制冷循环系统中，当制冷剂回到压缩机前必须完全气化。因此在制冷剂进入压缩机前必须将气态和液态分离，让气态制冷剂进入压缩机，才不会让压缩机导致液积，液态制冷剂在器体内慢慢蒸发，待蒸发后才会进入压缩机。为了使系统中残存冷冻油回到压缩机，在气液分离器中的回气管底部设有回油孔，在系统中残存的冷冻油到了气液分离器中，会随气态制冷剂一起回到压缩机中。有了气液分离器的保护，压缩机的寿命才会更持久，系统循环才会更正常。
In circulatory system, the refrigerant must be convert became gas before returning to compressor. So it has to separate gas and liquid before the refrigerant enters into the compressor. And let the gas refrigerant enters into the compressor will not cause strike. The liquid refrigerant evaporate slowly in the vessel, then enter the compressor after evaporation. In order to make the residual refrigerant oil come back to compressor, there is no hole in the bottom of tube in Accumulator which may let the oil come back. When the residual refrigerant in the system come into Accumulator, it will go back to compressor with gas refrigerant. Because of the protection from Accumulator, The life time of compressor can be longer and the circulatory system can run better.
