In this paper, an experimental investigation of the performance improvement of a heat pump equipped with a two-phase ejector, called an "ejector-expansion heat pump (EEHP)", is proposed. The system performance of the EEHP is compared with that of a vapor-compression heat pump (VCHP). The improvement potential is determined and discussed. The heat pump test system based on a water-to-water heat pump that can experiment with both the EEHP and the VCHP is constructed. A two-phase ejector with a cooling load of up to 2500 W is installed for the experiment. The results show that the EEHP always produces a higher heating rate and COP(HP )than the VCHP under the specified working conditions. The heating COPHP is increased by 5.7-11.6 depending on the working conditions. It is also found that, under the same heat sink and heat source temperature, the EEHP can produce a lower compressor discharge temperature and a lower compressor pressure ratio than the VCHP. This is evidence that the two-phase ejector can provide the compressor with better working characteristics, which yields a longer compressor lifetime. It is demonstrated that the expansion pressure ratio is key to the performance of the EEHP. A larger expansion pressure ratio yields greater improvement potential when compared with the VCHP.
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机译：本文提出了一种配备两相喷射器的热泵（称为“喷射器-膨胀热泵（EEHP）”的性能改进实验研究。EEHP的系统性能与蒸汽压缩热泵（VCHP）的系统性能进行了比较。确定并讨论改进潜力。构建了基于水对水热泵的热泵测试系统，该系统可以同时使用EEHP和VCHP进行实验。为实验安装了冷却负荷高达 2500 W 的两相喷射器。结果表明，在规定的工况下，EEHP的升温速率和COP（HP）始终高于VCHP。根据工作条件，加热COPHP增加5.7-11.6%。还发现，在相同的散热器和热源温度下，EEHP可以产生比VCHP更低的压缩机排气温度和更低的压缩机压力比。这证明两相喷射器可以为压缩机提供更好的工作特性，从而延长压缩机的使用寿命。结果表明，膨胀压力比是EEHP性能的关键。与VCHP相比，更大的膨胀压力比产生更大的改进潜力。
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