Abstract: With the miniaturization and high-speed development of rotary compressors, the velocity of the fluid within the compressor significantly increases. The high-speed refrigerant is prone to carrying away a large amount of lubricating oil, resulting in a high oil circulation rate. This can lead to decreased energy efficiency and even wear failure due to insufficient lubrication. Conducting numerical simulations to analyze the internal flow field behavior of a compressor with a high oil circulation rate, we found that positioning the outlet on the side of the muffler is the main reason for this phenomenon. Subsequent analysis of different outlet positions of the muffler revealed that a muffler with a top exhaust port can significantly increase the stator edge backflow, experiments confirmed that this design significantly reduces the oil circulation rate. Numerical simulations and experiments have both confirmed the significant effect of the muffler on the oil circulation rate, and optimizing the muffler is an effective method to reduce the oil circulation rate of the compressor.

Key words: Rotary compressor, Oil circulation rate, Numerical simulation, Muffler