In practical use, the expansion val

In practical use, the expansion valve should be selected according to the principle that the capacity of the expansion valve matches the load of the evaporator. The capacity of the expansion valve refers to the product of the refrigerant flow rate flowing through the expansion valve at a certain opening under a certain pressure difference and the difference between the enthalpy at the entrance of the expansion valve and the saturated vapor enthalpy at the evaporation temperature, which is called the valve capacity of the expansion valve under this pressure difference and evaporation temperature. If the valve is operating in nominal conditions, it is called nominal capacity.