Experimental study and performance analysis of R290 in automotive air-conditioning compressors for new energy vehicles

A testing system for R290 automotive air-conditioning compressors was established to investigate the application of environmentally friendly refrigerant R290 in new energy vehicle air-conditioning systems. One new method with the density was employed to determine the system's Oil Circulation Rate (OCR). Experimental measurements were conducted under variable OCR, compressor speeds, and evaporation/condensation temperature conditions, yielding comprehensive performance parameter curves. The main conclusions are as follows: (1) The density method is able to achieve precise dynamic characteristics of OCR variation during compressor operation compared to conventional oil separation techniques; (2) Discharge temperature decreases with the increase of OCR, while the actual cooling capacity shows a positive correlation with OCR. When OCR increases from 5% to 12%, both isentropic and volumetric efficiencies exhibit a certain degree of improvement; (3) At a constant compressor speed, discharge temperature shows an inverse relationship with evaporation temperature ( T eva ) while exhibiting a positive correlation with condensation temperature ( T con ). The OCR, actual cooling capacity, COP, and both volumetric and isentropic efficiencies increase with the increase of evaporation temperature but decrease with the increase of condensation temperature. Though compressor power is virtually insensitive to evaporation temperature, compressor power displays condensation temperature-correlated enhancement.