Principle Of Cryogenic Refrigerator

The cryogenic refrigerator adopts two working principles: one is two-stage compression refrigeration; the other is multi-component cascade refrigeration. According to the nature of the refrigerant, the single-stage compression refrigeration system can generally only produce a temperature of about -25~-35°C. To further reduce the temperature, the single-stage compression refrigeration system cannot be used. The main reason is that its suction and exhaust pressures depend on the evaporation temperature and condensation temperature. If a lower temperature is to be obtained, the evaporation pressure will inevitably be reduced, which will result in an increase in the pressure ratio, and the increase in the pressure ratio will also increase. It will reduce the displacement of the compressor. The pressure ratio of the refrigeration compressor is limited. Generally speaking, the pressure ratio of suction and exhaust should not be greater than 10.