The function of thermal expansion valve
Thermal expansion valve is also called temperature regulating valve. In the refrigeration system, the thermal expansion valve is installed on the liquid supply pipe of the evaporator inlet and has three functions:
① Throttle and reduce pressure
The high-temperature and high-pressure refrigerant condensed by the condenser is throttled and decompressed, turning it into a low-temperature and low-pressure vapor-liquid mixture that is easy to evaporate. It enters the evaporator to evaporate and absorb external heat.
② Adjust flow
Based on the temperature signal obtained from the temperature sensing bag or gas tank head, the expansion valve can automatically adjust the refrigerant flow entering the evaporator to adapt to the changing needs of the refrigeration load.
③ Maintain a certain degree of superheat and prevent liquid shock and abnormal overheating
The expansion valve allows the evaporator to have a certain degree of superheat by adjusting the flow rate, ensuring the effective use of the total volume of the evaporator and preventing liquid refrigerant from entering the compressor and causing liquid shock; at the same time, it can control the superheat degree within a certain range to prevent abnormal overheating. occur.
