Effect of oil in circulation on automotive A/C component and system performance

Lubricant;Automotive air-conditioning system

Liu, Xuan ; Hrnjak ; Predrag S.

关键词: Lubricant;    Automotive air-conditioning system;   

Others  :  https://www.ideals.illinois.edu/bitstream/handle/2142/89075/LIU-THESIS-2015.pdf?sequence=1&isAllowed=y

美国|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

In Automotive air-conditioning system, oil is mixed with refrigerant and runs in the system.Although some amount of oil is beneficial to compressor to reduce compressor wear and prevent leakage, the existence of oil in circulation influences the performance of the air-conditioning system and components. In this study, the effect of oil in circulation on automotive A/C system is investigated, and the effect on evaporator and condenser distribution is also discussed.First, experiments are conducted on a real automotive A/C system with R134a and PAG46 as the combination of refrigerant and oil in both I35a condition and M35a condition. Six different amount of oil in circulation ratio (OCR) are investigated in each of the two conditions. The experiment results are analyzed for system capacity, heat transfer, pressure drop over heat exchangers and suction lines, compressor work, as well as COP. In addition, infrared images of both evaporator and condenser are taken in each experiment. The results are then compared with two previous findings to have a more generalized conclusion on the OCR effect on heat exchanger’s distribution. Furthermore, an EES model of evaporator and condenser is developed to validate the OCR effect on heat transfer and pressure drop over heat exchangers. Comparison between model and experiment results is made to validate each other.