排风余热回收型热泵热水器动态性能实验研究

Experimental Investigation on the Transient Performance of an Exhaust-air Heat Pump Water Heater

提出了一种新型热泵热水器机组,利用浴室排风余热作为热源,通过热泵循环提高其能源品位后用于加热生活用水,并对其动态性能进行了实验研究。排风余热回收型热泵热水器全套装置全部置于室内,避免了空气源热泵机组在冬季工况下运行时室外换热器的结霜问题及热泵系统一年四季工况变化造成的压缩机压比过大、系统性能系数(COP)降低等问题,可在任何外界气候条件下高效稳定工作,且对浴室环境温度没有影响。实验结果表明,实验热泵热水器样机可在45m in内将85kg水从18℃加热至出水温度50℃;当水箱出水温度在33-40℃时性能系数达到最大值为3.4,整个加热过程中的平均性能系数为3.15,平均耗功率为800W。同时,实验发现冷凝盘管制冷剂上进下出布置方式可使水箱中水温产生严重的分层效应,从而产生较大的制冷剂过冷度,对于实验样机最大过冷度可达28℃。

An exhaust air heat pump water heater （EAHPWH） unit, in witch the exhaust air is used as heat source and water is heated by using heat pump cycle, was introduced and its transient performance was investigated experimentally. The EAHPWH unit is located in house, so it is avoided that the frost accumulates on the evaporator coils of the air source heat pump, and that the performance of coefficient （COP） reduces due to the increase in the pressure ratio of the compressor in winter. The unit can run high -efficiently and steadily in any outdoor climate, and there is no effect on the indoor temperature. The experimental resuits indicate that in about 45 minutes the temperature of water by weight of 85 kg was risen from 18℃ to 50℃. When the water temperature was at the range of 33 - 40℃, the COP of the heat pump system was greatest. The maximum COP was about 3.4, the average COP on the total heating process was 3.15, and the average consumption power of the EAHPWH unit was about 800 W. At the meantime, it is found that due to the up - in and down - out type arrangement of the condensing coils, the stratified hot water was formed in the reservoir and the supercooling degree of the refrigerant increased with the heating time, and at the end reached 28℃ for the EAHPWH prototype.