Measurements of thermodynamic properties for the 50 mass% R1234yf + 50 mass% R1234ze(E) blend

Measurements of pressure-density-temperature-composition properties, saturated densities, and critical parameters for the low-global warming potential refrigerant blend of the 50 mass% R1234yf (2,3,3,3-tetrafluoroprop-1-ene; CF₃CF = CH₂) + 50 mass% R1234ze(E) (trans-1,3,3,3-tetrafluoroprop-1-ene; CF₃CH = CHF) were measured with two types of isochoric methods. As for the PρTx properties, 38 data along five isochores in one phase region were obtained by the isochoric method. This measurement was made in the range of temperatures from 340 to 430 K, of pressures from 1693 to 6774 kPa, and of densities from 100 to 900 kg·m⁻³. As for the saturated densities, nine saturated vapor densities and six saturated liquid densities were measured by the direct observation of meniscus disappearance. These experimental data were obtained in the temperature range from 354.62 to 374.28 K and densities between 219 and 870 kg·m⁻³. On the basis of the present data, the critical temperature T_c = 374.28 K, critical density ρ_c = 480 kg·m⁻³, and critical pressure P_c = 3524 kPa for the 50mass% R1234yf + 50mass% R1234ze(E) blend were determined. In addition the critical locus correlations corresponding the composition were proposed for the R1234yf + R1234ze(E) blend.