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Version 3.9
Models
Super TRAPP Thermal conductivity model
The Super TRAPP thermal conductivity model has been added. This is an extended corresponding states model that uses propane as a reference fluid. The model offers improved predictions compared to the existing CLS model, particularly for petroleum fluids.
Linear Gradient Theory surface tension model
The Linear Gradient Theory model may be used to calculate vapour-liquid or liquid-liquid interfacial tension. Predictions are based on the density gradient that exists across the interface. The model works in conjunction with any of the cubic equations of state or the SAFT equation. It may be used to model the interfacial tension between gas-oil, gas-water and oil-water.
CSMA model
Thirteen new components have been added to the CSMA model. These are Carbonyl Sulphide, Ethanol, Cyclohexane, iso-hexane, Krypton, Nitrogen Trifluoride, neo-pentane, Sulphur Dioxide, SF6, Toluene, R141b, R142b and R41. A new model for propane by Lemmon and Span has also been added.
Electrolyte model
The model has been to improve performance when there is an appreciable solubility of hydrocarbons in the aqueous phase. Some small differences between versions 3.8 and 3.9 may be noticed.
New BIPs
The binary interaction parameters for H2S, CO2, methane, ethane, propane and water have been revised to improve the VLE predictions for the cubic equations of state, CSMA, LKP and SAFT models. For the CPA model, the CO2-water and H2S-water
association parameters were also improved.
Matching
Bubble point, GOR and water cut
The procedure for simultaneously matching a GOR and bubble points has been extended to include the specification of the amount of water. The GOR and water cut may be matched even if no bubble point data are available.
Viscosity
A new option to match the viscosity of the stock tank oil composition has been added.
Databanks
DIPPR
The latest version of DIPPR available is 2009. There are now 1973 components in the databank. A list of the additional components is available on request.
Infodata
The number of components in Infodata has increased to 247. Those added for Multiflash 3.9 are:
R227EA
The following property values have been revised:
Methane: surface tension correlation.
Saturated liquid thermal conductivity correlation: butane, pentane, neo-pentane, iso-pentane, hexane, cyclohexane, heptane, octane, nonane, benzene, toluene, methanol, ethanol,
H2S: critical parameters, acentric factor, boiling point, vapour pressure, liquid density, latent heat, perfect gas Cp, surface tension.
CO2: triple point parameters, liquid density, latent heat.
Windows GUI
Model selection
The model selection dialogue has new methods for selecting transport property models. The default thermal conductivity model has been changed from CLS to Super TRAPP. The default surface tension model for most cases has been changed from MCS to Linear Gradient Theory.
Drag and drop for .mfl files
.mfl files can be opened by using drag and drop on the Multiflash GUI window from Windows Explorer.
Current opened file
The GUI now keeps track of the currently opened file. Its complete path is shown on the window title bar. Menu items “Save Problem” and “Save Problem As…” are available allowing the user to save the current file immediately.
Component selection
Multiple components can be selected for deletion.
Log file
The ten most recent log files are kept. The naming sequence is mflash.log; mflash_1.log etc.
Excel Interface
Error state information
If the Excel Add-in fails to load, more information is provided to the user in MF39 so that the relevant actions can be taken to solve the problem.
New flash function arguments
A new surface tension model is implemented in Multiflash 3.9. This model is a true two phase model, so a second phase has to be supplied to the flash functions in Excel.
Multiflash DLL Location
Starting with Multiflash 3.9, the Excel add-in will search automatically for the DLL. This avoids extra installation steps when running the add-in. Now the addin will not crash if the Multiflash DLL is not found.
Deprecated functions
The functions MF_PVT_ANAL and MF_PVT_CNAM were removed as they only worked with the original PVT analysis method, which is no longer available in Multiflash 3.9.
The function MF_MATCH was also removed as it provided only limited functionality to match functions. The GUI should now be used for all match functions.
Property Tables
Prosper
A PVT table file can be generated for the Petroleum Expers Prosper program. For the details, see “Prosper PVT files” on page 39.
Pipesim and OLGA
A “Clear” button has also been added to the Pipesim and OLGA PVT table option to clear all previous entries in the table if necessary.
Obsolete features
Characterisation method 1
The original PVT characterisation method (PVTANAL1) has been removed. It is superceeded by the revised method, PVTANAL2.
Multisolid wax model
The Multisolid wax model has bee removed. It is superceeded by the Coutinho wax model.
Version 3.8
Models
CSMA model
Two new components have been added to the CSMA model. These are R245fa and R143a. The model for H2S has been improved.
Electrolyte model
In MF 3.8 the electrolyte model has been extended to handle halide scales. The equivalent ions supported by MF38 are now Na+, K+, Ca++, Cl- and Br-. An additional option has been added so that you can specify the brine in terms of equivalent Na+ and Cl- only. This effectively reduces the new electrolyte model to the original electrolyte model.
LK model
In MF 3.8, the LK model is available. The LK and LKP methods are 3 parameter corresponding states methods based on interpolating the reduced properties of a mixture between those of two reference substances, see “Lee-Kesler (LK) and Lee-Kesler-Plöcker (LKP) equations of state” on page 32.
Peng-Robinson 1978 (PR78) equation of state
The 1978 revised version of the Peng-Robinson equation is available in MF 3.8. The model has a different treatment for the a parameter. This model removes a defect in the original equation where heavy components with higher acentric factors become more volatile than components with somewhat lower acentric factors. For more information see “Peng-Robinson 1978 (PR78) equation of state” on page 29.
PSRK-NRTL equation of state
PSRK-NRTL equation of state is the same as the PSRK model except that the excess Gibbs energy is provided by the NRTL equation. So unlike the PSRK equation, the PSRK-NRTL variant requires that BIPs are provided for the NRTL equation in order to give accurate results. Its advantage is that, provided the BIPs are fitted to relevant phase-equilibrium data, the model can give more accurate predictions than the PSRK equation.
Thermal properties for activity models
The enthalpy, entropy and heat capacity values calculated by liquid phase activity models are different from previous versions. This is because the contribution of the Poynting correction (pressure correction) to the thermal properties has been revised. The difference in properties is small but noticeable.
Model preferences
In MF 3.8 an option is available for defining preferred models under Preferences. This allows you to set up the same models for all the calculations beforehand. After setting it up, the same models are defined automatically whenever Multiflash is launched again.
Salt calculator
The salt calculator form for the electrolyte model has been extended in MF38 so that the salt/ion analysis data can be converted into the equivalent ions such as Na+, K+, Ca++, Cl- and Br- or Na+ and Cl- only.
Fluid characterisation
D86 and TBP characterisation
New options have been introduced to enable fluids to be characterised using either TBP or ASTM D86 distillation data.
Volume Blending
The volume blending option has been added to the blending facility in MF38 and the associated form modified to incorporate this. Please note that volume blending requires the input of the blending conditions such as temperature and pressure or the density of the blended mixture.
User specified Cuts for pseudocomponents
In previous version of Multiflash, the distribution of the pseudo components was determined automatically. In MF38 there is an option to allow the boundaries of the pseudo components (as carbon numbers) to be specified by the user.
Matching
Water component ignored in matching
The water component is now ignored for bubblepoint, dewpoint, viscosity, wax and asphaltene matching in MF38 if the amount of water is not zero.
Matching viscosity data
The plotting of viscosity data on matching has been modified to improve the plotting range.
Databanks
DIPPR
The latest version of DIPPR available is 2008. There are now 1944 components in the databank. A list of the additional components is available on request.
Infodata
The number of components in Infodata has increased to 246. Those added for Multiflash 3.8 are:
Br-
R1243B
1-nonene
Chemical equilibrium
The chemical equilibrium flash calculations have been removed from the Multiflash 3.8 GUI. If you still require these flash calculations, the previous version of Multiflash, e.g. MF37, should be used
GUI
Toolbar button
The chemical equilibrium button has been removed as these flash calculations are no longer supported in MF38.
Preferences
The “Preferences” option in Multiflash has been expanded to include “General” and “Models” in MF38. “General” supports those preferences available in earlier versions while “Model” is used for defining your preferred models.
Select components
A Clear button has been added to clear the text boxes that have previously been used to define a single petroleum fraction from ‘Infochem Petroleum Correlations’.
Tables
Pipesim and OLGA tables
A “Clear” button has also been added to the Pipesim and OLGA PVT table option to clear all previous entries in the table if necessary.
CAPE-OPEN interface
The CAPE-OPEN interface has been rewritten to improve efficiency and to add new facilities.
Support for Persistence and Editing of Property Packages has been added. All software components are now provided in a single dll. Support for new constant properties and mixture properties and derivatives has also been added.
