Experimental Study on Flow Coefficient of Refrigeration Electronic Expansion Valve

Owing to the limited amount of test data available for flow coefficient correlation fitting, there is a large deviation when applying the correlation formula to the flow coefficient calculation of valves with different diameters. To solve this problem, the flow characteristics of an electronic expansion valve were studied experimentally. The experimental results indicated that the valve diameter, valve opening, and subcooling were the main factors affecting the flow coefficient of the electronic expansion valve. The flow coefficient decreased with an increase in the valve opening. The flow coefficient of a valve with a large diameter (DPF2.0) was greater than that of a valve with a small diameter (DPF1.65) under the same opening degree, and the flow coefficient increased with the subcooling degree. A correlation formula for the flow coefficient that considered subcooling degree <italic>T</italic>_sub and flow area <italic>A</italic> was fitted using the experimental data, and the relative deviation was calculated to be within ±5% when using this fitting correlation formula.