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Problem Statement: What is a Calculator variable?
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Solution: Calculator variables are a means to access stream property correlations in Aspen HYSYS from the object navigator window.
By default, all streams in Aspen HYSYS will have a standard set of properties displayed. In addition to this default list, further correlations such as Gas properties (HC Dew Point, Water Dew Point, Wobbe Index, HHV, LHV), Petroleum properties, Electrolyte properties, Black Oil properties and Solid properties can be added to the stream property view using the append correlations button (green plus sign as shown below).
To connect these additional properties to other simulation features (i.e. PFD table, Workbook, Spreadsheet, etc.), the Calculator is used as the base object to access these variables. When searching for stream correlations within the variable navigator, select Calculator as the Variable and the desired property correlation as the Variable Specifics, as shown below:
Keywords: Calculator, Variable Navigator, Variable, Workbook, Report, PFD table, Spreadsheet
References: None
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Problem Statement: What is the diffference between saving a case to an XML file from Save As and exporting the case as XML?
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Solution: There is no difference between the two methods if you don't change any default when you export it via Simulation menu.
Keywords: XML, export, save
References: None
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Problem Statement: It is desired to simulate a vessel in Hysys, dynamic mode. This vessel has 2 outlet streams (top and bottom) and under normal operation 3 phases (vapor, light liquid and heavy liquid). The outlet streams are calculated according to phase levels and nozzle positions/diameters. For instance, if the heavy liquid covers completely the nozzle in the bottom, this outlet stream will consist only of heavy liquid. However, in some cases the vessel is well agitated and the outlet liquid will have the properties of the combined liquid inside the vessel. Is there any workaround to simulate this process?
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Solution: The workaround to simulate this process is to use the Spreadsheet to calculate the new position of the nozzle, so that the amount of each liquid phase in the outlet stream is equal to the amount of each phase in the combined liquid stored in the hold-up. The nozzle position is calculated by the equation:
h = l + d*(0.5 - fh)
where:
h: nozzle position
l: heavy (aqueous) liquid level
d: nozzle diameter
fh: molar fraction of heavy (aqueous) liquid in the vessel hold-up
Using the drag and drop features of Hysys, it is very easy to import and export values to the Spreadsheet. See attached case, created using Hysys 3.0.1.
Keywords: Mixing, Agitated, Dynamics, Nozzle, 3-Phase, Vessel, Hold-up
References: None
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Problem Statement: How does Aspen HYSYS use the Stage Overall / Component Efficiencies I enter?
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Solution: The stage efficiency used is a modified Murphree stage efficiency, the equation is as follows:
En = (Vn*yn - Vn+1*yn+1) / (Vn*Kn*xn - Vn+1*yn+1)
Where:
E = efficiency
Vn = total vapour molar flow leaving stage n (if the stage has a side vapour draw then this is included)
y = vapour mole fraction
x = liquid mole fraction
n = tray number (measured top down)
Note: Kn xn = yn (i.e. y-star, the composition of vapour in equilibrium with the tray liquid)
This equation applies to both component and overall tray efficiencies. If you specify an overall tray efficiency, the program will assign each component the same efficiency.
If the vapour flow is constant (i.e. Vn = Vn+1; Constant molar overflow), then this modified efficiency reduces to the standard Murphree stage efficiency.
Note: If you are using an Amine column see Appendix C of the Basis Manual, since amine columns use a mass transfer model rather than an equilibrium stage model.
Note: It is recommended that you use a tray efficiency of 1.0 for stages with draws or feeds.
Keywords: Stage Efficiency, Overall, Component, Tray Efficiency, Modified Murphree, Constant molar overflow
References: None
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Problem Statement: What do I do to have a different Valve Type than the standard HYSYS ones?
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Solution: If you have a different valve type than the standard HYSYS ones, you can manipulate the HYSYS linear valve to behave like your valve. This can be done by using a spreadsheet. You can send the controller signal to the spreadsheet and have it calculate the equivalent linear valve opening for you. Alternatively, you can use the spreadsheet to change the Cv of the valve every time the OP is changed to match the performance of your specific valve.
Keywords: Valve, Valve Type, Custom Valve Type
References: None
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Problem Statement: How to set an isentropic flash and see the effect on the Pressure
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Solution: For achieving this you can add an expander or a compressor and set the polytropic efficiency to 99.99% and the adiabatic efficiency will be calculated. You can specify only one efficiency, either adiabatic or polytropic. If you specify one efficiency and aSolution is obtained, HYSYS back calculates the other efficiency, using the calculated duty and stream conditions.
The example can show the above mentioned.
In HYSYS, compressor and expander models perform isentropic calculation for compressible fluids. Whereas, pump models assumes incompressible calculations. Valve model can also be used if you are doing isenthalpic calculations. I hereby attach the multiple models for expanding a liquid in expander and pump as a sample.
So depending on which unit-operation model you select
expander - adiabatic efficiency, compressible fluid
pump - adiabatic efficiency, incompressible fluid
But, let me tell you that the pump calculations that HYSYS performs assume that the liquid is incompressible. The density is constant, and the liquid volume is independent of pressure. This is the usual assumption for liquids well removed from the critical point, and the standard pump equation given above is generally accepted for calculating the power requirement. However, if you want to perform a more rigorous calculation for pumping a compressible liquid (for example, one near the critical point), you should install a compressor to represent the pump, ignoring the warnings that will appear.
If you choose to represent a Pump by installing a Compressor in HYSYS, the power requirement and temperature rise of the Compressor is always greater than those of the Pump (for the same fluid stream), because the compressor treats the liquid as a compressible fluid. When the pressure of a compressible fluid increases, the temperature also increases, and the specific volume decreases. More work is required to move the fluid than if it were incompressible, exhibiting little temperature rise, as is the case with a HYSYS Pump.
Please note that for a pump, an efficiency of 100% does not correspond to a true isentropic compression of the liquid.
For more information, please refer to the Unit Operation guide, underSolution 132071
Keywords: isentropic flash,pressure
References: None
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Problem Statement: What is Improved in Aspen HYSYS V7.3 - HYSYS Physical Properties
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Solution: Aspen HYSYS V7.3 includes a number of improvements in the HYSYS physical property methods and the Simulation Basis.
New Binary Parameters for the SRK Property Package
Twenty additional pairs of binary parameters for the SRK property package were added in V7.3. The additional binary pairs are listed below:
Methane-Methanol
Argon-Ethylene Glycol
H2S-TEG
Propylene-Ethylene Glycol
n-Butane-Ethylene Glycol
Methane-Ethylene Glycol
O2-CO2
Ethylene-Ethylene Glycol
Propane-Methanol
i-Butane-Methanol
N2-Methanol
CO2-TEG
Ethane-Methanol
Propane-Ethylene Glycol
i-Butane-Ethylene Glycol
Argon-H2O
H2S-Methanol
Ethane-Ethylene Glycol
n-Butane-Methanol
H2O-Ethylene Glycol
New Method for Liquid Thermal Conductivity
There is a new option for liquid phase thermal conductivity calculation for PR-type EOS packages and Chao-Seader type packages to let you select the method API 12A3.2-1 or API 12A1.2-1. In the Fluid Package Setup view Parameters tab, make the selection using the Thermal Conductivity parameter.
The default method is API 12A3.2-1, which is the current API recommended method. The API 12A1.2-1 method is based on an older API method and is retained for upward compatibility.
New Method for Liquid Density
There is a new option for predicting liquid density based on the Rackett model (API 6A2.3, 9th edition) for several equation of state and activity based property packages, specifically Chao Seader, Chien Null, Extended NRTL, General NRTL, Glycol Package, Grayson Streed, Kabadi-Danner, NRTL, Peng-Robinson, PR-Twu, PRSV, Sour PR, Sour SRK, SRK, SRK-Twu, Twu-Sim-Tassone, UNIQUAC, and Wilson.
New Method for Surface Tension
There is a new option for prediction of surface tension based on the API procedure 10A3.2. The packages affected are Chao Seader, Glycol Package, Grayson Streed, Peng-Robinson, PR-Twu, PRSV, Sour PR, Sour SRK, SRK, SRK-Twu, and Twu-Sim-Tassone.
Improved DBR Amine Package
The DBR Amine Package has been improved to better handle:
Flash calculations of DEPG mixtures.
Flash calculations of material streams with zero amine.
Reaction models of MDEA and carbon dioxide mixtures.
Support for five additional components: 1,2 butadiene, 1,3 butadiene, 2,2 MBUTANE, 2-MPENTANE and 2,4 MPENTANE.
New Phase Identification Method
In earlier versions, the method used to identify the state of the phases resulting from flash calculations was based on the work of Poling and Prausnitz1. This method uses the isothermal compressibility to identify the state or phase type.
In HYSYS V7.3, we have implemented a new phase identification method based on the work of Pasad, Venkatarathnam, and Oellrich2. The new method was shown to be more reliable than the existing method and was therefore implemented for the following property packages: Peng-Robinson, SRK, Glycol Package, PR-Twu, SRK-Twu, Twu-Sim-Tassone, Sour PR and Sour SRK.
Use the Fluid Package Setup View > Parameters Tab > Phase Identification parameter to select one of the two choices. The original method (Poling-Prausnitz) is now called the Default method. The new method is called Vankatarathnam-Oellrich.
1. B.E. Poling and J.M. Prausnitz, ?Thermodynamic properties from a cubic equation of state: avoiding trivial roots and spurious derivatives?, Industrial and Engineering Chemistry Process Design and Development, 20(1) (1981) 127-130.
2. G.V. Pasad and G. Venkatarathnam A method for avoiding trivial roots in isothermal flash calculations using cubic equations of state?, Industrial and Engineering Chemistry Research, 38 (1999) 3530-3534.
Dense Phase Tuning Factor
In HYSYS V7.2, the option ?Dense Phase Tuning? was implemented for PR-type EOS packages. In V7.3, this option was extended to MBWR and BWRS property packages.
Keywords: Binary Interactions, Liquid Density, Thermal Conductivity, Surface Tension, DBR Amine package, Properties, Dense Phase, Property package, Phase
References: None
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Problem Statement: The cold property utility reports strange values for the RON (Research Octane Number). For example, a stream with 90% isooctane, 9.9% n-heptane, and 0.1% benzene reports a RON of around 35, while the actual RON should be around 90.
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Solution: The cold property utility in HYSYS calculates the RON based on a proprietary correlation, and is valid for systems with a D86 50% < 220 C (SeeSolution document 109286).
The cold property utility is only recommended for use with straight run gasoline's and light naphthas and is therefore not suitable for the calculation of RON's for branched hydrocarbons such as trimethyl pentanes or pure components like benzene.
For this reason the best option would be to use Aspen Hysys Petroleum Refining (formerly RefSYS), where the RON calculation is more accurate and robust.
The attached example, created in v7.1 shows the difference in results (a license for HYSYS Petroleum Refining is needed to open this case).
In the example, it can be seen that for the same stream (90% isooctane, 9.9% n-heptane, and 0.1% benzene), the Cold Properties utility predicts a RON of 35.67, while the RON predicted by the correlations in RefSYS is 90.11.
Results from the Cold Properties Utility:
Results with the correlations from RefSYS:
Keywords: HYSYS petroleum Refining, RefSYS, Cold Properties, Octane, RON, MON
References: None
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Problem Statement: The insulation thickness cannot be modified when the detailed heat loss model of a pipe segment is selected.
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Solution: Fortunately, based on the definition of thermal resistance (Equation 1) and the formula to calculate the insulation mass (Equation 2), aSolution to this limitation can be formulated.
(Equation 1)
where Rins is the insulation thermal resistance
Dx is the insulation thickness
Do is the pipe outer diameter
kins is the insulation thermal conductivity
Figure 1. Thermal resistances
(Equation 2)
where Mins is the insulation mass
rins is the insulation density
L is the pipe segment length
Do is the pipe outer diameter
Dx is the insulation thickness
Figure 2. Thermal insulation
TheSolution to this problem depends on the the following two scenarios:
+ If no insulation is required, enter a very large value for thermal conductivity, then Rins will be practically zero. Enter a very small value for both heat capacity and density as well.
+ If a insulation thickness is required, based on Equation 1, the insulation thermal conductivity to be specified in Aspen HYSYS is determined based on Equation 3.
(Equation 3)
where kins is the insulation thermal conductivity that has to be entered in Aspen HYSYS
is the required value of insulation thermal conductivity
Do is the pipe outer diameter
Dxdef is the default Aspen HYSYS insulation thickness value
Dxreq is the required value of insulation thickness
Based on Equation 2, the insulation density to be specified in Aspen HYSYS can be calculated by using Equation 4.
(Equation 4)
where rins is the insulation density that has to be entered in Aspen HYSYS
is the required value of insulation density
For example:
Do = 114.3 mm
Dxdef = 30 mm (3.000e-2 <m>)
Dxreq = 50 mm
= 0.1 W/m K
= 500 kg/m3
From Equation 3, kins = 0.0671 W/mK
From Equation 4, rins = 948.8 kg/m3
Figure 3. Information entered in Aspen HYSYS
Keywords: Detailed heat loss model, thermal resistance, insulation, dynamic simulation, insulation thickness, pipe segment
References: None
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Problem Statement: What method is used by Grayson-Streed Thermodynamic model to calculate Liquid Density?
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Solution: Hysys uses COSTALD Method to calculate Liquid density for Grayson-Streed package.
There is no option to switch to another Liquid density model hence no other estimation method for Liquid density estimation can be selected.
Keywords: Grayson-Streed, COSTALD, Liquid density
References: None
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Problem Statement: How do I set the default version when I have more than one Aspen HYSYS version installed on my PC?
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Solution: For any Aspen HYSYS - Excel automation work it is necessary to set the desired Aspen HYSYS version as the default version if there are more than one Aspen HYSYS version installed on the PC. Any Aspen HYSYS version can be registered and unregistered manually. To make this simple a command line script file can be used to register a specific version and un-register all other versions. A script file is attached with thisSolution.
1. Save the attached file RegHYSYS.txt in a folder.
2. Change the file name RegHYSYS.txt to RegHYSYS.bat
3. Double-click on the file to un-register all Aspen HYSYS versions and register v7.3.
The file can be edited using Right-mouse click and Edit option. If Aspen HYSYS V7.1 is required to use for the automation work then used the word REM for V7.3 and remove this word from V7.1 in the script file and rerun this by using a double-click on this file.
Note that you also need to use the correct version of Aspen HYSYS type library in the Excel VBA after registering the Aspen HYSYS version (seeSolution ID 129694).
Keywords: Automation, Excel, Register
References: None
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Problem Statement: How can I place a group of unit ops into a new sub-flowsheet?
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Solution: Use the following approach:
Using your mouse, select the items you wish to place into the new sub-flowsheet.
Press the right mouse button.
Select Cut/Paste Object -> Combine Into Sub-flowsheet.
If your selected objects contain another subflowsheet, you will be asked whether or not you would like a new subflowsheet created or if you would like to place them in the existing flowsheet.
Keywords: combine operations into subflowsheet
References: None
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Problem Statement: How to keep open the workbook and spreadsheet or any two windows inside a HYSYS file side by side?
For drag and drop purpose, I need two windows side by side. They one hides once the other is open is open. How can I keep them side by side?
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Solution: It can be done in three ways.
Method # 1: Go to Window menu and select the two objects, one at a time. This way you can bring the two already opened object windows to the front view of the Aspen HYSYS desktop. The following picture shows an example.
Method # 2: If one of the two windows needs one click to open, open this one last. Like, first open spreadsheet and then open the workbook by clicking on the workbook icon on the Toolbar (needs one click). Both of them should be visible now.
Method #3: When you see one window is hiding from the other, minimize the PFD. Now, both of them should be visible. The hiding one was actually hiding behind the PFD. If you have too many windows open, it may become tougher to find the relevant windows.
Keywords: Two windows side by side, side by side, side by side windows, two windows, drag and drop side by side
References: None
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Problem Statement: Why is the Wobbe index displayed in my stream different than the one in the Gas Properties Extension?
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Solution: The difference you see is due to the two different reference temperatures being used. In the Gas Properties extension (seeSolution 110060), the Wobbe index is calculated at 15C. For the Wobbe index of the stream the value can be calculated at 0C or 15C. To select the reference temperature at which the Wobbe index is calculated for your stream, select Correlation Manager from the Tools menu. In the Correlation Manager window expand the Gas branch and select Wobbe Index. In the Parameters group you can select which reference temperature you want to use.
Keywords: Wobbe Index, Gas Props, Gas Properties
References: None
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Problem Statement: I get different results when using Beggs and Brill (1979) and Beggs and Brill (1973) flow correlation
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Solution: The original Beggs and Brill model (1973) was developed for smooth pipes. As a result, the pressure drop predicted by this correlation does not depend on the roughness (because the friction factor is that of smooth pipes.) The improvements made in the 1979 model were to include the roughness in the friction pressure drop and to modify the hold-up for inclined pipes.
Because these are horizontal pipes, the difference between the 1973 and 1979 models are a result of the friction factor calculation. If you change the roughness to 0 for the 1979 model, then you will get the same results as the 1973 model for horizontal pipes.
Keywords: Flow correlation, Beggs and Brill (1979) & Beggs and Brill (1973)
References: None
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Problem Statement: What does the error message Not licensed for Crude Distillation (Distillation of high NBP hypothetical components) mean?
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Solution: The license which enables operation of the Aspen HYSYS application controls the options/features a user has access to. One of them is the Crude option. Without the Crude option set on the key, simulations are limited in the number of components which can be included if running a column in the case such as Not licensed for more than 25 components with columns. In such circumstances, the program can be put on hold and the number of components changed to a maximum of 25.
Also note that if a distillation column is set up with more than 25 components AND if one of those components has a NBP > 533K, the program will complain. For example, 24 components (one with NBP > 533K) is OK, as is a case with 26 components where all of them have NBP < 533K.
A case with 50 inorganic hypotheticals where some hypos have NBP>533K will also run. This is because it is the hydrocarbon hypothetical that invokes the check.
The only way around it is to have the Crude option licensed, or the Refinery option, which covers both the Crude AND the Oil options.
Previously, HYSYS Product Manager has advised us not to mention the 533K limitation to outside users. In other words, we tell customers about the limit on 25 components without mentioning the 533K limit, unless they are really pressing on the issue. So if you run into one of such situation, you probably should consult with the new Product Manager, just to confirm.
Keywords: Crude, Oil, components, hypothetical, limit, not licensed for, NBP
References: None
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Problem Statement: Where can I find my own extensions in Windows XP Registry table?
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Solution: You should be able to find your extension at the following key for HYSYS V7.3:
HKey_Local_Machine\Software\Classes\Software\hyprotech\Hysys\1.7\extension.
You also can find the extensions registering in other Hysys versions: 1.6 for V7.2, 1.5 for V7.1 and so on.
Keywords: Registry table, extension, HYSYS
References: None
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Problem Statement: Can I generate hydrate curve using Infochem Multiflash property package in Aspen HYSYS?
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Solution: The answer is NO. The Infochem Multiflash package in Aspen HYSYS does not support hydrate calculation . The menu Select/Model set/Hydrates form is locked. User can make hydrates calculation within Infochem Multiflash itself (i.e., standalone), but not when it is called from Aspen HYSYS.
The Infochem features exposed in Aspen HYSYS were based on our commercial arrangement with Infochem. The main reason was to enable to use the PVT capability and the thermo and flash engine of Multiflash in Aspen HYSYS environment. Hydrate prediction was not included in the scope of the project.
Keywords: Hydrate curve, Hydrates, Infochem multiflash
References: None
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Problem Statement: Aspen HYSYS V7.3 and earlier has a performance slider in bottom right-hand corner of the gray pane. We set this from the default Auto-Calculate to Max. Where can I find this feature on Aspen HYSYS V8?
Does this feature have equivalence with the Aspen HYSYS V8 calculation speed?
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Solution: On HYSYS V7.3 and earlier, the Calculation/Responsiveness icon enables user to control how much time is spent updating the screen vs calculations, i.e. there is no equivalence with calculation speed.
The performance slider is no longer present in Aspen HYSYS V8 GUI. The change of architecture to the WPF dispatcher queues no longer allows the application to check for pending input to adjust the solver task's yielding.
Keywords: .
HYSYS New GUI, Calculation/Responsiveness icon
References: None
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Problem Statement: What is the purpose of the Lock Create Mode button in the Object Palette in Aspen HYSYS?
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Solution: This mode is entered by clicking on the Lock icon in the Object Palette.
This allows you to add multiple objects (of the same type either Streams or Unit Operations) to the PFD without having to return to the palette everytime.
Please note that after adding required number of objects to the PFD, you will need to click on Lock Create Mode to exitA this mode.
Keywords: Lock Mode, Lock Symbol, Lock Create Mode
References: None
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Problem Statement: Where is the API Gravity property located in HYSYS?
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Solution: API Gravity may be displayed in the Stream Properties view. To change the Mass Density property to API units you must first clone your existing unit set and then change the mass density units to API. The conversion is completed automatically. The path is: Tools|Preferences|Variables. Then click on the Clone button. Then scroll down to the Mass Density property and use the drop-down menu to select API units. NOTE: API Gravity = 141.5/SG - 131.5
Keywords: API
Mass Density
Gravity
References: None
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Problem Statement: When attempting to run the pipe segment, Aspen HYSYS displays the error The requested pressure drop function could not be found. Check to ensure presdropcorr.dll is available.
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Solution: The error is displayed when two required dll's (LIBIFCOREMD.dll, LIBMMD.dll) are missing from the system. These files were not released in the 2006 installation DVDs; therefore they were not copied to the system during Aspen HYSYS installation.
To resolve this problem, download the enclosed zip file (which includes the above dll's), then unzip and copy them to the C:\windows\system32 folder. After re-starting Aspen HYSYS, the error message should no longer appear.
This problem will be addressed in the upcoming 2006 CP1 patch.
Keywords: pipe, flow, correlation, calculations, presdropcorr, presdropcorr.dll
References: None
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Problem Statement: The Column Cut Point (ASTM D86) spec does not match the results in Boiling Point Curves Utility.
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Solution: Users need to define all Assays with the same D86-TBP Interconversion method (Assay property view, Calculation Defaults tab, Conversion Methods group).
The Oil Output Settings (accessed via the Oil Characterization property view) also need to be changed to the same method as this is used to make the conversion between the internal TBP curves used in the HYSYS and the results displayed for the ASTM D86 in the Boiling Point Curves Utility.
For example if the conversion method used by the Column Cut Point (ASTM D86) spec is API 1994 while the Boiling Point Curves utility is using a different conversion method (API 1974) as determined by Oil Output Settings you will see a difference in the results. To see the same results, change the conversion method to API 1994 in the Oil Output Settings.
Keywords: ASTM D86, interconversion, method, boiling point curve utility, utility, assay
References: None
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Problem Statement: How can I use ACX with HYSYS?
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Solution: In order to use ACX with HYSYS, you must have ACX installed and running on your machine. Then, create a new file, and go to Select, Import HYSYS Exchanger, and choose the exchanger you want from the drop down list. The exchanger you want must be a simple cooler, not an air cooler.
Keywords:
References: None
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Problem Statement: Can I plot more than one variable after running a case study?
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Solution: It is possible to specify which variables are to be plotted by activating the appropriate variables on the Display Properties pagetab of the Case Studies setup form.
Note that a maximum of two variables can be plotted on a graph at the same time.
Keywords: databook, case, study, 3D, plot
References: None
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Problem Statement: What does the Use Initialization File option do?
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Solution: Use Initialize File: When this box is checked, a SAV file is used as initial estimates for the MASS solver. The SAV file is created upon pressing the Create Initial File button on the Connections page (only for when the Solving Mode is Sequential Modular). Checking this option can aid in the convergence of cases by providing the MASS solver with better initial values.
Keywords: MASSBAL, use initialization file
References: None
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Problem Statement: Will unit operation
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Solution: tolerances have an impact on my optimization problem?SolutionSolution tolerances on unit operations such as recycles, columns, and heat exchangers should be tightened to minimize any potential noise in the Jacobian.
If tolerances chosen are too loose, there is a very real possibility that they will interfere with successfulSolution of the optimization problem.
A general recommendation is to consider whether it may be worth tightening the default HYSYS tolerances by one or two orders of magnitude.
For column operations, open the column runner and look under Parameters | Solver to find the Equilibrium Error Tolerance and the Heat/Spec Error tolerance. Consider tightening these as tight as possible while ensuring that the column still converges. A starting point may be to tighten the tolerances by a couple of degrees of magnitude.
The following example will illustrate how poorly chosen tolerances may cause problems in the case of the recycle operation:
Consider the case where you are manipulating the flow rate of a stream which is located upstream of a recycle operation. The current flow rate is 1000 mol/h, and the min. and max. range for the optimization is 800-1200 mol/h, giving a range of 400 mol/h.
Suppose the perturbation factor you are using is 0.01. This means the optimizer will perturb the flow rate by (0.01*400) = 4 mol/h.
The recycle operation default tolerance for flow rate is 10. This is a multiplier for the internal tolerance, which is a relative tolerance of 0.001 (See recycle FAQs under Unit Operations | Logical Operations for more info), giving a relative tolerance of 0.01. So if the molar flow of your stream is 1000 mol/h, this translates into a tolerance of 10 mol/h across the recycle.
When you perturb the inlet flow rate by 4 mol/h, this flow rate is within the 10 mol/h tolerance of the recycle. The recycle convergence tolerance is satisfied, and the flowsheet operations downstream of the recycle will not re-solve. The constraint and objective function variables will not change, and the gradient associated with changing the recycle flowrate will be calculated as zero.
If you tighten theSolution tolerance by an order of magnitude to 0.1, the flowsheet will re-solve, because the perturbation of 4 mol/h is greater than the recycle tolerance of 1 mol/h. This will give you non-zero gradient values.
If the constraints or objective functions variables are expected to be sensitive to small changes in the recycle flow, you may wish to increase the tolerance even tighter.
Keywords: optimizer,
References: None
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Problem Statement: How Can I Convert The HYSYS Enthalpy to the HYSIM Enthalpy Basis?
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Solution: Although the HYSYS enthalpy reference basis cannot be modified internally, the conversion of an absolute enthalpy value generated by HYSYS to a different basis such as HYSIM can be performed using the output from HYSYS. The offset between the HYSYS and HYSIM enthalpy reference basis for a given component is provided on the Component Property View (Point tab) in HYSYS. The value of this offset can be added to the enthalpy calculated by HYSYS to get the enthalpy value corresponding to the HYSIM basis. For a mixture, the sum of [Xi * OFFSETi] can be applied.
For example, the enthalpy basis offset for ethane is -9.67e4 kJ/kgmole. The molar enthalpy of a stream of pure ethane in HYSYS at 25 øC and 1 atm matches the heat of formation of ethane at the same conditions (as seen also in the Component Property View, Point tab). To convert this stream enthalpy value from HYSYS to HYSIM, the enthalpy basis offset is subtracted such that -8.47e4 - (-9.67e4) = 11904 kJ/kgmole. This means that in HYSIM, the same stream of ethane will have an enthalpy value of 11904 kJ/kgmole.
The same conversion can be applied to mixtures. For example, the enthalpy conversion for a mixture of equal molar ethane and propane, can be expressed as
-1.0389e5 - (-1.194e5) = 15510 kJ/kgmole for propane and
-8.480e4 - (-9.6704e4) = 11904 kJ/kgmole for ethane
0.5*15510 + 0.5*11904 = 13707 kJ/kgmole for the mixture
The difference between this value (13707 kJ/kgmole) and the one (13631 kJ/kgmole) in a corresponding HYSIM case file is due to the assumption of ideal mixing involved by the manual calculation above; HYSYS, by comparison, performs rigorous calculations using the selected property package.
Keywords: enthalpy, HYSIM, reference, basis
References: None
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Problem Statement: The molecular weight, viscosity or density of my oil stream does not match my data. How do I fix it?
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Solution: As you supply more information to Aspen HYSYS, the accuracy of the Oil Characterization increases. Supplying any or all of the bulk properties, such as molecular weight, density or Watson (UOP) K factor will increase the accuracy of your pseudo component properties. Moreover, if you supply laboratory curves for molecular weight, density and/or viscosity, the accuracy will increase further. If you cannot supply property curve data, Aspen HYSYS will generate internal curves using the available information. This information is applied using correlations. You can change the default set of property correlations as required.
Refer to Appendix B-Petroleum Methods/Correlations of the Simulation Basis manual for information on the correlations used in the Oil Environment.
The simulation will improve if you can supply independent or dependent property (viscosity, density, molecular weight) curve data. See the Aspen HYSYS Simulation Basis manual, Chapter 4 (v2004), for the definitions of independent and dependent property data. If you don't have curve data then the bulk data should be supplied.
If you supply both bulk and curve data, the bulk data will be matched at the given conditions and the curve will just be shifted to match the bulk value.
Other things to look for:
1. Ensure that you do not have two very different assays in the blend. If this is the case, Aspen HYSYS may not be able to find proper values for the pseudo components to match the data for either oil.
2. If your data is independent, ensure that you have entered mid-point values.
3. Ensure that you have entered your data correctly, it is in the correct units and on the correct basis.
4. Beginning with version 2.3, Aspen HYSYS allows users to manage how light ends are used in the oil calculations as well as putting weights on the curve fitting methods. Press the LE Handling and Bulk Properties Options button on the assay view.
Keywords: bulk, curve, molecular weight, density, viscosity
References: None
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Problem Statement: Why my TBP curve in the oil manager and the one reported in the boiling point curve utility is not the same?
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Solution: The TBP curve in the Boiling Points Curve utility is not the copy of the distillation curve you have provided in the oil environment. Basically it is converted result. The curve you provide and the curve you get are not supposed to match 100%. In order to match the data I have done the following (see attached case):
The distillation curve in the oil manager is the following:
So if you go to the boiling point curve utility the results are the following, they are not matching:
So in order to match your data is good to have the values of the initial and final boiling point, so I just added them and now they are matching almost 100%
So if you go to the boiling point curve utility the results are the following, they are matching:
Please check that the basis should be the same.
For more information please refer to the followingSolution129911
Keywords: TBP, Boiling point curve
References: None
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Problem Statement: What is the definition of Cv?
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Solution: The Cv coefficient of a valve is defined as the flow of water at 60 F, in gallons per minute, at a pressure drop of 1 lb/in^2 across the valve.
Keywords: Cv
References: : Crane Handbook - Chapter 2 - Flow of fluids through valves and fittings
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Problem Statement: A user does not wish to display certain stream components in the Composition page of the Workbook. However, if these columns are deleted, the calculated compositions for all other components appear as <empty>.
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Solution: If the user chooses to delete a stream column in the Compositions page of the Workbook, This will be deleted in the main flowsheet Thus, the flowsheet will be unable to solve completely. This is not a defect, but the way the Workbook is implemented.
User should select the option ‘Hide object’ instead. This makes the column disappear in the workbook, while retaining the values for the non-displayed stream in the flowsheet.
Keywords: Workbook, composition, stream, page, hide, delete
References: None
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Problem Statement: How does one specify different temperature and pressure conditions for the outlets from a component splitter?
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Solution: A component splitter in Aspen HYSYS will split a material stream into two outlet streams with specified compositions. By default, this is an adiabatic process. You can specify two state variables for one of the outlets, and only one for the other. The enthalpy from the inlet equals the sum of the enthalpy of the two outlets. The program calculates the enthalpy for the outlet with two specs during flash calculation, and assign the enthalpy for the other using the above constraint.
If you want to specify two state variables for both outlets, the enthalpy constraint has to be relaxed. This can be done by adding a energy stream to the component splitter. Now the program will calculate the enthalpy for both outlet streams. The total duty of the energy stream equals the sum of the enthalpy of the two outlets minus the enthalpy of the inlet.
An example with this setup is attached for Aspen HYSYS version 2004.2 and later.
Keywords: component splitter
References: None
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Problem Statement: How can I do the rating of the reboiler of a distillation column?
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Solution: You cannot directly do the rating of your distillation column since if you didn't specify it differently, it is only a heat exchanger called reboiler in which you have this option but it won't be a good option because when you type the sizing information the distillation column will lost all the results. But if you still want to do it, do it using the Column Input Expert, in step 2, select the kind of reboiler you want to model as you can see below:
Please be aware that you will only be able to run the column using the Modified HYSIM Inside Out Solver method which allows heat exchangers modeling and it could take longer to converge.
The other option is to create another heat exchanger just with other streams that will be defined using a Spreadsheet to maintain the results updated with the distillation column. Now, the rating could be done better and the user can also export the results to EDR and perform the rating there.
Keywords: Reboiler, column, rating
References: None
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Problem Statement: I have already specified (and not overspecified) the sizing and heat transfer information; however, my pipe segment says Not Solved. What should I check or do?
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Solution: 1. If the status bar of the pipe segment unit operation says Not Solved and you get the error (either in a pop up window or in the trace window) Negative pressure calculated on increment....., probably the flow is choked. Go to Design|Calculations and toggle the Check Choked Flow check box. Now, if the status bar of the pipe-segment says Flow is Choked, please refer to the followingSolutions - note: only the last paragraph ofSolution 114041 is applicable to this situation:Solution 114041 andSolution 110043
2. If you still get the same error Negative pressure...., increase the number of increments (Rating tab|Sizing page). Now the flow should not be choked.
3. If the status bar of the pipe segment unit operation says Increment dp > 10%. Check Trace., please refer to the followingSolutionSolution 109431
4. If none of the above is true and pipe segment says Not Solved, try to change the pipe flow correlation (Design tab|Parameters page) and see if that helps.
5. If the status bar of the pipe segment unit operation says Solid particles (e.g. ice pellets) have been detected inside pipe, please refer to the followingSolutionSolution 109985
6. Check the trace window for any other error (e.g. OLGAS: Error detected in OLGAS or some Flash Calculation error) and contact AspenTech Technical Support ([email protected]).
Keywords: pipe segment, choked, flow, negative pressure, increment, solid particles
References: None
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Problem Statement: How do I change the default unit set in the Equipment Grid Summary when I activate Economic Evaluation in Aspen HYSYS?
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Solution: You are able to change the available template options under Costing Options .
1. Click on Browse tab then select required template from available choices:
2. After selecting the required template, click on open.
3. Then, click on Activate Economic Evaluation > Load simulation > Map Unit Operations >
Size It > Evaluate Cost, and then check View/Edit Equipment Data Summary.
Please note that after doing above steps, if you want to change to different unit set then you must Reinitialize and follow the steps mentioned in Step 3.
Keywords: Equipment Grid Summary Unit, Unit Set, Costing Options, Economic Evaluation
References: None
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Problem Statement: What is pressure gradient in the Slug Tool? How does it differs from the Pressure drop in the defined Pipe System?
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Solution: The Pressure Gradient is the pressure drop over a slug/bubble unit, the pressure drop of a defined pipe system is calculated using the selected correlation.
The overall pressure drop calculated by HYSYS is the sum of Friction, Static Head, and Fitting Pressure drops.
Keywords: Pressure drop, Pressure gradient, slug tool.
References: None
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Problem Statement: What's new in the Cold Properties utility in Aspen HYSYS 2006?
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Solution: The Cold Properties utility display the cold properties of a stream, as summarized in the table below:
In version 2006, some new options have been added to the Cold Properties utility. On the Design tab, it is now possible to select the methods used to calculate some of the cold properties. To make this selection, press the Options radio button under View Picker. The displayed table allows selections of the calculations for the Reid Vapor Pressure, Flash Point, and Cetane Index. On the Performance tab, it is possible also to select the method used to calculate the ASTM D86 distillation curve.
Attached with thisSolution is a quick demo. You are more than welcome to download it and take a look at it.
Keywords: Cold Properties, Reid Vapor Pressure, True Vapor Pressure, Flash Point, Pour Point, Refractive Index, Cetane Index, RON, Research Octane Number, D86 Distillation Curve, PNA,
References: None
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Problem Statement: I have a column involving two sets of identical hypothetical components generated from the same assay using the Oil Manager. I find it extremely difficult to get the column converged. Why? What should I do in this situation?
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Solution: It is unfortunately quite common for Aspen HYSYS to generate a singular matrix when solving equations (leading to difficulty converging columns) if there are two sets of identical components and all have on-zero compositions assigned to them based on the streams fed to the column. Suppose you try to separate two components, one is benzene and another one is named differently but has almost the exact same properties as those of benzene. Based on the relative volatility of each component, it may be nearly impossible for Aspen HYSYS to solve the column, depending upon the active specifications.
If your simulation requires you to have two sets of hypo components from the same assay, it is recommended that you change the cut number of one of the blends in order to avoid generating identical sets of components. In general, you should avoid generating identical component pairs if they are ultimately going to be used in the same column.
Keywords: column, hypothetical, hypo, convergence, identical
References: None
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Problem Statement: Why are the inserted parameters / variables not visible on the strip chart?
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Solution: 1. Check the axes scale is setup properly for all curves. (Right click on the strip chart | Select Graph Control)
2. The temperature curves might be overlapping on the strip chart, Go to Graph Control | Curves and un-check the 'Show Curve' check box for undesired curves that are displaying, then the hidden curve will show up.
Keywords: strip chart, curve, display
References: None
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Problem Statement: How do I know which assays have been installed in the Simulation Environment?
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Solution: To see which assays have been installed you need to be in the Oil Environment. The Oil Environment is accessed via the Basis Environment by navigating to the Oil Manager tab and clicking the Enter Oil Environment button.
Once in the Oil Environment navigate to the Install Oils tab. This tab displays the streams and flowsheets in which the assays have been installed.
Keywords: assay, oil environment
References: None
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Problem Statement: This
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Solution: contains some tips for arranging your Aspen HYSYS window.Solution
This is perhaps the most trivial information you've ever read on dynamic simulation, yet it is valuable information intended to make things a bit easier. The idea is to separate the trivial from the modelling problems, so you can better focus on the real work. Most of this should be done while still in steady-state mode to make sure that you only need to do the formatting work once.
See more details in the attached document.
Keywords: arrange, windows, strip chart, PFD, display
References: None
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Problem Statement: What can I do if I get the Hysys.Economix Error - Economix Table Failed to Load: Table Case .\Basis\IcBasisStandardBasis.ptb 2
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Solution: The problem is that Economix is not able to find its key data files.
The picasso.ini config file setting(found in the same directory as HYSYS.exe) is set incorrectly:
Section: General
Key: DataRoot
This key in the config file must point to the root directory where the Economix scripts and tables are stored. On a typical install this will be in Hysys/Scripts, i.e. on a typical install the section from the Picasso.ini file should look like:
[General]
ConfigPath
= E:\HYSYS22.Plant\Config
DataRoot
= E:\HYSYS22.Plant\scripts
UserLibs
= E:\HYSYS22.Plant
Either the picasso.ini file is missing or it is incorrect.
If you have not done a typical install, then you can find the Scripts directory by searching for .ptb and .psc files. There are a large number of files ending in .PTB and .PSC in the Scripts directory, so once you find the files, you will find the directory.
When the Scripts Directory is found, the Picasso.ini file, which must be in the same directory as HYSYS.exe, needs the proper setting as shown above, with no trailing backslash. You can modify the picasso.ini file with any text editor, such as Notepad.
Keywords: Economix, Table
References: None
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Problem Statement: What are the steps I should follow to model a packed column?
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Solution: There are already some existingSolutions (#109251, #109339, and #114510) available in our knowledge base that are related to packed column simulation. But if this is your first time modeling a packed column in Aspen HYSYS, you would appreciate the detailed instructions in thisSolution.
Once you have a converged column, where liquid and gas flow rates as well as the number of theoretical stages are known, go to the Aspen HYSYS top menu bar to select Tools|Utilities. This will open a window where you Add the Tray Sizing utility.
Select the Tray Section (TS) you want to work with (with the help of the HYSYS navigator) and confirm your selection.
Press the Autosection button to bring up the Tray Section Information window. Check the Packed radio button as the Internal Type and select the type of Packing. Press the button on the Next page to Complete AutoSection.
Once the section (Aspen HYSYS will determine if more than one section is required) is completed, the utility in Design Mode will give you the calculated Column Diameter, along with other results, on the Performance tab page with the specified design constraints.
Rating of existing columns can be also performed by selecting Rating option on Specs page.
Any other packing not in the list can be added by the user modifying the file Packinfo.DB located in the Support folder under Aspen HYSYS directory.
Aspen HYSYS default calculation method is the Robbins correlation (L. Robbins, Dow Chemical, 1991). The other option is the SLE correlation proposed by Sherwood, and modified by Leva, then Eckert. The Packing Factor (SLE or Robbins) used will depend on the pressure drop correlation chosen.
Keywords: tray sizing utility, column sizing, packed column,
References: None
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Problem Statement: What is the External Data Linker Unit operation?
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Solution: This unit operation is used for case linking and collaboration.
It allows you to access streams which have been published to the RTI (Run-Time Integration) Server, and include their data in your simulation.
To add this operation:
select Flowsheet | Add Operation (or press F12)
select the Logicals radio button
select the External Data Linker operation and press Add
Keywords: External Data Linker unit operation, RTI server
References: None
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Problem Statement: How are compressor and expander calculations in HYSYS performed?
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Solution: Attached find a document describing the compressor and expander calculations in HYSYS.
Keywords: compressor calculations, expander calculations, equations, head, polytropic, centrifugal
References: None
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Problem Statement: I added a new stream to the model in the dynamics mode, and it appears to know all its specs although I didn't specify any thing, what is happening?
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Solution: In dynamics every stream needs an initial estimate for the dynamic solver to start running. So as soon as you add a new stream Hysys give it default initial estimate (all components have equal composition, temperature = 25C and pressure = 1 atm). This can be used if this is an intermediate or a product stream, since these values will be updated as soon as the integrator runs. For feed streams though, you should be very careful since these default specs can result in erroneous results.
Keywords: dynamics; specifications
References: None
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Problem Statement: How to check tray vapor as well as liquid transport properties in a column?
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Solution: By default when you look at column transport properties results in tabular format, only liquid transport properties are displayed.
In order to get vapor as well as liquid transport properties, you must select radio tabs in the example below.
In attached file, double click on Depropanizer column then go to Performance tab.
Plots/Transport Properties/View Table
Please select Properties tab then set the phase to Vapor. You will notice light liquid has been already selected as the default option.
Keywords: transport properties, tray properties, column etc;
References: None
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Problem Statement: A stream or couple streams out from a column are not connected on the PFD. They are actually connected but not showing connected on the PFD. Is there a way to show them connected on the PFD?
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Solution: Disconnect the stream from subflowsheet and reconnect. If it does not work, add a (any) unit operation after the stream and then delete the unnecessary unit operation.
Keywords: Disconnected stream, not connected stream, broken PFD, colum, stream, broken stream, hanging stream
References: None
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Problem Statement: How can I undo what I just did to my simulation?
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Solution: The much anticipated Undo feature has finally become available in Aspen HYSYS 2006.
The Undo function can be accessed either through the Edit | Undo menu function or through the Ctrl-Z keystroke.
The feature enables the user to undo up to 10 actions in the property view. This includes specifying or changing values for a variable or field.
Note that the undo queue is only maintained for an individual property view as long as that view is kept open. Once the view has been closed, the changes made are committed and cannot be undone.
The feature also enables the user to undo sizing and moving objects in the PFD.
Attached with thisSolution is a quick demo. You are more than welcome to download it and take a look at it.
Please keep in mind that as any new features, the Undo feature in Aspen HYSYS has its limitations. We welcome your feedback and suggestions.
Keywords: Undo, change, recover
References: None
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Problem Statement: How to set up tray sizing utility to display liquid from tray as net or total flow?
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Solution: Tray sizing utility display net liquid from tray or total liquid from tray, depends on the settings on the 'Design page. If '% Liquid draw' is 0%, the result will be net flow. If you change it to100%, results will be total flow.
Keywords: Tray sizing utility, net liquid flow, total liquid flow
References: None
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Problem Statement: How to match the heating values with the calculated reactor duties?
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Solution: There are two different heating values in practical use, the upper heating value and the lower heating value. The difference is the final phase for water. In calculating the upper heating value the water is considered to be in liquid phase. While for the lower heating value, the water is in vapor phase with all other products.
For combustion processes, the heat values will match the calculated duties of the reactors. In the attached model, we use two types of reactors, Gibbs reactor and conversion reactor. The feeds to the reactors are at 15 C and 14.7 psia. These are the default metering reference conditions in HYSYS, and may be changed to 0 C and 14.7 psia. However, the combustion reference conditions are fixed at 15 C and 14.7 psia. The product streams are set at the same conditions. With this setting, the heat of reactions equals equals the reactor duty, and it matches with a heating value of the feed.
The attached model demonstrates the setup in HYSYS. In the Gibbs reactor, the Gibbs free energy is minimized to determine the final compositions, and all of the products from combustion reactions leaving the reactor as vapor. The calculated duty matches the lower heating value.
When the same feed passes through the conversion reactor, the specified combustion reactions are used to determine the final compositions. For the same outlet conditions as those for the Gibbs reactor, a flash calculation will give an aqueous product and a vapor product leaving the reactor. The calculated duty will match the higher heating value.
Keywords: Heating value, reactor duty, Gibbs reactor, conversion reactor, combustion, furnace
References: None
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Problem Statement: How is the Overall Heat Transfer Coefficient calculated in PIPESYS?
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Solution: The .pdf file from Neotec entitled Estimation of the Overall Heat Transfer Coefficient for the Calculation of Pipeline Heat Loss/Gain should answer this question.
Keywords:
References: None
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Problem Statement: Pipe Segment: Why is my 3-phase flow indicating that my flow regime is Liquid Only?
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Solution: Currently, HYSYS Pipe Segment is only able to deal with either two-phase fluid or single phase fluid (Vapour or liquid). The aqueous phase may be considered a solid when the temperature is too low.
Keywords:
References: None
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Problem Statement: The Tabular package has default values for the different coefficients. What is the reference for this data?
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Solution: Aspen Hysys Tabular uses a default library and the tabular coefficients are retrieved from the database. These coefficients were regressed using data from DIPRR database (Thermophysical Property Database for Pure Chemical Compounds).
Keywords: Tabular, data, default, coefficient
References: None
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Problem Statement: How do I resolve the error Could not construct adapter for case when activating an Aspen Simulation Workbook case in Aspen HYSYS?
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Solution: For Windows 7 or Vista:
1. Open windows command processor as administrator, cmd is located on C:\Windows\System32
2. Access the path where CxsInteropCOMV22.DLL file is located (C:\Program Files (x86)\Common Files\AspenTech Shared\)
3. Enter RegSvr32 CxsInteropCOMV22.DLL
3. A window will be displayed with the following message:
Other version:
1. Open Run | Windows Start Menu
2. Verify the files path on your computer
3. Enter: Regsvr32 ?C:\Program Files\Common Files\AspenTech Shared\CxsInteropCOMV22.DLL?
(The path should match the files location in order to register successfully)
Keywords: ASW, Excel, case, adapter, case, construct, active, enable
References: None
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Problem Statement: How does HYSYS represent <empty> or null values internally? How can I check in code if a value is <empty>?
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Solution: Unknown values are shown as <empty> in the HYSYS interface. Internally HYSYS uses the integer -32767 to represent these values.
As an example, if the following code is used to retrieve the temperature of a process stream for which a temperature has not been specified, a value of -32767 is returned.
Dim hyStream As HYSYS.ProcessStream
Dim dblTemp As Double
'... Code to link to HYSYS, establish an object for the stream, etc... goes here
dblTemp = hyStream.Temperature.GetValue(C)
All HYSYS RealVariable type objects (e.g. hyStream.Temperature in this case) have an IsKnown property that returns a Boolean indicating whether the value is known or not. Hence you can use code like that below to check if the property is <empty>.
If hyStream.Temperature.IsKnown Then
dblTemp = hyStream.Temperature.GetValue(C)
Else
'Temperature is not known
End If
Keywords: -32767, Empty, IsKnown, RealVariable
References: None
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Problem Statement: I get an error when I try to run the Design phase in Hysys.Economix, what is wrong?
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Solution: If you get the following error:
Economix: Initializing Design and Costing Engine...
Economix: *** Error: Failed starting Icarus Server
Economix: Ensure that there are no IcServer.exe processes running Economix: *** Error: Initialization of Design and Costing Engine failed
in the Trace Window, there are a number of problems that could cause this:
1. Did you install the Icarus JP1 software first and then Hysys? If not, please uninstall and reinstall in that order.
2. Is the com port where the Icarus Firmware key attached working? Is it the same com port as you indicated during the installation process?
3. Have you turned off any PDA software that might be using that Port?
4. Have you closed any windows (including Windows Explorer) that might be open to the Icarus Project Path? If so, you must close them.
5. Have you checked your picasso.ini file (located in the Hysys root directory) to ensure that all paths in that file are correct? If not, correct them.
6. If all of the above fail, please put the Icarus Program path (found in the picasso.ini file) in your Path Variable (Control Panel/System/Environment for Win NT).
If these all fail, please contact [email protected]
Keywords: Economix, picasso, icarus server, icarus.exe, Design and Costing Engine
References: None
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Problem Statement: Is there a way to change the default temperature for each the fraction name on the list under Oil Characterization | Assay Data Type Chromatograph?
Is there a way of add more Fraction Name, for instance, if you have information for C31, C32,....?
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Solution: The temperatures cannot be changed. They represent the boiling point of the components. Although for hydrocarbons the boiling point is usually provided as a range, in Aspen HYSYS this is fixed.
Regarding additional components, you cannot add anything more. It is also fixed.
Keywords: Crude, Oil Characterization, Chromatograph
References: None
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Problem Statement: Error running integrated products such as Pipesim Link, Extensions, Refsys, APEA in Aspen Hysys on Windows 7 platform.
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Solution: Need to run Hysys.exe as administrator.
User can create Hysys shortcut on desktop, then right click select Properties.
Go to Shortcut tab, click on Advanced button as shown screenshot below.
Select ?Run as administrator?.
Keywords: Pipesys link error, refsys error, extensions, APEA integration, Windows 7
References: None
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Problem Statement: How can I get the utilities to work in Dynamics?
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Solution: By default utilities are not enabled in Dynamics. Beginning in HYSYS version 2.2, a Dynamics tab has been added to any utilities capable of calculating in dynamics. To activate the utility in dynamics select Enabled in Dynamics. On the same tab, you may also select the frequency of re-calculation for the utility by either entering Control Periods or checking the Use Default Periods check-box.
Note that the utilities slow down the integrator significantly, so only enable the utilities you need.
In versions prior to HYSYS 2.2, it was possible to enable utilities in dynamics. Here are the required steps:
1- Open the workbook.
2- From the Workbook menu, select setup.
3- From the Setup window, Add a new Workbook Tab (Press the Add button on the Workbook Tabs frame on the left hand side of the window). 4- When prompted to select an abject type, select Utility Objects and Press OK. 5- Close the setup window.
6- When you return to the workbook you will find a new tab added (named Utility objects). 7- The third row of this tab is titled Enabled in Dynamics and it has a check box for each utility. 8- Check the box that corresponds to the desired utility.
You can also change the sampling rate of these utilities by un-checking the Use Default Periods box on the workbook tab, then specifying your own Control Period.
Keywords:
References: None
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Problem Statement: Can I use mild steel as a value if my pipe is made of stainless steel?
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Solution: The mild steel value has different properties than stainless steel and the thermal conductivity is much lower.
If you want to use Stainless Steel this needs to be used through the User defined material option.
When you add a Pipe segment, under Rating Tab append a segment. Here you can select the material of construction for the pipe. Select User specified and define the thermal conductivity of the material.
After this is done, when you go to Heat Transfer and select Estimate HTC and select to include the pipe wall conductivity, this value will be used to obtain the total heat loss calculations.
Keywords: Pipe segment, stainless steel, material
References: None
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Problem Statement: Why isn't my PIPESYS unit operation solving?
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Solution: If you have registered the extension properly, you should be able to double click on the unit operation and see all the information entered for that pipe segment. If the status bar indicates Insufficient Information in a Pipeline Unit check the Status window at the bottom left hand corner of the HYSYS program. The Required Info will be written in red. If the status bar on the Pipesys operation says Error check the status window. The reason for the error may be Failure due to low pressure in Pipeline Unit Pipe 1. If this is the case, you'll have to increase your pipe diameter or decrease the flow rate.
Keywords: pipesys, solving, error
References: None
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Problem Statement: When I print the workbook in the attached simulation, it shows several additional components that are not part of the component list in my simulation. Is there a way to remove these components?
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Solution: There was a similar issue that was fixed for v7.2. But if a component is deleted on an earlier version and then opened on v7.2 or v7.3, then the problem shows up again.
The only available workaround is to manually add the unwanted components to the simulation. And then remove them from the list. Then save the case. This will remove the components from the master component list.
Keywords: Unwanted components
Workbook
Delete
References: None
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Problem Statement: What is New in Aspen HYSYS V7.3 - New Hydrate Model for High Pressure
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Solution: As oil companies have gone to deeper depths to find and produce oil, the pressure and temperature ranges of the thermodynamic models must be extended. In particular, the accuracy of commonly used hydrate formation prediction models decreases for pressures over 100 bar.
In V7.3, the HYSYS Hydrate Formation Utility includes a new model from the Colorado School of Mines (Clathrate Hydrates of Natural Gases, 3rd Edition) that more accurately predicts hydrate formation at these higher pressures.
This new model includes:
New thermodynamic / statistical thermo model of the hydrate phase
New thermodynamic model for the aqueous phase
Uses the SRK model for the vapor and liquid hydrocarbon phases
Results comparing the new model results against experimental data are given in the plot below.
The new model is implemented within the existing Hydrate Formation Utility available in HYSYS. The new Colorado School of Mines model (CSM) is the default model in V7.3. The heritage model from Ng & Robinson is also still available from the Model drop-down menu.
Keywords: Hydrate Formation Utility, Hydrate, CSM Method, V7.3
References: None
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Problem Statement: Is there an AutoBackup?
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Solution: Yes. You have the ability to choose whether or not Hysys will back up your cases periodically. Backup cases will be stored in the working directory, with the extension .bk*. Options you have include setting the frequency of the autosave functionality, specifying the number of backups which are saved, and whether or not the autosave should be invoked when integrating during dynamic simulation. To find AutoBackup settings, select Tools | Preferences, and look on the Files tab of the Session Preferences view. When HYSYS autosaves a file, a message is posted in the trace window (the white window at the bottom right hand corner of the program).
Keywords: autosave, backup file, preferences
References: None
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Problem Statement: How can I copy streams from one case to another case?
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Solution: Ensure that all of the components used by the case you are copying from are in the Fluid Package used by the target case. If copying stream to a new case:
Export the Fluid Package from the Original Case
Create a New Case and Import the Fluid Package
Open the original case
Select the stream(s) you are interested in and and use Object Inspect (ie. right-button click); select Cut/Paste Objects \ Copy Selected Objects**
Switch to the target case (use Window menu \ Load Workspace \ select the appropriate case)
Object Inspect the PFD and select Cut/Paste Objects \ Paste Objects
NOTE: only user modifiable variables (in blue) will be copied. If the properties of stream in question are all calculated you will want to create a user defined copy of the stream first. To do this create a new stream (press F11), give it a name and select the Define from Other Stream... button at the bottom. Selecting the stream of interest will make the new stream a clone of the original but with Composition and Conditions as user defined, not calculated. Then copy / paste this clone.
Keywords:
References: None
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Problem Statement: Can I access the Stream Cutter object via Automation?
|
Solution: The stream cutter operation is not yet 'wrapped' for normal automation access. However it can be accessed via 'Backdoor' methods. Attached is some example code that shows how to get to the important properties.
Public Sub AccessStreamCutter()
'
'Description: Access all the important properties of the stream cutter object
' Some properties require backdoor access
'
' NB Backdoor methods are only recommended when there is no other alternative, the internal
' HYSYS monikers may not remain constant between versions
' so care should be exercised when upgrading
'
'Declare Variables
Keywords: None
References: None
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Problem Statement: New in HYSYS V7.3 - Start page with RSS feeds
|
Solution: Aspen HYSYS V7.3 makes it easier than ever to stay informed with news about upcoming webinars, training events, how-to knowledgebase articles, and short animated tutorials. The new Start Page features quick links to help topics, including a summary of new features of HYSYS V7.3 and previous versions. There are quick links to the customer support pages for HYSYS, and links to the training site so you can find a training course in your area.
The Support Live Chat link opens an interactive chat window where you can receive help directly from AspenTech's staff of professional Customer Support Engineers. This option for getting immediate help is also available directly from the customer support web site.
The right hand side of the new start page includes a set of live news feeds. The Product News tab shows news items related to HYSYS and closely related products that interoperate with HYSYS. These news items will include training opportunities, 'how-to' knowledgebase items, short animated tutorials, webinar announcements, and important information about future service packs or software patches.
Most news articles link to more detailed information - just click the blue headers to read the full text , to get access to attached sample files, and to view animated tutorials.
The second tab is customizable. You can populate this sheet with a news feed related to your organization, a professional organization, or to any other RSS feed. The second tab can also be customized through scripted installations - allowing your organization to use this tab to send messages to your internal user base, so you can keep your staff informed about internal training programs, or maybe just to share best practices with each other.
Go to Tools| Options | Start Page to customize the start page options, including the update frequency and the ?My News? URL.
Keywords: None
References: None
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Problem Statement: Why can I not find the referenced spreadsheet for the FRI Tray Rating utility?
|
Solution: The FRI Tray Rating utility in Aspen HYSYS provides an interface to the FRI tray rating calculations. The spreadsheet itself, however, is licensed by a third party (Fractionation Research Inc.).
If desired, you can verify if your company is currently entitled to have the FRI spreadsheet via the FRI website (http://www.fri.org). Once you have the appropriate license, you will be able to use this feature with Aspen HYSYS.
Keywords: FRI, utility, spreadsheet.
References: None
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Problem Statement: How do I link cases/ use the case collaboration feature in HYSYS?
|
Solution: Consider the situation where you have two cases, for example:
Case 1: heat exchangers upstream of a column which deliver the column feed at appropriate conditions
Case 2: a simulation case containing the column. Now suppose you want to link the product stream of Case 1 (the source case) as a feed to the column in Case 2 (the destination case). There are three major steps which you must take:
CONFIGURE SERVER AND CLIENT MACHINES
PUBLISH STREAM FROM SOURCE CASE TO SERVER
INSERT PUBLISHED STREAM FROM SERVER INTO DESTINATION CASE
CONFIGURE SERVER AND CLIENT MACHINES
First, ensure that the RTI server functionality has been properly configured.
A machine on your network should be running the RTI Message Server software, and the copy of HYSYS which is running the actual cases to be linked should have the machine name entered in the appropriate fields under Tools | Preferences | RTI Server.
For help with this, see the FAQ entitled: How do I set up the RTI Server functionality (which is used for case collaboration)?
PUBLISH STREAM FROM SOURCE CASE TO SERVER
CONNECT TO MESSAGE SERVER
from Case 1, under Tools, select Case Collaboration
press the Connect to Message Server button
you should see a message in the Trace Window confirming that you are connected to the message server
PUBLISH STREAM
right click on the product stream of Case 1, and select Publish Stream
fill out the notes and publisher information, and press the button to publish the stream
INSERT PUBLISHED STREAM FROM SERVER INTO DESTINATION CASE
CONNECT TO MESSAGE SERVER
Under the Tools menu, choose Case Collaboration, and press the Connect to Message Server button
you should see a message in the Trace Window confirming that you are connected to the message server
ADD EXTERNAL DATA LINKER UNIT OPERATION
In the flowsheet, insert an External Data Linker Unit Operation (you can find it grouped with the other logical operations at the bottom of the Object Palette (the icon with red arrows) or you can find it under Flowsheet | Add operation | Logicals)
On the External Data Linker Unit Operation, select the stream from the RTI server and add a corresponding stream name in your source case
You can also select here whether or not you wish to have the stream automatically update to reflect any changes in the source case or not.
Keywords: RTI Server, case linking, case collaboration
References: None
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Problem Statement: How do I use the Case Security features introduced beginning with HYSYS 3.0?
|
Solution: HYSYS 3.0 introduces a new level of Case Security to ensure the integrity of the intellectual property contained within a HYSYS model.
This feature was developed to give the Case author the required level of comfort when distributing HYSYS models that they have invested a lot of time and knowledge in. In addition to the ability to password protect a case, the author can also lock the case to a specific piece of computer hardware or Hyprotech security key.
The user's password is given an expiration date to further protect the business interest of the case author. These capabilities are accessed from the Case Security option in the Tools menu.
Keywords: case security, case protection
References: None
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Problem Statement: How does changing the diameter of a pipe help getting out of slug flow regime?
Why does a smaller diameter pipe predict slug flow but not a larger diameter pipe for the same stream?
|
Solution: Either increasing or decreasing diameter of pipe can help getting out of a slug flow regime. It depends on what are the current conditions and which way you want to move. Consider current conditions are at point A in the Beggs and Brill flow regimes are shown in the figure below. It is currently in the intermittent (slug and plug) flow regime. You can see you can get out of the flow regime either by increasing or decreasing Froude number. As Froude number is directly proportional to velocity, you can get out of a slug flow regime either by decreasing or increasing diameter. Smaller diameter does not always turns you away from slug flow regime. Consider point B as the current conditions. If you reduce the diameter, you will head right into the slug flow regime instead. This type of behavior can be observed for other correlations as well.
Keywords: slug flow, diameter, velocity
References: None
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Problem Statement: Where can I see the description of each Extension available in V7.3 Object Palette?
|
Solution: The following extensions are available in Aspen HYSYS V7.3 Object Palette
1. Saturate Extension
Purpose: Calculates the amount of water needed to saturate a gas stream
For more description of this extension please view KBSolution 110073
2. Ejector Extension
Purpose: It computes the pressure increase or motive gas requirements for a steam ejector.
For more description of this extension please view KBSolution 110065
3. Mach Number Extension
Purpose: Calculates the Mach number for a given pipe or stream
For more description of this extension please view KBSolution 110068
4. Virtual Stream Extension
Purpose: Live ?link? between two streams, with the information from one stream transferred to the other stream
For more description of this extension please view KBSolution 110889
5. Well Head PQ Extension
Purpose: Well Head including PQ (Performance curves)
For more description of this extension please view KBSolution 110076
6. Equlibrium Plots Extension
Purpose: Generates binary plots (XY, Txy, Pxy) and ternary plots (VLE, LLE) using the 2-D plotting capability in HYSYS
For more description of this extension please view KBSolution 110066
Keywords: Extensions, Well Head, Equilibrium, Saturate, Virtual Stream, Mach, Ejector.
References: None
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Problem Statement: What are the definitions of Phase Fraction [Molar Basis], Phase Fraction [Mass Basis], Phase Fraction [Vol. Basis] on the stream Worksheet\Properties page?
|
Solution: These properties represent the fraction of the stream occupied by a particular phase, expressed in various ways:
Phase Fraction [Molar Basis] = Phase Mole Flow / Total Mole Flow
Phase Fraction [Mass Basis] = Phase Mass Flow / Total Mass Flow
Phase Fraction [Vol. Basis] = Phase Std Ideal Liq Vol Flow / Total Std Ideal Liq Vol Flow
The Phase Fraction [Molar Basis] also corresponds to the values HYSYS reports for the Vapour / Phase Fraction on the Worksheet ... Conditions page.
Note that these phase fractions are reported even for a stream without a defined flow rate, since they can be calculated from the phase molar, mass and std ideal liquid densities, respectively.
Keywords: Vapour Phase Fraction, Phase Fraction [Molar Basis], Phase Fraction [Mass Basis], Phase Fraction [Vol. Basis], vap. frac.
References: None
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Problem Statement: Hydrate Utility CSM model - estimation of Fugacity of Water in Hydrate.
|
Solution: The CSM model relies on the equilibrium equivalence of the fugacity of water in the hydrate phase to that of water in the fluid (Aqueous, liquid hydrocarbon or vapor) phase,
fw H = fw k
where:
fw H = fugacity of water in the hydrate phase
fw k = fugacity of water in the fluid (Aqueous, Liquid hydrocarbon or Vapor) phase
Fugacity of Water in Hydrate
In order to solve thermodynamic equilibrium, fugacity of water in the hydrate phase must be known. In the Parrish and Prausnitz formulation (as used in the Ng & Robinson model), the fugacity of water in hydrate is related to the fugacity of water in the aqueous (or ice) phase. This can be inconvenient when an aqueous phase does not exist. Ballard and Sloan (2002) proposed a more convenient expression:
Where:
fw0 is the ideal gas fugacity of water at 1 bar (=1bar),
gw0 is the Gibbs energy of pure water in the ideal gas state at 1 bar,
μwH is the chemical potential of water in the hydrate
R is universal gas constant
T is temperature in K
The key quantity is μwH ? the chemical potential of water in hydrate, which can be written as:
Where:
gwβ is the Gibbs energy of water in the standard (empty) hydrate lattice at the given volume and the system temperature and pressure.
υm is the number of cages of type m divided by the number of water molecules in the hydrate lattice.
θim is the fractional occupancy of guest molecule i in hydrate case m.
γwH is the activity coefficient of water in the hydrate. It accounts for non-idealities due to the inclusion of the hydrate guests, which caused the volume of the standard hydrate to be different from the volume of the equilibrium hydrate. This non-ideality was not present in the original van der Waals and Platteeuw model.
Fugacity of Water in the Aqueous Phase
The fugacity of water in the aqueous phase is calculated using a modified Helgeson (Geochim. Cosmochim. Acta 52 (1988) 2009) equation of state combined with the Bromley (AIChE J. 19 (1973) 313) activity model. The Helgeson equation of state describes the hydrocarbon-water systems, while the Bromley activity model accounts for the interactions with the aqueous phase when salts and methanol (or other inhibitor) are added. These models are very complex and will not be described in details here. Interested users can refer to Jager, Ballard and Sloan (2003) for detailed descriptions. Note that the current hydrate utility does not consider the presence of salt.
Fugacity of Water in Hydrocarbon Liquid or Vapor Phase
The fugacity of water in the hydrocarbon liquid or vapor phase is calculated from the equation of state model that is used in the fluid package. This is limited to the Peng Robinson, SRK or Glycol equations of state.
The CSM model is the most advanced model currently available. Extensive comparisons against experimental data and other models have been made and reported by Ballard and Sloan (A.L. Ballard, E.D. Sloan, Fluid Phase Equilibria 216 (2004) 257-270).
This advanced model is recommended over the Ng & Robinson model. However, since it has been newly introduced in Aspen HYSYS, it is not used by default at this time.
Keywords: Hydrate, CSM Model, fugacity, Utility.
References: None
|
Problem Statement: How can I export data from my workbook (or any table in Hysys) to a spreadsheet program such as Excel?
|
Solution: This can be accomplished in two easy steps.
You can easily export a sheet from a workbook or any other Hysys printed tables by printing the specsheet in comma delimited format. For example, if you wish to export the contents of a workbook sheet, this can be done by right clicking on the workbook title bar, then selecting Print Specsheet. You can select the page(s) you wish to print. Then, select Text to File (ASCII output). If you are planning on importing it into Excel, I would recommend delimiting using CSV format, which means that fields in columns will be separated by commas.
Open the file in the desired spreadsheet program Then you can just open the file in Excel, and Excel will recognize that it is an ASCII file and ask you how the file is delimited. (Note that Excel does not filter by *.dmp, so when you open it in Excel, you must choose to display all files, ie. . ) You should select comma as the delimiter, and then you should have no trouble opening it and having it look nice in Excel.
Keywords:
References: None
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Problem Statement: How do I change unit of Std Ideal Liq Vol Flow?
|
Solution: To change units of Std Ideal Liq Vol Flow-
1. Go to Tools=>Preferences
2. Click on the variables tab
3. Find variable Liq.Vol. Flow in the list and change display units that are desired. It will change units for Std Ideal Liq Vol Flow.
Keywords:
References: None
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Problem Statement: How do I get my STX exchanger to solve in HYSYS?
|
Solution: If the link is established between the two programs (they are linked when you can press the View Design button on the Design Parameters page and STX comes up) but the exchanger does not solve in HYSYS, it might be best to save the process data in STX as an .sti file and run the model in STX stand-alone. This is because the information provided through STX standalone is much more detailed than through the HYSYS - STX link. For example, if you are getting the errors STX diagnostics for E-100 * Negative temperature difference. The errors listed above were found during input data checking. in the HYSYS trace window, go into STX and save the exchanger. Then exit the program. You can close HYSYS too at this point. Open STX up again in stand-alone and open and run the exchanger. In the trace window in STX, some suggestions on why the design or rating is failing will be presented.
Keywords: stx rating, exchanger not solved, stx diagnostics, stx
References: None
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Problem Statement: What is the difference between Actual Volume Flow and Standard Gas Flow?
|
Solution: Actual volume flow takes the non-ideality of the system into account and this depends on the fluid property package used in the simulation. This is calculated at the stream conditions.
Std. gas flow assumes ideal gas behaviour and is calculated from standard ideal molar volume.
It is important to note that actual volume flow is not necessarily same as std gas flow at standard conditions (15 C, 1 atm) because the earlier takes the non-ideality into account with the property package in use.
Keywords: Actual Volume Flow, Standard Gas Flow
References: None
|
Problem Statement: The Standard Gas Flow of a particular stream is different in both the Stream Worksheet and the Workbook.
|
Solution: The Standard Gas Flow value shown in the stream Worksheet tab, Properties page is calculated by the correlation that utilizes the conversion of 23.6444359 m3/kgmole at standard conditions of 15 C and 1atm. The molar flowrate of the stream is multiplied by this conversion to give the standard gas flow in STD_m3/h and it does not change with change in standard temperature (Tools/Preferences/ Standard Temperature Settings).
The value shown in the Workbook is calculated by the stream itself and uses the standard ideal molar volume of 23.6444364 m3/kgmole, which is also based on the standard temperature. Changing the simulation standard reference temperature will have an effect on this Standard gas flow result. This feature was introduced in versions released after 2010.
In order to view the same results that show in stream properties in the workbook, add the standard gas flow rate, through the Calculator variable, to the Workbook. Go to Workbook set-up/Add Variable, in the variable picker navigate to the Calculator Variable, in the Variable Specifics window select Standard Gas Flow.
Keywords: Standard Gas Flow, Workbook
References: None
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Problem Statement: How do I model a delivery point (outflow) inside the PIPESYS extension?
|
Solution: A Side Stream Pipeline Unit in PIPESYS can be used to add or remove flow from the elevation profile. For pipelines with multiple sources, this provision eliminates the need to create multiple streams and multiple pipeline units. This is especially useful if pressure losses in the side stream are either inconsequential (very short lines) or irrelevant to the analysis. What would otherwise be a complex system of pipes, can often be reduced to a few pipelines with side streams. Data for the calculations are entered in the Parameters tab of the Side Stream Pipeline Unit and main line results are displayed for the streams before and after the side stream.
In the Flow Direction group box there are two radio buttons from which you can choose the direction of the flow: Inflow or Outflow. Selecting the flow direction and flow rate specifies addition or removal of flow. The side stream?s flow rate can be specified as a:
Molar flow rate
Mass flow rate
or a Standard liquid volume flow rate.
For an inflow stream when calculating the flowing fluid temperature profile, the temperature or vapour mole fraction of the stream can be optionally specified. If the flowing fluid temperature profile is being specified or the temperature or vapour mole fraction are left empty, then the inflow stream?s temperature and vapour mole fraction are obtained from main line stream conditions. The Before Side Stream main line stream?s data is used when calculations are done in the direction of flow. For calculations done against the direction of flow the After Side Stream main line stream?s data is used.
The outflow stream always obtains its temperature and vapour mole fraction data from the main line streams. Similarly, as when the inflow stream?s temperature and vapour mole fraction data are left empty the Before Side Stream main line stream?s data is used when calculations are done in the direction of flow. For calculations done against the direction of flow the After Side Stream main line stream?s data is used.
Keywords: side stream, delivery point, pipe line, inflow, outflow
References: None
|
Problem Statement: Head loss under downcomer is too large?Y?Y么?OZv?H ??么???r?H
|
Solution: ???I?OZv?Ydowncomer head loss 值`?`??B ?YTray Sizing Utility???CPerformance | Trayed | Trayed Results | Downcomer | DC Head Loss栏???A?E查??结?E值?B?e响Head Loss计ZZ值?IZ??v?oZq?YDowncomer Clearance?B ?v???????x???C调??Downcomer Clearance(?n统?z?E值?Y 1.500)?I值???z?x???M`??i???????B
Please find theSolution 124197 for the original English version.
Keywords: head, loss, downcomer, warning, error, tray, sizing, utility, CN-
References: None
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Problem Statement: Will the Peng Robinson Property Package simulate Amine systems for sour natural gas plants?
|
Solution: No, the Peng Robinson PP will not simulate amine systems. When you attempted to find the amine components, you probably could not find them when selecting PR as your property package. Some amines are available with the PRSV property package, but we do not recommend using it to model sour gas treating. The only property package that accurately models the equilibrium solubility of acid gases in aqueous amineSolutions is AMSIM (or the Amines Property Package).
Please refer to the HYSYS Simulation Basis manual, Appendix C, for more information regarding the Amines Property Package in HYSYS.
Keywords:
References: None
|
Problem Statement: How do I set the default version of Aspen HYSYS in Windows 7?
|
Solution: To change the default version of Aspen HYSYS in your machine, you can run the attached .bat file. The attached .bat file will set the default version to Ver. 7.3. This will also set the correct version of Hysys.tlb which you need to run any automation through VBA.
To change the default version to V7.2 or other versions, open attached file with Notepad and change 7.3 to 7.2 (or any other version you like).
Important note: To run .bat file in Windows 7, you need to have administrator privileges. Even if your account has admin rights, in Windows7 you will still need to right mouse click on the .bat file and select Run as administrator.
Keywords: Default version, Window 7
References: None
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Problem Statement: How can I regress Binary Interaction Parameters (BIP) for my EOS based in Solubility data using COMThermo Workbench?
|
Solution: Go to Start Menu -> All Programs -> AspenTech -> Process Modeling -> Aspen Hysys Thermodynamic COM Interface
Click in the Fluid Package Manager
Append a new fluid package by clicking in the Add Fluid Package Icon
Select the Fluid package that you required as you would do to install a COMThermo package and select the components associated
Click in the Thermodynamic Workbench Manager and select FluidPhaseRegression and click on the Add button.
Select the package that you created and click in the Add button to append new dataset
Select the Type of data and input your experimental results, then click in the Calculate Error button
Review the result of the Statistical data and select any other option that you might need to consider before clicking on the Optimize button. The results will be displayed in the Variables page of the Fluid Phase Regression window.
Keywords: Regression, Binary Interaction Parameters, COMThermo, Fluid Phase Regression
References: None
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Problem Statement: How can I see what is in the Column SubFlowsheet from the Main Environment PFD?
|
Solution: You can view the Column PFD from the Main Flowsheet PFD. Object Inspect the Column which you are interested in, and from the menu select the Open PFD option This PFD displays all internal streams for the Column, as well as the number of stages in the Column. Note: when this view is opened from the Main level, you cannot make connections, drag and drop, or delete connections.
Keywords:
References: None
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Problem Statement: What is the Vapour Load in the Flooding section of the Tray Sizing utility?
|
Solution: On the Tray Sizing utility, Performance Tab, Trayed Page, click on the Flooding radio button, the column that says vapour load represents the following:
vap load = (vaprate) * sqrt( vapden / (liqden - vapden) )
Where the vaprate is the vapour rate shown on the Tables page of the Tray sizing utility, and liqden and vapden are the corresponding tray liquid and vapour densities, as shown on the Tables page of the tray sizing utility.
A good reference for this equation is Henry Kister's Distillation Design, 1992, equation 6.1.
Keywords:
References: None
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Problem Statement: Can I change the flow rate of the assays in a blend via OLE?
|
Solution: Yes, the attached VBA code illustrates this. Paste the attached code into the Excel VBA editor (or similar) and make the HYSYS type library reference.
Public Sub EditBlendFlowRates()
'
'Description: Demonstration of how to edit a flow rate for the Assays making up a Blend
' Assumes the R-1.hsc sample case is loaded
'
'Declare Variables
Keywords: None
References: None
|
Problem Statement: In HYSYS versions like 2006.5, V7.0 and V7.1, users can find the XML data view/report by going to Simulation | View XML from the main menu on top of the HYSYS diagram, as described in
|
Solution: 122745.
However, there is no such Simulation | View XML option in HYSYS V7.2 or V7.3. ThisSolution describes Where to generate and view the XML data input summary in HYSYS V7.2 and V7.3.
Solution
In HYSYS versions newer than V7.1 (exclusive of V7.1), i.e. V7.2 and V7.3, the previous option Simulation | View XML has been replaced by a new option which is Simulation | Input Summary.
This is exactly the same function to generate the XML data form of input summary for the HYSYS case, which is of wide range of use including attempts to open a newer version HYSYS case with older version of HYSYS program, the details of which can be found inSolution 109662.
Keywords: View XML, Input Summary, V7.1, V7.2, V7.3, XML
References: None
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Problem Statement: How can I calculate a rate of change for a variable in Dynamics?
|
Solution: The way to achieve this is to use the Transfer function logical operation to set a delay time for the variable of interest. The output from the Transfer function and the current value of the variable can then be read into a spreadsheet operation and then the rate of change can be calculated using a simple numerical derivative.
Rate of Change = (Current Value - Delayed Value)/Time Delay
The attached HYSYS case (version 2.4.1 built 3870), illustrates this principle.
Keywords: Rate of Change, Transfer Function, Delay
References: None
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Problem Statement: Why can?t I rate a valve in HYSYS? Is this option included in Steady State?
|
Solution: On earlier releases, HYSYS did not include the option to rate the valves in steady state (i.e. define C1, Cv or K and opening percentage and calculate pressure drop), but starting with V7.3 this option is included.
The following scenarios are supported:
a. Mass Flow and P2 (downstream) are known, P1 could be calculated;
b. Mass Flow and P1 (upstream) are known, P2 could be calculated;
c. P1 and P2 (downstream) are known, Mass Flow could be calculated;
d. P1 and Delta P are known, Mass Flow and P2 could be calculated;
e. P2 and Delta P are known, Mass Flow and P1 could be calculated;
The checkbox ?Use sizing methods to calculate Delta P? in the Design tab > Parameters need to be checked to enable this calculation option.
Keywords: Rating, control, valve, steady, state
References: None
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Problem Statement: How does one view process utility consumption in Aspen HYSYS?
|
Solution: The Aspen HYSYS Process Utility Manager lets you define and apply utility tags to material and energy streams, to designate them for calculation of energy and utility consumption and costs.
User can view overall Utility consumption data per utility tag, or User can view data for each utility at the stream level.
1. Click the Flowsheet | Flowsheet Summary menu option.
2. Click the Utility Consumption tab (Drag to expand the dialog to the right if necessary).
When the Overall Summary radio button is selected, the overall consumption of each utility type is listed.
Use the Stream Level Summary radio button to view the flowsheet utility data at the stream level. For each utility selected in the Utilities column, the stream associated with the utility and the returned values are displayed.
Keywords: utilities, process utilities, utility consumption
References: None
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Problem Statement: Validation of water content in natural gas calculations by Peng-Robinson property method in Aspen HYSYS .
|
Solution: Predictions of water content in natural gas by Peng-Robinson property method are very good. Results are validated against GPSA and experimental data.
Results are compared against
1. Experimental data from Olds, Sage and Lacey, Phase Equilibria in Hydrocarbon Systems. Composition of Dew-Point Gas in Methane-Water System, Ind. Eng. Chem. 34, 1223-1227 (1942) and
2. GPSA charts Figure 20-4. The values are read from the chart.
The figure below shows the comparison.
Keywords: Water content, natural gas, validation
References: None
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Problem Statement: How does one use the Electrolyte NRTL model in Aspen HYSYS?
|
Solution: 1). From Simulation Basis Manager Components/Databank select Aspen Properties then add only molecular species.
2). Create a Fluid Package then select Aspen Properties then select Property Package as Electrolyte NRTL.
3) Click on the Electrolyte Wizard button.
4). In the ensuing window, include the water dissociation reaction
5). Select the components that are involved in the ionic system and click the button Get Reactions. Uncheck any reactions which you think not relevant to your case, then click on OK
The remainer of the simulation can then be created as with any non-electrolyte property model.
Keywords: Aspen Properties, ElecNRTL etc
References: None
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Problem Statement: How does Aspen HYSYS deal with heat of mixing?
|
Solution: If an equation of state (EOS) model is used, the heat of mixing is inherent in the enthalpy calculation based on thermodynamic relationships.
However, it will not be accounted for if an activity model is used.
You should consider adding your own data through the Tabular package when significant heat of mixing is involved and the selected property package does not include it in the enthalpy calculation by default. Detailed instructions on how to use the Tabular package can be found in the Aspen HYSYS Simulation Basis manual.
Keywords: heat of mixing, excess enthalpy
References: None
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Problem Statement: I can't find User Variables that I know are there. What should I check?
|
Solution: I know my case contains user variables, because I can see them by going to Simulation ... Import and Export User Variables, however when I go to the User Variables page of my stream / operation they are not on the list - where have they gone?
In order to see / enable the user variables you will have to first click the Green tick (Flyby says: Show/Hide Variable enabling checkboxes) above the user variable table. This will bring up another column with checkboxes. Ticking these will enable the user variable, hence it will appear on the list for that stream / operation, and be calculated when appropriate.
Keywords: User Variables, Show/Hide Variable enabling checkboxes
References: None
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Problem Statement: Aspen HYSYS Stream Reoport (HSR), Workbook Dump, Aspen HYSYS Browser and Excel (with Macros) do not work. How to fix it?
|
Solution: Reason 1: The number 1 reason for not working any Excel file with Macros / Visual Basic code is high macro security.
Reason 2: Multiple versions of HYSYS. Excel gets confused which version of HYSYS to use.
Reason 3: Type library referenced to wrong version of HYSYS.
To solve the problem try the following step(s). Check the Excel file after every step. If it works you don't have to go to the next step.
Step 1: If you are using an Excel file with macros published by us, please check if there the file is version dependent or not. UseSolution document 110050 for HSR, 110052 for HYSYS Browser. Workbook dump is currently version independent.
Step 2: Make Macro Security low (medium may work) or enable all macros.
For Excel 2003 or older version, go to Tools || Macro || Security || choose Low or Medium
For later version of Excel, go to Developer || Macro Security || choose Enable All Macros. The screenshot below shows the options.
Step 3: Restore File Associations (for 2006 or newer version). The path to it for default installation is Start || All Programs || Programs || AspenTech || Aspen Process Modeling (version) || Aspen HYSYS || Restore File Associations.
If the HYSYS version is 2004.2 or older, go to the next step.
Step 4: Unregister all versions of HYSYS and then register only the version you want to use.
Go to Start || Run and browse for hysys.exe file. The default location is C:\Program Files\AspenTech\Aspen HYSYS (version)\hysys.exe.
Type /regserver (to register) or /unregserver (to unregister) after the file location and a space. In short, command should look like C:\Program Files\AspenTech\Aspen HYSYS (version)\hysys.exe /regserver
Click Ok and wait till you get OLE registration successful or OLE Registration Removed message depending on the command.
Reminder: You have to unregister all versions of HYSYS you have in your computer. Then register only the version you want to use.
Step 5:
Keywords: HSR, Workbook Dump, HYSYS Browser, couldn't link to HYSYS
References: the correct type library.
Open MS Excel and Press Alt+F11 to activate the VBA editor.
From the main menu select Tools || References || Browse to hysys.tlb || Open. The defualt localtion of the file is C:\Program Files\AspenTech\Aspen HYSYS V7.1\hysys.tlb
Verify no other version of HYSYS type library is referenced.
Close the VBA editor.
Save the Excel file. If necessary, close the Excel file and open it again.
Step 6: Directly change the VBA code to reference exact version of HYSYS.
Open VBA editor (Alt+F11)
Find code(s) where HYSYS.Application is referenced. Make them version specific. Such as, HYSYS.Application.V7.2. If it is V7, use V7.0.
You may have HYSYS.Appliation in more than one places. Change all of them.
Note: You have to modify version if you want to use the Excel with a different version of HYSYS. So, use this option as last option.
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Problem Statement: How can I model a check (non-return) valve in dynamics ?
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Solution: A check valve can be modelling by adding a regular valve to your flowsheet and selecting the Check Valve box on the Dynamics -> Specs page of the valve property view.
Keywords: Valve, Check Valve, Non-Return
References: None
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Problem Statement: What is the difference between Net and Total Flows in the Column?
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Solution: Net Flows are the flows within the column.
Total Flows also include the draw(s) from the stage.
In the Column Environment, Net Flows are displayed on the Tray Section Performance tab (Main TS Property View, Performance tab, Flows ply).
In the Main Environment, Net Flows are displayed in the Column Runner (Column Property View) on the Performance tab, Column Profiles tab. Either Net or Total Flows are displayed on the Performance tab, Plots page, depending on the option chosen: for the Tray by Tray Properties Flow, view the table or the graph and click on the Properties button. You will then have the option to select net or total for the Tray Flow Basis.
Consider the enclosed example case (ver 3.2 - build 5029). This is a Propane - Butane splitter with liquid and vapour draws on the feed stage (11), both draws have a flow of 1 kg/h.
First go to the Column Environment and select the Main TS Property View. On the Performance tab, Flow ply, the liquid and vapour flows leaving the stage (i.e. the Net Flows) are reported.
For stage 11:
The vapour leaving the stage has flow rate (161.3 kg/h)
The liquid leaving the stage has flow rate (170.5 kg/h)
In the Main Environment, the same Net Flows are shown on the Column Runner, on the Performance tab, Column Profiles ply.
Also on the Column Runner, you can view the Total Flows by going on the Performance tab, Plots ply. Select Flow under the Tray by Tray Properties group and click on View Table (or View Graph). Click on the Properties button: if you select Total as the Tray Flow Basis, you will see that the vapour and liquid flow rates both increase by 1 kg/hr (i.e. including the draws on stage 11).
Keywords: Column, Net Flow, Total Flow, Volume Flows, Tray Section
References: None
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