户用空气源热泵机组除霜方法的实验研究

试验对比一台户用整体式空气源热泵机组的3种除霜方案：旁通制冷膨胀阀、风机提前启动和热气旁通融霜。结果表明,用外径16 mm的铜管旁通制冷膨胀阀是比较适合测试样机的除霜方法,在-3℃/90%工况下除霜时间由205 s缩短至99 s;当除霜温度设定为0℃时,提前启动风机可以避免系统的高低压出现大幅度的波动;而热气旁通融霜会导致机组的制热能力下降,但有利于机组在低温工况下的运行稳定性。最后对试验需要改进的地方进行简要说明。

Experimental research on defrosting methods for household air-source heat pump unit

Compares and analyzes three defrosting methods for the household air-source heat pump experimentally： by-pass refrigeration expansion valve,fan pre-start and hot gas by-pass defrosting.The experiment results show that the by-pass refrigeration expansion valve with an OD16 mm copper tube is a better defrosting method,the defrosting time is reduced from 205 s to 99 s under-3 ℃/90%;the method of fan pre-start can avoid the large pressure fluctuation with the setting defrosting temperature of 0 ℃;the third method is beneficial to the operation stability of unit under the low temperature condition,but leads to lower heating capacity.Finally,illuminates simply some improvement advices for the experiment.