Experimental and numerical analysis of the performance of the R290 rotary compressor used in a split-room air conditioner at high ambient temperature

To respond to new energy efficiency standards and environmentally friendly policies in hot climate regions, it is necessary to develop high-efficiency air conditioners. The environmentally friendly and favorable thermophysical properties of R290 and the high efficiency of rotary compressors have led to the proposal of R290 rotary compressors for use in split-room air conditioners in hot climate regions. The performance of R290 rotary compressor at high temperatures requires in-depth research. In this study, an R290 rotary compressor was experimentally and numerically studied at different ambient temperatures (ta = 35 °C, 46 °C, and 55 °C), using different oils (mineral oil and synthetic oil). The results show that the volumetric efficiency (ηv) and adiabatic efficiency (ηad) of the R290 rotary compressor decrease by only 5% and 6%, respectively, from ta= 35 °C to 55 °C; even at 55 °C, ηv and ηad are 89% and 67%, respectively, while the decrements of the R32 rotary compressor both reached more than 10%. In addition, the R290 rotary compressor performance differs with different oils because of miscibility, solubility, and viscosity influences on leakage and friction losses.