Measurement and Correlation for the Viscosity of R1234yf/POE85 and R1234ze(E)/POE85 Solutions

Owing to zero ozone depletion potential (ODP) and extremely low global warming potential (GWP), 2,3,3,3-tetrafluoroprop-1-ene (R1234yf) and trans-1,3,3,3-tetrafluoropropene (R1234ze­(E)) as most potential refrigerants have attracted much interest in refrigeration and air conditioning (RAC). For a better insight into the refrigeration performance using R1234y and R1234ze­(E) as refrigerants, the thermophysical properties of refrigerant/lubricant blends should be well understood, especially the viscosities of the refrigerant/lubricant blends. Using a self-designed-capillary apparatus, the viscosity measurements were performed for blends of POE85 oil saturated with R1234y and R1234ze­(E) between 303.15 and 343.15 K. Viscosities of both R1234yf/POE85 and R1234ze­(E)/POE85 have a similar trend. With an increase in solubility, the viscosity plunges dramatically at the beginning and then drops slowly. The results indicate that the refrigerant dissolved in oil has a large impact on the lubricant viscosity. The experimental data were successfully correlated by Eyring’s absolute rate theory coupled with modified two-suffix-Margules (Eyring-MTSM model)