Configure the equilibrium options for a Fluid Type that uses the Dortmund UNIFAC method

The Equilibrium Options section in the Fluid Editor provides a set of advanced equilibrium options that allow you to adjust your equilibrium calculations to suit your needs. The equilibrium options that are available depend on the type of thermodynamic method that you use as the System method for your Fluid Type.

While the Dortmund UNIQUAC Functional-group Activity Coefficient (UNIFAC) method is a liquid activity coefficient (LACT) method, it uses group contribution data instead of binary interaction data. As a result, the equilibrium options for the Dortmund UNIFAC method differ from those available for the other LACT methods. Therefore, we document the equilibrium options for the Dortmund UNIFAC method separately from the other LACT methods available in AVEVA Process Simulation.

Configure the equilibrium options

1. Open the Fluid Type in the Fluid Editor if the Fluid Type is not already open.

2. Expand the Equilibrium Options section if it is not already visible.

   

3. If the option selected in the Phases list in the System section includes a vapor phase, in the Vapor Equilibrium list, select the thermodynamic method that you want AVEVA Process Simulation to use when it calculates the vapor phase equilibrium properties.

4. Configure the Henry's Law options as you desire.

   See Configure the Henry's Law options for a Fluid Type for more information.

5. (Optional) Select the Use Poynting Correction checkbox to include the Poynting correction factor in the equilibrium calculations.

   The Poynting correction always uses the pure component volume data calculated from the temperature-dependent property correlations for liquid density, as defined in both the PURECOMP data bank from the thermodynamic library that the Fluid Type uses and the local thermodynamic data overrides specified on the Temp Dep tab in the Component Data section of the Fluid Editor. See Effects of specifying thermodynamic method overrides for more information.

6. (Optional) Select the Include Fugacity Coefficient Variables in Fluid State checkbox to add variables for the fugacity coefficients to the Fluid State model.

   You can now view the calculated values for the fugacity coefficients or use them in other areas of the Simulation.

7. (Optional) If the option selected in the Phases list in the System section includes a liquid phase, select the Include Activity Coefficient Variables in Fluid State checkbox to add variables for the activity coefficients to the Fluid State model.

   You can now view the calculated values for the activity coefficients or use them in other areas of the Simulation.