Solubility of R-1233zd(E) in PVE 68 Oil and the Oil Presence Impact on Evaporator Performance

In this work, solubilities were measured for R-1233zd(E) in PVE 68 oil between (283.15 and 343.15) K using an isochoric saturation method. The nonrandom two liquid (NRTL) model was applied to represent the solubility behavior of the R-1233zd(E)/PVE 68 oil mixture. According to the experimental data, we studied the differences in enthalpies between pure R-1233zd(E) and the R-1233zd(E)/PVE 68 oil mixture as well as the oil effect on the evaporator performance with different superheating and oil circulating mass fractions (Cg). In the pressure-enthalpy-vapor quality diagram, isotherm curves of pure R-1233zd(E) and the R-1233zd(E)/oil mixture have a separation point called the critical vapor quality that is mainly connected to solubility and Cg. Moreover, the enthalpy change rate (Rh) and nonevaporation quality (NEQ) are also associated with the solubility and Cg, especially at low superheating. A lower solubility and Cg will result in higher Rh and lower NEQ, which are favorable to the refrigeration cycle.