A new method is proposed for rapid and accurate calculation of steam properties in the regions of the state plane of greatest importance to the steam power industry. The method makes direct use of the derivatives of that Helmholtz function that is the best available wide-ranging scientific formulation of the properties of steam. It is rapid because, with a six-term Taylor series expansion, it uses property values and derivatives evaluated once and for all from the Helmholtz function and stored in tables pertaining to an optimized state plane grid configuration. The method eliminates the need for iterative property calculations and is amenable to any region of the state plane. For properties in the ranges of temperature from 0 to 800°C and pressure from 0 to 100 MPa the core memory requirement for three functions of any given pair of independent properties is less than 1 Mb. With this memory allocation it is possible everywhere in the stated range to satisfy the specific volume and enthalpy tolerances specified by the International Association for the Properties of Water and Steam. An optimized formulation of the method is demonstrated in this paper for enthalpy, entropy, and volume functions of pressure and temperature in the superheat region.

Issue Section:
Power
Topics:
Steam, Enthalpy, Pressure, Temperature, Energy industry, Entropy, Water
1.
The 1967 IFC Formulation for Industrial Use, edited by the International Formulation Committee of the 6th International Conference of the Properties of Steam, ASME, New York.
2.
Properties of Water and Steam Using the 1967 IFC Formulation for Industrial Use and other IAPWS Releases (a computer program package), ASME 1990, 1991, New York.
3.
Skeleton Tables of Thermodynamic Properties of Single-Fluid Phase of Ordinary Water Substance: Table 1: The most probable specific volumes with their associated tolerances, Table 2: The most probable specific enthalpies with their associated tolerances. International Association for the Properties of Water and Steam, 1985.
4.
Setzmann
V.
, and
Wagner
W.
,
Int. J. Thermophysics
, Vol.
10
,
1989
, p.
1103
1103
.
5.
Miyagawa, K., “Simplified Functions for Quick Calculations of Steam and Water Properties,” in: Physical Chemistry of Aqueous Solutions, Proc. 12th International Conference on the Properties of Water and Steam, Orlando, FL, Sept 12-16, 1994, New York, Begell House.
6.
Schiebener, P., and Straub, J., “Fast Evaluation Algorithms for Properties of State Exemplified With Ordinary Water Substance,” Proc. 11th International Conference on the Properties of Steam, Sept 11–17, 1989, Prague, M. Pichal and O. Sifner, eds., Hemisphere, New York, 1990.
7.
Campbell, J. W. E., “Review of the Present Status of the 1967 IFC Formulation for Industrial Use and the Need for Its Replacement in the United Kingdom,” 1981; letter communicated to the IAPWS Subcommittee on Industrial Calculations, 1992.
8.
Hill, P. G., “Integration of Industrial and Scientific Formulation: for the Thermodynamic Properties of Water and Steam,” in: Physical Chemistry of Aqueous Solutions, Proc. 12th Int. Conference on Properties of Water and Steam, Orlando, FL, Sept. 1994, New York, Begell House.
9.
Pruss, A., and Wagner, W., A New Fundamental Equation for Water, Bochum, Dec. 1994.
10.
Miyagawa, K., Oguchi, K., Ohta, M., Okita, N., Sato, T., and Tsumita, Y., “Required Accuracies of the Inverse Equations, T(h, P) and T(s, P) for Superheated Steam, Determined by Power Cycle Calculations,” in: Physical Chemistry of Aqueous Solutions, Proc. 12th International Conference on the Properties of Water and Steam, Orlando, FL, Sept. 12-16, 1994, New York, Begell House.
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