Paper No 1141 – Research Progress of Defrosting Methods for Air Source Heat Pump – 14th IEA Heat Pump Conference, Chicago, USA
With the proposal of the national "double carbon" strategic goal, air source heat pump (ASHP), as a highefficiency and energy-saving product, will be more and more widely used. Frosting is one of the main factors to reduce the heating capacity of ASHP in winter. The main technical solution for the problem is delaying frosting and high efficient defrosting. The research of domestic and foreign scholars on restraining frosting technologies and defrosting methods for ASHP are summarized. The researches show that changing the inlet air parameters and the structure of evaporators can realize restraining frosting without or only consuming less energy; electric heating defrosting needs consuming additional electrical energy; for small scale refrigeration and heat pump equipment, reverse-cycle defrosting and hot gas by-pass defrosting are most commonly used; a new defrosting method with small energy loss, continuous heating and non-stop defrosting needs to be developed in the future.