In the refrigeration process, the heat transfer from low temperature to high temperature is due to the consumption of external energy, which depends on the work done by the compressor.

Boiling; boiling water requires heat absorption, boiling at 100 degrees; Freon begins boiling at-30 degrees, absorbing heat.

The simplest refrigeration system consists of four main elements: 1 Compressor; 2 Condenser; 3 Throttle valve; 4 Evaporator.

Evaporation process in a refrigeration cycle:

Evaporation process: through the throttle valve after the closure of the low-pressure liquid, in the evaporator from the surrounding media endothermic refrigeration in the evaporation process, the refrigerant temperature and pressure remain unchanged.

The compression process of a refrigeration cycle:

Compression process: after refrigeration, the temperature and pressure of the gas from the evaporator increase sharply after compression by the refrigeration compressor. The gas emitted by the compressor becomes hot steam with higher superheat. When compressed gas, the compressor must consume certain compression work, but the refrigerant entropy value is not changed.

The condensation process of a refrigeration cycle:

Condensing process: the superheated steam discharged from the refrigerator at high temperature and high pressure, entering the condenser to exchange heat with cooling water or air, makes the superheated steam gradually become saturated steam, and then becomes saturated liquid. When cooled with cooling water, the temperature of the saturated liquid continues to decrease, resulting in supercooling. The pressure remains constant during condensation.