竖直地埋管蓄取热特性试验与模拟  

Experiment and Simulation of Heat Storage and Release Characteristics of Vertical Buried Pipe

作　　者：吴晅[1] 侯正芳 温建军[1] 何丽娟[1] 金光[1] Wu Xuan;Hou Zhengfang;Wen Jianjun;He Lijuan;Jin Guang(School of Energy and Environment.Inner Mongolia University of Science and Technology,Baotou 014010,China)

机构地区：[1]内蒙古科技大学能源与环境学院,内蒙古包头014010

出　　处：《流体机械》2020年第3期58-67,共10页Fluid Machinery

基　　金：内蒙古自治区自然科学基金项目(2018MS05043);教育部“春晖计划”合作科研项目(CHJH2018);内蒙古自治区科技成果转化项目(CGZH2018150)。

摘　　要：在搭建的砂箱试验台试验分析了在单一工况蓄/取热运行模式对双U地埋管动态传热特性的影响。在试验验证的基础上,建立三维动态传热数理模型,数值分析了单一工况运行模式下土壤分层和地埋管管径等因素对双U型地埋管土壤传热特性的影响,并对比分析了单/双U型地埋管传热特性。试验研究结果表明:单一蓄/取热下,连续运行时土壤温度变化幅度随径向距离的增加而减小;蓄热时,进口温度为50℃和60℃的单位井深换热量要明显比进口温度为40℃时高;取热时,进口温度为4.2℃的单位井深换热量较进口温度为6.8℃时高。间歇蓄热运行模式下土壤温度波动幅度随开停比的减小而增加;间歇取热运行模式下在同一时间内开停比越小,土壤温度越接近土壤初温。模拟研究结果发现:在土壤分层下,双U型地埋管单位井深换热量较单U型地埋管单位井深换热量高19.87%;土壤温度均随地埋管管径的增加而增加,单U型地埋管以管径为32 mm时的单位井深换热量为最好,而双U型地埋管以管径为25 mm时的单位井深换热量为最好,前者单位井深换热量较后者低11.56%。By building a sandbox experimental system,the influence of the thermal storage/heat extraction mode on the dynamic heat transfer characteristics of the double U buried pipe under single working condition was analyzed experimentally.Based on the experimental verification,a three-dimensional dynamic heat transfer mathematical model was established.The influences of such factors as soil layers and diameter of buried pipe on the double U-shaped buried pipe in the mode of single operating condition were analyzed numerically.The heat transfer characteristics of single/double U-type buried pipes were compared.The experiment results show that the range of soil temperature increases with increase of the radial distance during continuous operation under single storage/heat release conditions.The average quantity of heat exchange per meter of well depth at an inlet temperature of 50℃ and 60℃ was significantly higher than that at inlet temperature of 40℃ in the heat storage,and the average quantity of heat per meter at an inlet temperature of 4.2℃ was higher than that at the inlet temperature of 6.8℃ in the heat release.The fluctuation range of the soil temperature increases with the decrease of on-off ratio.The smaller the on-off ratio is,the closer the soil temperature to the initial temperature under the intermittent operation mode within the same time.The simulation results show that the average quantity of heat exchange per meter of well depth of the double U-shaped buried was 19.87%higher than that of the single U-shaped buried under the layers of soil.The soil temperature increases with increase of the buried pipe diameter.The average quantity of heat per meter of well depth of the single U-shaped buried pipe with the pipe diameter of 32 mm was the best,and the double U-shaped buried pipe with the pipe diameter of 25 mm for the best.The average quantity of heat exchange per meter of the former was 11.56%lower than that of the latter.

关 键 词：地埋管 土壤分层 单位井深换热量 蓄热 取热 

分 类 号：TH12[机械工程—机械设计及理论] TU83[建筑科学—供热、供燃气、通风及空调工程]