Analysis of phase behaviour of R1243zf/lubricant oil mixtures and its impact on the performance of vapour-compression refrigeration cycle

Abstract

Due to the extremely low ozone depletion potential and global warming potential, 3,3,3-trifluoropropene (R1243zf) is considered a good substitute for traditional hydrofluorocarbons used in vapour-compression refrigeration cycles. The phase behaviour of refrigerant with lubricant oil is a critical factor affecting the performance of the cycle. However, comprehensive analysis of phase behaviour of R1243zf/lubricant oil mixture and quantitative assessment of its impact on the cycle efficiency is still lacking. Therefore, this work employs the Soave-Redlich-Kwong (SRK) equation of state, combined with the modified van der Waals-Berthelot mixing rule and hypothetical oil model proposed by Yokozeki, to investigate the phase equilibrium data of R1243zf/oil mixtures and the phase behaviour of R1243zf with different lubricant oils. Furthermore, the impact of oils on the performance of the vapour-compression refrigeration cycle is quantitatively analysed. Results show that polyolester (POE)-type lubricant oils exhibit superior performance in R1243zf-based refrigeration systems.