In the refrigeration system, the expansion valve is one of the four major components of the refrigeration system [compressor, condenser, throttle valve (expansion valve), evaporator].
Throttle valves can also be called expansion valves or regulating valves.
Peculiarity
1. The expansion valve adopts a dual-flow balanced flow port with advanced structure.
2. Due to the use of double flow thermostatic expansion valve, the refrigeration system saves the number of expansion valves, check valves and solenoid valves.
3. The balance flow port of the expansion valve in both directions makes the static superheat change with the condensation pressure or the change of pressure drop through the valve port.
4. The expansion valve has a stable superheat, which makes the system run stably.
5. The expansion valve is suitable for various working needs such as refrigeration and air conditioning.
6. Evaporation temperature range of expansion valve: -40°C to +10°C.
7. The expansion valve is suitable for R12 (Freon), R22 (difluorochloromethane), R134a and other media.
Classify
From the perspective of balance mode, expansion valves can be divided into two types: internal balance type and external balance type.
The equilibrium pressure of the inner balanced type is taken at the inlet of the evaporator, and the equilibrium pressure of the outer balanced type is taken at the outlet of the evaporator. Internal balance expansion valves are generally used in household air conditioners. The cooling capacity of car air conditioners is generally relatively large, and the pressure loss of refrigerant in the evaporator is also large, so only the external balance type is used.
From the perspective of the adjustment structure of superheat, the expansion valve is divided into internal adjustment type and external adjustment type.
The internal adjustment type can only be adjusted before the installation of the air conditioning system, and its advantages are small size, compact structure, suitable for batch stereotyped products. The externally adjustable type can be adjusted at any time on the air conditioning system according to the situation, which has great flexibility, but the increase in parts makes the size and weight larger.
