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Problem Statement: This knowledge base article explains why the Aspen Batch Configuration Utility (BCU) scripts in the scheduler table may sometimes have the status waiting for data. | Solution: The status waiting for data means that a BCU script is about to fire, but needs additional data. For instance, the conditions for the trigger have been met, but the BCU script does not have all the data (yet) to write to the Aspen Batch.21 database. A common cause for this is that you specified to use interpo... |
Problem Statement: Sometimes, a user may return a lot of rows of data with the AtGetTrend function in the Excel Add-ins. However, Excel 97 is limited to a 64k limit. As such if the data exceeds the 64k limit, then no data is returned to the Excel spreadsheet | Solution: We can overcome this with a macro. An example is shown below.
Dim tmp
Dim i As Integer
tmp = ATGetTrend(atcai, New Server, , 9/1/2000 07:47:15 AM,
10/4/2000 09:47:15 AM, 9528, 5m, 0, 25, 0, 1)
For i = 0 To UBound(tmp)
Cells(i + 1, 11).Value = tmp(i, 0)
Cells(i + 1, 12).Value = Format(tmp(i, 1), dd-mm-yyyy hh:... |
Problem Statement: Error starting BCU - Failed to start unit scheduling: '(null)' 80004005 | Solution: For Version 3.1.2 and 4.0.1:
To resolve this error complete the following:
Remove the bcu.areas file from the BCU directory.
Then using the BCU Administrator - Tools | Options, click the Configure button.
From this window, click the Add button and select the desired Area from the pulldown menu and click OK. R... |
Problem Statement: When a user tries to use the Aspen Process Data Add-In (Excel Add-In) to pull attributes from the InfoPlus.21 database by going to:
Aspen/ ProcessData / GetData / AttributeValues....,
an 'Attribute Values' dialog box appears. If the user then enters a tag name and cell reference location on the box, ... | Solution: This error occurs because Desktop ODBC is not installed on the client PC. Desktop ODBC is only required to list the attributes.
Please install the InfoPlus.21 ODBC driver on the PC where the error message occurs. This is usually accomplished by installing SQL+ client on the PC.
Wordaround:
If the user enters ... |
Problem Statement: The Marginal Cost and Marginal Revenue curves indicate important information for a specific amount of feedstock purchased or product sold.
The Marginal Value (DJ) calculated by Aspen PIMS relates both curves at a given amount of material and can be used to calculate one of them given the other.
This ... | Solution: Note: Please seeSolution 124710 for a Report Writer Template that automates the creation of these curves, the cumulative break even calculation and the Objective Function plot.
Description of the Marginal Cost Curve
The Marginal Cost curve indicates for any given unit of material the cost to purchase or produ... |
Problem Statement: The Batch Query Tool (BQT) may give the following run time error immediately upon opening:
Run-time error 2007. Invalid bands collection index.
The above error message often appears after an Oracle application called ADI (Applications Desktop Integrator) has been installed on the computer.
OKing this... | Solution: may help.
Solution
There are a few ways to reset the query tool and hopefully get it to work again.
Make sure the default data source and area are valid and correct
Delete the toolbar file
Delete a bunch of Query tool run time information from the registry.
Check the version, size and date on the following fi... |
Problem Statement: Can I change the maximum amount of velocity that a flare system can handle in Aspen Flare System Analyzer? | Solution: Yes it is possible from V7.2 version onwards.
A new textbox is provided in the Calculation Options Editor to specify the maximum velocity a Flare System can handle. The default value is 500 m/s. In previous versions, this value was hard-coded and if the actual velocity exceeded this, Aspen Flare System Analyz... |
Problem Statement: How do I change all the PSV into a conventional type valve? | Solution: There is not a easy way to change all the valve types to conventional type. You can change one by one in build-nodes.
Another way will be to export your case to excel using Export Wizard. If you use the default definition file, you can change the value to 1 in 7th column (G column) on ReliefValves worksheet i... |
Problem Statement: How can I view the Pressure Profile in the Pipe Segment in Aspen Flare System Analyzer? | Solution: Generally, Aspen FLARENET does not report the pressure profile in the pipe segment. The program will only display the calculated upstream and downstream pressure values. Notwithstanding, the elements are still divided internally. The program just does not expose the calculated pressure values for each interva... |
Problem Statement: What is the pressure drop correlation used for the inlet piping of the PSV? | Solution: Flarenet uses the same methods to calculate the pressure drop in the inlet piping as it does in the main piping, which depends on the correlation chosen. You can check the correlation in use from the Calculation Options.
Keywords: Inlet piping, pressure drop
References: None |
Problem Statement: How can I choose a the printer I want to use in Aspen Flare System Analyzer? | Solution: Aspen Flare System Analyzer will use the default printer in your computer so in order to choose a different one, you need to select the desired printer directly in Control Panel and after that go ahead and print what you need from Aspen Flare System Analyzer
Keywords: Printer
References: None |
Problem Statement: How to model a molecular seal in Aspen Flare System Analyzer? | Solution: There is no standard tool in Aspen Flare System Analyzer to model the molecular seals. The pressure drop by molecular seal can however be accounted for by using the Use Curve method for the flare tip. The pressure drop data can be obtained from the flare tip manufacturers.
Following are the other options avai... |
Problem Statement: Why does not Aspen Flare System Analyzer take my composition when I import data from MS Excel? | Solution: In order to take the composition correctly from MS Excel, please check the following information:
a) You have to have the exact components and order between your input data and Flarenet. This error especially occurs when you add more components to an existing case study. You might need import the existing com... |
Problem Statement: How does one change the roughness for all pipes in a simulation? This option is not available from the File | Preferences menu. | Solution: The parameters for all pipes in a given simulation can be edited at the same time using the Pipe Manager. While the File | Preferences option is used to determine the parameters for new pipe that is added to the PFD, existing pipes can be edited using the Pipe Manager which can be accessed via the Build | Pip... |
Problem Statement: Can I model dynamic depressuring in FLARENET? Does FLARENET have dynamic mode? | Solution: Flarenet does not have dynamic feature at this time, however this functionality is slated to be incorporated into a future release.
If desired, one can import dynamic depressuring case results from HYSYS into Flarenet and create different scenarios to represent specific time steps.A To link FLARENET and HYSYS... |
Problem Statement: Why is the coefficient not deleted once the pipe fitting has been removed? | Solution: Click on the LINK button after you delete a fitting. If you have already left the fitting screen, go back to that form (i.e. double click on the Pipe | Fittings tab), select the fittings type, then press the LINK button. This should remove the extraneous coefficient.
Keywords: pipe, fitting, delete, coefficie... |
Problem Statement: In the Solver tab of the Calculation Options Editor, there is a section to input Damping Factors for the properties and for the Loop. What is a damping factor and how is it applied in the calculation? What are the correct damping factors to get most accurate results? | Solution: In general, a damping factor is a multiplication factor that controls the step size used in the loops. The damping factor is used in the iterativeSolution procedure.
The damping factor in the Properties field is the damping factor applied to the pressure step when solving the inner properties / pressure loop.... |
Problem Statement: Why does rated flow fluctuate in pure component system with superheat 0 when MAWP is changing a little bit? | Solution: The problem here is that for a single component, it has a fixed bubble point/dew point. So when you flash with a exact zero superheat or subercool, Flare System Analyzer has difficulty to know the vapor fraction(it can be either 100% vapor or 100% liquid). The flash usually calculates a value based on which s... |
Problem Statement: Why I am getting warning message: Mach Number Violation at Flange for source, Chocked Flow at Flange for Source? | Solution: Flarenet solves for the pressure backwards, starting at the flare tip. If at any point the local velocity is higher than the sonic velocity, the pressure at the point is increased until the velocity is just equal to sonic so that the Mach number is equal to one. Flarenet then continues to solve upstream.
User... |
Problem Statement: How to add an expander at the outlet of the Relief Valve in Aspen Flare System Analyzer | Solution: Aspen Flare System Analyzer performs expansion/contraction calculations from the orifice of the valve to the tailpipe.
If you want to consider the flange connection to the tailpipe you only need to specify the diameter of the flange in the source tab.
However, very frequently there are additional enlargers or... |
Problem Statement: How do I create data tables in Aspen HYSYS? | Solution: Data Table in Aspen HYSYS V8.3 and higher enhances the usability of HYSYS Simulation. This let the users to monitor key process variables in both steady state and dynamic modes. Data Tables can be placed in the PFD and can be exported to Excel.
Adding Data Tables
1. Click Data Tables in the Simulation Na... |
Problem Statement: Different fitting loss methods for TEE give different results; which is correct? | Solution: Different fitting loss methods available for TEE's are shown below:
Equal Static Pressure (Ignored) - balances static pressure across the tee.
The pressure drop across the TEE is not calculated.
Simple - uses a constant flow ratio independent K factor for the loss through the branch and run.
The Simple me... |
Problem Statement: How can a Flare System be modelled as a simple open pipe without any engineered tip? | Solution: The correct theoretical approach for an open-ended pipe is to set a Fittings Loss Coefficient of unity and use a Fittings Loss Coefficient Basis of Total Pressure (on the Flare Tip|Calculations page).
Note however that the overall effect of this is that a static pressure drop of zero would be observed at th... |
Problem Statement: Why are my results not calculating for the case file in Aspen Flare System Analyzer? | Solution: Go to Calculation | Options | Scenario Tab | Select 'Current Scenario' or 'All Scenario'. At present you might selected, 'Selected Scenario' and no scenario is selected.
Also make sure in PFD view, you are looking for the scenario results you are interested in.
Keywords: None
References: None |
Problem Statement: When opening APS or MBO the next dialog box appears stopping the program execution:
with the message Splash.CreateInstance Failed - - HRESULT: -2146959355 | Solution: In order to fix the problem follow the next steps:
1. Open a command window using admin rights.
2. For a 64-bit OS go to the next folder:
C:\Program Files (x86)\Common Files\AspenTech Shared
For 32-bit OS the folder is:
C:\Program Files\Common Files\AspenTech Shared
3. Unregister and register... |
Problem Statement: What are the different print options available in the PFD Toolbar for printing a PFD? | Solution: In the PFD toolbar, there is a PRINT button in the top left hand corner; next to this is a PRINT PREVIEW button to view a copy of what you are going to print.
To the right of the PRINT PREVIEW button is a drop down menu which determines what is printed. There are four options here:
All - Single Page
The... |
Problem Statement: Is there any way in APS to set a default rate so that when a user creates an event the rate is automatically set, so there is one less thing for the user to do? | Solution: The default rate is specified in the TRANS_MODE table. The EVENT_TYPE column identifies the event type to which the transportation mode/rate applies.
If an specific event type has not been defined in the TRANS_MODE table. The default rate to be used is the first rate with EVENT_TYPE set to NULL.
E.g:
Notice... |
Problem Statement: How can I change default pipe segment icon color scheme on PFD? How can I change font type and size on PFD? | Solution: By default pipe segment color scheme is in grey color.
But if user wish to change then it can be changed to white color icon by changing below settings
File/Preferences/PFD/ Please select check box Use wire frame icon in display
File/Preferences/PFD/ Please select font type from drop down menu box (by default... |
Problem Statement: When printing the MBO Blend Details dialog (using the PRINT button), it would be nice if it would print in color so that the hard copy would have all the great new color indicators that you see on screen. | Solution: 1. Turn on the printing of background color in Internet Explorer.
From 'Internet Explore', Tool | Internet Options | Advanced tab,
2. Open your model in MBO
3. Go to Blend Details dialog
4. Click Print to File, verify the html file has table printed in the same colors as on the dialog
5. Click Print, s... |
Problem Statement: What is the consequence of changing the ‘Source inlet velocity basis’ option in the Calculation Options Editor, shown below? | Solution: This option influences the velocity used at the inlet of the source element (valve) for purposes of calculating the kinetic energy in the energy balance across the valve only. It is not a velocity specification. Thus, when the option ‘Zero Velocity’ is chosen, the static pressure upstream the valve does not e... |
Problem Statement: What does Beta=1 and Theta=0 mean in the fitting that is called Ball Valve (Beta=1, Theta=0)? | Solution: Beta (β) is the ratio of valve seat diameter divided by pipeline diameter.
β = dvalve / dpipe
Theta (θ) is called the reducer angle of approach.
So, a value of Beta =1 and theta = 0 means that the valve has the same diameter as the pipe. These two parameters are used to calculate the resistance coefficient fo... |
Problem Statement: How to obtain the whole system volume of Flarenet's network? | Solution: There is no direct way to get the whole volume of the network. The simple Excel Macro is written to calculate the volume. In order to run it, you have to keep the flarenet case study open.
The attached version is only working for Flarenet 4.1 or lower version. If you have new version, you can change the refer... |
Problem Statement: How do I add a constant superimposed back-pressure on a pressure safety valve in an Aspen Flare System Analyzer model? | Solution: The pressure at the flare tip is equal to the atmospheric pressure plus the pressure drop across the flare tip. This value is also the superimposed back pressure.
There is no option to directly set the superimposed back pressure to a constant value. However, the user can use the following workarounds that mod... |
Problem Statement: How to add Mercaptan as a component, I can NOT find in the component database? | Solution: Select M-Mercaptan from the component list.
Note: You can use * as wildcard character if you do NOT know the first few letter or last few letter of the component name. For example for Mercaptan type in *Mer, you will see the component name.
Keywords: Mercaptan, component
References: None |
Problem Statement: In the File | Preferences... menu, what does the Display Velocity Properties Used By Pressure Drop Calculations option do? | Solution: In Aspen FLARENET, there is a checkbox on the General pagetab of the session preferences labeled Display Velocity Properties Used By Pressure Drop Calculations. When this option is activated, the velocity dependent properties (i.e Mach number, rho v^2 term, Reynolds number etc.) that are displayed for a given... |
Problem Statement: Is there a way to set the system to bubble point or dewpoint? | Solution: If you enter a sub-cooling value, this is the temperature difference between the bubble point and the stream temperature. FlareNet calculates the bubble point, then the required temperature based on the specified sub-cooling. Similarly, for superheating, FN calculates the dew point, then the required temperat... |
Problem Statement: Which method should I use 'Compressible' or 'Incompressible' for Swage calculations of Relief Valve? | Solution: Under Swage Method field: Compressible assumes compressible flow, Incompressible assumes incompressible flow, and transition first calculates the pressure drop assuming incompressible flow, but if the pressure drop (expressed as percentage of inlet pressure) is greater than the value specified in the Compress... |
Problem Statement: Where can I see the flow map in Aspen Flare System Analyzer? What is the basis? | Solution: User Can able to see Flow Regime results from Toolbar/View ->Results-> Flow Map
The flow map available in Flare System Analyzer displays the flow pattern correlation of Gregory Aziz and Mandhane, which is currently the most widely used method. It was based on almost 6,000 flow pattern observations, from a var... |
Problem Statement: Can I directly input fluid properties in Aspen Flare System Analyzer? | Solution: In Aspen Flare System Analyzer, you can not directly input the properties of the fluid. You have to set up the components or create hypos to represent your fluid. You have to input composition or molecular weight for each valve. The fluid properties will be calculated rigorously based on your input and thermo... |
Problem Statement: How is the MABP approach calculated? | Solution: The MABP Approach is calculated as follows:
As an example, please refer to PSV 1 located in Sample-S1 (C:\Program Files (x86)\AspenTech\Aspen Flare System Analyzer V7.3\Samples\Convergent). The atmospheric pressure in this case was set as 1.01325 bar.
The Downstream static pressure is reported in the Summ... |
Problem Statement: How to add Single Source Scenarios for multiple relief and control valves? | Solution: There are two options available
A. Go to tools on the menu bar and select Add Single Source Scenarios. If there are 100 relief valves, then this step will add 100 new scenarios with only one valve relieving to the network.
B. Clone the base scenario on the Build menu and Scenario option. Edit each scenario an... |
Problem Statement: How to enter the vendor curve information for the flare tip | Solution: Aspen Flare System Analyzer allows the user to input a characteristic pressure drop curve. The program interpolates along the curve to calculate the pressure drop based on the flow rate. Aspen Flare System Analyzer also allows the user to supply multiple curves at different reference molecular weights to acco... |
Problem Statement: Is it possible to ignore a pipe in one scenario, but allow it in other scenarios? | Solution: Please note that in Aspen Flare System Analyzer the geometry and configuration of network are fixed. If you change something (i.e pipe diameter) in one scenario, it will be changed in all other scenarios too. What you can do that is only applicable per scenario is to change source conditions and ignore some u... |
Problem Statement: How to add multiple lines of Annotation on the PFD? | Solution: Use the letter A on the PFD toolbar to enter Annotation.
At the end of first line enter CNTROL and ENTER key on the keyboard to type in next line of annotation.
Press Enter key only on the keyboard once you finish entering the Annotation.
To edit the annotation double click on the typed annotation on the PFD.... |
Problem Statement: What is the difference between the 'mixture velocity' and the 'superficial phase velocity' constraint options? | Solution: When check vel. constraint with is set to Mixture velocity in Scenario Editor | constraint tab the velocity violation occurs when the Mixture velocity is higher than lower of liquid velocity constraint & vapor velocity constraint,
When check vel. constraint with is set to superficial phase velocity in Scenar... |
Problem Statement: Why am I unable to connect objects on the Aspen FLARENET PFD? | Solution: Try pressing the Toggle Connect/Arrange Mode button. While in Arrange mode, the user can move items on the PFD, but is not given the ability to connect objects.
Keywords: toggle, connect, arrange, PFD, object
References: None |
Problem Statement: How to read Aspen Flarenet file, saved in newer version, in older version? | Solution: User would need to export the File in MS Access / Excel / XML format and then the file can be imported back in older version of Flarenet to read it.
For example, if file is saved in v 2006.5 and user wants to read it in version 3.51a, follow the steps below
1. Go to File | Export Wizard (Cntr+E) and export th... |
Problem Statement: How does one include the file path and filename when printing a PFD? | Solution: Select File | Preferences from the main menu in Aspen FLARENET, then activate the Use Footer checkbox on the Formatting tab.
Keywords: filename, file, path, name, PFD, print
References: None |
Problem Statement: What pressure drop correlations are available in Aspen FLARENET and when should they be used? | Solution: A brief description of the different pressure drop correlations available in Aspen FLARENET is provided below. For more information on these methods please refer to the Aspen FLARENET
Keywords: Pressure, Drop, Correlations
References: Manual.
Isothermal/Adiabatic Gas
These methods are for vapour phase only ... |
Problem Statement: When running Aspen Flare System Analyzer in a Window Server 2003 you received the following error:
. | Solution: This isSolution only applies to the Windows Server 2003 operating system. When running Aspen Flare System Analyzer on a Window Server machine you need to explicitly exclude it from the Data Excecution Prevention Services check.
To do this, right click on My Computer and select Properties.
On the Advanced tab,... |
Problem Statement: I have multiple Aspen HYSYS versions on my computer. How can I select which version to use when importing data? Aspen Flare System Analyzer is trying to open the Aspen HYSYS file with an older version. | Solution: Starting with Aspen HYSYS version 2006, select Programs | Aspentech | Aspen HYSYS | Restore File Associations from the Windows START menu for the desired version of HYSYS.
For earlier versions of Aspen HYSYS (i.e. v2004.2 and older), simply open and close the version you wish to use, and this will automatical... |
Problem Statement: What is the maximum allowed molecular weight of a hypocomponent in Aspen Flare System Analyzer? | Solution: In the field of molecular weight the program requires a numeric value not smaller than 2 and not larger than 500.
This is because if you defining a hypo component based only on the molecular weight, a value higher than 500 can lead to a poor estimate of properties and a critical temperature above the limit.
O... |
Problem Statement: Aspen Flare System Analyzer heat transfer solver is calculating unrealistic temperature at pipe outlet. What should I do? | Solution: 1. Choose Yes for Multiple Element Calculation in the Heat Transfer tab of the corresponding pipe. This will make sure that the heat transfer calculations are performed in as many elements as hydraulics calculations are performed. If heat transfer calculation are failing, using multiple elements will most lik... |
Problem Statement: How to model a constant pressure drop in a horizontal separator. | Solution: In Flarenet, there is no direct way to set a pressure drop in KO drum. Since KO drum only considered inlet and outlet pressure changes, we can model a bleed for constant pressure drop between two KO drums to represent the horizontal separator.
In the attached example, you will find that a bleed is used to s... |
Problem Statement: What is the meaning of fields on the calculation tab of flow bleed? | Solution: Flow bleed is the calculation block that allow you to specify a fixed pressure drop. Following input fields are available on the Calculations tab:
Field
Description
Offtake Multiplier
Specify the offtake multiplier. The default value is 0.
Offtake Offset
Specify the offset fo the offtake to compensate the cha... |
Problem Statement: Why do I receive inlet piping pressure drop violation for ignored relief valve? | Solution: The warning message Inlet piping Non -recoverable pressure Drop Violation for ignored Sources is related to the inlet pipe to the relief valve and not related to the flare network in which the flow is ignored. It does not matter whether the valve is ignored or not, Aspen Flare System Analyzer calculates them ... |
Problem Statement: I'm getting an Inner Loop Failure message when running my Aspen FLARENET case. What does this error mean and how do I correct it? | Solution: The Inner Loop Failure message usually indicates that Aspen FLARENET has just not been able to reach aSolution, and is often a result of flows that are too large and/or diameters that are too small. Increasing pipe diameters and/or reducing flowrates will usually rectify the problem.
Other things to try/che... |
Problem Statement: Why does the component selection from a specific component family (for example, hydrocarbon, aromatics etc) affect the relieving capacity of the Relief Valve in Aspen Flare System Analyzer. | Solution: Depending on the component type selected on the relief valve editor, (i.e Relief Valve >> Compositions Tab >> Fluid Type Drop down option), the program calculates the different properties based on the components in which the composition is splitted internally. This is expected, and will therefore impact the r... |
Problem Statement: How do I import source data using text file format? | Solution: Originally such feature was designed to import the HYSIM files in to Aspen Flare System Analyzer. Since HYSIM is no more released in the market, so this feature is not supported. However, you can use the following information.
Refer to the attached text file.
Text_Import.prn: File to be used for import. You n... |
Problem Statement: When starting Aspen FLARENET, the following error message Pipe Schedule Database Missing appears. How does one eliminate this problem? | Solution: By default, the database files for components, pipe schedule and pipe fittings are not installed in the 'FLARE NET' folder; instead, they are usually found in the following location:
C:\Documents and Settings\All Users\Application Data\Aspen Tech\Aspen FLARE NET(version)\Database.
In this folder, there sh... |
Problem Statement: Why the temperature increases through connector or tee instead of temperature decrease? | Solution: In the compressible flow, flarenet use equation Eq 2.57-2.63 in HTFS DR38 for swage calculation. Equation looks like H1 + (M1^2)/ )/(2 *rho1^2) = H2 + (M2^2)/ )/(2 *rho2^2).
H1 and H2 are inlet and outlet enthalpy
M1and M2 are inlet and outlet mass flowrate
There are two types of calculation that you can do i... |
Problem Statement: Why I don't get a choked flow error message for my orifice? | Solution: In Aspen FLARENET, the thin plate orifice equation is used for orifice calculations. A thin orifice won't choke, as the flow will continue to rise as the downstream pressure falls further because the vena contracta grows in diameter.
Ref : Orifice Meters with Supercritical Compressible Flow, RG Cunningham; AS... |
Problem Statement: What are the best practices to build a simple Aspen Flare System Analyzer model? | Solution: A. Components Basis
1. Use MW (Molecular Weight) as composition basis for only vapor phase systems.
2. Use Composition basis as mole fraction or mass fraction for multi phase systems.
3. Components with composition close to zero should be removed from the component list. Any additional compo... |
Problem Statement: Why is the flaretip velocity calculated as zero? | Solution: The Aspen FLARENET solver does not calculate flaretip velocity. This calculation should be done using third party software such as Flaresim?. For more information on this product, visit:
http://www.softbits.co.uk/fs_overview.php
Keywords: flaretip, velocity, Flaresim
References: None |
Problem Statement: The values for K(Cp/Cp-R) and Compressibility appear as empty values when reviewing the relief valve conditions. | Solution: One possible reason for this is that you directly specified the Rated Flow instead of allowing Aspen Flare System Analyzer to calculate it. As explained inSolution 135381, these values should only appear if the Auto checkbox has been activated. Note that the Rated flow parameters can also show up if you click... |
Problem Statement: Why do I receive the message “Sequence contains more than one matching element� when attempting to import data from Safety Analysis into Aspen Flare System Analyzer? | Solution: This message shows up if there are multiple valves on the Aspen HYSYS/Aspen Plus file that share the same name. When this happens, Aspen Flare System Analyzer (AFSA) will not be able to complete the import process, even if the user is not interested on importing this duplicated valve.
In some cases, it has be... |
Problem Statement: Are tank inventories used during each period optimization in Aspen Refinery Multi Blend Optimizer? | Solution: Yes. MBO balances all tanks at every period ensuring that the inventory constraints are enforced. If there is no way to make a tank feasible in a given period then penalty structure will be activated. The penalty value used is based on the interpolation between the time of the particular period and the begin... |
Problem Statement: Why does the 'wall temperature violation' warning appear for a pipe segment? | Solution: The Wall Temperature reported in the P/F Summary is the internal wall temperature. The reported wall temperature in the P/F summary is an average over the length of the pipe.
The wall temperature violation may appear sometime even if you do not expect the average temperature to go beyond specified temperature... |
Problem Statement: The PFD is always printing in conner of page and not in middle of page. | Solution: There may be empty space on the top left side of the PFD corner.
Zoom in or out your whole flowsheet and make the whole network visible. Then make sure the bottom and right window scroll bars of PFD are at the end. Select whole network and drag it to the left-top coner of PFD. Click print review and check whe... |
Problem Statement: How will AspenTech handle the support activity for the old HTFS Research Network (web version) after we release the new HTFS Rresearch Network (aspenONE Exchange) starting in V8.8? | Solution: Starting in V8.8, all HTFS Research Network resources can be accessed from aspenONE Exchange, which is accessible in Aspen Exchanger Design and Rating (EDR), Aspen Plus and Aspen HYSYS programs. AspenONE Exchange offers a convenient way to search research literature and documentation about EDR and no longer n... |
Problem Statement: I am getting error messages for Inlet Piping pressure Drop Violation even though the Pressure Safety Valve(PSV) is ignored and I have ticked the option for calculate ignored sources with zero flow. | Solution: American Petroleum Institute(API) recommends that the pressure drop in the inlet pipe should not be more 3.0% of the Maximum Allowable Back Pressure (MAWP) at rated flow of the relief valve. This is a standard engineering practice for designing inlet pipes (that is the pipe connecting the source and the relie... |
Problem Statement: How to get heat exchanger, or cooler/heater duty in user variable? | Solution: The two sided heat exchanger, and heater/cooler store the duty differently. The attached model contains a cooler unit and a heat exchanger unit. Each has a user variable and its code to retrieve duty variable.
Keywords: Duty, heat exchanger, cooler, heater
References: None |
Problem Statement: Why the temperature increases through connector or tee instead of temperature decrease? | Solution: In the compressible flow, flarenet use equation Eq 2.57-2.63 in HTFS DR38 for swage calculation. Equation looks like H1 + (M1^2)/ )/(2 *rho1^2) = H2 + (M2^2)/ )/(2 *rho2^2).
H1 and H2 are inlet and outlet enthalpy
M1and M2 are inlet and outlet mass flowrate
There are two types of calculation that you can do i... |
Problem Statement: What is meant by the error message: Molecular weight is not bound by composition? | Solution: If Mol. Wt. is selected as the source basis on the composition tab and there are multiple components added to the model, then Aspen FLARENET will distribute the composition according to the closest two molecular weight components. For example; if methane (MW=16), ethane (MW=30 and propane (MW=44) are the avai... |
Problem Statement: How can I display variables with object names throughout the PFD? | Solution: By default, each object on the PFD has a label that displays its name. If desired, you can enhance all object labels to include the current value of a key variable. To select the label type for all pipe segments and nodes shown on the PFD, navigate through the PFD tool bar and click on the drop down list to s... |
Problem Statement: How does the combine option works for components in Aspen FLARENET? | Solution: The combine option is used to replace multiple components by a single component. The process is used to reduce the calculation time. The step is recommended once the the user has multiple components with zero or close to zero composition.
Please Note: Once you have done this, you cannot undo the grouping.
1. ... |
Problem Statement: Where can I find the complete name of a component in Aspen FLARENET? In the component manager I can only see the component abbreviation. | Solution: To see the name of a abbreviated component, follow the steps below.
1. From the main menu, select Database | Components.
2. In the component editor window, move the scroll bar towards right until you see Aspen Name.
3. Expand the Aspen Name cell to view the full name of the component, as shown in the figure b... |
Problem Statement: In scenario of one source, I want all other valves not lifted but all other sources not completely ignored. How can I do that? | Solution: You need to include calculation of ignored sources with zero flow. To enable this option, select Calculations | Options, then activate the Calculate Ignored Sources with Zero Flow checkbox.
Keywords: one source, scenario, back pressure
References: None |
Problem Statement: How do I change PSV and control valve's value for all scenarios? | Solution: There is not a direct way to change the value of sources for all scenarios in Aspen Flare System Analyzer. However, workaround will be to export your case to MS Excel file, change the values in Excel and import back to Aspen Flare System Analyzer again.
Keywords: All scenario, relief valve, control valve
Refe... |
Problem Statement: How does Flarenet calculate rated flow for two-phase flow? | Solution: For API 1976 method and API 1993 method, Flarenet calculation is based on the method described in API 2000 section 3.6 with some minor differences. This calculation is applicable for single phase gas/vapor.
In API 2000, Flarenet can also calculate rated flow for the following cases:
1. Two phase system ... |
Problem Statement: Why is the allowable backpressure used instead of the actual downstream pressure to calculate the rated flow? | Solution: Aspen Flare System Analyzer will try to use all the available information that has been specified to a valve in order to calculate the rated flow.
The specified allowable backpressure on the Conditions tab will be used to calculate the rated flow in cases where the simulator fails to detect a specification fo... |
Problem Statement: What does Char. Volume mean when creating Hypothetical component? | Solution: Char. Volume is characteristic volume for the COSTALD model. It is different with critical volume. It can be found in most of pure component databank. It should be available in Aspen plus databank (VSTCTD) and Aspen Hysys for most of component.
Keywords: Flarenet, pure component, Char volume.
References: None |
Problem Statement: In the Calculation Options Editor / Warnings, users can specify a minimum and a maximum temperature for carbon steel pipes and for stainless steel pipes.
Is this temperature checked against the wall pipe temperature or against the fluid temperature? | Solution: The minimum temperature specified in the Calculation Options Editor (see below) is based on the fluid temperature.
This is because the fluid temperature is smaller than the pipe wall temperature as shown below.
Hence, checking against the fluid temperature will be a more conservative approach as low temperatu... |
Problem Statement: What is the difference between link and paste options in Pipe Editor | Fittings? | Solution: Both link and paste transfer the coefficients of the fittings for the selected equation into the Fittings Loss box.
Link also maintains the list of fittings and you will not be able to change the fitting loss value by typing because the value is linked and shown as gray out.
Whereas Paste will not retain the ... |
Problem Statement: How to define the import and export definition file? | Solution: In the attached report, the detailed procedure is given. More information can also be found in Aspen Flarenet reference manual.
Keywords: Import, export, definition file, Excel.
References: None |
Problem Statement: Is it possible to see Total Pressure in the plot? | Solution: Currently, Aspen Flare System Analyzer only displays the Static Pressure in the plot, but in the Pressure/Flow Summary table you can include total pressure and export the table to Excel.
To have the Total Pressure in the Pressure/Flow Summary, check Display Total Pressure under:
File | Preferences | General.
... |
Problem Statement: How do I customize the labels shown on the Flowsheet in Aspen Flare System Analyzer? | Solution: By default, a label with the name of each Object is displayed in the Flowsheet as shown below:
You have the option to include additional labels to show the results of your AFSA model. This option is available under the Process Flowsheet tab. Go to the Modify tab and locate the Labels section.
When you click ... |
Problem Statement: Why is the pressure calculated for all the upstream operations from my orifice plate displayed as NaN? | Solution: A NaN value stands for Not-a-Number and is often found when noSolution was found for a certain variable.
In the particular case of objects upstream of an orifice plate, the problem appears if the specified Orifice diameter is bigger that the Internal Diameter of the upstream pipe. Because it is impossible to ... |
Problem Statement: Why un-checking or checking rated flow of the tail pipe does not make a difference in back pressure? | Solution: Rated flow calculations in tail pipes require two steps: (1) Choose Tail Pipe = Yes in the connections page of the tailpipes and (2) check rated flow of the tail pipe under Calculations || Options.
If you have un-checked (or checked) rated flow of the tail pipe and it did not make a difference in back pressur... |
Problem Statement: The total pressure in the system is below atmospheric pressure. Is this an operating concern? | Solution: The total pressure in the line can drop below atmospheric pressure if there are downhill pipes in the flare network and especially at lower flow rates.
Total pressure only takes into account static pressure and kinetic head. It ignores the pressure change due to elevation. At commonly-encountered flow rates, ... |
Problem Statement: Can I export the PFD to some other program? | Solution: You can save the PFD as .emf or PDF file. The picture below shows where the option is. Exporting the PFD as PDFformat requires the icons to be wire frame icons. To change the icons to wire frame icons go to File || Preferences || PFD || check for Use Wire Frame Icons.
You can copy the PFD to paste it in oth... |
Problem Statement: How does one change the orientation of PFD icons in Aspen FLARENET? | Solution: 1. Choose the target object on the PFD using your left mouse button
2. Click on the Rotate Selected PFD Objects icon found on the PFD toolbar ( )
3. Select the desired option (i.e. Rotate 90, Rotate 180, Rotate 270, Flip X or Flip Y)
Keywords: transform, rotate, PFD, icon, flip, mirror
References: None |
Problem Statement: Why is the calculated pressure in the PSV downstream piping higher than the pressure at PSV outlet? | Solution: The static pressure in the inlet of the downstream pipe or tailpipe can be higher than the pressure of the PSV outlet if there is a flange in the PSV and diameter of the flange smaller than the diameter of the pipe. Static pressure recovery usually occurs in sections of the flare system where there is an incr... |
Problem Statement: Why is there a difference in the heat transfer coefficients calculated in Aspen Flarenet compared to the Aspen HYSYS pipe-segment? | Solution: The differences comes from two sources:
1. Aspen HYSYS does not support the Radiation Heat Transfer. In the Aspen Flarenet model, you can disable the radiation, in the heat transfer page of the Pipe editor. This will reduce the difference between Aspen HYSYS & Aspen Flarenet calculation.
2. Alth... |
Problem Statement: Is it possible to do heat transfer calculations under sea water? | Solution: Starting with Aspen Flare System Analyzer V7.0, the capability to do heat transfer calculations under sea water has been implemented. The calculated heat transfer coefficient is a function of the following parameters:
a) External medium Velocity (user input)
b) External medium Temperature (user in... |
Problem Statement: When using Rated Flow for tailpipes calculations, by default the velocity results reported are the ones calculated with Mass Flow.
Is it possible to have the velocity results based on the Rated flow? | Solution: When the option Rated Flow for tailpipes is checked, the rated flow is used to calculate the pressure drop. Other properties are calculating using mass flow. Nevertheless you can change this for velocity. To report velocity using rated flow rather mass flow, user needs to:
1. Go to File>Preferences and chec... |
Problem Statement: How do I link to an application using VBA in Aspen Flare System Analyzer V7.3? | Solution: Aspen Flare System Analyzer V7.3 could not use CreateObject or GetObject to link the application. You will have to use new key word.
Dim FlarenetApp As Object
Set FlarenetApp = New AspenTech_FlareSystemAnalyzer_Interfaces.Application
FlarenetApp.Visible = True
FlarenetApp.OpenModel YOURFILEFOLDER_And_FILENA... |
Problem Statement: I have enabled heat transfer calculations in the Calculation Options Editor, but Aspen FLARENET is still not performing heat transfer calculations. What should I do? | Solution: Heat transfer calculations need to be enabled in both the Calculation Options Editor and individual pipe segments (Heat Transfer tab) in order for Aspen FLARENET to do them. Note that local settings within a pipe will override the values set in the Calculation Options Editor.
For information on enabling hea... |
Problem Statement: Rated flow for relief valve in V7.0. | Solution: Rated flow: Rated flow is the manufacturer guaranteed flow and it is stamped on the relief valve nameplate. The Aspen Flare System Analyzer (Aspen FLARENET) calculation for rated flow is based on API 520.
Aspen FLARENET 2006.5 and earlier
Single Phase System:
API-520 -1976 and API-520 -1993 are used for singl... |
Problem Statement: Why do I get some inner loop failure warning messages in design mode? | Solution: In design mode, the diameters of pipes will start from initial values. For some of pipes, those initial diameters could be too small for your relief loads. In this case, Aspen Flare System Analyzer will give you these warning messages. However, those warning message most likely are intermediate messages. You ... |
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