住宅地源热泵系统设计及冬季运行性能分析

Design and Performance Analysis under Winter Condition of a Residential Ground-source Heat Pump System

本文对扬州某住宅小区地源热泵系统进行了设计计算,测试并评估了地源热泵系统的冬季运行性能,结合小区全年空调能耗数据分析了系统的热平衡问题。结果表明:该地源热泵系统需要1087口竖井进行换热,测试期间地埋管出口水温为8.5~9.0℃,机组性能系数为3.67~4.17,系统性能系数为2.66。系统性能系数较低的主要原因可能是:一方面,结合测试数据得出,低部分负荷率下系统小温差大流量运行,导致水泵能耗较高;另一方面,结合小区全年空调能耗数据得出,系统冬季取热量和夏季放热量不平衡,导致土壤温度有所下降。

A ground source heat-pump system for a residential community in Yangzhou was designed and tested under winter conditions.The operating performance was evaluated and ground thermal imbalance problem was also analyzed based on the annual energy consumption of the air conditioning system of the community.The results showed that the ground source heat pump system requires 1087 vertical wells for heat transfer,the water temperature at the outlet of the buried pipe was 8.5-9.0℃,the coefficient of performance(COP)of heat pump unit was 3.67-4.17,and the system COP was 2.66.Based on the test data,it is concluded that the main reason for the low system COP is that the system operates at low temperature differences between inlet and outlet and large flow rate at low partial load rates,and thereby resulting in higher pump power consumption.Conversely,based on the combined annual air-conditioning energy consumption data of the community,it is concluded that the system′s heat extraction in winter and the heat release in summer are unbalanced,and thereby resulting in a decrease in soil temperature.