Fast calculations of the properties of superheated steam from the saturation curve up to 600°C and 30 MPa

Abstract

A set of eleven simplified equations describing the thermodynamic properties of ordinary water in the region of superheated steam from the saturation temperature up to 600°C between 0.001 and 30 MPa is presented. The thermodynamic quantities are given as functions of the most frequently used couples of independent variables in power engineering. The equations are thermodynamically inconsistent but they reproduce the superheated steam data from the 1984 IAPS Formulation within the following deviations: pressure and specific volume ±0.05%, temperature ±0.1° C , enthalpy ±1 kJ kg −1 and entropy ±0.0005 kJ kg −1 K −1 . The comparison shows that the present equations can be used in the above stated range both for direct industrial computations and for estimates in iterative calculations using exact equations of state. A universal program for computation of the properties of superheated steam has been developed using simplified equations.