中文摘要：

用两相流引射器代替膨胀阀，可回收两相流引射制冷循环中高压工质的压力能，提高制冷系统效率。对以R134a为工质的两相流引射制冷系统性能进行了实验研究，分析了喷嘴喉部直径和混合室直径对R134a两相流引射器及引射制冷系统性能的影响。实验结果表明，在固定工况条件下，存在使引射比达到最大的最佳喷嘴喉部直径和混合室直径组合。在蒸发温度为3℃、冷凝温度为55℃的工况下，当喷嘴喉部直径为2．0mm、混合室直径为16mm时引射器的引射比最大。在固定工况条件下，使引射比达到最大值的喷嘴喉部直径和混合室直径的最佳组合与使系统COP达到最大值的几何参数组合并不一致。这可能是由于在引射器中产生了激波等因素引起的，其中机理尚需要进行更深入的研究。

英文摘要：

In order to increase the coefficient of performance （COP） of the refrigeration system, the expansion valve is replaced by a two-phase ejector in the two-phase ejector refrigeration cycle to recover the potential energy of the high pressure refrigerant. The performance of two-phase ejector refrigeration system with refrigerant R134a as working fluid is experimentally investigated. The effects of the throat diameter of the nozzle and the diameter of the mixing chamber on the performance of the ejector and the two- phase ejector refrigeration cycle system were analyzed. The experimental results indicate that there is an optimal combination of the nozzle throat diameter and the mixing chamber diameter to maximize the entrainment ratio under a fixed working condition. The entrainment ratio of the ejector reaches to the maximum value with the throat diameter of 2.0mm and the mixing chamber diameter of 16mm under the conditions of 3℃ evaporating temperature and 55℃ condensing temperature. Under a fixed working condition, the optimal combination of the nozzle throat diameter and the mixing chamber diameter for maximum of the entrainment ratio is not consistent with the one for maximum of the COP of the refrigeration system. This may be caused by the shocks in the ejector, which should be investigated deeply.