Vapor-liquid equilibrium measurements for the binary mixtures of pentafluoroethane (R125) with 2,3,3,3-Tetrafluoroprop-1-ene (R1234yf) and 3,3,3-Trifluoropropene (R1243zf)

R1234yf and R1243zf have received extensive attention as environmentally refrigerants. However, the application of the pure R1234yf and R1243zf are limited due to their flammability and low volumetric refrigerating capacity. The mixed refrigerants are expected to achieve excellent thermophysical performance, safety, and environmental protection. Vapor-liquid equilibrium (VLE) is an extremely important thermophysical property of mixtures. By using a recirculation-analytical type VLE apparatus, the VLE data of the (R125 + R1234yf) and (R125 + R1243zf) binary systems were measured along six isotherms from 263.15 K to 313.15 K. The PR + vdW model is used to correlate the VLE data. The overall average relative deviation of pressure (ARD(p)) and the average absolute deviation of vapor phase mole fraction (AAD(y)) are 0.15% and 0.0011 for R125 + R1234yf system; and the ARD(p) and AAD(y) are 0.16% and 0.0011 for R125 + R1243zf system. The model has a good description of the two binary systems.