地埋管换热器热响应测试与模拟研究

摘要：【中文摘要】 对48m深双U型地埋管进行热响应测试,并使用线热源模型对实验数据进行分析。计算得到该测试地点土壤导热系数为1.44W/(m.K),进水温度为37℃时,每米井深散热量为91.14W/m。在实验的基础上,建立地埋管全尺寸换热模型,该模型水流进口条件与实验一致,土壤导热系数、地下初始温度等均为实验测得数据。以换热量比较,模拟结果与实验结果相差6.8%。在验证模型精度的基础上,对50m、60m、70m埋深的单U及双U型换热器进行模拟比较。进水温度为36.85℃时,对于单U型管,单位井深换热量分别为59.19W/m、56.23W/m、53.40W/m;对于双U型管,单位井深换热量分别为94.16W/m、90.00W/m、85.93W/m。不同深度的地埋管,双U型换热性能优于单U型,散热量约高37%,但是单U型管出水温度低于双U型管。 【英文摘要】 A thermal response test has been carried on double-U tube ground heat exchanger,and Line-Source Model was used for data analysis.As shown in this result,soil thermal conductivity of the place where the test carried out is 1.44 W/(m·K) and when the temperature of inlet water is 37℃,heat dissipating capacity per unit depth of borehole is 91.14 W/m.Based on the test result,full-size model of borehole heat exchanger has been established.All the parameters of the model were set the same value as the test or its result,such as the state of inlet water,soil thermal conductivity,undisturbed initial ground temperature.Compared simulation result with the test result,the error is 6.8%.As the error is acceptable,further researches have been made on different kinds of borehole heat exchangers and the depth are 50 m,60 m,70 m.The results show that the heat dissipating capacity per unit depth of borehole is 59.19 W/m,56.23 W/m,53.40 W/m with single-U tube ground heat exchanger and 94.16 W/m,90.00 W/m 【中文关键词】 地埋管换热器; 热响应测试; 传热模型; 数值模拟【英文关键词】 ground heat exchanger; thermal response test; heat transfer model; numerical simulation