Based on the Peng Robinson (PR) equation of state combined with the Wong-Sandler (WS) mixing rule

and combined with the UNIFAC group contribution method used in the Predictive Soave Redlich Kwong (PSRK) equation

a gas-liquid equilibrium prediction model of the mixture (PRWS-UNIFAC-PSRK) was constructed. The results indicate that for the R32/R1234yf binary mixture

the deviations between the experimental and calculated data for the pressure and vapor phase mass fraction are within ±2.5% and 0.02

respectively. For R134a/R1234yf/R600a ternary mixture

the relative deviation between the measured pressures and calculated results are within ±3% and the absolute deviation of vapor phase mass fraction is within ±0.04. In ternary phase equilibria diagram of R1234yf/R290/R134a

the mass fraction of R1234yf/R290/R134a at around 0.25/0.7/0.05 has an azeotropic point. The VLE (vapor liquid equilibria) prediction model can be further improved by using the multi-parameter equation of states

improving the activity coefficient models and obtaining more accurate binary interaction coefficient.