.Modelica.Media.Water.WaterIF97_base

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:

1. 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.
2. 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.
3. 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-critical states.

The following quantities are always computed:

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.

Contents

Name	Description
SaturationProperties
ThermodynamicState	Thermodynamic state
BaseProperties	Base properties of water
density_ph	Computes density as a function of pressure and specific enthalpy
temperature_ph	Computes temperature as a function of pressure and specific enthalpy
temperature_ps	Compute temperature from pressure and specific enthalpy
density_ps	Computes density as a function of pressure and specific enthalpy
pressure_dT	Computes pressure as a function of density and temperature
specificEnthalpy_dT	Computes specific enthalpy as a function of density and temperature
specificEnthalpy_pT	Computes specific enthalpy as a function of pressure and temperature
specificEnthalpy_ps	Computes specific enthalpy as a function of pressure and temperature
density_pT	Computes density as a function of pressure and temperature
setDewState	Set the thermodynamic state on the dew line
setBubbleState	Set the thermodynamic state on the bubble line
dynamicViscosity	Dynamic viscosity of water
thermalConductivity	Thermal conductivity of water
surfaceTension	Surface tension in two phase region of water
pressure	Return pressure of ideal gas
temperature	Return temperature of ideal gas
density	Return density of ideal gas
specificEnthalpy	Return specific enthalpy
specificInternalEnergy	Return specific internal energy
specificGibbsEnergy	Return specific Gibbs energy
specificHelmholtzEnergy	Return specific Helmholtz energy
specificEntropy	Specific entropy of water
specificHeatCapacityCp	Specific heat capacity at constant pressure of water
specificHeatCapacityCv	Specific heat capacity at constant volume of water
isentropicExponent	Return isentropic exponent
isothermalCompressibility	Isothermal compressibility of water
isobaricExpansionCoefficient	Isobaric expansion coefficient of water
velocityOfSound	Return velocity of sound as a function of the thermodynamic state record
isentropicEnthalpy	Compute h(s,p)
density_derh_p	Density derivative by specific enthalpy
density_derp_h	Density derivative by pressure
bubbleEnthalpy	Boiling curve specific enthalpy of water
dewEnthalpy	Dew curve specific enthalpy of water
bubbleEntropy	Boiling curve specific entropy of water
dewEntropy	Dew curve specific entropy of water
bubbleDensity	Boiling curve specific density of water
dewDensity	Dew curve specific density of water
saturationTemperature	Saturation temperature of water
saturationTemperature_derp	Derivative of saturation temperature w.r.t. pressure
saturationPressure	Saturation pressure of water
dBubbleDensity_dPressure	Bubble point density derivative
dDewDensity_dPressure	Dew point density derivative
dBubbleEnthalpy_dPressure	Bubble point specific enthalpy derivative
dDewEnthalpy_dPressure	Dew point specific enthalpy derivative
setState_dTX	Return thermodynamic state of water as function of d, T, and optional region
setState_phX	Return thermodynamic state of water as function of p, h, and optional region
setState_psX	Return thermodynamic state of water as function of p, s, and optional region
setState_pTX	Return thermodynamic state of water as function of p, T, and optional region
setSmoothState	Return thermodynamic state so that it smoothly approximates: if x > 0 then state_a else state_b