Modulation method of scroll compressor based on suction gas bypass

The air conditioners and heat pumps tend to work in much mild environments and part load situations rather than provide the rated full capacity under severe rated testing conditions. Both the capacity and inner compression ratio of the compressor should be regulated according to the working condition for higher energy efficiency and occupants’ comfort. A potential modulating technology of the scroll compressor, suction gas bypass, is investigated in this paper. The principle and operation method are illuminated and the adaptability is validated by experiments and simulations. As a conclusion, an appropriate suction gas bypass can reduce the inner compression loss of the scroll compressor under over compression conditions, enhance the system COP and also largely decrease the heating/cooling capacity of the refrigeration/heat pump system.

► Suction gas bypass (SGB) is an effective regulating method of scroll compressor.
► SGB reduces the inner compression loss under over compression conditions.
► SGB largely decreases the heating/cooling capacity of the refrigeration system.