22 May 2002
The defrosting system should operate timely for an air heat pump at lower temperature. Investigations have indicated that the period for defrosting is one of the important factors that affects the operating characteristics of the air heat pump. To frame the control method, several aspects should be studied, including frost growth process, system operating point variation and the control method. In this paper, system-operating characteristics were analyzed and a defrosting control method is presented based on average heating capacity .