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.
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references
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