The simulation accuracy of the thermophysical properties of gas-liquid equilibrium of a single refrigerant based on a conductor-like screening model for real solvent (COSMO-RS) is investigated in this work. The research results show that in order to improve the simulation accuracy

the scale factor of the surface area of the molecules needs to be adjusted. A single refrigerant is divided into inorganic substances

hydrocarbons

and HFCs. The simulation results under an optimum scale factor are compared with the values from NIST. The relative errors for CO2 and NH3 in inorganic matters are less than ±3% and ±1%

respectively. The relative error for the hydrocarbon refrigerant is within ±3%

and that for HFCs is not more than ±2%. Then the rule of the scale factor of the molecules is studied and the saturated vapor-pressure equation of a single refrigerant is fitted. Therefore

COSMO-RS can predict the gas–liquid equilibrium of a single refrigerant and provide a method for the gas-liquid equilibrium of new refrigerants.