The function and working principle of automobile air conditioning compressor

1. The automobile air-conditioning compressor is the "heart" of the automobile air-conditioning refrigeration system. Its function is to maintain the circulation of the refrigerant in the refrigeration system, suck in the low-temperature and low-pressure refrigerant vapor from the evaporator, and compress the refrigerant vapor to increase its pressure and temperature. Rise and deliver the refrigerant vapor to the condenser.

2. There are three working principles of automobile air-conditioning compressors:

(1) The displacement of the fixed-displacement compressor increases in direct proportion to the increase in engine speed, and the power cannot be automatically changed according to the refrigeration demand, which has a great impact on engine fuel consumption. Its control is generally by collecting the temperature signal of the air outlet of the evaporator. When the temperature reaches the set temperature, the electromagnetic clutch of the compressor is disconnected, and when the temperature of the compressor stops rises, the electromagnetic clutch is connected and the compressor continues to work;

(2) The fixed capacity compressor is controlled by the pressure of the air conditioning system. If the pressure in the piping is too high, the compressor will stop;

(3) The variable displacement compressor can automatically adjust the output according to the set temperature. The air-conditioning control system does not collect the temperature signal of the evaporator air outlet, but controls the compressor compression ratio to automatically adjust the air outlet temperature according to the pressure change signal in the air-conditioning pipeline. In the entire refrigeration process, the compressor is always working, and the adjustment of the refrigeration intensity depends on the pressure regulating valve set inside the compressor. When the pressure at the high-pressure end of the air-conditioning pipeline is too high, the pressure regulating valve shortens the piston stroke in the compressor, reduces the compression ratio, and reduces the cooling intensity; when the pressure on the high-pressure side drops to a certain level, and the pressure on the low-pressure side rises to a certain level, The pressure regulating valve will increase the piston stroke and increase the cooling intensity.