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Thermodynamic Properties of Ordinary Water Substance for Industrial Use

in region 5 of IAPWS-IF97

Developed by Russian National Committee (RNC) of

International Association for the Properties of Water and Steam (IAPWS).

This calculation page is based on the

"Revised Release on the IAPWS Industrial Formulation 1997 for the Thermodynamic Properties of Water and Steam" [1] (named as IAPWS-IF97)

provided by IAPWS.

Detailed information about used equations, constants, range of validity etc is presented in PDF version of IAPWS Release which can be downloaded from IAPWS web site www.iapws.org

Authors (and responsible persons):

Moscow Power Engineering Institute (MPEI). Last update: 2015/06/30

Note that displayed last digits depends on numeric implementation of underlying formulations.

Input parameters

Formulation reference values

Dimensionless input parameters

Main equations

The specific Gibbs free energy is represented by the equation

Eq. (32) in [1]

The ideal-gas part of the dimensionless Gibbs free energy is represented by the equation

Eq. (33) in [1]

The residual part of the dimensionless Gibbs free energy is represented by the equation

Eq. (34) in [1]

Dimensionless Gibbs Free Energy and it's derivativies

The ideal-gas part of the dimensionless Gibbs free energy

Coefficients from Table 10 [1] (can be downloaded here in text format):

Extracting data to vectors:

The derivatives of ideal-gas part of the dimensionless Gibbs free energy

Eq. from Table 40 in [1]

The residual part of the dimensionless Gibbs free energy

Coefficients from Table 38 [1] (can be downloaded here in text format):

Eq. from Table 41 in [1]

Thermodynamic properties

Specific volume:

Eq. from Table 39 in [1]

Density:

Specific internal energy

Specific entropy

Specific enthalpy

Specific isochoric heat capacity

Specific isobaric heat capacity

Speed of sound

pt-diagramm with the given point

Region 2

Region 5

Reference

1. Revised Release on the IAPWS Industrial Formulation 1997 for the Thermodynamic Properties of Water and

Steam. Lucerne, Switzerland, August 2007, available at http://www.iapws.org