Modification of Tao-Mason equation of state: Application to refrigerant fluids

The present work addresses a simplified procedure for the calculation of certain parameters in the Tao-Mason (TM) equation of state needed to estimate thermodynamic properties of 12 ozone-friendly refrigerants fluids. The calculations cover wide ranges extending from the dilute vapor or gas to highly compressed liquid and supercritical region. The theoretical equation of state (EOS) is that of Tao and Mason which is based on statistical mechanical perturbation theory. The novelty of the present work is that we use two scaling constants, the enthalpy of vaporization and the molar density, both evaluated at the normal boiling temperature. This approach contrasts with the original procedure that employs five scaling constants including the critical temperature, the critical pressure, the Boyle temperature, the Boyle pressure and the acentric factor for calculating three parameters second virial coefficient and temperature-dependent parameters. The modified TM EOS predicts thermodynamic properties with equal or better accuracy than those emerging from the original TM EOS. (C) 2010 Elsevier Ltd and IIR. All rights reserved.