Simulation and Experimental Study on the Oil Circulation Rate (OCR) of R290 Electrical Vehicle Compressors

This paper establishes a simulation model for the performance of an R290 variable frequency compressor in automotive air conditioning and sets up a compressor performance testing system. It investigates the effects of different evaporation temperatures, condensation temperatures, compressor speeds, and pressure ratios on the oil circulation rate (OCR), as well as the impact of various oil circulation rates on the performance of the R290 compressor. As the comparison between simulation and experimental data shows, compressor performance predictions from the simulation model align with experimental results when the OCR is not taken into consideration. Experimental results indicate that the OCR increases with a rising evaporation temperature, decreases with a lowering condensation temperature, and increases with higher compressor speeds. The simulation model shows a minor deviation when predicting volumetric efficiency, while errors are larger when predicting isentropic efficiency and the discharge temperature. Isentropic efficiency and the discharge temperature show a notable impact from the OCR. Additionally, for system cooling capacity, power, and COP predictions, when the OCR is within the range of 2~10%, the accuracy of the simulation model proves satisfactory, with deviations within 5%.