Impact of oil presence on the evaporator enthalpy working with R1234ze(E) and R1234yf

R1234ze(E) and R1234yf, as green refrigerants, have received more and more attention in recent years. To better understand the performance of the evaporator working with a refrigerant/lubricating oil mixture, the solubilities of R1234ze(E)/POE85 and R1234yf/POE85 were measured using the isochoric saturation method in the temperature range from 278.15 K to 348.15 K. The NRTL model was used to correlate the new data. Using the new data, the pressure-enthalpy-vapor quality diagram and superheat-non-evaporation diagram were presented. The results show that the enthalpies of refrigerant/lubricating oil are always lower than those of pure refrigerant. The critical vapor quality is related to the refrigerant/oil solubility and oil circulation mass ratio. The enthalpy change ratio is directly proportional to the superheat and inversely proportional to the oil circulation mass fraction. The non-evaporation quality decreases as the superheat increases and increases as the mass fraction of oil circulation increases.