复叠式空气源热泵相变蓄能除霜低温适应性实验研究

Experimental Study on the Low Temperature Adaptability of Energy Storage Defrosting for Cascade Air Source Heat Pumps

复叠式空气源热泵的几种常规除霜方式都存在一定的弊端,为此提出了复叠式空气源热泵相变蓄能除霜方法。为研究复叠式空气源热泵相变蓄能除霜的低温适应性,通过改变室外侧环境温度、相对湿度和结霜时间,设计了6种不同室外工况。并通过实验研究6种工况下,系统开启除霜模式时的运行特性。实验结果表明:6种工况下,除霜时间都在520～770 s范围内,且每个工况下机组运行正常,系统除霜性能稳定,同时室内侧平均供热量也达到正常供热的57.4%以上,说明本系统具有良好的低温适应性。

There are certain disadvantages in several conventional defrosting methods for cascade air source heat pumps. For this reason, an energy storage defrosting method for cascade air source heat pumps was proposed. In order to study its low temperature adaptability, six different outdoor simulated conditions were designed by changing the ambient temperature, relative humidity of outdoor side and frosting time. The characteristics of the energy storage defrosting mode under these six conditions were experimentally studied. The experimental results indicate that, the defrosting durations under six conditions are within the range of 520~770 s, the system operates normally under each working condition, the system defrosting performance is stable and the average indoor heating capacity can reach more than 57.4% of the normal heating capacity. The results show that the system has good low temperature adaptability.