This study was developed the electronic expansion valve using CO2 refrigerant. The electronic expansion valve consist of bellows, stepping motor, 3-stage reduction gear, poppet and orifice. Structural and flow analysis of electronic expansion valve are carried out using commercial code ANSYS and CFX version 14. Structural analysis was conducted for three type bellows(basic, rib and straight type). Asresults, value of maximum equivalent stress showed that basic type was smaller than rib and straight type.

In this paper, we analyzed the characteristics of the mass flow rate and velocity of the refrigerant in response to a change in the number of holes and the diameter size(Type-1～4) of the valve guide refrigerant to flow from Pc to Ps when the pressure is constant. Type-1 is 40% higher mass flow flowing in the direction of Ps as compared with the Pc mass flow rate. Type-2 is 64% higher mass flow flowing in the direction of Ps as compared with the Pc mass flow rate. Type-3 is 50% higher mass flow flowing in the direction of Ps as compared with the Pc mass flow rate. Type-4 is 47% higher mass flow flowing in the direction of Ps as compared with the Pc mass flow rate.