The refrigeration cycle system consists of four basic components: compressor, condenser, evaporator and expansion valve.

1. Bitzer Compressor:
Inhale the steam in the evaporator to maintain its low temperature and low pressure; Compress high pressure and high temperature steam. Why compress? Because the refrigerant needs to be recycled. If it is not compressed, it shall be directly discharged into the condenser. The normal temperature is higher than the boiling point temperature of the refrigerant, and cannot be cooled and condensed into liquid.

2. Condenser:
Cooling the high-temperature and high-pressure steam discharged from the compressor into liquid; The heat released is taken away by water or air. It can be divided into three types: water-cooled, air-cooled and water-air mixed cooling. The condenser of cold storage mostly adopts fin-coil structure. In order to improve the heat exchange efficiency, aluminum alloy fins are often pressed into various shapes to increase the heat exchange area.

3. Throttle device:
When the refrigerant fluid passes through a small hole, a part of the static pressure changes into the dynamic pressure, the flow rate increases sharply, and becomes turbulent flow. The fluid is disturbed, the friction resistance increases, and the static pressure decreases.
4. Evaporator:
Evaporate liquid into gas; Absorb heat. Since the fins of the evaporator will continuously produce condensate and hinder the flow of air, the fin spacing of the evaporator is larger than that of the condenser. In addition, hydrophilic treatment (hydrophilic aluminum foil) should be carried out on the surface of the evaporator fins to reduce the surface tension of the condensate and increase the cross-sectional area of the air flow.