packagePropane_Pentane_Liq
Extends from ThermalSeparation.Media.BaseMediumLiquid (base class for liquid medium package).
Information
This model calculates medium properties for water in the liquid, gas and two phase regions according to the IAPWS/IF97 standard, i.e., the accepted industrial standard and best compromise between accuracy and computation time. For more details see Modelica.Media.Water.IF97_Utilities. Three variable pairs can be the independent variables of the model:
- Pressure p and specific enthalpy h are the most natural choice for general applications. This is the recommended choice for most general purpose applications, in particular for power plants.
- Pressure p and temperature T are the most natural choice for applications where water is always in the same phase, both for liquid water and steam.
- Density d and temperature T are explicit variables of the Helmholtz function in the near-critical region and can be the best choice for applications with super-critical or near-critial states.
| Variable | Unit | Description |
| T | K | temperature |
| u | J/kg | specific internal energy |
| d | kg/m^3 | density |
| p | Pa | pressure |
| h | J/kg | specific enthalpy |
In some cases additional medium properties are needed. A component that needs these optional properties has to call one of the functions listed in Modelica.Media.UsersGuide.MediumUsage.OptionalProperties and in Modelica.Media.UsersGuide.MediumUsage.TwoPhase.
Many further properties can be computed. Using the well-known Bridgman's Tables, all first partial derivatives of the standard thermodynamic variables can be computed easily.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Real[nSubstance] | phi | {1, 1} | association factor of each substance, if this substance is to be the solvent - used for claculation of diffusion coeffcients |
| Integer | nSubstance (from BaseMediumLiquid) | 2 | number of components |
| SI.Temperature[nSubstance] | Tcrit (from BaseMediumLiquid) | ||
| SI.Pressure[nSubstance] | pcrit (from BaseMediumLiquid) | ||
| SI.MolarVolume[nSubstance] | Vcrit (from BaseMediumLiquid) | ||
| Real[nSubstance] | omega (from BaseMediumLiquid) | acentric factor | |
| SI.ElectricDipoleMomentOfMolecule[nSubstance] | mu (from BaseMediumLiquid) | ||
| SI.MolarMass[nSubstance] | MMX (from BaseMediumLiquid) | ||
| Integer[nSubstance] | eq_Tsonopoulos (from BaseMediumLiquid) | no. of equation for equation a and b in Table 4-5 in Properties of Gases and Liquids, 5th ed. | |
| Boolean[nSubstance] | henry (from BaseMediumLiquid) | true if liquid fugacity of substance is to be calculated with Henry's law | |
| Boolean[nSubstance] | has_etaSubstance (from BaseMediumLiquid) | true if substance i provides a value for the pure dynamic viscosity at system pressure and temperature | |
| Integer[nSubstance] | ic (from BaseMediumLiquid) | zeros(nSubstance) | ionic charge of the components, i.e. H+ = 1, OH- = -1, H2O=0 |
| Integer | n | nSubstance | number of components |
| SI.MolarMass[n] | MM_substances | MMX |
Contents
| Name | Description |
|---|---|
 BaseProperties | |
 CalcSpecificEnthalpy | |
 HenryCoefficient | |
| DiffusionCoefficient | |
| ActivityCoefficient | calculates the activity coefficient for each component in the liquid phase |
| FugacityCoefficient | calculates the fugacity coefficient at the saturation point for each component in the liquid phase |
| ThermodynamicFactor | |
| EvaporationEnthalpy |