Thermodynamic Properties of Steam in the Critical Region

TLDR

The paper analyzes experimental data on steam’s thermodynamic properties in the critical region. The authors use a revised and extended scaling model with closed parametric equations, fitting 16 adjustable parameters to PVT and speed‑of‑sound data. The model accurately predicts steam properties from 200–420 kg/m³ and 644–693 K, provides new critical parameter estimates, and confirms consistency of experimental data.

Abstract

An analysis is presented of the experimental data on thermodynamic properties in the critical region of steam. The model used is that of revised and extended scaling, as given by the modern theory of critical phenomena. All thermodynamic properties are given in closed (parametric) form. The model has, in addition to three universal constants that are given by theory, sixteen adjustable parameters that were obtained by least-squares fit to PVT and speed-of-sound data. It is valid in the range 200–420 kg/m3 in density and 644–693 K in temperature. It accurately represents the experimental data for equation of state, vapor pressure, latent heat, specific heats Cp and Cv and speed of sound. Our analysis permits new estimates of the critical parameters of steam, and has led to a number of conclusions regarding the mutual consistency of the experimental data. Tabulated values of the thermodynamic properties of steam are appended to the paper.