Based on the operation testing of new air-water double source composite heat pump system (AWDSHPS-N), three defrosting modes were investigated under the same ambient condition, which included the condenser outlet refrigerant recooling defrosting(D-I), the low temperature-hot water defrosting(D-II), the condenser outlet refrigerant recooling and low temperature-hot water defrosting at same time (D-Ⅲ). Total coefficient of performance (COP) of AWDSHPS-N was used to evaluate the influence of the three modes. The influence on the total COP, defrosting operating characteristics and energy consumption of D-I, D-II and D-Ⅲwere discussed and compared with those in the reverse-cycle defrosting mode, under the same ambient condition. The results of test conditions indicated that for D-I and D-II, the total COP can be decreased by 0.42% and 3.93%, respectively, compared with the COP of frosting period. The heating power and COP during D-II defrosting were 27.4% and 17.8% higher than those of frosting operation, respectively. The total COP of AWDSHPS-N choosing D-I, D-II and D-Ⅲ were 26.06%, 29.79% and 17.02% higher than that of verse-cycle defrosting, and the defrosting energy consumption of D-I, D-II and D-Ⅲ were only 3.11%, 34.78% and 28.26% of the reverse-cycle defrosting energy consumption.%基于新型空气-水双热源复合热泵系统(AWDSHPS-N),实验研究了AWDSHPS-N采用冷凝器出口制冷剂再冷却除霜(D-I)、低温热水除霜(D-II)、低温热水+冷凝器出口制冷剂再冷却除霜(D-Ⅲ)3种除霜模式进行除霜时对系统整体性能系数(COP)的影响,除霜期间系统运行特性及除霜所消耗的能量,并与逆循环除霜模式进行了对比分析.测试工况下的实验结果表明,除霜模式D-I和D-Ⅲ仅使系统整体COP较结霜运行期间的COP分别降低了0.42%和3.93%;D-II除霜期间系统的制热功率和COP分别较结霜运行期间提高了27.4%和17.8%.D-I、D-II和D-Ⅲ完成一次除霜能耗仅分别为逆循环除霜能耗的3.11%、34.78%和28.26%;采用此3种除霜模式时系统整体COP较采用逆循环除霜时分别提高了26.06%、29.79%和17.02%.
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