| 摘要 |
PURPOSE: An electric expansion valve with a changed design of needle shape is provided to linearly control the flow rate of a CO2 refrigerant passing through an orifice because of a changed shape of a needle head unit and to increase the efficiency of the electric expansion valve. CONSTITUTION: An electric expansion valve(30) comprises an inlet(31), an outlet(32), an orifice(20), and a needle(10). CO2 is delivered through the inlet and the outlet. The orifice is installed in the outlet. A through-hole(21) is formed in the orifice so that the CO2 refrigerant passes therethrough. The needle is installed inside the electric expansion valve and allowed to move up and down, thereby changing the cross-sectional area(S) of the orifice. The needle expands the delivered CO2 refrigerant by changing the cross-sectional area of the orifice. |
