The high pressure liquid from the condenser is throttled and depressurized, so that the liquid refrigerant vaporizes and absorbs heat at a low pressure (low temperature). Therefore, it is an important component for maintaining high pressure in the condenser and low pressure in the evaporator.
The throttle member can be divided into a capillary tube and an expansion valve according to the form, and the capillary tube is used in a small refrigeration device, such as a capillary tube installed between the condenser and the evaporator in the refrigerator, which is a type of throttle mechanism.
The expansion valve is used in larger refrigeration equipment. The throttle mechanism used in large and medium-sized units is a throttle valve. There are three types of throttle valves commonly used, namely manual expansion valve, float ball regulating valve and thermal expansion valve. Two are automatically adjusted throttle valves. The expansion valve can be classified into an electronic expansion valve and a thermal expansion valve according to the type of expansion.