Single stage cooling:

1. The single-stage refrigeration cycle means that the refrigerant goes through the four processes of compression, condensation, throttling and evaporation successively in the refrigeration system to complete the cycle of the single-stage refrigerator, that is, to achieve the purpose of refrigeration. Single-stage refrigeration chiller is a widely used type of refrigerator, which can be used in card making, electronics, refrigeration, medicine and industrial production processes.

2. It is composed of evaporator, single-stage compressor, condenser, throttle valve and other auxiliary equipment, which are connected to each other through pipes to form a closed system. Among them, the evaporator is a device for conveying cold energy. After the liquid refrigerant evaporates, it absorbs the heat of the cooled object to achieve refrigeration; the compressor is the heart of the system, which plays the role of inhaling, compressing and outputting refrigerant vapor; The discharged high-temperature refrigerant vapor is condensed into a saturated liquid; the throttle valve acts as a throttling and depressurization effect on the refrigerant while controlling and adjusting the flow of the refrigerant liquid flowing into the evaporator, and divides the system into two parts: high-pressure side and low-pressure side.

Two-stage cooling:

1. The two-stage refrigeration chiller is developed on the basis of the single-stage refrigeration cycle. The compression process is carried out in two stages. The refrigerant vapor from the evaporator first enters the low-pressure stage cylinder and is compressed to the intermediate pressure. After intermediate cooling Then enter the high-pressure cylinder, compressed to the condensing pressure and enter the condenser. Generally, when the evaporation temperature is -25.7℃~-49.8℃, two-stage compressor should be used for refrigeration.

2. The two-stage refrigeration system consists of evaporator, two-stage compressor, condenser, intercooler, throttle valve and other auxiliary equipment, which are connected to each other through pipes to form a closed system. Among them, the intercooler uses a small amount of liquid refrigerant to vaporize and absorb heat under the intermediate pressure, so that the superheated steam discharged from the low pressure stage is cooled.