New Equation of State for Ordinary Water Substance in the Critical Region

Abstract

A new equation of state for ordinary water substance in the critical region was formulated based upon the International Skeleton Tables (1963). The new equation of state is given in a form of pressure as a function of temperature and specific volume, and is valid in the ranges of temperatures from 350°C to 650°C, of pressures from 165.37 bar to 1000 bar, where the specific volume is less than about 10 cm³/g. The new equation has a comparatively simple functional form which is convenient for the practical computations with electronii computers and fulfils the condition of the thermodynamic consistency at the critical point in itself, and moreover it can cover the above mentioned entire region by a single formula. The specific volume and specific enthalpy computed from the equation agree well with the Skeleton Table values within the tolerances. The new equation was adopted as one of the subformulations of the 1967 IFC Formulation for Industrial Use.