Thermophysical property measurements for R1234yf + R1234ze(E) mixture.

Measurements of PρTx properties, saturated densities and critical parameters for low GWP refrigerant mixtures of 50.00 mass% R1234yf (2,3,3,3-tetrafluoroprop-1-ene; CF3CF=CH2) + 50.00 mass% R1234ze(E) (trans-1,3,3,3-tetrafluoroprop-1-ene; CF3CH=CHF) system were measured with two types of isochoric methods. As for PρTx properties, 5 isochores were obtained in the range of temperatures from 310 K to 430 K, of pressures from 837 kPa to 6774 kPa, and of densities from 100 kg·m-3 to 900 kg·m-3. As for the saturated densities, 9 saturated vapor densities and 6 saturated liquid densities were measured for temperatures from 354.622 K to 374.280 K and for densities between 219 kg·m-3 and 870 kg·m-3. On the basis of the present data, the critical temperature Tc = 374.28 K, critical density ρc = 480 kg·m-3, and critical pressure Pc = 3524 kPa for 50% R 1234yf + 50% R 1234ze(E) mixture were determined by the direct observation of meniscus disappearance.