Contents - Index
STEAM, STEAM_NBS, Water, R718, and Ice
Thermodynamic properties of water substance have been implemented using the thermodynamic property correlation of Harr, Gallagher, and Kell, NBS/NRC Steam Tables, Hemisphere Publishing Co., 1984. The correlations are valid up to a pressure of 815 bar. This formulation is now slightly outdated since a more recent formulation for the properties of water substance that extends to pressures of 1000 MPa is available in substance STEAM_IAPWS.
EES will return the properties of ice at temperatures below 0°C and pressures above the saturation vapor pressure of ice 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. The isothermal compressibility of ice is from equation 22 of Hyland and Wexler, Formulations for the Thermodynamic Properties of Dry Air from 173.15 to 373.15 and Saturated Moist Air from 173.15 to 372.15 K at Pressure to MPa, ASHRAE Trans., Part 2A, Paper 2794, 1983.
Enthalpy and entropy values are referred to 0 for saturated liquid at 0°C.
Note that substances STEAM, STEAM_NBS, WATER, R718 and ICE all use the same correlations for water substance in the solid, liquid and vapor regions and provide exactly the same properties. Earlier versions of EES used the less accurate correlations for substance Water, Steam, and R718. Substance Ice has been implemented to allow preference to ice properties in the calculations when specific volume is provided as one of the inputs. In this case, there may be two solutions. Specifying Ice as the substance will generally force the lower temperature solution as in the following example.
The solution to these equations will be:
The transport property correlations are from Electrical Research Association, 1967 Steam Tables, Thermodynamic Properties of Water and Steam; Viscosity of Water and Steam, Thermal Conductivity of Water and Steam, Edward Arnold Publishers, London, 1967. The transport functions are valid for temperatures between 273.15 K and 815 K at pressures up to 830 bar.
The thermal conductivity of solid ice is provided by a correlation from:
Willard Coles, Experimental Determination of the Thermal Conductivity of Low Density Ice, National Advisory Committee for Aeronautics, Technical Note, 3143, Lewis Flight Propulsion Laboratory, Cleveland, OH, 1954
Fluid Property Information