空气吸热除霜技术在不同空气源热泵系统中的应用特性研究*
摘要：
空气源热泵冬季结霜会导致其制热性能显著下降,除霜是当前最有效的解决方法。本文选取3种典型的空气源热泵系统作为研究对象,通过实验测试,从多个维度探究了空气吸热除霜技术的运行性能,并与常用的逆循环除霜技术进行了性能对比。结果表明:除霜期间,采用空气吸热除霜技术时机组的出水温度和压缩机吸、排气压力随除霜换热器的轮换而波动,出水温度最大降低幅度在2.23～3.57 ℃之间。机组A采用空气吸热除霜技术时,压缩机吸、排气压力的波动幅度较采用逆循环除霜时分别降低80.4%和77.9%;而机组B采用2种除霜技术时压力波动幅度相近。在制热性能方面,采用空气吸热除霜技术时机组表现更优,相比采用逆循环除霜技术时,机组制热能力提高7.0%～10.9%,综合能效提升3.9%～9.3%。
Abstract：
The frosting of air-source heat pumps in winter can significantly reduce their heating performance, and defrosting is currently the most effective solution. In this research, three typical air-source heat pump systems are selected as research objects. Through experimental tests, the operational performance of air heat absorption defrosting technology is investigated from multiple dimensions and compared with the commonly used reverse cycle defrosting technology. The results indicate that the outlet water temperature, and the compressor suction and discharge pressures of the units using air heat absorption defrosting technology fluctuate with the alteration of the defrosting heat exchangers during the defrosting phase, with the maximum drop of the outlet water temperature ranging from 2.23 ℃ to 3.57 ℃. For unit A, which uses the air heat absorption defrosting technology, the fluctuation ranges of the compressor suction and discharge pressures are reduced by 80.4% and 77.9% respectively, compared to those of the unit with reverse cycle defrosting technology. However, unit B with two defrosting technologies shows similar pressure fluctuation ranges. Regarding heating performance, the unit with air heat absorption defrosting technology exhibits superior performance. Compared to the units with reverse cycle defrosting technology, the heating capacity of the units with air heat absorption defrosting technology increases by 7.0% to 10.9%, and the overall energy efficiency improves by 3.9% to 9.3%.
Keywords:air-source heat pump; air heat absorption defrosting; reverse cycle defrosting; heating capacity; energy efficiency