Thermal expansion valve’s flow characteristic under different conditions is one of the most important factors affecting refrigeration system performance. So it is necessary to detect the actual refrigerant flow of thermal expansion valve. A thermal expansion valve test-bench was developed and its range of refrigerating capacity was 1.7~10 kW. In the system

in order to avoid the influence of flow resistance difference of the high pressure part on the measured results

inlet pressure of expansion was treated as the testing condition. The uncertainty of flow measurement is 0.5% and temperature control accuracy is ±0.5 ℃. Performance of a 7 kW capacity H-type thermal expansion valve was tested in the standard condition

and the property of flow-opening

temperature-opening

flow-temperature was acquired and analyzed. In the thermal expansion valve’s work range

the flow increases linearly with the increase of temperature. Through the quantitative analysis of thermal expansion valve's gain and hysteresis

the performance of thermal expansion valve is judged.