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Study of the defrosting operation of the flexible heat pump cycle.


Heat pumps are considered as one of the key technologies for decarbonizing the heating sector and yet major improvements are still needed to tackle the hurdles blocking their widespread uptake. Among them the frosting issue for air source heat pumps leads to a drop of efficiency and an interruption of heating supply. Recently, the author’s group developed a flexible heat pump concept that integrates heat storage into the standard Evans-Perkins cycle to recover part of the subcooling heat carried by the hot liquid refrigerant leaving the condenser. The stored heat can then be used as an ancillary heat source for the heat pumps’ operation. One important application of the recovered heat is for defrosting the evaporator. The defrosting of the evaporator is provided by subcooling the refrigerant inside. It can provide continuous heating during defrosting and improve the heat pumps efficiency at the same time. In this paper, we present theoretical research of the defrosting mode of the flexible heat pump. For a heat pump with a heating capacity of 3.6kW and for a condensing temperature of 35℃, when defrosting is operated it can still theoretically save 5.6% in compressor power consumption compared to a heat pump using a reverse cycle defrosting.

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  • Original title: Study of the defrosting operation of the flexible heat pump cycle.
  • Record ID : 30031429
  • Languages: English
  • Subject: Technology
  • Source: Proceedings of the 26th IIR International Congress of Refrigeration: Paris , France, August 21-25, 2023.
  • Publication date: 2023/08/21
  • DOI:


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