Theoretical Assessment of R 32 / R 125 / R 600 a as a Potential Replacement for R 22

Many fluids of hydrocarbon derivatives were used as working fluids in refrigeration and air conditioning during the past few decades. The phase out of chlorofluorocarbons and hydrochlorofluorocarbons has initiated research on finding an alternative working fluid for the existing. In this article, some working fluids with zero ozone depletion potential have been assessed for their suitability as alternatives to R22. Among those refrigerants, the performance of R22, R422A, R422B, R422C, R422D and the ternary mixture contains R32, R125 and R600a (0.4:0.4:0.2 by mass) designated as RM20 has been assessed. Also the thermodynamic performance of RM20 compared with R22 and R422 series of refrigerants with respect to vapour pressure, latent heat, liquid density, vapour density, vapour specific heat, liquid specific heat, liquid and vapour viscosity, molecular weight, boiling point, critical temperature, critical pressure, ODP and GWP values. The obtained results were discussed and presented. RM20 found to have higher vapour pressure, latent heat and lower values for liquid density, critical temperature, critical pressure, molecular weight and boiling point. Keywords—Refrigerants, thermodynamic properties, ternary mixture, ozone depletion potential, global warming potential.