1) Determine the type of refrigerant in the system;
2) Determine the evaporation temperature range of the evaporator;
3) Refrigeration capacity;
4) Pressure difference between the inlet and outlet of the thermal expansion valve;
5) Internal or external pressure balance method;
6) Pipe diameter specification.
1. Selection: According to R, Q0, t0, tk, liquid pipeline and valve resistance loss.
1.1. 1) Determine the pressure at both ends of the expansion valve; 2) Determine the valve type; 3) Select the valve model and specifications
Determine the valve type: Choose internal balance or external balance, which depends on the pressure drop in the evaporator. For example: For R22 system, when the pressure drop exceeds the corresponding evaporation temperature by 1°C, an external balanced thermal expansion valve should be used.
