低温环境下复叠式空气源热泵热水系统的实验研究

Experimental Research on Hot Water System Based on Cascade Air-source Heat Pump under Low Temperature Conditions

本文借鉴复叠式制冷原理,研制了复叠式空气源热泵热水系统样机,以期在-25℃的低温工况下制取80℃高温热水。分别选取R134a和R410A作为高、低温级制冷工质,采用等压缩比法对中间冷凝压力进行控制,通过实验测得样机在额定工况下制取80℃热水的系统COP达到了1.82;在极端工况下,即室外环境温度-25℃时制取85℃热水,系统COP也达到了1.37。另外,实验数据验证了系统的可行性。

In this paper,refer to the theory of cascade refrigeration,a prototype of hot water system based on cascade air-source heat pump was manufactured,the objective was to obtain 80 ℃ hot water under -25 ℃ working condition. In detail,R134a and R410A were selected as the refrigerant for high and low temperature levels respectively, and the principle of equivalent compression ratio was used to control the intermediate pressure. The experimental results indicated that system COP could reach to 1.82 for obtaining 80 ℃ hot water under rated operating condition. Furthermore,in the extreme case for obtaining 85 ℃ hot water under - 25 ℃ environmental temperature,system COP could also reach to 1.37. In addition,this system Was proved to be feasible by sufficient experimental data.