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A platform for research: civil engineering, architecture and urbanism
Experimental study on hot liquid subcooling defrosting of an air source heat pump with multi-connected outdoor units
Highlights The common defrosting methods of air source heat pump are summarized and their advantages and disadvantages are analyzed. A hot liquid subcooling defrosting method with multiple outdoor units connected in parallel is adopted to defrost the air source heat pump. The influence of outdoor temperature and relative humidity on defrosting of air source heat pump were discussed. The performance of hot liquid subcooling defrosting and hot gas bypass defrosting were compared, and their advantages were analyzed.
Abstract Air source heat pumps (ASHPs) are widely used in clean heating because of the high efficiency, energy saving and economic advantages. Efficient defrosting technology for continuous heating is a key issue that must be addressed when operating the large ASHP at low temperatures. To solve the technical problem, this paper designed and built an experimental ASHP system with multi outdoor units connected in parallel, and used the hot liquid from the outlet of the condenser to defrost outdoor units in turn to study the change of heat pump performance with defrosting start time at different outdoor temperatures and outdoor humidity, and compared the system performance of the hot liquid subcooling defrosting (HLSD) with that of the hot gas bypass defrosting (HGBD). The experimental results showed that the HLSD enabled the heat pump to complete rotational defrosting with good defrosting effect in the case of continuous heating. The lower the outdoor ambient temperature and higher the air relative humidity, the worse the heating performance, and the longer the defrosting time. When using the HLSD, the heating capacity and energy efficiency ratio of heat pumps could be increased by 10% to 20% compared with the HGBD.
Experimental study on hot liquid subcooling defrosting of an air source heat pump with multi-connected outdoor units
Highlights The common defrosting methods of air source heat pump are summarized and their advantages and disadvantages are analyzed. A hot liquid subcooling defrosting method with multiple outdoor units connected in parallel is adopted to defrost the air source heat pump. The influence of outdoor temperature and relative humidity on defrosting of air source heat pump were discussed. The performance of hot liquid subcooling defrosting and hot gas bypass defrosting were compared, and their advantages were analyzed.
Abstract Air source heat pumps (ASHPs) are widely used in clean heating because of the high efficiency, energy saving and economic advantages. Efficient defrosting technology for continuous heating is a key issue that must be addressed when operating the large ASHP at low temperatures. To solve the technical problem, this paper designed and built an experimental ASHP system with multi outdoor units connected in parallel, and used the hot liquid from the outlet of the condenser to defrost outdoor units in turn to study the change of heat pump performance with defrosting start time at different outdoor temperatures and outdoor humidity, and compared the system performance of the hot liquid subcooling defrosting (HLSD) with that of the hot gas bypass defrosting (HGBD). The experimental results showed that the HLSD enabled the heat pump to complete rotational defrosting with good defrosting effect in the case of continuous heating. The lower the outdoor ambient temperature and higher the air relative humidity, the worse the heating performance, and the longer the defrosting time. When using the HLSD, the heating capacity and energy efficiency ratio of heat pumps could be increased by 10% to 20% compared with the HGBD.
Experimental study on hot liquid subcooling defrosting of an air source heat pump with multi-connected outdoor units
Ma, Guoyuan (author) / Lu, Tianyu (author) / Liu, Fusheng (author) / Niu, Jianhui (author) / Xu, Shuxue (author)
Energy and Buildings ; 291
2023-04-20
Article (Journal)
Electronic Resource
English
| DOAJ | 2022
| Taylor & Francis Verlag | 2018