重庆地区垂直双U地埋管换热器保温性能研究

以层换热理论为基础,重庆某示范楼工程土壤源热泵系统为对象,建立实验系统,测试了实际运行状况下的地埋管换热器供回水管不同深度的水温.从地埋管不同时刻的平均水温和换热能效两个方面分析了实测数据,研究了回水管保温与不保温时垂直双U地埋管换热器的换热情况.结果表明,在冬季,保温地埋管典型日不同时刻的换热能效比不保温的高出14.09%,月平均换热能效比不保温的高出23.08%,季平均换热能效比不保温的高出40.54%.在夏季,保温地埋管典型日不同时刻换热能效比不保温的高出10.76%,月平均换热能效比不保温的高出28.57%;季平均换热能效比不保温的高出41.48%,回水管保温有利于加大地埋管换热器的换热能力.

Study on the Thermal Insulation Performance of the Vertical Double U Underground Heat Exchange with Outlet Pipe Insulated in Chongqing

Based on the layer heat transfer theory, this paper tested the water temperature of the underground heat exchanger at different depth on the basis of the ground-coupled source heat pump system of a Demonstrative Building in Chongqing. After the date processing through two aspects, i.e., the daily temperature of different time and temperature difference between inlet pipes and outlet pipes, this paper compared thermal performance between the vertical double U-shape underground heat exchangers with outlet pipe insulated or not. The comparison demonstrated that: in winter, the rate of improvement in average heat transfer energy efficiency of the heat exchangers with insulated outlet tube is 14.09% in typical winter day, 23.08% in the coldest month and 40.54% in the whole cooling season compared with the heat exchangers without insulation. Meanwhile, the rate of improvement is 10.76% in typical summer day, 28.57% in the hottest month and 41.48% in the whole cooling season in summer. The insulated outlet pipe is helpful to increase heat transfer capacity of underground heat exchanger.