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Supplementary Backward Equations p(h,s) for the Critical and Supercritical Regions (Region 3), and Equations for the Two-Phase Region and Region Boundaries of the IAPWS Industrial Formulation 1997 for the Thermodynamic Properties of Water and Steam*

Published

Author(s)

Allan H. Harvey, J S. Gallagher, H J. Kretzschmar, J R. Cooper, K Knobloch, Radim Mares, K Miyagawa, N Okita, Roland Span, I. Stocker, Wolfgang Wagner, I Weber

Abstract

In modeling advanced steam power cycles, thermodynamic properties as functions of enthalpy and entropy are required in the critical and supercritical regions (region 3 of IAPWS-IF97). With IAPWS-IF97, these calculations require cumbersome two-dimensional iterations of temperature T and specific volume v from specific enthalpy h and specific entropy s. While these calculations are not frequently required, the computing time can be significant. Therefore, the International Association for the Properties of Water and Steam (IAPWS) adopted backward equations for p (h,s) in region 3. For calculating properties as a function of h and s in the part of the two-phase region which is important for steam-turbine calculations, a backward equation Tsat (h,s) is provided. In order to avoid time consuming iterations in determining the region for given values of the variables h and s equations for the region boundaries were developed. The numerical consistency of the equations documented here is sufficient for most applications in heat cycle, boiler, and steam-turbine calculations.
Citation
Journal of Engineering for Gas Turbines and Power-Transactions of the Asme
Volume
129

Keywords

enthalpy, entropy, industrial calculations, steam, thermodynamics, water

Citation

Harvey, A. , Gallagher, J. , Kretzschmar, H. , Cooper, J. , Knobloch, K. , Mares, R. , Miyagawa, K. , Okita, N. , Span, R. , Stocker, I. , Wagner, W. and Weber, I. (2007), Supplementary Backward Equations p(h,s) for the Critical and Supercritical Regions (Region 3), and Equations for the Two-Phase Region and Region Boundaries of the IAPWS Industrial Formulation 1997 for the Thermodynamic Properties of Water and Steam*, Journal of Engineering for Gas Turbines and Power-Transactions of the Asme, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=50440 (Accessed May 29, 2024)

Issues

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Created October 10, 2007, Updated October 12, 2021