Miscibility of POE and PVE oils with low-GWP refrigerant R-1234ze(E)

摘要

This article presents an experimental study on the miscibility of polyolester (POE) and polyvinylether (PVE) oils with the low-global warming potential refrigerant R-1234ze(E) as an alternative of R-123. The ISO viscosity grades are 68 cSt for both oils (POE68 and PVE68). The miscibility of R-1234ze(E) with POE68 and PVE68 oils is measured in the temperature range of -35 degrees C to 80 degrees C and the mass fraction of the oil in the temperature range of 0 to 70wt%. Saturation vapor pressures are also measured for the refrigerant R-1234ze(E) and polyolester/polyvinylether oil mixtures and are found to decrease with the increase in the mass fraction of the oil in both cases. The miscibility test results indicate that the POE68 and PVE68 oils are completely miscible with the refrigerant R-1234ze(E) at the mass fraction below 20% and 10%, respectively, for all the temperature ranges considered. Refrigerant-oil phase separations are observed for certain mass fractions of the oil and temperature ranges, indicating that the refrigerant-oils are not miscible. It is concluded that POE68 is a more suitable oil for the refrigerant R-1234ze(E) than PVE68.