Frequently Asked Questions
GasVLe - Gas Properties Calculator
This page provides a list of answers to frequently asked questions regarding the GasVLe - Gas Properties Calculator.
Q. How do I know what the component names are ?
A.GasVLe - Help - Components displays a list of the component names. You can copy and paste the names from the list.
Alternatively you can set up a spreadsheet to use as a template. NatGas.xls is provided as an example.
Q. How do I add my own synonyms?
A.There is a text file in the GasVLe folder called GASNAM. You may edit this using a text editor such as Notepad to add your preferred names for the library components.
Q.Why does the pressure look wrong?
A. All pressures are absolute, except for barG and psiG which are gauge.
Q. How do I get ideal calorific values rather than real gas values?
A. Use the Ideal gas method (IG). (Of course Molar and mass based values are not affected.)
Q. How can I get a volumetric calorific value at a different pressure to 101.325 kPa (1 atm)?
A. Select the properties of molar calorific value and molar density, and using the AGA8 method do a FLSH or GAS calculation at the pressure required. Multiply the molar CV and molar density together to get a volumetric CV in your energy/volume units.
Q. How can I use the high accuracy pure component equations of state?
A. Enter the following in the Settings - Methods - Equation of state box : BWR="nam"
where nam is the 3 character extension for the GASBWR. data file to use from the GasVLe folder. nam could be CH4, N2, H2O or many others.
Q. How can I simulate a compressor or expander?
A. From the Add-in the iso-S calculation simulates a 100% efficient compressor or expander. Select 2 temperature cells (the second cell should be empty) and 2 pressures cells. The first temperature and pressure are the inlet conditions, the second pressure specifies the outlet and GasVLe will calculate the missing outlet temperature for you.
The standalone version of GasVLe can simulate a compressor or expander in a number of different ways.
Q. How can I input one component's amount in g when the other components; amounts are in mol?
A. If you put g in the cell immediately to the left if your names are vertically arranged or immediately underneath if your names are horizontal, then that components amount will be in g and the other components will be in the usual quantity units.
(The following units are recognized : mg, g, lb, oz, gr, mol, scm, scf)
Q. How can I define my own units?
A. Edit the appropriate units box to "xyz"=X abc where xyz is your unit name, abc is an existing unit and X is the conversion factor, e.g. "oz"=1/16 lb
To permanently enable a unit, you have to edit the text file GASSYS. in the GasVLe folder and add the same command on the UNI= line.
A.GasVLe - Help - Components displays a list of the component names. You can copy and paste the names from the list.
Alternatively you can set up a spreadsheet to use as a template. NatGas.xls is provided as an example.
Q. How do I add my own synonyms?
A.There is a text file in the GasVLe folder called GASNAM. You may edit this using a text editor such as Notepad to add your preferred names for the library components.
Q.Why does the pressure look wrong?
A. All pressures are absolute, except for barG and psiG which are gauge.
Q. How do I get ideal calorific values rather than real gas values?
A. Use the Ideal gas method (IG). (Of course Molar and mass based values are not affected.)
Q. How can I get a volumetric calorific value at a different pressure to 101.325 kPa (1 atm)?
A. Select the properties of molar calorific value and molar density, and using the AGA8 method do a FLSH or GAS calculation at the pressure required. Multiply the molar CV and molar density together to get a volumetric CV in your energy/volume units.
Q. How can I use the high accuracy pure component equations of state?
A. Enter the following in the Settings - Methods - Equation of state box : BWR="nam"
where nam is the 3 character extension for the GASBWR. data file to use from the GasVLe folder. nam could be CH4, N2, H2O or many others.
Q. How can I simulate a compressor or expander?
A. From the Add-in the iso-S calculation simulates a 100% efficient compressor or expander. Select 2 temperature cells (the second cell should be empty) and 2 pressures cells. The first temperature and pressure are the inlet conditions, the second pressure specifies the outlet and GasVLe will calculate the missing outlet temperature for you.
The standalone version of GasVLe can simulate a compressor or expander in a number of different ways.
Q. How can I input one component's amount in g when the other components; amounts are in mol?
A. If you put g in the cell immediately to the left if your names are vertically arranged or immediately underneath if your names are horizontal, then that components amount will be in g and the other components will be in the usual quantity units.
(The following units are recognized : mg, g, lb, oz, gr, mol, scm, scf)
Q. How can I define my own units?
A. Edit the appropriate units box to "xyz"=X abc where xyz is your unit name, abc is an existing unit and X is the conversion factor, e.g. "oz"=1/16 lb
To permanently enable a unit, you have to edit the text file GASSYS. in the GasVLe folder and add the same command on the UNI= line.
