Contents - Index


STEAM, WATER, STEAM_IAPWS and R718

 

Starting with EES version10.364, keywords Steam, Water, Steam_IAPWS, and R718 all use the Steam_IAPWS property correlation.

 

Steam_IAPWS implements high accuracy thermodynamic properties of water substance with the 1995 Formulation for the Thermodynamic Properties of Ordinary Water Substance for General and Scientific Use, issued by The International Association for the Properties of Water and Steam (IAPWS).  This correlation replaced the 1984 formulation of Haar, Gallagher, and Kell (NBS/NRC Steam Tables, Hemisphere Publishing Co., 1984) which is implemented in substance STEAM_NBS.  The new formulation is based on the correlations of Saul and Wagner (J. Phys. Chem. Ref. Data, 16, 893, 1987) with modifications to adjust to the International Temperature Scale of 1990. The modifications are described by Wagner and Pruss (J. Phys. Chem. Ref. Data, Vol. 31, No. 2, 387, 2002). 

 

This correlation provides accurate results for temperatures between 273.15 K and 1273.15 K at pressures up to 1000 MPa.  The formulation allows extrapolation of properties to 5000 K.  

 

Water also provides steam properties, but they use less accurate correlations which require significantly less computational effort.  Use Steam or Water for the properties of ice at temperatures below 0 C based on ice property information from Hyland and Wexler, Formulations for the Thermodynamic Properties of the Saturated Phases of H2O from 173.15 K to 473.15 K, ASHRAE Trans., Part 2A, Paper 2793, 1983.

 

Enthalpy and entropy values are referred to 0 for saturated liquid at 0 C.

 

The surface tension correlation for Steam_IAPWS is from:

J. Kestin, J.V. Sengers, B. Kangmar-Parsi, and J.M.H. Levelt Sengers, 

Thermophysical Properties of Fluid H2O 

J. Phys. Chem. Ref. Data, 13, 175 (1984).  

 

The viscosity correlation is from:

M. L. Huber, R. A. Perkins, A. Laesecke, D. G. Friend, J. V. Sengers,M. J. Assael and I. N. Metaxa, E. Vogel, R. Mareš, and K. Miyagawa

New International Formulation for the Viscosity of H2O

J. Phys. Chem. Ref.Data Vol 38, No.2, (2019), 101 ~125

https://aip.scitation.org/doi/10.1063/1.3088050

 

The thermal conductivity is determined from:

M. L. Huber, R. A. Perkins, and D. G. Friend, J. V. Sengers, M. J. Assael and I. N. MetaxaK. MiyagawaR. Hellmann and E. Vogel

New International Formulation for the Thermal Conductivity of H2O

J. Phys. Chem. Ref. Data 41, 033102 (2012); doi: 10.1063/1.4738955

https://dx.doi.org/10.1063/1.4738955

 

The sublimation pressure curve (valid for temperatures between 50 K and 273.16) is determined from:

Wagner, W., A. Saul, and A. Pruß, 

New Equations for the Sublimation Pressure and Melting Pressure of H2O Ice Ih

J. Phys. Chem. Ref.Data 23, 515 ~1994

 

The melting pressure and meltng temperature functions for ice form 1h (valid for temperatures between 251.165 K and 273.16) is determined from:

Wagner, W., A. Saul, and A. Pruß, 

New Equations for the Sublimation Pressure and Melting Pressure of H2O Ice Ih

J. Phys. Chem. Ref.Data 23, 515 ~1994

 

Fluid Property Information