Thermophysical properties of R32/advanced PVE mixture and parametric analysis on oil transport characteristic of compressor suction line

Advanced PVE was developed as the coupled lubricant oil for the alternative refrigerant R32 and R32/PVE will be a potential working pair of R32 refrigeration systems. This paper presented modeling study of physical properties of PVE lubricant oil with viscosity grade 68 and R32/PVE mixture. Thermal conductivity, specific heat and surface tension of PVE oil were measured experimentally. New calculation models for properties of pure oil were developed based on the experimental data. Moreover, the solubility, miscibility and viscosity of R32/PVE mixture were also well correlated with the new correlations. Further, a parametric analysis was performed to study oil transport and retention characteristics in compressor suction line, based on the force balance method. A new consolidated database for oil retention was amassed from six existing literatures, including 187 data points. A new correlation for oil retention was established by incorporating influence factors derived from the parametric analysis. The validation result showed that the oil retention correlation exhibits satisfactory prediction accuracy, which achieved mean absolute error of 14.43% and 87.70% of data fell within +30% error bands. The property models and oil retention correlation could serve as tools to accurately predict oil retention amount of suction line with R32/PVE mixture.

Automated summary

This paper presents a modeling study of the physical properties of PVE lubricant oil and R32/PVE mixture. New calculation models and correlations were developed based on experimental data. The oil retention characteristics in compressor suction line were also analyzed. The new oil retention correlation exhibits satisfactory prediction accuracy.