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1. Evaporation process: The evaporation process is carried out in the evaporator, which is a constant pressure and constant temperature process. The refrigerant at the inlet of the evaporator has both liquid and vapor state, but most of it is liquid. When the liquid refrigerant flows through the evaporator, it evaporates and absorbs heat, becomes a gas, and produces a refrigeration effect, so the evaporator is set where refrigeration is required. Vapor refrigerant flowing through the evaporator does not produce phase change, does not produce refrigeration effect, therefore, from the design and maintenance point of view, the more liquid refrigerant flowing into the evaporator after the capillary throttling, the less vapor state, the better the refrigeration effect.
2. Compression process: The compression process is carried out in the compressor, which is the process of increasing pressure and heating. The compressed steam is superheated steam, and its temperature is much higher than the condensing temperature. R12 must be compressed and its pressure raised to reach the condensing pressure before it can be condensed into a liquid in the condenser.
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3, condensation process: The condensation process is carried out in the condenser, which is a constant pressure process. The condenser is divided into two sections, the inlet section is the cooling section, the superheated steam is cooled into saturated steam, the temperature of this section is higher, is a cooling section, the outlet section is a condensation section, the saturated steam is condensed into saturated liquid, the temperature of this section is close to room temperature, is a constant temperature section. Therefore, the inlet section of the refrigerator condenser has a high temperature, the middle part is warm, and the outlet section is close to room temperature. Whether in the inlet or outlet section of the condenser, the refrigerant is exothermic.
In the inlet section, the refrigerant does not undergo phase change and emits sensible heat to reduce the temperature of the refrigerant. The latent heat is released in the outlet section to change the refrigerant from gas to liquid.
4. Throttling process: the throttling process is carried out in the capillary, which is the process of reducing pressure and cooling. After the liquid refrigerant is throttled, a small amount of liquid becomes vapor. The more liquid and less vapor after throttling, the greater the cooling capacity in the evaporator.