Simulation study on a novel vane-type expander with internal two-stage expansion process for R-410A refrigeration system

Large volumetric expansion ratio of HFCs is the major obstacle to develop positive displacement expander for HFCs air-conditioning system. The paper presented a novel vane-type expander with two internal expansion stages for R-410A system. Simulation models were established to estimate the characteristics and performances of the expander and the system. The structure and operating principle of the expander were presented, the major influences of structural parameters on the built-in volumetric ratio of the expander were analyzed, and the unique mass transition process between stages was discussed. The study showed that the proposed expander obtained built-in volumetric ratio up to 7.6 with isentropic efficiency of 55.9% at 2000 rpm and theoretically improved the coefficient of performance from 4.0 to 4.56, by 14.2%, under design operating condition. The expander outperformed in vapor compression refrigeration system under conditions of relatively higher condensation temperature, higher rotating speed, lower evaporation temperature and smaller degree of subcooling.