设计了一套带喷射器的跨临界CO_2热泵热水器系统实验平台,开发了相应的计算机测控系统.进行了改变冷却水体积流量和进口温度对系统性能影响的实验研究,分析了制热系数、制热量、压比、喷射系数、升压比、喷射器效率等参数的变化趋势.实验结果表明:随着冷却水体积流量减小或进口温度增加,喷射系数增加的同时,升压比也增加,而喷射器效率却降低;在测试工况范围内喷射器效率最高达到34%,升压比最高达到1.165;在蒸发温度为-5℃时,制热系数达到3左右.带喷射器的跨临界CO_2热泵热水器循环的压缩机压比与传统循环相比减少了12%～14%,喷射器的引入有效地提高了跨临界CO_2热泵热水器循环的效率.%An experimental water heater system using a transcritical CO_2 heat pump with an ejec-tor was designed, and a measurement and control system was developed. Experiments were con-ducted to assess the effects of cooling water flow rate and inlet temperature on the system per-formance. The changes of the heating coefficient of performance (C_r), heating capacity, pressure ratio, entrainment ratio, pressure lift were and ejector efficiency were analyzed. The experimen-tal results show that the entrainment ratio and the pressure lift were increased while the ejector efficiency was decreased with the decrease in the cooling water flow rate or the increase in the in-let temperature. Under the experimental working conditions, the ejector efficiency was up to 34%, and the pressure lift was up to 1. 165. The C_r reached about 3.0 when the evaporation tem-perature was -5℃. Compared with that of a conventional system with an expansion valve, the pressure ratio of the compressor in the present water heater system is decreased by 12%-14%. It appears that the ejector can improve the system performance of transcritical CO_2 heat pump water heaters effectively.
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