A novel thermodynamic model has been proposed so as to calculate the thermodynamic properties at the vapor-liquid coexistence of HFC (hydrofluorocarbon) refrigerants and their binary mixtures. This model has been developed by modifying the Patel-Teja equation, well-known cubic equation of state, for HFC refrigerants, R- 32, R-125, R-134a, and their binary mixtures for temperatures from 220 K to their critical temperatures. The developed model has features in calculating various thermodynamic properties with ease but accurately.
The calculated results on the vapor-liquid equilibrium (VLE) properties by the present model illustrate its superiority to the conventional cubic equations of state. A comparison of the proposed model with the so-called modified Benedict-Webb-Rubin (MBWR) model and the multi-term Helmholtz function model confirms equivalent effectiveness and accuracy by the present model and, therefore, it would be concluded that the proposed model is very powerful in various practical application in refrigeration industry.