Configure a compositional Fluid Type that uses a generalized method or the Regular Solution Model method

These Fluid Types use Compositional as their Thermo Type.

Configure a compositional Fluid Type that uses a generalized method or the Regular Solution Model method

1. Open the Fluid Type in the Fluid Editor.

2. Expand the System section.

3. In the System list, select one of the following thermodynamic methods, which AVEVA Process Simulation uses to model the system and perform all thermodynamic calculations:

   • Ideal

   • Grayson-Streed

   • Improved Grayson-Streed

   • Regular Solution Model

   

4. In the Phases list, select the phases that you want the thermodynamic calculation system to model; for example, if you model a flare process where liquids are not present, select Vapor Only.

5. (Optional) If you set the Phases list to Vapor/Liquid (VLE), select the Include non-equilibrium solid components to include any solid components in the composition calculations of the liquid phase.

   See Specify components as solids in a compositional Fluid Type for more information.

6. (Optional) If you set the Phases list to Vapor/Liquid/Liquid (VLLE), in the Liquid/Liquid Algorithm list, select the algorithm that you want to use to characterize the liquid-liquid equilibrium (LLE) phases, including the key component identification:

   • Original — A default algorithm that provides accurate and robust LLE identification.

   • Modified Original — An improved version of the Original algorithm that includes better initialization logic. This algorithm is currently in the experimental phase.

   • Embedded K — An algorithm that uses different open-form equations for the vapor-liquid-liquid equilibrium (VLLE) than the Original algorithm. This algorithm maintains the K-values by rigorously solving the VLLE flash calculations and providing the corresponding sensitivities. This algorithm is currently in the experimental phase.

   All Fluid Types initially use the Original algorithm by default. Because the different LLE algorithms can produce significantly different results, we highly recommend that you capture a snapshot of the simulation before you change the selected LLE algorithm for a Fluid Type.

   We also recommend that you do not select the Embedded K algorithm if a simulation is currently using the Fluid Type.

   See Key components for the liquid phases and Switch between liquid-liquid equilibrium algorithms for more information.

   

7. (Optional) If you set the Phases list to Vapor/Liquid/Water (VLWE), review the option selected in the Water Solubility Option list.

   The Water Solubility Option list indicates the correlation that AVEVA Process Simulation uses to calculate the water solubility (that is, the composition fraction of water) in the hydrocarbon liquid phase. Currently, you cannot change the correlation.

   

8. (Optional) By default, AVEVA Process Simulation uses its own data bank of pure components and pure component data. If you want to override the properties in the default data bank with those in a custom data bank, in the Pure Component Property Override Data Bank box, enter the name of the custom data bank that contains the property data that should be overridden.

   This custom data bank should contain only the components of interest and only data for the property values that you want to override.

9. (Optional) Select the Report Fluid Configuration Warnings and Thermodynamic Calculation Warnings checkbox to see warnings related to the fluid configuration and the thermodynamic calculations.

10. Add components to the Fluid Type and specify any required data.

    See Add a pure or petro component to a compositional Fluid Type for more information.

11. (Optional) Expand the Equilibrium Options section, and then configure the equilibrium options for your Fluid Type.

    See the following sections for more information:

    • Configure the equilibrium options for a Fluid Type that uses the Ideal method

    • Configure the equilibrium options for a Fluid Type that uses the Grayson-Streed or Improved Grayson-Streed method

    • Configure the equilibrium options for a Fluid Type that uses the Regular Solution Model method

12. (Optional) Expand the Property Options section, and then configure the equilibrium options for your Fluid Type.

    See the following sections for more information:

    • Configure the property options for a Fluid Type that uses the Ideal method

    • Configure the property options for a Fluid Type that uses the Grayson-Streed or Improved Grayson-Streed method

    • Configure the property options for a Fluid Type that uses the Regular Solution Model method

13. (Optional) Expand the Transport Mixing Rules section, and then select the desired mixing rule for the following transport properties:

    • Vapor thermal conductivity

    • Liquid thermal conductivity

    • Liquid surface tension

    • Vapor viscosity

    • Liquid viscosity

      See Change the mixing rules for transport property calculations for more information.

14. (Optional) Expand the Starting Values section, and then enter the Initial value, Minimum value, and Maximum value for the Pressure and Temperature.