Thermodynamic properties of hydrofluoroolefin (R1234yf and R1234ze(E)) refrigerant mixtures: Density, vapour-liquid equilibrium, and heat capacity data and modelling

Liquid-phase and vapour-phase densities are reported for the binary refrigerant mixtures (R125 + R1234ze(E)), (R134a + R1234ze(E)), (R143a + R1234ze(E)), (R1234ze(E) + R1234yf), (R125 + R1234yf), (R143a + R1234yf) and (R125 + R152a). The measurements span temperatures from (252 to 294) K and pressures from (0.8 to 4.2) MPa. Vapour-liquid equilibria (VLE) and liquid isobaric heat capacities are also reported for some mixtures. These measurements and previously published data were used to tune binary interaction parameters in existing Helmholtz energy models. Significant improvements in the predicted densities were achieved, for example the root mean squared relative deviation decreased from 0.33% to 0.021% for (R143a + R1234yf). The most significant improvement in the description of VLE occurred for (R1234yf + R1234ze(E)) where the root mean squared deviation in the predicted vapour phase compositions decreased from 0.010 to 0.00084 (a factor of 12)