水流量对热泵热水器性能影响的实验研究

摘要

针对空气源热泵热水器运行工况多变,制热效率不稳定的特点,设计了循环加热式热泵热水器实验装置,系统由制冷剂循环和水循环两部分构成,重点研究了水流量对系统性能的影响.实验结果表明:逐时能效比随水温的升高而下降,加热前期水流量越大能效比越低,加热后期刚好相反;水流量越小系统越容易吸气带液,吸气带液会使制热量降低,能效比下降速率增大,导致系统性能变差;吸气带液时,制冷剂流量减小,换热系数增大,与换热系数相比制冷剂流量对制热量的影响更大.该结果为系统实际运行和进一步研究提供参考.%In view of the changeable operating conditions and unstable heat efficiency of air source heat pump water heater,a circulating heat pump water heater experiment device composed of refrigerant circulation and water cycle was utilized to study the effect of water flow rate on system performance.The results show that COP decreases with the increase of water temperature.In the early stage of heating,higher the water flow,lower the COP,but the latter period was opposite.The system with small water flow rate is easy to cause liquid refrigerant sucked in,which lead to the heat decrease,the descent rate of COP rise and the worse performance of the system.When compressor suck with few liquid, the refrigerant flow rate decreases and the heat transfer coefficient increases.Compared with the heat transfer coefficient, the refrigerant flow rate has more effect on the heat generation.The results provide reference for the practical operation and further study of the system.