The compressor is regarded as the heart of the refrigeration system, and the special term that can best express the characteristics of the compressor is called "steam pump". The actual duty of the compressor is to raise the pressure and raise the suction pressure state to the exhaust pressure state.
Compression ratio is a technical expression of pressure difference, which refers to the absolute pressure on the high pressure side divided by the absolute pressure on the low pressure side. Absolute pressure value must be used when calculating compression ratio. In order to avoid the calculated compression ratio being negative, absolute pressure must be used instead of gauge pressure when calculating the pressure ratio. It is meaningful to use the absolute pressure value to make the calculated compression ratio positive.
There are five types of compressors used in refrigeration and air conditioning industry: reciprocating compressor, screw compressor, rotary compressor, scroll compressor compressor and centrifugal compressor, among which reciprocating compressor is the most widely used compressor in small and medium-sized commercial refrigeration systems. Screw compressors are mainly used in large commercial and industrial systems. Rotary compressors and scroll compressor are mainly used in household and small-capacity commercial air-conditioning devices, while centrifugal compressors are widely used in air-conditioning systems of large buildings.
Various reciprocating compressors are generally classified according to the form of compressor shell and the arrangement of driving mechanism. According to the shell form, there are open and closed semi-closed compressors. Enclosed means that the whole compressor is installed in a shell.
References:
Baidu Baike compressor