Numerical and experimental investigation for performance of HFC410A two-stage rotary vane expander

To improve coefficient of performance (COP) of refrigerating system and reduce irreversible system throttle loss due to the traditional restricting element, the experiments for two-stage rotary vane expander in small and medium refrigerating systems were conducted in the case of variable speed, condensing pressure and subcooling degree, and the experimental data were compared with the numerical simulation. The results show that the leakage of two-stage rotary vane expander can be reduced by increasing the revolving speed, the volumetric efficiency thus rises, and the output work and isentropic efficiency rise firstly and then drop for increasing frictional resistance. The system COP reaches the maximum for revolving speed of 1 400 r·min^-1. The increasing condensing pressure results in decreasing volumetric efficiency for the increased differential pressure between the expander import and export, and the isentropic efficiency and the output work rise firstly and then drop. The decreasing subcooling facilitates improving system performance, the output work rises by 2.2% when the subcooling degree decreases by 1℃. The two-stage rotary vane expander is feasible for small and medium refrigerating systems, and the system performance can be improved by adjusting revolving speed, condensing pressure and subcooling degree.