Experimental measurements and correlation of isothermal vapor-liquid equilibria for HFC-32 + HFO-1234ze (E) and HFC-134a + HFO-1234ze (E) binary systems

Currently, refrigeration industry is facing the challenge of developing new highly efficient alternative refrigerants with zero ozone depression potential (ODP) and global warming potential (GWP) lower than 150. Mixtures, composed of hydrofluoro-olefins (HFOs) with either hydrofluorocarbons (HFCs) or natural refrigerants, are of great interest, because they could meet both thermodynamic and environmental requirements. This work investigated the phase behavior of two low GWP binary refrigerants containing trans-1,3,3,3-tetrafluoropropene (HFO-1234ze (E)) and two HFCs. Isothermal vapor-liquid equilibrium (VLE) data for two binary mixtures of difluoroethane (HFC-32) + HFO-1234ze (E) and 1,1,1,2-Tetrafluoroethane (HFC-134a) + HFO-1234ze (E) were measured by a static-analysis apparatus at four temperatures ranging from (283.15 to 323.14) K. The VLE data of HFC-32 + HFO-1234ze (E) system was compared with literature, and good consistence was obtained. The experimental VLE data were correlated by Peng-Robinson (PR) equation of state (EOS) combined with van der Waals (vdW) mixing rules. The binary interaction parameters of two mixtures were obtained, and correlation deviation was acceptable. Our work provides fundamental thermodynamics properties of new mixed refrigerants which are crucial to evaluate their cycle performance and optimize the design of refrigeration system.