What are the refrigeration principles of commercial refrigerators？

1. Compression process of refrigeration cycle:

Compression process:

After the refrigeration is completed, the steam from the evaporator is compressed by the refrigeration compressor, and the temperature and pressure rise sharply. The gas discharged from the compressor becomes hot steam with a large degree of superheat. When compressing gas, the compressor requires a certain amount of compression work, but the entropy of the refrigerant remains unchanged.

2. Condensation process of refrigeration cycle:

Condensation process:

The high-temperature and high-pressure superheated steam discharged from the refrigerator enters the condenser to exchange heat with cooling water or air, so that the superheated steam gradually becomes saturated steam, which is then called saturated liquid. When cooling with cooling water, the temperature of the saturated liquid continues to decrease, resulting in overcooling. The pressure remains constant during the condensation process.

3. Throttle process of refrigeration cycle:

Throttle process:

The liquid coming out of the condenser is throttled through the expansion valve, and becomes a low-temperature and low-pressure liquid during the throttle process. The refrigerant enthalpy does not change.

4. The evaporation process of the refrigeration cycle:

Evaporation process:

The low-pressure wet steam intercepted by the capillary tube absorbs heat from the surrounding medium in the evaporator and gradually increases its dryness. In this way, the gas coming out of the evaporator has become dry saturated steam or slightly superheated steam. During the evaporation process, the humidity and pressure of the refrigerant remain unchanged.