Technical Paper
Transient Oil Migration and Flow Behavior during Automotive Compressor Startup
2023-04-11
2023-01-0142
Oil migration has a great impact on vapor compression systems, especially for automobile air conditioning systems which require frequent on-off cycling without sufficient oil management inside the compressor. Excessive amounts of oil retained in the system and lack of oil returned to the compressor can cause low system efficiency and potential compressor failure. This paper explores and quantifies the transient effects in oil migration and property changes at the compressor suction and the discharge. Oil flow behavior and oil migration are quantified and analyzed by the high-speed camera recording and optical method at the compressor discharge and the liquid line under different compressor startup speeds and on-off frequencies. The flow under cold and warm startup conditions is studied and compared. The oil-refrigerant mixture flow at the suction and discharge during cold startup transitions from two-phase flow to vapor refrigerant flow and oil annular mist flow.