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Thermodynamic Properties of Ordinary Water Substance for Industrial Use

in region 3 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: 2014/08/20

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

Input parameters

Formulation reference values

Dimensionless input parameters

Main equations

The specific Helmholtz free energy is represented by the equation

Eq. (28) in [1]

Dimensionless Helmholtz Free Energy and it's derivativies

Coefficients from Table 30 [1] (can be downloaded here in text format):

Extracting data to vectors:

The dimensionless Helmholtz free energy

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

Eq. from Table 32 in [1]

Thermodynamic properties

Pressure:

Eq. from Table 31 in [1]

The internal energy

The specific entropy

The specific enthalpy

The specific isochoric heat capacity

The specific isobaric heat capacity

Speed of sound

Joule-Thomson coefficient

Isothermal throttling coefficient

Isentropic temperature-pressure coefficient

pt-diagramm with the given point

Region 3

Region 1

Region 2

Region 5

References

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