This paper has briefly summarized the development of refrigerant compressor; and accounted the statistic of the electrical efficiency for positive displacement refrigerant compressor. After comparing and analyzing the above data

it is shown that the electrical efficiency of scroll compressors basically varies from 0.5 to 0.75

with a focus on section 0.6 - 0.7; efficiency of piston compressors is basically between 0.4 and 0.7

with a focus on section 0.5-0.65; efficiency of screw compressors is basically between 0.5 and 0.75

with a focus on section 0.65 - 0.75. Besides

the results show that the efficiency of compressors reaches its best when its compression ratio is between 2 and 4

which provides foundation and basis for designing

checking and calculation of refrigeration compressor

and guides the performance improvements for refrigeration system.