Experimental investigation of two-phase ejector liquid recirculation cycles with R410A.

Abstract

Two-phase ejectors have gained attention in recent years due to their ability to directly unload the compressor in vapor-compression cycles. However, ejectors can also improve cycle performance by providing liquid recirculation. In this paper, cycles using the work recovered by an ejector to provide liquid recirculation are investigated experimentally with R410A. The ejector recirculation cycle, in which the ejector is used to recirculate liquid through the evaporator but not directly unload the compressor, and the standard two-phase ejector cycle, in which the ejector can directly unload the compressor and overfeed the evaporator, are compared to each other and to a DX cycle without an ejector. The effect of evaporator geometry and ambient temperature on the performance of the cycles is also investigated. The results show that the ejector recirculation cycle is more favorable at lower ambient temperature, and the COP improvement of both cycles can be influenced by evaporator design.