Our refrigerator refers to a mechanical equipment that uses a compressor to change the pressure change of refrigerant gas to achieve low-temperature refrigeration. It is composed of five parts connected in series: compressor, condenser, evaporator, drying filter and expansion throttle valve, in which an appropriate amount of refrigerant is injected, and electrical appliances control the compressor operation according to the environmental requirements to achieve the purpose of refrigeration and heat transfer.Our refrigerators are mainly air-cooled refrigerators and water-cooled refrigerators.Water-cooled-the cooling effect is good, but it needs cold water.Air-cooled-flexible and convenient, without cooling water, suitable for water-deficient areas or places where movement is needed.We have achieved the purpose of refrigeration through the four processes of compression, condensation, throttling and evaporation in the refrigeration system.Figure 1- Diagram of Refrigerant Circulation System of Air-cooled Refrigerator

Figure 2- Diagram of Refrigerant Circulation System of Water-cooled Refrigerator

Composition of refrigerator:1. Compressor-the heart of the refrigeration system (the compressor used in our box is American grain wheel, and the compressor used in screw type is Taiwan Province Hanzhong) 2. Condenser 3. Evaporator 4. Drying filter 5. Expansion throttle valve.The working process of the refrigerator:The operation of industrial water chiller system is through three interrelated systems: refrigerant circulation system, water circulation system and electrical automatic control system.Working principle of refrigerator:Based on the principle of heat exchange, the unit reduces the temperature of chilled water to the required temperature (normal ≥5℃, low temperature ≥-20℃) through the heat exchanger, and the water is pumped into the evaporation water tank by the chilled water pump for heat exchange to generate chilled water, which is sucked by the water pump and pumped into the evaporator water tank for circulation. When the chilled water is insufficient, the chilled water flow can't push the water flow switch blade, and the refrigerator stops running. At this time, the automatic water replenishing device starts to work to replenish water, and the water level of the water tank can be judged by the liquid level display, and the water chiller is started again.