading.
IsConnectedDCSWrite
This flag is automatically set or reset at runtime. A value of TRUE for this flag indicates that the entry is connected to an IO Source tag for writing.
IsConnectedHistory
This flag is automatically set or reset at runtime. A value of TRUE for this flag indicates that the entry is connected to a local history store and will be historized by the RTE environment.
IsConstant
If TRUE, the entry is not changeable by reading an IO tag. It does not mean that the value of the user-defined variable cannot be changed by a calculation. A user-defined variable with IsConstant set as true can be changed by the engine.
IsHistorized
If set to TRUE, the entry will be connected to a local history store at runtime.
IsInput
If TRUE, the entry value is refreshed from an IO tag (if one is configured) at runtime.
IsConstant and IsInput cannot both be true.
IsIoTagRequired
When set to TRUE, the application configuration software may require an IO tag be configured for this entry. DMC3 Builder automatically adds the user-defined variable to the Configure Connections page.
IsOperatingValue
If TRUE, the runtime entry value will be preserved when the application is redeployed i.e. any change to the value of the user-defined variable that is made offline would be disregarded when redeployed. IsTuningValue and IsOperating cannot both be true.
IsPublish
When set to TRUE, the entry value will be written to the IO Source (if there is an IO tag configured) at runtime, regardless if the value is changed or not.
IsReadOnly
If TRUE, the entry value is not changed by the application at runtime. Can only be true if IsInput is true.
IsReadWrite
If TRUE, the entry value may be changed by the application at runtime. Note: IsReadWrite is not used by this version of the software.
IsTuningValue
If TRUE, the entry will be replaced when the application is redeployed i.e. any change to the value of the user-defined variable that is made offline would replace the value in the online controller when the application is redeployed. IsTuningValue and IsOperating cannot both be true.
LogChange
This parameter is not user changeable. If TRUE, a message will be logged whenever the entry is changed by a user at runtime.
IsOperatingValue vs IsTuningValue
The distinction between IsTuningValue and IsOperatingValue is that on a redeployment of the application, an entry with IsOperatingValue will receive its initial value from the already deployed version of the application, overriding whatever entry value had been set in DMC3 Builder, whereas an entry with IsTuningValue will receive its initial value from the new version of the application being deployed, the value as set in DMC3 Builder.
Mapping of DMCplus CCF entry keywords and DMC3 IOFlag combinations
This section describes the minimum IO Flag settings to achieve the same effect as the various DMCplus CCF keywords. Not all keywords have a mapping (usually because they are handled some other way in DMC3 controllers).
You can set additional flags to achieve additional effects (such as logging changes or capturing a history of changes). Some IO Flags are mutually exclusive (see the description of the IO Flags in the previous section for examples).
Note: To ensure proper operation, each user-defined entry should have one of these flags set true: IsConstant, IsOperatingValue, or IsTuningValue.
**By default, all user-defined entries have the IsInput and IsTuningValue flags enabled. It is strongly recommended that users review the IO Flag settings for all user-defined variables before deploying the controller online.
The table below summarized the minimum required set of IO Flag settings in order to replicate the behavior of the most commonly used keywords from the traditional DMCplus environment. A full list of DMCplus keywords including additional details about each individual keyword can be found in the glossary that follows the table.
IsInput IsConstant IsReadOnly IsPublish IsTuningValue IsOperatingValue
WRITE F F
AWRITE F F T T
PWRITE F F
LWRITE F F
RDWRT T F
READ T T
LOCAL T
CONFIG T T T
CONS T T T
Glossary: DMCplus Keyword
AWRITE
Intent: Always write this value to a tag in the PCS (Process Control System).
Equivalent IO Flags: IsPublish, IsTuningValue
Note: any entry value without IsConstant and IsPublish set true, and mapped to an IO Tag, are only written when the value changes.
BUILD
Intent: Reserved keyword for Build-only entries
Equivalent IO Flags: not applicable
CALGET
Intent: Input Calculation (only allowed in the Calculation section)
Equivalent IO Flags: not applicable (the input user calculations take the place of CALGET entries)
CALPUT
Intent: Output Calculation (only allowed in the Calculation section)
Equivalent IO Flags: not applicable (the output user calculations take the place of CALPUT entries)
CONFIG
Intent: Configuration parameter set once at CCF load time
Equivalent IO Flags: IsConstant, IsPublish, IsTuningValue
CONS
Intent: Constant value, set once at load-time (not changeable)
Equivalent IO Flags: IsConstant, IsPublish, IsTuningValue
INIT
Intent: Initialize value associated with the PCS (Process Control System) tag at initialization time
Equivalent IO Flags: not applicable. INIT is ignored in DMCplus
LOCAL
Intent: Local value in DMCplus shared memory (changeable by View, Calculations and Transforms)
Equivalent IO Flags: Could be None; could be IsOperatingValue
LWRITE
Intent: Low priority write to a PCS (Process Control System) tag after all other writes are finished
Equivalent IO Flags: not applicable; DMC3 does not have multiple write lists.
PWRITE
Intent: High priority write to a PCS (Process Control System) tag before any other writes occur
Equivalent IO Flags: not applicable; DMC3 does not have multiple write lists.
RDWRT
Intent: Read and write from/to a PCS (Process Control System) tag (middle priority)
Equivalent IO Flags: At a minimum use IsInput so that reads happen.
READ
Intent: Read only from a PCS (Process Control System) tag (middle priority)
Equivalent IO Flags: IsInput and IsReadOnly.
WRITE
Intent: Write only to a PCS (Process Control System) tag (middle priority).
Equivalent IO Flags: Do not specify IsInput and IsReadOnly.
XFORM
Intent: Transform
Equivalent IO Flags: not applicable. Transforms are specified in the controller configuration, not via IO Flags.
Keywords: DMC3 Builder
User-defined parameters
IO Flags
Communications
References: None |
Problem Statement: In tube rupture scenario, where is the default value of flow coefficient (C) coming from? | Solution: For the flow coefficient (C), the default value used in HYSYS (0.74 when from tube to shell or 0.60 when from shell to tube) is as given in the paper:
Wong, Wing Y. PRV Sizing for Exchanger Tube Rupture. Hydrocarbon Processing (Feb. 1992), p. 59,
and the author's correction letter published on p. 44 in the May 1992 issue.
The author makes reference to the figures in Crane, but does not give any details on how he arrived at the specific recommended coefficients. The best explanation is that the author chose the C corresponding to the minimum diameter ratio for tube-into-shell, and the maximum diameter ratio for shell-into-tube, both for arbitrarily large Reynolds numbers. For a shell-into-tube break, a lower C value might be justified depending on the channel dimensions relative to the tube diameter.
Key Words
Tube rupture
PRV Sizing
Flow coefficient
Keywords: None
References: None |
Problem Statement: How accurate is the cost estimate given in EDR? Could I compare it with the quote from the vendor? | Solution: Yes, EDR’s cost section provides a simulation of a fabrication shop (welding, drilling, machining, grinding, milling, etc.). Fabrication shop efficiencies can be customized. The biggest unknown are material prices (based on customer’s location and material quantity purchased). EDR provides reasonable material costs that can be used to compare EDR runs using different materials. You can also customize it in the Costing Database under the Customize tab.
Key Words
Heat exchanger
Costing Database
Customize
Keywords: None
References: None |
Problem Statement: Are there the velocity slip correlations which are suitable for vertical downflow RPLUG reactors? | Solution: There is the method which is useful in the consideration of the slip. The Beggs and Brill method is a proper consideration. This can handle the slip and valid for vertical flow download. More details you can see in our Help menu (button F1), if you search for the next: Beggs and Brill Correlation.
Keywords: RPLUG, Beggs and Brill, vertical downflow, slip correlations, vertical flow.
References: None |
Problem Statement: What are the different types of compressors Aspen HYSYS can help model? | Solution: Aspen HYSYS allows users to model 4 types of compressors; Centrifugal, Reciprocating, Screw, and Wet Gas Compressor. Users can select the operating mode On the Design tab | Parameters page of the Compressor.
Centrifugal Compressor: This compressor is used to increase the pressure of an inlet gas stream with relative high capacities and low compression ratios. Depending on the information specified, the Centrifugal Compressor calculates either a stream property (pressure or temperature) or a compression efficiency.
Reciprocating Compressor: This compressor is used for applications where higher discharge pressures and lower flows are needed. It is known as a positive displacement type. Reciprocating Compressors have a constant volume and variable head characteristics, as compared to the Centrifugal Compressor that has a constant head and variable volume.
Screw Compressor: This compressor is also a positive displacement machine. The performance of the Screw Compressor can be calculated using either the Leakage flow or Performance curve method. Users can model oil injected or dry feed screw compressors. This compressor model was introduced in HYSYS V9.
Wet gas Compressor: This compressor can be used to ensure accurate design of the subsea process. This compressor model supports the presence of a liquid phase inside the centrifugal compressor by allowing you to specify the performance curves at various inlet gas mass or volume fractions. This compressor model was introduced in HYSYS V11.
Keywords: Centrifugal Compressors, ReciprocatingCompressors, Screw Compressors, Wet Gas Compressors,
References: None |
Problem Statement: Is it possible to add revision control to a library? | Solution: In the Class Library Editor, a revision can be set for a library. Only the current revision will be able to be modified.
The current revision can be closed at which point no further changes will be allowed to the library until either the revision is reopened or a new version is created.
To create, modify, reopen or close a revision:
1) Select the current library or an included library in the ‘Library’ view.
2) Right click on the library name and click on the ‘Properties’ option to launch the ‘Library Properties’ dialog.
3) Select the ‘Revision’ tab. Enter a name for the label and revision. By clicking on the ‘Close’ revision, the current revision will be locked and no changes will be allowed until the mentioned in the second paragraph above is done.
Keywords: Class Library Editor, Library, Revision, Control.
References: None |
Problem Statement: How to enable Marginal Cost calculation in Utilities Planner? | Solution: To enable Marginal cost calculation for fuel, steam etc, please go to
Optimization tab > Settings > Check the Marginal Cost Box
Then please go to each respective Header block and make sure “Include Marginal Cost” is set to True.
Key Words
Demand, Marginal Cost, Utilities
Keywords: None
References: None |
Problem Statement: In tube rupture scenario, why the pressure of the high pressure side is different from the pressure of the reference stream? | Solution: In HYSYS, the ambient pressure in the Safety Environment is maintained separately from the ambient pressure in the Simulation Environment.
To set the ambient pressure basis in the Simulation Environment, please refer to this Knowledge Base article:
How can I change the absolute atmospheric pressure basis in HYSYS?
https://esupport.aspentech.com/S_Article?id=000047545
However, if you want to do PSV sizing, you need to set the ambient pressure in the Safety Environment as well. If the ambient pressure setting in the Safety Environment is different from the ambient pressure in the Simulation Environment, then you may see a different gauge pressure of the high pressure side compared to the pressure of the reference stream. For example, in the screenshot below, the high pressure side is 1498 psiG. However, the reference stream shows 1500 psiG in the flowsheet. There is a 2 psi difference.
To set the ambient pressure in the Safety Environment, open the “Preference Manager” under the Home tab, then adjust the “Barometric Pressure” under the “General Setup” tab.
Key Words
Ambient pressure
Barometric pressure
Keywords: None
References: stream
PSV Sizing |
Problem Statement: Can I merge cells after a field has been placed in a cell? | Solution: When creating or modifying a datasheet in the ABE Datasheet Definer, do not merge cells after a field has been placed in a cell.
Instead:
1) Delete the field using the ‘Delete’ toolbar button.
2) Merge the cells left and / or up.
3) Add a new field to the empty cell.
Keywords: ABE Datasheet Definer, Field, Merge, Merged Cell, Cell.
References: None |
Problem Statement: How to prevent Results Error 3008 “An inconsistency has been found when setting up a non-symmetrical bundle arrangement”? | Solution: As the message states, the error is related with some inconsistency in the bundle arrangement. Aspen Air Cooled allows symmetrical and non-symmetrical bundles to be entered, depending upon the data items that have been specified. Symmetrical bundles will have the same number of rows per pass, whereas non-symmetrical bundles may not.
Once you specify the Tube Layout (Exchanger Geometry | Geometry Summary) as the bundle type, number of tubes, tube rows, tube passes, etc, Aspen Air Cooled evaluate if these inputs can form a reasonable tube layout. If the current selection is inconsistent, you will get the Result Error 3008 once you try to run the model. For example, as shown below, number of tubes per bundle (220) and tube rows deep (4) are both even numbers, so ACol+ will require a bundle type that is even (staggered-even rows to left, or similar).
NOTE: you can check if the software is able to generate a layout with the current specifications on Exchanger Geometry | Geometry Summary | Tube layout, even before running the model.
To overcome this error, go to Exchanger Geometry | Geometry Summary | Tube Layout and check you have reasonable inputs.
Additional information to specify the tube pass layout can be found on the article How do I enter the tube bundle layout using the input forms or the graphical interface in Aspen Air Cooled Exchanger?
Keywords: Error 3008, Non-symmetrical, Bundle arrangement, Tube Layout, Number of tubes, Bundle type, Tube rows.
References: None |
Problem Statement: Aspen Shell & Tube Exchanger has 2 Calculation Methods available: Advanced and Standard. With the Advanced calculation method (Input | Problem Definition | Application Options) you have control over the convergence parameters used for the calculations, something that is not available in the Standard method. In most cases, it is not necessary to alter these parameters, unless the model presents convergence problems, in which case a warning/error message will be displayed: “Results Warning 1113: The Checking or Simulation calculation has not converged after x iterations” | Solution: Under Input | Program Options | Calculation Options, there are 3 major parameters that can be changed to aid convergence.
In order of importance and usefulness, they are:
- Maximum number of iterations: In most simulations converge in a few tens of iterations. If a case does not converge, but there is a warning message indicating convergence is close, it may be worth increasing the number. The upper limit of iterations is 1000.
- Calculation grid reSolution The reSolution determines the number of calculation grid points along/across the exchanger. There are four levels of reSolution, Low (few points), Medium (default), High and Very High. The actual number of points used depends on the shell type, number of shells in series and the number of passes per shell. In a typical E-shell, Medium gives 20 points along the shell, for the shell side and for each tube side pass.
Using more calculation points (Very high grid reSolution) may increase the accuracy when there are regions with very different heat transfer coefficients. The number of points will be reflected under Results | Calculations Details | Analysis along shell/tubes.
- Relaxation parameter: The basic heat transfer calculation involves updating the current heat load profile using a value calculated from the predicted heat transfer. The relaxation parameter R is used in the relationship;
Updated value = (1 - R) x Current value + R x Calculated value.
For calculation stability, reduced values of R are used in early iterations, or if potentially difficult convergence situations are encountered. To aid convergence, smaller Relaxation parameters can be used
As a general recommendation if you are facing convergence issues, increase the number of iterations and the grid reSolution, this will work for most cases. If it still doesn’t work, you can decrease the relaxation parameter.
Note: The Advanced Method is not available for K shells (Kettles).
Keywords: Convergence, grid re
References: None |
Problem Statement: Is the Preference file same for the Safety Analysis Environment and Aspen HYSYS? | Solution: Aspen HYSYS and Safety Analysis have different preference files. Aspen HYSYS preference file format is .PRF and Safety Analysis environment preference file is .SPRF.
Aspen HYSYS preference file (.PRF) is loaded/saved from the ribbon, click File | Options to open the dialog box for Aspen HYSYS settings. Users can set the default options as user preferences and saving the preferences.
Safety Analysis environment preference file (.SPRF) is set from within the Safety Analysis environment, on the Home tab of the ribbon, click Preferences Manager to open the Preferences Manager, which lets you specify default values for safety calculations. Defaults are saved with the model and apply to new safety analysis calculations initiated in that model. Users can save and load sets of default values from the Preferences Manager.
Both the preference files are generally available at the following location: C:\Users\<username>\AppData\Roaming\AspenTech.
Keywords: Preference File, PRF, Safety Analysis, SPRF, Setting Preferences.
References: None |
Problem Statement: Where can I find the list of APS calc unit built-in formulas and samples? | Solution: Calc units are similar to User-Defined unit, except that Calc units allow the user to define calculations internally (via the Calculations dialog box) rather than externally in the Units workbook (Units.xls). To find more information about built-in functions in APS calc unit, please refer to C:\Program Files (x86)\Common Files\AspenTech Shared\Help\En\ AT_ASPEN_CALC.CHM
Keywords: None
References: None |
Problem Statement: How does Aspen Capital Cost Estimator calculate freight cost for quoted items? | Solution: Aspen Capital Cost Estimator calculates the freight cost for a quoted item as a function of it's weight and cost associated with the contractor for the quoted equipment. By default, both the quoted equipment weight and contractor freight cost are 0. The contractor domestic freight cost can be adjusted under:
Project Basis View | Basis for Capital Cost | Contracts | Contractor
then choose contractor and edit. If you put in $5/lb, the form would appear as follows:
But the quoted equipment weight defaults to 0:
So unless you put in a weight, there would be no freight charge. To enter a weight, just put it in the weight field. For this example, if the quoted item weighed 1000 pounds, it would look as follows:
Keywords: None
References: None |
Problem Statement: If I am asking Aspen Process Economic Analyzer to size my packed column instead of using the sizing information from the simulator, can Aspen Process Economic Analyzer use the actual packing type (ie SS Raschig Rings, SS Pall Rings, etc.) to affect the tower it sizes? | Solution: No. If you are letting Aspen Process Economic Analyzer do the packed tower sizing instead of letting the simulator size the tower, you can not size based upon the actual type (such as SS Rashig). You can tell it the type such as RANDOM or STRUCTURED, and characteristics (such as Packing Factor, Derating Factor, etc.), but not the packing type such as Rashig Rings or Pall Rings. This is done under:
Project Basis View | Towers | Packed
Once the tower is sized, you can go to the Project View and open the input form for your sized tower, and choose the actual packing type there to get the column costed properly.
Keywords: sizing, packed, tower, APEA
References: None |
Problem Statement: What are some publications that discuss simulation and troubleshooting? | Solution: Listed below are some publications that are available from the literature.
Constant Volume problems
Horwitz, B. A., The Case of the Collapsing Can, Chem. Engr. Prog. June 1997, pp 61-65
Distillation
Kister, H.Z. Troubleshooting Distillation Simulations, Chem. Eng. Prog. 91, 63 June 1995.
Taylor, R., R. Krishna, and H. Kooijman, Real-World Modeling of Distillation Chem. Eng. Prog. July 2003.
Dynamic Simulation
Cassata, J.R. S. Dasgupta and S.L. Gandhi, Modeling of Tower Relief Dynamics Part I Hydrocarbon Processing, October 1993.
Cassata, J.R. S. Dasgupta and S.L. Gandhi, Modeling of Tower Relief Dynamics Part II Hydrocarbon Processing, November 1993.
Feliu, J.A., I. Grau, M.A. Alos, and J.J. Macias-Hernandez, Match Your Process Constraints Using Dynamic Simulation Chem. Eng. Prog. December 2003.
General
Schneider, D.F. Build a Better Process Model Chem. Eng. Prog. April 1998.
Sowell, R. Why a Simulation System Doesn't Match the Plant Hydrocarbon Processing March 1998.
Glasscock, D. A. and J.C. Hale, Process Simulation: The Art and Science of Modeling, Chemical Engineering, November 1994. pp 82-89.
Gallier, P.W. and T.P. Kisala, Process Optimization by Simulation, Chem. Eng. Prog., Aug 1987.
Heat exchangers and HX networks
Sigal, R.,Challenges in simulating heat exchanger networks, Hydrocarbon Processing, October 1996, pp 125-132.
Physical Properties
Carlson, E.C., Don't Gamble With Physical Properties For Simulations, Chem. Eng. Prog., 92 (10), pp 34-46.
Sadeq, J. H.A. Duarte, R.W. Serth, Anomalous Results From Process Simulators Chemical Engineering Education, Winter 1997.
Liu, Y. and S. Watanasiri, Successfully Simulate Electrolyte Systems Chem. Eng. Prog. October 1999.
Agarwal, R., Y.K. Li, O. Santollani, M.A. Satyro, and A. Vieler, Uncovering the Realities of Simulation Chem. Eng. Prog. May and June (2001).
Chen, C.C. and P.M. Mathias, Applied Thermodynamics for Process Modeling AIChE J. February 2002.
Additional references are listed for specific thermodynamic and transport property models in the Physical Properties Methods and Models reference manual, and in Reid, Prausnitz and Poling. The Properties of Gases and Liquids, 4th ed. McGraw-Hill, New York, NY (1987).
Heat and Material Balances
Agreda, V.H., R.C. Schad, Heat and Material balances: Making It All Add Up, Today's Chemist At Work, 2 pp 24-29 (1993).
Schad, R.C., Don't Let Recycle Stream Stymie Your Simulation, Chem. Engr. Prog., 90 (12) pp.68-76 (1994).
Reactive Distillation
Nijhuis, S.A. and F.P.J.M. Kerkhof, Multiple Steady-States during Reactive Distillation of Methyl tert-Butyl Ether, Ind. Chem. Res. Vol. 32, pp. 2767-2774, 1993.
Other
Gruber, G. and J. L. Rak, Model of a Wiped Film Still Chem. Engr. Prog. Dec 1989.
Rahbar, M.T., Imporve the Design and Operation of Desalination Plants by Computer Modelling and Simulation, Desalination 92, pp. 253-269, 1992.
Keywords: None
References: None |
Problem Statement: Why cant I see the Add Heat Stable Salts option when using the Acid Gas Property Package in Aspen HYSYS? | Solution: Add Heat Stable Salts option appears when the components associated with Acid Gas Cleaning are included in the component list. These salts may be present in the amine treating process and can decrease the efficiency of the amine present inSolution. Therefore, you should add the HeatStable Salts to the simulation so that the components can be modeled accurately.
One must add all the required components (Amine or Amine Blend, CO2, H2S & H2O) to view the Add Heat Stable Salts option. If one of the required components is not included in the component list, user will not be able to include the heat stable salts.
For more information on how to add and then view/modify Heat Stable Salts in an amine-based Acid Gas Cleaning process, check the KB article below.
http://esupport.aspentech.com/S_Article?id=000066016
Keywords: Heat Stable Salts, Acid Gas Property Packages
References: None |
Problem Statement: What is causing the log messages and what are some things that can be done to troubleshoot and fix the problem? | Solution: Per the log file, the scan and store processes in this example (OVOPC_SC and OVOPC_ST) are running on a Cim-IO server machine called Example1 but the last two lines in each stanza of the log above show that there is a problem with that name.
Try these troubleshooting suggestions:
1. From the Cim-IO server machine open a Windows OS command prompt and issue this command:
NSLOOKUP <servername>
Use the name of the server that shows up in the error message (in our case it is EXAMPLE1).
In this example the NSLOOKUP is NOT successful:
C:\Users\albersd>nslookup EXAMPLE1
Server: UnKnown
Address: 10.nn.nn.nn
*** UnKnown can't find EXAMPLE1: Non-existent domain
In this example the NSLOOKUP IS successful:
C:\Users\albersd>nslookup C-47SKYTRAIN
Server: UnKnown
Address: 10.nn.nn.nn
Non-authoritative answer:
Name: C-47SKYTRAIN.corp.aspentech.com
Address: 10.nn.nn.nn
Try to make network-related adjustments so that NSLOOKUP comes back successfully if you are certain of the server name. After making the adjustments perform the actions listed in the Cim-IO Clean RestartSolution.
2. If you are not certain of the Cim-IO server name look for the 'This PC' Windows System icon and right-click on it and choose 'Properties'. On the screen that appears there will be an entry called 'Computer name'. That is what should be used in this context. The system will normally use that name UNLESS there is a file that overrides that setting. Here is that file name and location:
C:\Program Files (x86)\AspenTech\CIM-IO\etc\cimio_nodename.txt
The file just has a server name it. The cimio_nodename.txt file above is NOT normally on the system - it would have been added manually. It's use is described in thisSolution. If the file exists and the name inside it matches the bad server name then rename the cimio_nodename.txt and perform the clean restart as mentioned in step 1.
3. If the problem is not yet resolved then look in:
C:\Program Files (x86)\AspenTech\CIM-IO\etc\cimio_logical_devices.def
on the Aspen InfoPlus.21 (Cim-IO client) machine. Its contents may look like this:
C47Test C-47SkyTrain C47Svc
These values are LogicalDeviceName, NodeName, and DLGPServiceName. Is the second value (C-47SKYTRAIN in this example) the correct Cim-IO server name as determined previously? If not then adjust it accordingly, save the file, and perform the clean restart as mentioned previously.
Keywords: None
References: None |
Problem Statement: How to make sure user defined “Absolute equation tolerance” value is incorporated in exported ACM model for Aspen Plus or Hysys? | Solution: Current ACM model export function does not include carrying user defined “Absolute equation tolerance” value. For example, it will carry default 1e-5 but not any new value of 1e-8. This may make the exported ACM model failed in Aspen plus or Hysys if it needs tighter tolerance for convergence.
The workaround is to create an EBSOLVE script and associate it with the Model in “Custom Modeling” folder. The Script must contain following code (Please modify the tolerance value as needed):
DECOMP_SPARSE.NonLinear.ABSTol=1e-8
SOLVE
Key Words
Absolute Tolerance, Script, EBSOLVE
Keywords: None
References: None |
Problem Statement: Does EDR report the axial thermal expansion in operation? | Solution: Yes, it does.
On a fixed tubesheet unit, transfer data from thermal to mechanical (or input the data in mechanical).
Select Yes as shown below:
Run the mechanical program.
In the tubesheet section, Code details, find the ‘axial expansion’ for each operating load case (4 shown below):
Key Words
EDR
Aspen Shell and Tube Mechanical
Axial thermal expansion
Keywords: None
References: None |
Problem Statement: What is the benefit of using Line Sizing Manager in Aspen HYSYS V11.0? | Solution: Starting from Aspen HYSYS V11, Line Sizing Manager allows users to perform line sizing calculations for multiple streams and process lines. Users can design and evaluate piping based on criteria that checks certain flow parameters, such as maximum pressure gradient or a maximum velocity. The Line Sizing Manager can calculate the minimum pipe size (diameter) that satisfies the user specified criteria or check that the installed pipe (diameter) satisfies the necessary criteria.
To access the Line Sizing Manager, from the Home ribbon | Analysis group, click Equipment Design | Line Sizing.
The Line Sizing Manager offers the following advantages:
Permits multiple stream connections. You can size many lines within the same Line Sizing Utility.
Lets you size the pipe based on multiple criteria: Pressure Gradient, Velocity, and Rho V2.
Includes a single summary view that displays all of the lines in a system.
Aspen HYSYS V10 and earlier releases included a Pipe Sizing Utility, which let you quickly perform either a design or rating calculation based on a stream without having to add a pipe operation to the flowsheet. In V11, this utility was replaced with the new Line Sizing Manager. So, when users open a case containing Pipe Sizing Utilities in HYSYS V11, the Pipe Sizing Utilities are automatically converted to Line Sizing Manager objects.
Keywords: Pipe Sizing, Line Sizing Manager, Pipe Diameter, multiple criteria: Pressure Gradient, Velocity, and Rho V2.
References: None |
Problem Statement: Which Physical Property Database and Property Method should I use to generate the physical properties in my EDR model? | Solution: All the modules within the EDR suite (Shell and Tube, Plate Fin, Fired Heater, etc.) are compatible with three different types of database systems as listed below:
1. B-JAC database
2. COM-Thermo database
3. Aspen Properties database
The B-JAC database is a legacy database that comes from the Hetran program and has limited vapor-liquid equilibrium (VLE) and vapor-liquid-liquid equilibrium (VLLE) flash capabilities. This database is recommended for use only with frequently used pure components (e.g. water, light hydrocarbons, common chemicals) and common mixtures (e.g. glycol mixtures).
The COM-Thermo database comes from our Aspen HYSYS process modeling tool specialized for oil & gas and refinery applications. As such, use the COM-Thermo database for hydrocarbon component systems and component systems with ideal to slightly non-ideal behavior (i.e. non-polar components to slightly-polar components). For ideal and hydrocarbon systems, use Equation of State models (e.g. Peng-Robinson, SRK, etc.); for slightly non-ideal systems use PRSV as the property method.
The Aspen Properties database comes from our Aspen Plus process modeling tool specialized for chemical applications. As such, use Aspen Properties for chemical systems, where the components are polar or non-ideal. For polar and non-ideal chemical systems use an activity coefficient model such as NRTL or UNIQUAC at pressures below 10 bar, and use an Equation of State model (such as Peng-Robinson, SRK, PSRK, RK-Soave etc.) at pressures above 10 bar.
For any special system (pure water, electrolytes, solids, polymers, etc.) use Aspen Properties. Use the Method Assistant to get a recommendation for the property method or contact AspenTech Technical Support.
Aspen Properties can also predict the properties of ideal, slightly-polar and hydrocarbon systems equally well as COM-Thermo database methods.
Keywords: EDR, physical properties, database, property method, BJAC, COMThermo
References: None |
Problem Statement: How to get total energy exchanged with environment for Cyclic process? | Solution: If exchange energy with environment is enabled in “Energy Balance” tab, you can right click on Gas Bed > Forms > Report and get the exchanged energy reported.
The B1.Cycle_Total_Energy refers to total energy exchanged at current cycle while B1.Total_Energy refers to cumulative energy exchanged during completion of all cycles:
Key Words
Gas Bed, Environment, Duty
Keywords: None
References: None |
Problem Statement: HYSYS Case crashing while saving or case crashes while trying to modify something in simulation environment or in the basis environment. | Solution: HYSYS case files can get corrupted sometimes, since HYSYS files are saved as binary files. As a result of corruption, the case which was working fine until the last time you worked on it can crash while saving or trying modify the case the next time. A simple work around for this problem is as followed.
1. Open the HYSYS case which crashes while saving.
2. Go to Propeties Environment | Fluid Packages Folder.
3. Select the fluid package and click Export and save it in a known location on your computer. If you have multiple fluid packages repeat the above procedure. Files will be saved with an extension .fpk, which contains fluid package information and components information.
4. Now go to Simulation Environment and select all streams and unit operations.
5. Right mouse click on the PFD and go to Cut/Paste Objects | Select copy objects to file (Export). File will be saved with an extension .hfl.
6. Close this HYSYS case file.
7. From the start menu open a blank HYSYS file and go to File | New | Case.
8. Go to Fluid Packages Folder and click import, import the fluid package(s) from the previous file.
9. Enter Simulation Environment and right mouse click on PFD, select cut/paste objects | Paste objects from file (import).
10. Once the file is PFD is imported, all the streams and unit operations will be solved.
11. Save the new HYSYS case. By following the above procedure you should be able to recover the file and use it for further modification.
If the original file can't be opened at all on your system, try opening the file on other computer (co-worker) and save the file with different name. This should also fix the problem.
Keywords: Case Crashing, crash, HYSYS case crash
References: None |
Problem Statement: How to include energy released with Blow downstream to be accounted for in Boiler overall efficiency calculation? | Solution: All the earlier versions before V11, energy associated with blowdown stream was not included in Boiler overall efficiency calculation. In V11, users can decide whether Blowdown energy to be included or excluded for Boiler efficiency calculation.
Please select the option from “IncludeBDinEff”
Key Words
Boiler, Efficiency, Blowdown
Keywords: None
References: None |
Problem Statement: How to rectify issues with envelope calculations when using the Tabular Package option on Aspen HYSYS? | Solution: Please download the attached article which highlights some best practices while using the tabular package option on HYSYS. In some instances, users may have issues while performing envelope calculations. This article will go over why this occurs and how this may be avoided.
Keywords: Tabular Package, Envelope calculations, Enthalpy, Enable Tabular Properties
References: None |
Problem Statement: How do I add sulfur content as a user property in HYSYS Oil Manager? | Solution: Sulfur can be added to Oil Manager assays by creating a user property.
1) Add a new user property:
2) Select the correct Basis and Unit Type for your data (In this case, sulfur is defined as a wt% vs. assay wt%.)
3) Under ”Edit User Property Values” enter a value of 0 in the Property value cells for all library components (C1,C2,C3,i−C4, etc.)
4) Return to the Assay input, go to the User Curves tab, and attach the new user property to the assay
5) Calculate the assay and go to the simulation environment to add the property to the stream. To do this, select the stream and go to Attachments — Analysis — Select Create... — Add User Property
6) View results. The analysis will provide the bulk sulfur value for the stream as well as the concentration for each hypocomponent
Keywords: sulfur, user, user property, sulphur, Assay, Oil
References: None |
Problem Statement: Why is the tubeside pressure drop calculated differently between Aspen TASC and Aspen Exchanger Design and Rating (EDR)? | Solution: In Aspen TASC (sunsetted on 2008), the friction factor used to determine the pressure drop is based upon commercial tubes.
Starting with Aspen TASC+ (released on 2006), and subsequently renamed Aspen Shell & Tube Exchanger (EDR), the default value for the tube surface relative roughness is Smooth, which is what is normally appropriate to heat exchanger tubes for process industry applications, and has been recommended following consultations with the HTFS Tubular Exchangers Review Panel. Commercial pipe will normally give an overprediction of what is found in heat exchangers and should not be used unless you have a reason to believe your tubes are exceptionally rough.
On Aspen EDR, you can choose between Smooth or Commercial, and even specify an explicit tube wall roughness* from Input | Tubes | Tube | Tube surface
*Using specified roughness should be done with caution. Neither the smooth tube nor commercial pipe curves match up with any fixed roughness value.
Typical roughnesses are sometimes published for various types of tube. Two random examples are:
0.025mm, for new steel tubes (from The Heat Exchanger Design Handbook)
0.15mm, for steel tubes cleaned after long use (from the Wärmeatlas)
When specifying a roughness, make sure you have appropriate units selected. The units conversion utility might give poor conversion accuracy with very low lengths.
Keywords: Friction Factor, Roughness, Tube surface, Pressure drop, Smooth, Commercial pipes.
References: None |
Problem Statement: A shell and tube exchanger consists of a bundle of tubes located inside a cylindrical shell. The arrangement allows heat transfer between a fluid flowing through the tubes and a fluid flowing over the tubes. The latter flow is usually directed by a series of traverse baffles in cross flow over the tube bundle as shown below for a two pass AEL shell.
The heat transfer coefficient between the fluid and the tube inside wall is referred to as the tubeside coefficient.
The heat transfer coefficient on the outside of the tube bundle is referred to as the shellside coefficient. The traverse baffles as shown above (being of the single segmental type) have two purposes; to give high rates of heat transfer on the outside of the tubes due to crossflow and to support the tube bundle to minimize vibration. The flow direction on the shellside, due to the flow around the baffles is not pure crossflow but a combination of crossflow and longitudinal flow, where the departure from pure crossflow depends upon the baffle spacing and baffle cut. The flow in addition is further complicated by manufacture tolerances for assembly, which causes clearances between the tubes to baffle or baffle to shell for example. | Solution: Due to the by-pass that occurs due to the constructional gaps for assembly, only a portion of the total shellside flow passes over the bundle in crossflow. The flow on the shellside of a baffled exchanger is complex and is shown in the figure below:
The various flow streams are shown where sometimes they have different terminology as below:
Crossflow: B - Crossflow
Window: W - Window flow
Baffle hole - tube OD: A - Tube/baffle leakage
Baffle OD - shell ID: E - Shell/baffle leakage
Shell ID - bundle OTL: C - Bypass
Pass lanes: F - Inline pass partition
Crossflow: The fraction of the total shellside flow which flows across the baffle space, nominally in crossflow. In poorly designed exchangers this value may be low, where below a value of 0.3, the Shell and Tube program issues an Operation Warning 1336 to re-evaluate the design.
Window: The flow inside the window region (the area due to the cut away of the baffle).
Baffle hole - tube OD: The tube/baffle leakage flow is due to tube-to-baffle clearance which is required for assembly of the bundle.
Baffle OD - shell ID: The baffle/shell leakage flow is due to the baffle-shell clearance which is required to allow the bundle into the shell.
Shell ID - bundle OTL: Bypass flow due to the bundle-shell clearance and is determined by the type of construction. For example a greater clearance is needed for a removable bundle heat exchanger because of the space required for the floating head flange than in a fixed tube sheet unit.
Pass lanes: Bypass flow arises from gaps in the bundle itself due to the presence of pass partitions if multiple tube passes are used.
In the Aspen Shell & Tube, the shellside flow fractions are shown in Results | Thermal/Hydraulic Summary | Flow Analysis | Flow Analysis tab. The flow fractions are shown for 3 locations;
· Inlet; where the shellside flow enters the exchanger
· Middle; in the baffled portion of the exchanger
· Outlet; where the shellside flow leaves the exchanger
Using the stream letter and letting F denote a fraction of the total flow rate in the heat exchanger then a mass balance will give;
To achieve good heat transfer, the crossflow fraction should be high as possible.
It might be thought that decreasing the baffle spacing will increase the cross flow velocity and hence improve the heat transfer. However, in practice, decreasing the baffle pitch will increase the pressure drop in the exchanger and increase the leakage flows (A, E, C & F), which decreases the cross flow (B). As a general rule, decreasing the baffle spacing to 20% of the shell diameter or below may cause deterioration in the duty due to the cross flow fraction decreasing.
Another way to improve the crossflow fraction is to insert sealing strips that divert some of the Shell ID to bundle OTL (bypass) flow back into the bundle improving the heat transfer but increasing the shellside pressure drop.
Keywords: Flow fraction splits; Flow fraction, Operation warning 1336, Low Crossflow, Sealing strips.
References: None |
Problem Statement: When using the h21chgpaths.exe utility to alter the history fileset paths to reflect a new location, the result is simply to list the usage. No changes appear to be made:
eg.
h21chgpaths.exe C:\Program Files\AspenTech\InfoPlus.21\c21\h21\ E:\Archive\
Results in:
Usage: h21chgpaths old_string new_string
Changes all pathnames in the current config.dat file
replacing old_string with new_string.
This is puzzling because you are certain the old_string is correct and you have used double quotes to surround it to take account of the spaces in the path. What could explain the failure to search and replace? | Solution: The problem is caused by the fact that the backslash character (\) is acting as an escape character when it precedes extended characters like the double quote symbol.
You should replace the trailing two character combination (\) with just the double quote symbol (). Eg. For the example above, change it to read:
h21chgpaths.exe C:\Program Files\AspenTech\InfoPlus.21\c21\h21 E:\Archive
To demonstrate that backslash really is acting as an escape character, you could also achieve success by escaping all the backslash characters that precede the double quote symbols in order to stop the double quotes being included in the search/replace strings. Eg:
h21chgpaths.exe C:\Program Files\AspenTech\InfoPlus.21\c21\h21\\ E:\Archive\\
This double backslash approach would explicitly identify a folder called h21. This would have been required if there had been multiple sub-folders in c21 folder, all starting with h21.
Keywords: not working
nothing happens
repository
folder
search
config.dat
References: None |
Problem Statement: How to create a user variable in ACM products? | Solution: For many instances, we may need to create a dummy variable for ACM, Aspen Plus Dynamic or in Aspen Adsorption. For an example, if we need to create a new variable for Energy demand which does not exist in any units in the flowsheet. In that case, we can go to Flowsheet > Constraint and declare the variable as real parameter.
Now this variable will be listed in the “Local Variable” form and its value can be modified if needed. The user should be able to use this variable from “Task” window.
Key Words
User Variable, Constraint, Local
Keywords: None
References: None |
Problem Statement: Error message “Stream Feed1: Dynamic flash not possible with current (insufficient?) specifications” when running the depressuring tool at some time in Aspen HYSYS? | Solution: To get rid of the error message, what you would need to do will be:
1. When the feeder block pops up, select the temperature radio button. Then, press the Export Conditions to Stream button.
2. Close the feeder block window.
3. Run the depressuring utility again - it should run fine now.
Keywords: Aspen HYSYS, Depressuring, Error Message
References: None |
Problem Statement: How are sequential modular (SM) optimization problems solved in Aspen Plus? | Solution: You can use the Optimization feature to maximize or minimize a user-specified objective function by manipulating flowsheet variables. Equality or inequality constraints may be imposed on the optimization.
Optimization problems are solved iteratively. By default, Aspen Plus automatically generates and sequences a convergence block for the optimization problem, or you can enter your own convergence specifications on Convergence forms.
Algorithms for solving process optimization problems can be divided into two categories:
Feasible path methods: require that tear streams and equality constraints (Design-Specs) if any, be converged at each iteration of the optimization.
Infeasible path methods: can converge tear streams, equality constraints, and inequality constraints simultaneously with the optimization problem.
Three optimization algorithms are available in Aspen Plus: the SQP method (default), the COMPLEX method and the BOBYQA method. The user can select them from Convergence | Options | Defaults | Default Methods.
SQP method
The SQP (Sequential Quadratic Programming) method is a state-of-the-art quasi-Newton nonlinear programming algorithm that can converge tear streams, equality constraints and inequality constraints simultaneously with the optimization problem. The algorithm generally follows an infeasible path, but can be adjusted to follow a feasible path (converging the tear streams at each iteration of the optimization). The SQP method usually converges in only a few iterations, but requires numerical derivatives with respect to all decision and tear variables at each iteration. SQP is used for system-generated optimization convergence blocks and is recommended for user-generated convergence blocks.
The SQP method as implemented in Aspen Plus includes a feature in which the tear streams can be partially converged using the Wegstein method at each optimization iteration and during line searches. This usually stabilizes convergence and can reduce the overall number of iterations. The user can specify the number of Wegstein passes. Choosing a large value effectively makes SQP a feasible path (but not a black-box) method. The Aspen Plus default is to perform three Wegstein passes.
The SQP method can also be used as a black-box or partial black-box method by converging tear streams or tear streams and design specifications as an inside loop to the optimization problem (using separate Convergence blocks), thereby reducing the number of decision variables. The trade-off is the number of derivative evaluations vs. the time required per derivative evaluation. This trade-off is problem-dependent.
COMPLEX method
The COMPLEX method uses the well-known Complex algorithm and is a simple feasible path black-box pattern search. The method can handle inequality constraints and bounds on decision variables. Equality constraints must be handled as Design-Specs. Separate convergence blocks must be used to converge any tear streams or Design-Specs.
The COMPLEX method frequently takes many iterations to converge, but does not require numerical derivatives. It has been widely used for all kinds of optimization applications for many years and offers a well-established and reliable option for optimization convergence. It is especially useful for simple problems without recycle loops or equality constraints.
BOBYQA method
Starting on Aspen Plus V9, The BOBYQA (Bound Optimization BY Quadratic Approximation) solver is now available for solving constrained optimization problems without tear streams. This solver provides better robustness than the other optimization solvers in problems with noisy derivatives.
You can use the BOBYQA method for flowsheet optimization for simultaneous convergence of optimization problems with constraints (equality or inequality).
BOBYQA utilizes a trust region method. Variables must be scaled by the range of their bounds to ensure that magnitudes of the expected changes are similar. Constraints are supported by the use of a penalty function that is added to the objective functions.
For more information, refer to the articles below:
What is the BOBYQA Solver
Optimization Example for Minimizing Steam Use
Can Aspen Plus optimize on integer variables, such as feed stage to column?
Keywords: Optimization, COMPLEX, SQP, BOBYQA.
References: s:
Biegler, L.T. and J.E. Cuthrell, Improved Infeasible Path Optimization for Sequential Modular Simulators, Part II: The Optimization Algorithm, Computers & Chemical Engineering 9, 3, p. 257 (1985).
Lang, Y-D and L.T. Biegler, A Unified Algorithm for Flowsheet Optimization, Computers and Chemical Engineering 11, 2, p. 143 (1987)
M.J.D. Powell, The BOBYQA Algorithm for Bound Constrained Optimization without Derivatives. Report, Department of Applied Mathematics and Theoretical Physics, Cambridge University. DAMTP 2009/NA06. |
Problem Statement: When open excel related functions in APS, it gives error “programmatic access to visual basic project is not trusted”. This error message could be related with excel trust settings for VBA. | Solution: To solve error “programmatic access to visual basic project is not trusted”, please follow the steps below to change trust center setting in excel:
1. Open Excel and go to File, click Excel Options
2. Click Trust Center
3. Click Trust Center Settings
4. Click Macro Settings
5. Click to select the Trust access to the VBA project object model check box
6. Click OK to close the Excel Options dialog box.
7. Save Excel
Keywords: None
References: None |
Problem Statement: How can I allow multiple users to get access to Equipment Model Libraries and Unit Cost Libraries files? | Solution: A simple workflow to allow multiple users to access the same Equipment Model Libraries and Unit Cost Libraries files, is to place the libraries in a shared network drive so that all can access them.
The following information will show you how to relocate Equipment Model Libraries and Unit Cost Libraries on a network.
ACCE has specific locations to find and load Unit Cost Libraries (UCL) and Equipment Model Libraries (EML), each of these has their respective route:
Loading an EML file:
The Equipment Model Libraries are located by default in C:\Users\Public\Documents\AspenTech\Shared Economic Evaluation VX.X\Eml\, where X.X represents the version you're using.
If you have at some point changed this location, you may review your current EML folder by clicking on the Library tab of the Palette, and then clicking Cost Libraries | Equipment Model Library, review the Properties window to view your current folder.
The user should first open this location on the Personal Computer in order to find the Library (*.aee) and copy this file into any desired location, this can be in a shared network folder that multiple users can find and use.
Once the file has been transferred to the Network folder, all users that require access to this EML must map this new location to their program configuration.
In the Economic Evaluation programs, go to Tools | Options | Preferences and select the Locations tab.
At the lower half of the window, in the Other Location Specifications section, find and click the option EMLDir (side note reading This is the location used for creating and accessing Equipment Model Libraries).
Hit the ... button to browse for the new drive location and path for the network EML library.
Loading an UCL file:
The User Cost Libraries Model Libraries are located by default in C:\Users\Public\Documents\AspenTech\Shared Economic Evaluation VX.X\Ucl\, where X.X represents the version you're using.
If you have at some point changed this location, you may review your current UCL folder by clicking on the Library tab of the Palette, and then clicking Cost Libraries | Unit Cost Library, review the Properties window to view your current folder.
The user should first open this location on the Personal Computer in order to find the Library (*.aee) and copy this file into any desired location, this can be in a shared network folder that multiple users can find and use.
Once the file has been transferred to the Network folder, all users that require access to this UCL must map this new location to their program configuration.
In the Economic Evaluation programs, go to Tools | Options | Preferences and select the Locations tab.
At the lower half of the window, in the Other Location Specifications section, find and click the option UCLDir (side note reading This is the location used for creating and accessing Unit Cost Library files).
Hit the ... button to browse for the new drive location and path for the network UCL library.
After changing the library paths:
Make sure that the user Exits the Aspen Icarus software, then re-opens the application, otherwise, the changes will not be shown for the locations on the network.
NOTE: It's very important that all users use the same version of the software before making these changes. This is due to system differences between versions. Do not attempt this if some users are on older versions of the software.
Keywords: Equipment Model Library, EML, Unit Cost Library, Libraries, Preferences, Locations, Share, Path.
References: None |
Problem Statement: Is it possible to model a dephlegmator in Aspen Exchanger Design and Rating (EDR)? | Solution: A dephlegmator is a device arranged for the partial condensation of a multicomponent vapor stream. The vapor stream flows vertically upwards and the condensate (condensed vapor) runs back down under the influence of gravity. The vapor stream and condensate thus move countercurrently and are in direct contact with each other. In addition to heat transfer between the vapor stream and the cooling medium, mass is transferred between the rising vapor and falling condensate. The vapor leaving the device has become concentrated in the more volatile components, while the condensate is richer in the less volatile components.
In Aspen EDR, a knockback reflux condenser can work as a dephlegmator: vapor comes in at the bottom, cools against the shell side fluid with the condensate draining out the bottom.
This kind of condenser can be specified on Input | Problem Definition | Application Options | Hot Side | Condenser Type:
It's also important to define separate nozzles for liquid and vapor outlet on the hot side, directly on Exchanger Geometry | Nozzles:
Now, with this type of condenser, one should consider using the differential condensation option if the program calculates the condensation curve, as the liquid condensate is removed from the vapor, thus changing the equilibrium and lowering the dew point of the remaining vapor.
How can I specify integral or differential condensation?
For additional info, please refer to the Aspen HTFS papers and articles below:
HTFS CP15: Guidelines for the Design of Reflux Condensers
HTFS RS987: Dephlegmator Performance Calculations
What is the best exchanger configuration for tubeside, vertical condensation?
What does Warning 1917 mean on Exchanger Design and Rating?
Keywords: Dephlegmator, Knockback, Reflux Condenser, Differential Condensation, Condensation Curve.
References: None |
Problem Statement: How to modify user defined isotherm for 2-D spatial Dimension? | Solution: For Built-in isotherm, when 2-D spatial dimension is selected, both axial and radial nodes are automatically adjusted.
However, for user defined isotherm, we need to first select the number of radial nodes:
Then in isotherm equation need to write loading equation for each node (except first and last node):
Key Words
Spatial, User Isotherm, 2-D
Keywords: None
References: None |
Problem Statement: How can I close an Item Report? There is no Cancel or OK button available. | Solution: To close the Item Reports that are on the list view you will need to select the X button that is located just below the X that closes the entire program:
Using this button will allow you to avoid the accumulation of reports on each Window you use.
Keywords: Accumulation, Close Item Reports, ACCE, AIPCE, APEA, Reporter report.
References: None |
Problem Statement: I want to define my own Economic Evaluation (EE) templates, however, I want them to be saved in a different location than the default folder. How can I do that? | Solution: The default location where the Templates are saved is C:\ProgramData\AspenTech\Economic Evaluation VX\EE_Templates (where X stands for the installed version). The user has the option to define their own template folder location. To do so, follow the next steps:
1. Open EE (Aspen Capital Cost Estimator, Aspen In-Plant Cost Estimator, or Aspen Process Economic Analyzer).
2. Go to the Tools menu > Options > Preferences.
3. Select the Locations tab.
4. At the bottom of the window there is a section for Other Location Specifications. Scroll down the list and select UserTemplatesDir.
5. Click on the … button and browse for the desired folder location.
6. Click OK.
You need to have read and write privileges on that folder for the templates to be saved correctly.
Keywords: Templates izt directory
References: None |
Problem Statement: Do the Aspen Economic Evaluation products have backup copies of my projects? | Solution: Yes, the Economic Evaluator products do have backup copies of your projects. You can see the location, and change it if you would like, by going to the Locations tab on:
Tools | Options | Preferences
Under the Other Locations Specifications area, scroll to ProjectBackupDir and click on it. The location for your project backup files will appear in the filed below it.
Keywords: Project Backup, ACCE, APEA, AICE
References: None |
Problem Statement: When is the option “Use separate Outlet Nozzles for Hot/Cold side Liquid/Vapor flows” on the Shell Side & Tube Side Nozzles section useful? | Solution: The option “Use separate Outlet Nozzles for Hot/Cold side Liquid/Vapor flows” on the Shell Side & Tube Side Nozzles section is set to ‘No’ as default, however, this option must be changed to ‘Yes’ when the outlet is expected to have both phases and need separate nozzles.
The program will throw the Input Error 1208, this implies that two separate nozzles are required for the outlets. By setting the option “Use separate Outlet Nozzles for Hot/Cold side Liquid/Vapor flows” to 'Yes' will resolve this error.
Keywords: Input Error 1208, Nozzles, Use separate Outlet Nozzles for Hot/Cold side Liquid/Vapor flows.
References: None |
Problem Statement: What tube rows does Aspen Shell & Tube Exchanger consider for the vibration analysis? | Solution: The risk of vibration in any tube in an exchanger depends on where it is supported, by baffles or other supports, and on local flow velocities along its length.
Experience has shown that there are certain tube rows within an exchanger that are most likely to suffer vibration damage. These are basically the uppermost and lowermost tube rows with respect to the flow and the tube rows just inside or just above the edge of the baffle cut. The program automatically selects a small representative set of tubes to perform vibration checks on based on this experience.
The positions of the tubes are shown in the diagram below, for horizontal and vertical baffle cuts, for Tubes In Windows and No Tubes In Windows (NTIW).
Key factors are the support and the velocity impacting the tube. Clearly a tube in the window region of an exchanger is supported by every other baffle, whereas in the baffle overlap region a tube is supported by every baffle. This has an important effect on the calculation of, for instance, tube Natural Frequency and, hence, the likelihood of vibration.
To see vibration tubes in the Tubesheet Layout output, click the Vibration Tubes box above the diagram. A red V appears on the vibration tubes, and a table with further information on these tubes appears below the layout. If there is a very large number of tubes in the layout, you need to zoom in to be able to see this. If there is a vibration or resonance risk, the tube is drawn as two displaced circles to give a visual indication of the problem. For vibration, the tubes are displaced horizontally, and for resonance, vertically. Four displaced tubes are drawn when both effects are present. The extent of the risk is also indicated in the table below the layout.
Keywords: Tube Rows Exam, Vibration analysis
References: None |
Problem Statement: When using Aspen Shell & Tube Exchanger, users need to specify the shell type of the exchanger as part of the geometry inputs, under Input | Exchanger Geometry | Geometry Summary | Geometry tab.
This technical | Solution: contains a description of the different shell types available in the program, along with some general guidelines for selecting the shell type when designing a shell & tube exchanger.
Solution
Shell types for a shell and tube heat exchanger are identified by a letter, i.e. E, F, G, H, I, J, X and K, designated by TEMA. There are other shell types not designated by TEMA, such as ''Double piping'' and ''Multi-tube hairpin''.
- E-Shell: This is the most common type, where the shellside fluid enters at one end of the shell and leaves at the other in one pass. Generally they are considered to be the standard.
- F-Shell: This shell has a longitudinal baffle extending most of the way along the shell, dividing it into two halves. The shellside fluid enters at one end of the shell, flows in one half to the other end and then back in the other half, thus giving two shellside passes. In most F types there are also two passes on the tubeside, thus ensuring countercurrent flow. If a fixed tubesheet construction is used, then the longitudinal baffle can be seal welded to the inside of the shell, thus preventing leakage from the first shell pass to the second.
- G-Shell: This is sometimes known as the ''split flow'' shell. Fluid enters the shell through a nozzle placed at the centre of the shell. The shell has a central longitudinal baffle that divides the flow into two, so that each half makes two passes in its half of the shell before combining and exiting through a central nozzle.
- H-Shell: Sometimes called the ''double split flow'' type, this shell has two inlet and exit nozzles located ? and ? the way along the shell. There is a longitudinal baffle in each half of the exchanger, so that on entry each half of the flow is split again, either going to the end of the shell and back, or to the middle and back. Because of this flow split, this type has a low shellside pressure drop, and they are normally only used in horizontal thermosyphon reboilers.
In Aspen Shell & Tube Exchanger, for F, G and H shells, the number of tube passes must be even. The minimum number of baffles that may be specified for a G shell is 4, whereas 8 for an H shell. This is to maintain the cross flow path. Limiting the minimum number of baffles to 4 or 8 ensures that there are two baffles on each leg of the longitudinal baffle (i.e., 2+2 for G shell or 2(2+2) for H shell).
- I/J-Shell: Also known as ''divided flow'', this shell has a single central inlet nozzle and two outlet nozzles, one at each end of the exchanger. After entering the exchanger, the flow is split into half by a centrally located baffle. Since half the fluid flows through each half of the exchanger, the shellside pressure drop for a given service is much lower than an equivalent E shell. Thus J-shells are commonly used for low pressure condensers and other services with low allowable pressure drop. They are also known as J12 (or 1 nozzle in, 2 nozzles out). Although this type is usually depicted as having one inlet and two exit nozzles, shells with two inlets and one exit (sometimes called an ?I shell?, or J21) are also used.
- K-Shell: These are ''kettle'' reboilers and in practice are used exclusively for vaporising service. The fluid to be vaporised normally enters at the bottom of the shell. The shell diameter is larger than the bundle and boiling liquid flows up through the bundle, with any unevaporated liquid falling back to the bottom of the shell, before recirculating up through the bundle. The liquid level is maintained above the bundle by a weir plate (a level control valve may be used instead of a weir plate). The vapour formed is separated from the liquid in the enlarged shell and leaves through a nozzle at the top. Demister pads are sometimes placed at the vapour outlet to remove any entrained liquid. Unevaporated liquid flows over the weir.
- X-Shell: This is usually known as a ''cross flow'' shell, where the shellside fluid makes one pass ''diametrically'' across the shell. Some have single central inlet nozzles at the top of the shell and a single exit nozzle at the bottom. Others can have multiple nozzles at the top and bottom.
For X and K shells, Aspen Shell & Tube Exchanger does not allow baffles to be entered. However, you can enter mid space intermediate supports in order to help prevent vibration.
Some general guidelines to select from these shell types are:
- E-shells are standard and should be used, if possible
- F-shells give pure counter current flow with two tube passes (avoids very long exchangers). But longitudinal baffles are difficult to seal with the shell especially when reinserting the bundle into the shell after maintenance. For services that need multiple shells and removable bundles, F-shells should be considered as alternative
- G and H-shells are normally only used for horizontal thermosyphon reboilers
- I/J and X-shells normally give low shell side Δp, and can be used if allowable pressure drop cannot be achieved in an E-shell
- K-shells are only used as reboilers
Note that Aspen Shell & Tube Exchanger also handles ''double-pipe'' and ''multi-tube hairpin'' exchangers. The details for specifying these two shell types can be found in the article below:
Is it possible to model Double-pipe and Multi-tube hairpin exchangers in Aspen Shell & Tube Exchanger?
More detailed descriptions and layouts of the TEMA designated shell types can be found in TEMA (Standards of the Tubular Exchanger Manufacturers Association), Section 1, N-1 ''SIZE NUMBER AND TYPE DESIGNATION - RECOMMENDED PRACTICE''.
Keywords: Shell type, Shell & tube exchanger
References: None |
Problem Statement: What is the experimental / literature data against which the TEG-Water binary parameters of the CPA model were regressed? | Solution: The TEG-Water system binary parameters of the CPA model were regressed against the data presented on the following publication:
‘GLYCOL-TYPE GAS DEHYDRATION AND HYDRATE INHIBITION SYSTEMS - DESIGN AND ENGINEERING PRACTICE’
DEP 20.04.10.10-Gen.
Dec-94
Published by Shell
With the following validation results:
Keywords: TEG, Water, Binary Parameters, CPA, Regressed.
References: None |
Problem Statement: How can I comment rows or columns in EIU spreadsheet? | Solution: In some cases, we may need to comment some of the entries in EIU template to disable some data from importing to staging tables. Both rows and columns can be commented in EIU spreadsheets.
An asterisk (*) before any column name tells the application to ignore any value in that column and not to load the data into any staging or database table in the target application.
An asterisk (*) before any row description tells the target application to ignore the value in that row.
Keywords: None
References: None |
Problem Statement: How to create MTMF and MTMR correlations in Aspen PIMS? | Solution: Mobil Transformation ABML correlation is used to predict the research and motor octane numbers of motor gasoline (MoGas) blends. This method uses measured research and motor octane of components and measured olefins, aromatics, and paraffins.
ABML Function:
· MTMR
· MTMF
MTMF and MTMR correlations need to be set up in Table ABML in following format. Yellow represents the values of parameters and red represents PIMS property tags.
* TABLE ABML Table of Contents
*
TEXT OPTION ***
CORR14 MTMR
OPTION14
P1_14 P1
P2_14 P2
ENDOPT14
INPROP14
TRON Transformed Research Octane
TMON Transformed Motor Octane
OLE Olefin vol %
ARO Aromatic vol %
ENDIN14
OUTPRP14
RON Research Octane
MON Motor Octane
ENDOUT14
**************
CORR51 MTMF
OPTION51
P1_51 P1
P2_51 P2
ENDOPT51
INPROP51
RON Research Octane
MON Motor Octane
OLE Olefin vol %
ARO Aromatic vol %
ENDIN51
OUTPRP51
TRON Transformed Research Octane
TMON Transformed Motor Octane
ENDOUT51
Keywords: None
References: None |
Problem Statement: How to calculate a grouped composition? (eg group all the C6+ hydrocarbon components) | Solution: This can be easily accomplished with an User Variable. Please follow the next steps and add the attached code to an Aspen HYSYS simulation:
In a simulation open any material stream and go to User Variable.
Click on “Create a New User Variable” button and copy/paste the code attached.
Type “PostExecute” for the name and the Tag. Check the option “Is Variable Calculate Only” and select MoleFraction for the Units.
If this is planned to be reported for all the material streams, then select “Automatic” in the Activation section.
Click OK and for see the results of this User Variable it is needed to re-run theSolution (give another temperature or delete any feed value and enter it again)
Note: The commands C6PLUSSTART and C6PLUSEND represent the correct starting and ending positions in the component list for the components to be grouped (Component list numbering starts at 0)
Keywords: Grouped composition, User Variable.
References: None |
Problem Statement: Why is my building cost not changing as I increase the Explosion Gauge Pressure? | Solution: The building models in Aspen In-Plant Cost Estimator (AICE) are very simplistic models, basically driven by $/SF. Some of the fields are really information fields, so that in the reports people will know the various things about the buildings. The Explosion Gauge Pressure field is one of those fields (so is the foundation type). When you are on the field, if you check the help palette at the bottom right, you will see that it says it is information only:
Test 1 - Building
Since it is an information field, changing the value has no affect on the cost.
Keywords: Building, Explosion Gauge Pressure, Explosion
References: None |
Problem Statement: Many times, when writing models in Aspen Custom Modeler that use Aspen Properties, component property parameters are needed to perform detailed calculations. How do you access the pure component parameters in order to use them in model calculations? | Solution: Pure component property parameters can be retrieved using physical property procedure calls. For non-temperature-dependent parameters, the procedure is pParam. The pParam procedure input variables are the parameter name and data set number. The data set number will normally be 1, but could be 2 or greater if you have multiple data sets. The output variable is an array of parameter values that contains one value for each component. The array should be indexed over the componentlist.
Note: Parameter values are always returned in SI units.
pParam Example:
TB(componentlist) as realvariable;
call (TB) = pParam(TB,1);
Similarly, for temperature-dependent parameters, the procedure to be used is pParamT. The input variables will also be the parameter name and the data set number. The output variable is an array, where the first dimension should be the componentlist and the second dimension should be an integerset of the correct size for the number of values that the parameter has (To find this value, you would need to load your properties definition file in Aspen Properties and verify how many values each parameter has).
pParamT Example:
PLXANT(componentlist, [1:9]) as realvariable;
call (PLXANT) = pParamT(PLXANT,1);
There are similar procedures for retrieving other types of component data:
pParamBin - binary component property parameters that are not temperature dependant
pParamBinT - temperature dependant binary component property parameters
See the Aspen Custom Modeler Help for details on these physical property procedures.
For a more detailed example on how to retrieve temperature-dependent parameters, see the article below:
Example: Accessing T-dependent pure component parameters within Aspen Custom Modeler
Keywords: property parameters, property procedures, procedures, custom modeler
References: None |
Problem Statement: Using heat loss in RadFrac is not supported by Aspen Dynamics | Solution: If you use Heaters and Coolers option in Aspen Plus and add Heat Loss for the RadFrac column, then you won’t be able to run the model in Aspen Plus Dynamics.
Using heat loss is not supported by Aspen Dynamics, so the constant heat duties are not included in the energy balance equations. Currently, the option to include such heat duties are through the Heat Transfer option and model them as heat transfer with environment.
Key Words
RadFrac
Heat loss
Heat Transfer
Keywords: None
References: None |
Problem Statement: In Aspen Shell & Tube Exchanger, in addition to the common TEMA shell types, users can also model double-pipe (D-shell) and multi-tube hairpin exchangers (M-shell). This | Solution: explains the differences between these types of exchangers.
Solution
- A double-pipe exchanger is one pipe enclosed by another tube to form an outer annulus. Fluid then flows, normally in counter-current flow, exchanging heat across the tube wall:
Double-pipe exchangers tend to be used for small duties as they are relatively cheap, but larger duties can be accommodated by bolting several modules together, which can be model in Aspen Shell & Tube Exchanger by applying exchangers in series, where 3 shells in series are shown in the diagram below:
Besides specifying the shell type as ''D'' and the number of shells in series, you also must set the number of tubes to 1 (you will notice that the number of passes is not enabled, the only possible number of passes is 1):
A double-pipe shell (D-type shell) can also be associated with a U-bend rear head:
You need to be aware that for double-pipe exchangers with U-bends in Aspen Shell & Tube exchanger, the number of tube passes will still be disabled, and it will remain as 1. This is different from other U-bend exchangers. Specifying a Double-pipe exchanger with a U-bend rear head will result in a single double-pipe exchanger unit consisting of two straight legs of tubes joined by the U bend:
- A multi-tube hairpin exchanger consists of a bundle of hairpin tubes, with a separate shell on each leg of the hairpin and a special cover over the U-bend of the hairpin. The tubes may be longitudinally finned, but are usually plain tubes with baffles to cause crossflow:
To specify a multi-tube hairpin exchanger, besides setting the shell type as ''M'', you should set the rear end head type to a U type. In Aspen Shell & Tube Exchanger, the permissible input for the number of tube passes in a multi-tube hairpin exchanger is 1. This is based on one tube pass in each of the two exchanger shells. Unlike double-pipe exchangers, a multi-tube hairpin exchanger can have more than 1 tube, though the number of tubes in the bundle is usually much less than in a conventional shell and tube exchanger. Several multi-tube hairpin exchangers in series can also be set on the Geometry tab.
Note that Aspen Shell & Tube Exchanger does NOT generate the setting plan for double-pipe exchangers nor multi-tube hairpin exchangers. Only for multi-tube hairpin exchangers, the tube layout is reported.
Keywords: Double-pipe exchanger, Multi-tube hairpin exchanger, In series, U rear head, Setting plan, Tube layout
References: None |
Problem Statement: The Safety Analysis environment is calculating a wrong vapor fraction for my relieving stream. It does not match the vapor fraction from the Simulation Environment. This is causing the calculated orifice area to be incorrect. How do I fix this issue? | Solution: 1) Select the scenario from the left navigation window
2) View the Scenario Setup tab
3) For Relieving Temperature, click the drop-down option and choose Vapor Fraction
4) In the input box which appears to the right, enter the vapor fraction
5) The new relieving temperature should then calculate
Keywords: None
References: None |
Problem Statement: What are the necessary permissions to see and delete cases in V11 PIMS Database Management Tool? | Solution: The user needs to have EXECUTE permission on stored procedure DeleteSolutionCase that is in the PIMS database.
To grant EXECUTE permission, do steps taken from Microsoft website:
To grant permissions on a stored procedure
In Object Explorer, connect to an instance of Database Engine and then expand that instance.
Expand Databases, expand the database in which the procedure belongs, and then expand Programmability.
Expand Stored Procedures, right-click the procedure to grant permissions on, and then click Properties.
From Stored Procedure Properties, select the Permissions page.
To grant permissions to a user, database role, or application role, click Search.
In Select Users or Roles, click Object Types to add or clear the users and roles you want.
Click Browse to display the list of users or roles. Select the users or roles to whom permissions should be granted.
In the Explicit Permissions grid, select the permissions to grant to the specified user or role. For a description of the permissions, see Permissions (Database Engine).
Keywords: None
References: None |
Problem Statement: How do I change the default Aspen Process Economic Analyzer (APEA) template used through Activated Economics in Aspen Plus/ HYSYS? | Solution: Activated Economics in Aspen HYSYS and Aspen Plus always uses an APEA template file (*.IZT) that allows the economic evaluation to correctly process the project information, such as country basis, unit set, currency, operating costs, wage rates, design requirements, etc.
Several IZT files are already included in the program, allowing the user to swiftly change the country basis of a project. The default template that Activated Economics uses corresponds to US prices.
To change the default template first click on Economics | Cost Options under the Economics ribbon tab as shown in the screenshot below:
In the upcoming Costing Options window, you will find the Template field, where the US basis in English (IP) units can be found, you can then click on the Browse button to select the required template file.
Note: The default IZT files can be located in the path C:\ProgramData\AspenTech\Economic Evaluation V.XX\EE_Templates\Templates, where VX.X is the version of HYSYS/Plus/APEA being used.
The user can create and customize its own IZT files using APEA stand alone.
Solution
APEA, template, IZT, Country, Custom, Options, Project Basis
Keywords: None
References: None |
Problem Statement: How to use APS automation to update parameter values of an existing event? | Solution: Following is a VBA example that can be used to update event parameters.
======================================================
Sub updateparam()
Dim evntcoll As New orion.EventsColl
Dim evntitem As orion.EventItem
' Get the event by sequence number
Set evntitem = evntcoll.ItemByEventSeq(11)
' get parameters subitems
Dim subitemparm2 As orion.EventSubItem
Set subitemparm2 = evntitem.Item(EVPROP, 1)
Dim subitemparm3 As orion.EventSubItem
Set subitemparm3 = evntitem.Item(EVPROP, 2)
'modidy parameters
subitemparm2.Quantity = 0.5
subitemparm3.Quantity = 0.5
'save evnt
evntcoll.ModifyEvent evntitem
'clean memory
Set subitemparm2 = Nothing
Set subitemparm3 = Nothing
Set evntitem = Nothing
Set evntcoll = Nothing
End Sub
============================================================
Keywords: None
References: None |
Problem Statement: How can I establish the relationship among variables in my dynamic model to customize the way calculations are performed? | Solution: You can define the following in a flowsheet constraint definition:
Variables
Parameters
Equations and procedure calls
Assignments
Inequalities
You can use the flowsheet constraints section to write any equations that include variables from different blocks on your flowsheet, thus customizing your model from a mathematical standpoint.
To enter flowsheet constraints, within the ‘Simulation Explorer’, right-click on the ‘Flowsheet’ item which is in the ‘Flowsheet’ folder and select the ‘Edit’ option.
To refer to variables within blocks in the flowsheet you need to include the block name. For example, to refer to the variable ‘Tout’ (outlet temperature) in block ‘HX’ use:
HX.Tout
You can also refer to variables within streams in a similar way. For example, to refer to the variable ‘T’ (temperature) in stream ‘INLET’ use:
INLET.T
If you have a block and stream with the same name, or if you are editing an Aspen Plus Dynamic simulation, you need to explicitly define whether you are referring to a variable within a block or a stream. To do this use the syntax:
BLOCKS(BlockName).VariableName
STREAMS(BlockName).VariableName
For example:
BLOCKS(HX).TOut
STREAMS(INLET).T
If a block is within a hierarchy block you also need to include the hierarchy block name. For example, if ‘HX’ is in the hierarchy block ‘RefrigPlant’, then refer to ‘Tout’ as ‘RefrigPlant.HX.Tout’.
After writing down the equation(s) in the ‘Flowsheet Constraints’ section, you will need to compile them by either hitting the ‘F8’ (compile) key or right-clicking on a blank space in the editor and select the ‘Compile’ option. If no compilation errors occur, then your constraint(s) will be active in that very moment.
Keep in mind that in order for Aspen Plus Dynamics to solve a dynamic model, it must be a square system (zero degrees of freedom) and whenever you include flowsheet constraints, they will be considered as ‘fixed’ variables, so you will need to make ‘fixed’ variables into ‘free’ to fulfill this requirement.
In this article, an Aspen Plus model (find it in the attachments section) which contains two identical heat exchanger models (‘HX’ and ‘HX2’) and their respective inlet and outlet streams was brought to Aspen Plus Dynamics as a pressure-driven dynamic model.
In the dynamic model (both the *.dynf and *.appdf files are also included in the attachments section), a flowsheet constraint is used to correlate the pressure drop (in bar) of ‘HX’ as a function of the volumetric flowrate (in m3/hr) that it handles:
CONSTRAINTS
//Flowsheet variables and equations...
blocks(HX).P_drop = (-1*10^-9)*((streams(INLET).Fv)^2);
//Pressure drop is defined as a function of the inlet stream volumetric flowrate.
//blocks(HX).P_drop = Pressure drop calculated for the heater model.
//streams(INLET).Fv = Volumetric flowrate.
END
With this, the pressure drop across ‘HX’ during the dynamic run will be computed with the equation above and that of ‘HX2’ using the original heater model.
Note: The *.bkp, *.dynf and *.appdf files were built in V9. If using a newer version, please update the *.appdf file.
Keywords: Flowsheet Constraints, Equations, Compile, Blocks, Streams, Variables, Customize, Calculations.
References: None |
Problem Statement: How is the pH calculated when using the Sour Water Property package? | Solution: The pH value is calculated based on the activity of the ions in the sour waterSolution. We have no pH data to validate the Sour Water package. There are only VLE data available, and the predicted VLE match the experimental data, thus, the predicted ion activity and pH value should be reasonable.
Keywords: Sour Water, pH
References: None |
Problem Statement: In Aspen Shell & Tube Exchanger, the program will calculate Rho*V2 values for both the shell and tubeside at different positions of the exchanger. Why does the program calculate and report these values? Where can I find the relevant TEMA recommendations? What happens if any of the calculated values exceeds the TEMA recommended values? | Solution: The Tubular Exchanger Manufacturers Association (TEMA) provides limits to minimize erosion of tube bundle components due to the high-speed flow in the exchanger, on both the shell and tubeside.
For erosion protection purposes, TEMA gives recommendations of ρν2 values at shell inlet/outlet nozzle, shell entrance/exit, bundle entrance/exit, tube inlet/outlet nozzles and tube inlet/outlet regions. From TEMA 9th Edition, these recommended values can be found in Section 5 ''RCB-4 BAFFLES AND SUPPORT PLATES'', under sub-set ''RCB-4.6 IMPINGEMENT BAFFLES AND EROSION PROTECTION'', on page 5.4-6.
Within the program, these values will be reported under Results | Thermal / Hydraulic Summary | Flow Analysis | Flow Analysis tab:
If the calculated values by the program exceed the TEMA recommended values, the program will generate Operation Warnings, reminding users of the potential risk of tube bundle erosion:
Keywords: Operation Warning 1341, rho v squared, ρν2, TEMA recommended value, Erosion protection
References: None |
Problem Statement: Can I use Spreadsheet import/export in a Pipeline Project? | Solution: No. Upon creating a Pipeline Project in Aspen Capital Cost Estimator (ACCE), the Spreadsheet import/export functionality will be disabled, so the data from these projects will not be available to export into MS Excel, the option will appear grayed out.
Since this function only works with non-Pipeline Projects, as a workaround you can create a new Scenario with no Pipeline areas, you can then import all non Pipeline components and Areas to the new project and use the functionality on the second file. When the Spreadsheet usage has finished, the components can be re-imported to the Pipeline project from the Projects tab of the Palette.
Keywords: Pipeline Project, Pipeline, Spreadsheet, Blocked, Grey, Excel, Pipeline Areas
References: None |
Problem Statement: How can I ramp a variable in Aspen Plus Dynamics/Aspen Custom Modeler? | Solution: In Aspen Plus Dynamics/Aspen Custom Modeler, you can make the value of a variable change over a fixed duration of time by using the ‘ramp’ function. For example, you can heat up a stream to change its temperture from 30 C to 65 C in 10 min (of simulation time). Only input variables (‘fixed’ variables) can be the target of a ramp function.
There are two ways in which users can ramp variables:
1) Create a task and set up a ramp function using the Aspen Custom Modeler (ACM) language:
RAMP (variable, final value, duration); - for Linear ramp
SRAMP (variable, final value, duration); for S-shaped ramp
2) Open a form of either a stream or block (e.g., ‘Manipulate’ form of a stream), right-click on the fixed variable you want to ramp and click on the ‘Ramp…’ option. Next, define the parameters of the ramp function. This approach can only achieve linear ramp.
If you click on the ‘OK’ button, the ramp function will be enabled and the fixed variable you set it up for will be shown in red.
To disable the ramp function, right-click on the ramped variable and click on the ‘Cancel’ button under the ‘Variable Ramp’ dialog. The variable will then be shown in black again.
Keywords: Ramp, Change, Duration, Time, Fixed Variable, Input Variable.
References: None |
Problem Statement: I would like to create my own custom P&ID library within Aspen Capital Cost Estimator (ACCE). How can I do this? | Solution: Follow these steps to create your own Piping and Instrumentation Drawings and libraries:
1) Open ACCE and make sure all projects are closed. You may close any currently active projects by hitting File | Close.
2) Go to the libraries tab in the palette window and double click on the P&ID icon.
3) Right click on User P&ID Libraries and select to create a Category (folder to contain all your custom P&IDs) or a File (Single P&ID file).
Note that if you select File without Category, it has no impact on the result. The folder is for better management of your library.
4) Name the new drawing file and add an Item Symbol and Item Type. Use the ... buttons to display a list of Symbols and Types available.
5) When finished, click the OK button.
6) The new P&ID file will appear on the left section of the window. Double click on it to display a blank P&ID Editor. Use it to draw your item as desired.
To draw your P&ID objects:
- Use the Equipment section to add Equipment Icons
- Use the Piping section to add some valves and certain types of fittings
- Use the Instrumentation section to add sensors and instruments
- Use the Line Types section to add Piping/Instrumentation connection lines.
* Right click in lines and icons to re-route or remove the elements
* Double click in Piping lines and Instrument objects to add more information
7) When you finish the drawing, go to File | Save to save any changes to the drawing.
8) Repeat this process for as many components you wish to add.
Note: If you have two similar pieces of equipment with slightly different piping/instrumentation configuration, instead of starting from scratch, you can select an existing component and right click on it and choose Duplicate. With this, you can make the slight modifications to a component and save it as a separate drawing.
Keywords: P&ID, User Libraries, Custom.
References: None |
Problem Statement: How is MBO component mapped to APS stream when using Copy from APS? | Solution: When the Copy from APS button is used, the mapping is done via stream name in APS and component name in MBO. For example, for comp ALKY to copy rundown rate from APS into MBO, APS must have a stream called ALKY.
Keywords: None
References: None |
Problem Statement: In the Shell & Tube Thermal program, there is no input field for Front (or Rear) head dimensions (e.g. length). Why is this? | Solution: In the Shell & Tube Thermal program, the main results are related to thermal performance (duty, outlet temperatures, etc.), hydraulic performance (outlet pressures, pressure drop, etc.) and vibration analysis. In these calculations, the front (or rear) head length does not have any influence to the results. As such, it is not an input for this program.
NOTE: In the Mechanical program, the front/rear head length is a required parameter in the thickness calculations and will be a required input.
Keywords: Front head length, Rear head length
References: None |
Problem Statement: How to get the stream gas flow in cubic feet per minute (Cuft/min) in Aspen Plus V10?
Property = VVSTDMX, Units = cuft/min, Qualifiers: T = 60°F; P = 14.696 psia.
But, when user add this property to the Stream Report Table, it shows unit cuft/lbmol for all streams, not the stream flow in Cuft/min. Is there a way round this? | Solution: Open Aspen Plus simulation file in Aspen Plus V10
Click on Property Sets folder, click on Add button, select VVSTDMFL Property set
Add this property set in Setup - Report Options to see it in Result Summary - Streams
It shows unit as cuft/min” for all streams, Vapor phase property
Keywords: Cuft/min, VVSTDMX, VVSTDMFL, etc.
References: None |
Problem Statement: Note: This problem was reported on a Windows 2016 Server with Excel 2016. This is a rare issue; it does not occur on most systems, regardless of Windows or Excel version.
With two or more GDOT applications configured for Model Update, the first instance of Model update will complete startup, with messages in the log file like this:
03/11/2017 22:29:00 Starting up GDOT Model Update (Process ID C:\GDOT Apps\REF_OPT\REF_OPT.xlsm
03/11/2017 22:29:04 Successfully opened workbook: C:\GDOT Apps\REF_OPT\REF_OPT.xlsm
03/11/2017 22:29:04 Save Interval set to 1400 Executions
03/11/2017 22:29:04 Save a seperate copy of the workbook every saveinterval (this will fill up the directory so be careful)
03/11/2017 22:29:04 GDOT Model Update configuration completed
03/11/2017 22:29:04 Configuration for OPC Items completed. 63 Read Items, and 0 Write Items
03/11/2017 22:29:04 Data Collector initialised
03/11/2017 22:29:04 Start up of GDOT Model Update completed successfully
The second Model Update instance should startup and produce similar messages, ending with the “Start up of GDOT Model Update completed successfully”, but instead it hangs and never produces the “Successfully opened workbook: …” message.
If the first instance of Model Update is terminated, and the associated Excel instance terminates, then the second Model Update will complete startup successfully. | Solution: This problem occurs when Excel is unable to find or create the following directory:
C:\Windows\SysWOW64\config\systemprofile\AppData\Local\Microsoft\Windows\INetCache
When Excel is started by Model Update, Excel will create that directory if it is missing. If Excel is unable to create the directory, then additional instances of Excel (if started as background processes, via Model Update) will be blocked from opening workbooks.
You can manually create the directory to get past the problem. To do so:
Open a command prompt window using “Run as administrator …”
In the command prompt, use “CD” to navigate to C:\Windows\SysWOW64\config\systemprofile\AppData\Local\Microsoft\Windows
With that directory as the current directory, create new directory “INetCache” using this command:
mkdir INetCache
Stop all Model Update process and Excel processes. Restart the gain updates (Model Updates) and now multiple Model Update processes should be able to start successfully and run concurrently.
Keywords: GDOT, Model Update
References: None |
Problem Statement: How to run a case study? How to create a case study? | Solution: Go to the Navigation Pane and select the option “Case Studies” and click on “New”.
Set the dependent and independent variables, by clicking on the “Find Variables” button of each section.
Browse the variables from each stream or block.
Once the variables are set, provide the range (Start and end value), and the step size or the number of steps.
Note that there are 4 Case Studies Types:
Sensitivity: An isolated variable study for examine one variable at a time.
Nested: Examines all the possible combinations of variable changes.
Discrete: Studies for specific variables values.
Base & Shift: Allows to set a number of base cases and shifts off the base cases.
Click on “Run” button and, once the study finishes, go to “Results” tab to view the result in “Plots” for table format.
Keywords: Case study, Dependent Variable, Independent Variable, Setup.
References: None |
Problem Statement: What is the basis for the Reflux Ratio reported on the performance page of the Column Property view? | Solution: The basis for reflux ratio on the performance page is Molar basis and it is calculated including the vapor flow. It is calculated as shown below
Reflux ratio = NetLiq/Product flow,
where product flow = vapor flow + liquid flow.
Keywords: Column, Reflux ratio, Performance page
References: None |
Problem Statement: How to add Critical Properties to Workbook? | Solution: To add the critical properties, use the Object Type- Utility Objects - Critical Properties. Follow below steps for adding the properties.
1. First, add the Critical Properties Stream Analysis to the streams of interest.
2. Next, go to Workbook tab, Setup option. Add a new Tab, Object Type- Critical Properties.
3. Once the Critical Properties Type is added, select the variables.
Attached the document provides more details.
Keywords: Workbook, Critical Properties, Object Type- Utility Objects
References: None |
Problem Statement: Save sub-flowsheets as templates for possible use in future models. | Solution: Select the flowsheet that you want to create as a template. Do a right click, select Export to File. A *.hfl file is created and can be used when a Flowsheet Unit Operation is created in a case.
Open the file from Open\Case
The template can be converted using the Customize menu Option. Click on the Convert to Template button. The template is saved as a *.tpl file.
Keywords: Multiple subflowsheets, template
References: None |
Problem Statement: Why doesn't the pipe segment in dynamic model give the same flow or pressure drop as in steady state? | Solution: The pressure drop or flow rate in a pipe segment can give different results after converting from steady state to dynamic mode. In order to achieve a comparable results the user needs to check the following parameters:
1. Change the pipe flow model from Simple Pipe Friction Model Method to Pipe Model Correlations. This takes the pipe flow correlations selected for the steady state simulation. This option is available under the Dynamics tab of the pipe segment. See the screenshot below.
2. Open the Integrator page via the Simulation menu (Ctrl + I) and select the Static head contribution tick box under the Options tab. This takes the static head contributions in the pipe and making use of the orientation of the pipe segment. See the screenshot below.
Keywords: Pipe segment, Static head, Correlation
References: None |
Problem Statement: When using Aspen Shell & Tube Exchanger program, users need to specify the rear head type of the exchanger as part of geometry inputs, under Input | Exchanger Geometry | Geometry Summary | Geometry tab.
This technical | Solution: contains some general guidelines for selecting a rear head type when designing a shell & tube exchanger.
Solution
The various rear head types are:
- L, M and N-type: These are for fixed tube sheet exchangers and correspond to the A, B and N-type front end heads. L and N types would normally only be used for single (or odd) tube-pass exchangers, where they permit access to the tubes without dismantling the connections. For exchangers with an even number of tube-side passes generally an M-type is considered.
- S-type (floating head with backing device): This type is usually referred to as a ''split ring floating head'' or sometimes abbreviated to SRFH. The backing ring is split, i.e., made in two halves to permit removal so the floating tubesheet can be pulled through the shell. Because of the split backing ring, the rear tubesheet can be smaller than with a T type, meaning the shell diameter is smaller (although it is still larger than with fixed heads).
- T-type (pull through floating head): This is referred to as ''pull through'' as, unlike the S-type, the rear end can be pulled through the shell without first having to remove the floating head. To achieve this, the shell diameter must be greater than that of the corresponding S-type, making the T-type more expensive (except for kettle reboilers). This also affects the thermal design. T-types are easier to dismantle than S-types.
- P-type (outside packed floating head): The gap between the shell and floating tubesheet is sealed by compressing packing material contained between the rear head and an extended shell flange by means of a ring bolted to the latter. The packed joint is prone to leakage and is not suitable for hazardous or high-pressure services on the shell side.
- W-type (externally sealed floating tubesheet): Sometimes referred to as an ''O-ring'' or “lantern ring” type due to the lantern ring seals between the floating tubesheet and the shell and channel respectively. The packed joints are almost certain to show some leakage and therefore are suitable for low pressure, non-hazardous fluids on the shell and tube side.
- U-type (U-tube bundles): With the U or ''hairpin'' tubes only one tubesheet is required. Two pass U-tube units are also useful for handling tubeside two-phase mixtures which could separate with consequent misdistribution in the return headers of two pass straight tube types.
Note: If tubeside mechanical cleaning is required, some company specifications may consider U-tubes as not mechanically cleanable.
More detailed descriptions and layouts of front head types can be found in TEMA (Standards of the Tubular Exchanger Manufactures Association), Section 1, N-1 ''SIZE NUMBER AND TYPE DESIGNATION - RECOMMENDED PRACTICE''.
Keywords: Rear head type, TEMA, Selection, Shell & tube exchanger.
References: None |
Problem Statement: How can I use a non-constant ambient temperature for an adsorption bed? | Solution: Aspen Adsorption can consider heat transfer between the bed and the environment by specifying an ambient temperature. This “Tamb” variable is fixed, but it could change throughout the process.
To use a non-constant ambient temperature, you can create a Task that changes it at specific time intervals, or when a particular condition is met (following the same guidelines to define Tasks).
This example is a modification of the “AirTSA” example from the Aspen Adsorption library, and attempts to do the following:
1. Define a Task to change “Tamb” at specific time intervals
2. Use the Task in the adsorption bed to perform heat transfer calculations with the environment
Description:
- The basic setup of the model will be the same as the “AirTSA” example file. Heat Transfer with the Environment has been set to Rigorous:
- A Task has been created to increase the ambient temperature by 1 K every 720 seconds. The Task runs at t=0 (at the beginning of the run):
- The change in Tamb can be observed in the Specify form of the bed:
- The example file is attached.
Keywords: Ambient temperature, adsorption, bed, constant, Tamb
References: None |
Problem Statement: Why for some isotherm lower bound of standard-state pressure (Poi) is fixed at 1e-10 bar? | Solution: For IAST isotherms like “Dubinin-Radushkevich with I.A.S” the lower bound of standard-state pressure is fixed at 1e-10 bar. This is hard coded in Adsim as a safeguard for the Log.
As a workaround, user can select I.A.S Henry 1 type isotherm which allows modification of lower bounds of Poi.
Key Words
Isotherm, Saturation pressure, Lower Bound
Keywords: None
References: None |
Problem Statement: How to get access to the list of unit operations in Aspen HYSYS through VBA Automation and apply type filters: | Solution: The following code illustrates how to get access the collection of unit operations and apply type filters to narrow the return set:
'Note: Aspen HYSYS Type library must be referenced under Tools ...
Keywords: VBA, Automation, Typename, Access
References: s
'Require explicit variable declaration
Option Explicit
Const EMPTYTEXT As String = <empty>
Const NATEXT As String = ---
Public Sub OPS()
Dim hyApp As HYSYS.Application
Dim hyCase As HYSYS.SimulationCase
Dim hyOperations As HYSYS.Operations
Dim hyUnitOp As Object
Dim hyUnitOp2 As Object
Dim hyUnitOp3 As Object
'Link to Aspen HYSYS
Set hyApp = GetObject(, HYSYS.Application) 'Only works if Hysys is open
'Get the currently open case
Set hyCase = hyApp.ActiveDocument
If hyCase Is Nothing Then
MsgBox Make sure Aspen HYSYS is open with a case containing a pipe of the specified name, , Error
Exit Sub
End If
'Accessing to a specific unit operation by index number:
Set hyUnitOp = hyCase.Flowsheet.Operations.Item(1)
'Accessing to a specific unit operation by name:
Set hyUnitOp2 = hyCase.Flowsheet.Operations.Item(Flash) 'Must have the exact name of the Unit operation
'Accessing to a specific unit operation by operation type:
Set hyUnitOp3 = hyCase.Flowsheet.Operations(sep3op)
' Get index:
Dim index As Long
index = hyCase.Flowsheet.Operations.index(Flash) 'Must have the exact name of the Unit operation
'Get name:
Dim name As String
name = hyCase.Flowsheet.Operations.Names(1)
'Collection for all type of separators
Set hyOperations = hyCase.Flowsheet.Operations(HYSYS.OperationClassification_enum.oc_Vessels) 'OperationClassification_enum contains a collections of different unit operation types
'To select an specific vessel:
Set hyOperations = hyCase.Flowsheet.Operations(sep3op) 'For 3-Phase Separator
Set hyOperations = hyCase.Flowsheet.Operations(flashtank) 'For Separator
Set hyOperations = hyCase.Flowsheet.Operations(tankop) 'For Tank
End Sub |
Problem Statement: What’s New in V11: Add Steel Fireproofing to Mill Building | Solution: Previously, steel fireproofing was not generated by default for the BSTLMILL BLDG plant bulk. Steel fireproofing specified at the project and area levels is now applied to the steel mill building as is currently done for open steel structures and steel piperacks.
Keywords: V11, new, steel fireproofing, mill, building, steel, fireproofing
References: None |
Problem Statement: I am trying to generate a combustion reaction for 1,1,2,2-tetrachloroethane (C2H4Cl4) in RSTOIC.
However, there is no combustion on the tetrachloroethane generated. Why is that? | Solution: If you use Combustion to generate reactions, components containing atoms other than carbon, hydrogen, nitrogen, oxygen, and sulfur are ignored. That is why you didn't get the reaction for 1,1,2,2-tetrachloroethane, because it contains chlorine.
I suggest you trying to explicitly specify the reaction stoichiometry in RSTOIC, or trying the RGIBBS reactor (where you don't need to specify the reaction stoichiometry).
Key Words
RSTOIC
Generate combustion
Keywords: None
References: None |
Problem Statement: On some Oracle systems, upgrading the Aspen Production Record Manager database using the Aspen Database Wizard will fail with the error: ORA-02429: cannot drop index used for enforcement of unique/primary key. At this point, the wizard will fail. Subsequent attempts to run the wizard will also fail. | Solution: In this situation, check the DatabaseWizard.log file to see which table the wizard was upgrading at the time of failure - see In which directory can I find a log file for the Aspen Database Wizard?
The following log file entries come from a system which encountered this problem.
ALTER TABLE ASPENBATCH21.char_batch_data_history ADD CONSTRAINT fk_ch_batch_data_hist_batchid foreign key (batch_id, subbatch_id, parent_char_inst_path_id, char_id, char_inst) REFERENCES ASPENBATCH21.char_batch_data(batch_id, subbatch_id, parent_char_inst_path_id, char_id, char_inst)
DROP INDEX ASPENBATCH21.idx_char_batch_data_1
CREATE INDEX ASPENBATCH21.idx_char_batch_data_1 on ASPENBATCH21.char_batch_data (subbatch_id, parent_char_inst_path_id, char_id, char_inst, char_value) tablespace ASPENBATCH_DAT
DROP INDEX ASPENBATCH21.idx_char_batch_data_2
ERROR:
Keywords: None
References: None |
Problem Statement: In very rare cases, simulation file sizes can greatly increase due to ballooned ADS content. Is there a way to disable ADS reporting?
Description
Aspen Data Share (ADS) is a mechanism to transfer data between AspenTech applications. This can be turned-off, but will impact the following features (i.e. they will no longer will function as designed):
Activated Economic Analysis
ABE Datasheets, which is used mainly to generate reports in the Safety Environment.
Blowdown (HYSYS): it will still run but it will not be able to show plots and other results. | Solution: To turn-off, copy %LOCALAPPDATA%\AspenTech\ into Windows Explorer or similar. If you do not have an Aspen Data Share folder, create one and put the attached config.xml file there.
This will turn-off ADS reporting for both HYSYS and Aspen Plus.
Warning! Doing this will impact Activated Economic Analysis, ABE Datasheets and Blowdown (HYSYS).
CAUTION! Aspen Plus requires ADS to report stream results... ASPEN PLUS USERS SHOULD NOT USE.
Keywords: None
References: None |
Problem Statement: How to add a reference to the Aspen HYSYS type library in VBA. | Solution: Before you can perform early binding with Aspen HYSYS or other Applications in our Engineering Suite, you should to add the corresponding type libraries that contain metadata with the type definitions.
In VBA, from the “Tools” menu, click
Keywords: ActiveX, VB, VBA, Visual Basic, Automation Server, getting started, libraries, object browser.
References: s
Browse the drop-down menu and check, for instance “HYSYS 8.6 Type Library”. Depending on the version installed, you may find a library with a different reference name.
Now if you open “Object Browser” from the “View” menu, you will find the class “HYSYS” which contains all the properties and methods exposed as an automation interface by the program.
Now VB is configured to work with HYSYS Automation Server. |
Problem Statement: How do offset values for compressor performance curves work? | Solution: In Aspen HYSYS, you can enter offset values to build compressor curves in a simpler way.
The offset values will directly affect head and efficiency values of the specified performance curves.
If Head < 0, then the resulting head values for all performance curves will be calculated as follows:
Head (entered in the performance curve) = Head- abs(Head Offset).
If Head > 0, then:
Head (entered in the performance curve) = Head + (Head Offset)
For efficiency, the same applies:
If Efficiency < 0, then the resulting efficiency values for all performance curves will be calculated as follows:
Efficiency (entered in the performance curve) = Efficiency- abs(Efficiency Offset)
If Efficiency > 0, then:
Efficiency (entered in the performance curve) = Efficiency + (Efficiency Offset)
Keywords: Offset, Head, Efficiency, Performance Curves, Compressor.
References: None |
Problem Statement: Does the Aspen HYSYS pipe segment follow the API 521 method including choking pressure determination for the sonic velocity calculation? | Solution: The pipe segment follows a different approach as Aspen HYSYS computes static, friction and acceleration pressure gradients (for some selected methods only) in different parts and then adds them to get a total pressure gradient.
Static pressure gradients consider choking and are computed performing equilibrium calculations at operating conditions and then working their way from there based on the methods documented in the ‘Calculation Modes’ topic in the Help Menu Guide. Friction and acceleration terms account for the differences against API 521, so that a total pressure gradient can be calculated.
To model more rigorous systems, use Aspen Hydraulics / Safety Analysis / Aspen Flare System Analyzer.
Keywords: Pipe Segment, API 521, Static, Friction, Acceleration, Pressure Gradient, Choking.
References: None |
Problem Statement: Which Mass Transfer Coefficient (MTC) method is most suitable for Pressure Swing Adsorption? | Solution: Most of the available MTC methods are applicable for Pressure Swing Adsorption processes. However, “Pressure Dependent Arrhenius” model accounts for changes of total pressure which is very characteristic of PSA systems.
The correlation has a pressure term and pressure adjusted pre-exponential factor. This model was found to match experimental data very well.
Key Words
MTC, Pressure Swing, Adsorption
Keywords: None
References: None |
Problem Statement: How to convert Microsoft Access databases to SQL databases? | Solution: Prior to V11 release, the AUP used MS Access databases(.mdb) for configuring Optimization. Starting in V11, all Optimization configuration need to be done with SQL databases (.mdf). All existing .mdb formats need to be converted to .mdf for use in V11.
Here are the steps to convert:
Open the automatic conversion tool (ATUDatabaseConverter.exe) located in C:\ProgramFiles\AspenTech\AspenUtilitiesPlannerV11.0\bin\
Use “Add” tab to select the databases to be converted
You can use the “Browse” to put the new databases to a desired location. Otherwise they will be placed in default location.
Hit the “Convert” to start transferring to SQL format.
Key Words
SQL, Databases, Optimization
Keywords: None
References: None |
Problem Statement: Where is the ISBL/OSBL specification located in the Aspen Capital Cost Estimator (ACCE) software? | Solution: A Battery Limit is a boundary between two areas of responsibility, which may be physical or represented by a map coordinate.
ISBL = Inside Battery Limits
OSBL = Outside Battery Limits
To be able to see project Battery Limits information, follow the steps below:
1. Make sure that your project has a report group with an ISBL/OSBL flag and evaluate it. This can be found by right-clicking on the Report Group above the Area:
2. Go to C:\Users\'User Name\AppData\Local\AspenTech\EE Version\Projects and look for your project.
3. Inside your project's folder look for the BPROJID file and open it with the Notepad.
4. Look up for ArBatteryLimitLocation, you can use the Ctrl+F command:
Notes:
The B table (BProjID) is in the Database files.
The field is called PROPNAM (13th column) = ArBatteryLimitLocation, look up VALUET (5th column)
I = ISBL, O = OSBL
Keywords: ISBL, OSBL, Database files, Battery Limit, BProjID, ArBatteryLimitLocation.
References: None |
Problem Statement: What correlation does the pipe segment in Aspen HYSYS use to determine the sonic velocity for choked flow calculations when handling two-phase systems? | Solution: The correlation described in the KB Article ‘What criteria does the Pipe Segment use when checking for Choked Flow ?’ applies for both full-vapor and vapor-liquid mixtures.
Aspen HYSYS computes the fluid properties specifically for either a single phase or a mixture and then proceeds to perform the calculations described in the KB Article referenced above.
Keywords: Pipe Segment, Sonic Velocity, Choked Flow.
References: None |
Problem Statement: What are the viscosity methods for two liquid phases in Aspen Shell and Tube Exchanger? | Solution: Depending on the nature of the process (single phase, condensation, vaporization) and the amount of each liquid phase present in the mixture, a different viscosity method may be needed. There are 5 options to choose from in Aspen Shell & Tube Exchanger, available under Input | Program Options | Methods/Correlations | General | Viscosity method for two liquid phases:
The main characteristics of each option are listed below:
Method Description
HTFS selected method (Default) Uses the Higher viscosity method for condensing flows and the HTFS emulsion method for single phase and boiling flows.
HTFS emulsion method Used for single phase and boiling flows
HYSYS emulsion method Does not use a Brinkman type power law equation for effective viscosity, but the resulting viscosities are broadly similar to using a power of 2.5.
The major difference is that the oil is assumed to be dominant for oil volume fractions above 0.5, and the water is assumed to be dominant below 0.33. A weighted mean is used in the transition region.
Use higher viscosity Mostly appropriate for condensing flow. This option uses the higher of the two individual liquid phase viscosities.
It assumes that the higher viscosity liquid phase is immediately adjacent to the heat transfer surface, and so dominates the heat transfer and pressure drop processes. In a condensing system, the heavier phase condenses first and normally has a higher viscosity. This phase will cover the heat transfer surface and the lighter phase must initially condense on top of this phase. As condensation proceeds, the amount of the lower viscosity phase will increase, sometimes to the point where it dominates. The effective viscosity of the two phases is then assumed to be that of an emulsion of droplets of the higher viscosity fluid in a matrix of the lower viscosity fluid
Old HTFS method The Old HTFS method is the basic Brinkman method, an emulsion method in which the effective viscosity of the dominant phase varies inversely as its volume fraction to the power of 2.5. The lower of the two effective viscosities is used.
Note: The Use higher viscosity method was improved in V11. In earlier versions, the higher viscosity was used as long as that phase constituted above 5% (by volume) of the 2-liquid mixture. Below this, the viscosity was transitioned towards that of the lower viscosity phase. The updated method will almost always begin to transition at higher percentages. In some cases, this will result in significantly higher heat transfer and lower pressure drops than the earlier version predicted.
For more details, please refer to the Help menu.
Keywords: Viscosity, methods, two liquid phases
References: None |
Problem Statement: What factors can cause EIU to disappear from Excel? | Solution: Excel Integration Utility (EIU) is an import function used to import event, inventory and assays data into APS/MBO application. EIU is installed as an add-in in excel. Sometimes you may find EIU disappears from excel, which could be related to the following reasons:
EIU is not property installed at the beginning. Users may need to install EIU by steps in the KB article below:
https://esupport.aspentech.com/S_Article?id=000033887
For some machines, it is due to the windows updates or MS office updates. Users may want to check if the registry table is updated correctly.
https://esupport.aspentech.com/S_Article?id=000045830
We also see some conflicts related with Excel/COM add-ins, e.g. PI data. We would suggest users to selectively disable add-ins to narrow down to specific ones.
Keywords: None
References: None |
Problem Statement: How do I Turn off the costs associated with the Power Distribution and Process Control Systems? | Solution: A regular project in ACCE will automatically include certain elements to provide electrical power and process control to the plant. The user can, however, deactivate the costs associated to these elements in case these are not required in the estimate, the elements added by default in ACCE along with the process to deactivate their costs is shown below:
Power Distribution - Main SUB
To modify:
1. Go to the Project Basis View.
2. Look for the section Systems | Power Distribution and double click on it.
3. Expand the + sign next to the Project icon in the center window.
4. Right click on Existing Main (Main 1) and hit Edit.
5. Select - under Transformer required.
6. Select - under Switchgear required.
7. Hit OK to apply these changes.
Note: In a new project, these - options are selected by default, changing these options will allow you to include the cost of the Main SUB in your estimate.
Power Distribution - Unit SUB
To modify:
1. Go to the Project Basis View.
2. Look for the section Systems | Power Distribution and double click on it.
3. Expand the + sign next to the Project icon in the center window.
4. Right click on Unit (Unit 10) and hit Edit.
5. Select the - under Transformer required.
6. Select the - under Switchgear required.
7. Select the - under Motor control center required
8. Hit OK to apply the changes.
Note: Distance to supply can be set to 0 to remove wire costs.
Process Control - Operator Center
To modify:
1. Go to the Project Basis View.
2. Look for the section Systems | Process Control and double click on it.
3. Expand the + sign next to the Project icon in the center window.
4. Right click on Existing Ops (OPS 1) and hit Edit.
5. Select NONE under Operator center type.
6. Specify zero as the Number of operator display units, Number of indicating display and Number of printers
7. Select the - under the History module
8. Select the - under Engineer keyboard
9. Select the - under LCN cable.
10. Hit OK to apply your changes.
Note: The default Operator Center has most of the options active, it's only required to change the Operator center type as described on step 5.
Process Control - Control Center
To modify:
1. Go to the Project Basis View.
2. Look for the section Systems | Process Control and double click on it.
3. Expand the + sign next to the Project icon in the center window.
4. Right click on Ctl (CTL 1) and hit Edit.
5. Set the Control center type to NONE.
6. Leave the Digital control type BLANK.
7. Set the Distance to Operator center to 0.
8. Set the Marshalling Panel should to N.
9. Zero out all items under Design Data.
10. Distance to Motor Control Center must be 0.
11. Zero out all Hardware (EXCEPT Hardware speed class)
12. Zero out all Software, making sure Configuration complexity is set to N.
13. Click OK when done.
If all options are applied, this will get rid of all PC and PD costs, and leave only AREA lighting.
If you need to remove area lighting, you must go into each area and edit it to remove the lighting.
Keywords: Process Control, Power Distribution, Remove, Costs, Delete, Electrical, Instrumentation, Existing
References: None |
Problem Statement: Cost summary in the pipe rack bulk does not appear when evaluating locally within Aspen Capital Cost Estimator (ACCE). | Solution: Best practice for setting up Module Type PRMD (piperack) is to create an area where Area Type is set as ‘Module’ with the Module Type set as PRMD. The pipe rack plant bulk is specified in this Area so that pipe rack module details can be specified here. When running a local Evaluation on the pipe rack plant bulk, cost summary will not appear within the ACCE interface, but cost estimates will be run and included with the ICARUS reporter.
Note that estimating best practice also includes assigning the module to a contractor by choosing the Module Contractor option (M) for the contract definition.
Keywords: PRMD, piperack, pipe rack, Module
References: None |
Problem Statement: Is it possible to transfer simulation data from Aspen Plus or Aspen HYSYS user interface to Process Economic Analyzer? If yes, How? | Solution: Yes, it is possible to transfer simulation data from Aspen Plus user interface to Process Economic Analyzer. This article uses Aspen PLUS as the tool, however, the steps are similar for Aspen HYSYS as well.
Please follow the below mentioned steps to do this.
1. Open Aspen Plus simulation file. (You can also use the attached sample file by downloading to your local computer for learning purpose)
2. Re-initialize it and run the simulation.
3. Make sure your result does not have any error messages.
4. From the Economics Ribbon, click on Send to APEA as shown in screenshot below. This will load the Process Economic Analyzer in background, that means process economic analyzer license will be used.
5. As soon as you click this option it will bring up a properties window, which shows project name (same as your simulation file) and scenario name (by default it is scenario1). You can create a new project or select an existing one. Please refer to screenshot below for detail information.
You can select Unit of Measure in the next window.
6. After selecting appropriate options on properties window, click on OK button which will create a project in economic analyzer.
7. Next step is to select units of measure specification. You can modify each category or chose the default settings.
8. Once you click on the Close button on above window, you should get a window on general project data. You can provide additional details on the project (i.e. Location, Currency, Date) as appropriate.
9. Once you click OK, the load simulation data into Process Economic Analyzer message-box appears.
You can select Yes but if you pressed No, you can load the data from the Run menu.
It may take some time (depending on your simulation size) to load simulation data.
10. Once simulation data has been loaded, next step is to Map these data by selecting Map option from Run Menu as shown in screenshot below.
11. This will bring up a Icarus Map window as shown in screenshot below. Select the appropriate option. You can chose to size the equipment using ICARUS technology or you can ignore it so APEA uses the simulator sizing data.
12. Once you click on OK button on Map window it will bring you to the Project Component Map Preview window as shown below. Select appropriate option for mapping and click on OK button.
13. Before mapping is complete, a equipment will have Yellow color next to its name.
Once mapping is done, the colored arrow will appear indicating mapping has been complete.
14. Next step is to scan for errors.
If there are errors, you can double click on the error message to directly go to the form where input specification/modification is required.
Resolve any input missing error.
15. Once all the error has been resolved, evaluate the project by selecting the Evaluate Project option from Run menu or clicking on the scale symbol.
17. Once evaluation is done, you can run the report by clicking on the $ sign. Now you can see these results by selecting Equipment Summary or also you can select Open Economics Report from Costing option as shown below.
18. This will create Icarus file under the project location (step 5). You can open this file from Aspen Process Economic Analyzer at a later time and all mapping, sizing, and project data will be preserved.
Keywords: Aspen Plus, Aspen Process Economic Analyzer, APEA, Economic Evaluation
References: None |
Problem Statement: How do I import the fluid properties from an existing simulation in Aspen HYSYS? And what must be checked while importing this data? | Solution: To import the properties of an exchanger from Aspen HYSYS into EDR, do the following:
1. Open an existing EDR file or create a new one. Please note that just opening EDR is not enough, you need to open a specific EDR module (S&T, Air Cooler, etc.):
2. Within EDR, go to File | Import | Aspen HYSYS VX.X:
3. A File Explorer will show up to select the HYSYS simulation to be used. Once you select it, the HYSYS simulation will open:
Note: Since the HYSYS simulation is opened, this will consume a HYSYS license/tokens. Once the import process is finished, you can close the HYSYS simulation. Currently there is not a way to prevent the HYSYS simulation from opening.
4. After the HYSYS file launches, a window will pop up with a list of all the heat exchanger in the simulation. Select the heat exchanger you want to import into EDR.
When you import the properties from HYSYS into EDR, the program considers the inlet and outlet pressures and temperatures in the HYSYS model to define the pressure levels and temperature range at which the properties will be determined for the EDR model. However, these numbers can be modified in the Exchanger List window, along with the number of points that will be generated (maximum is 24).
Once the setup is complete you can click OK.
5. A new window will come up to map the streams from HYSYS to the Hot and Cold side in EDR. If everything Is correct you can click on OK:
6. The physical properties and process data will be available in the EDR file now
Keywords: Import, HYSYS, EDR, physical properties
References: None |
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