摘要
以地热埋管换热器为研究对象,对换热器各环节热阻进行了数值模拟.模拟利用Fluent软件,建立双U型埋管换热器二维模型,并对钻孔内外各传热过程进行数值模拟.将模拟结果与理论计算结果进行了比较,并讨论管间距半宽、PE管外径以及钻孔半径的变化对PE管内热阻、钻孔内热阻和钻孔外热阻的理论公式计算精度的影响.结果表明:对于PE管内热阻和钻孔外热阻而言,其模拟值和理论公式计算值非常相近,而钻孔内热阻的理论计算公式精度较差,其计算值和模拟值之间存在较大偏差;且管间距半宽和钻孔半径对理论值与模拟值的相对误差几乎无影响,而钻孔内热阻的理论值与模拟值之间的相对误差会随着PE管外径的增大而变大.
aking the geothermal heat exchanger as an object, the heat exchanger thermal resistance of each link was simulated by the Fluent software. A double U-tube geothermal heat exchanger of two-dimension model was established, and the heat transfer process of the drilling was simulated. The theoretical results and simulation results were compared to verify the accuracy of the simulation model, and the effect of the accuracy with the changes of tube pitch, PE tube outer diameter and borehole radius for thermal resistance of PE pipe and borehole were discussed. The results show that the simulation and theoretical values of the thermal resistance of PE pipe and borehole outside are very similar, while the accuracy of the calculated by the theory of borehole thermal resistance is poor. There is a large deviation between the calculated value and the analog value. Tube pitch and drilling radius have no effect on the relative error of the theoretical value and analog values. The relative error of the borehole thermal resistance between the theoretical value and the analog value grows while the PE pipe diameter increases. It can provide a good reference for the design of ground source heat pump.
作者
危日光
张晨
李聪
高建强
刘中良
WEI Riguang ZHANG Chen LI Cong GAO Jianqiang LIU Zhongliang(Key Laboratory of Enhanced Heat Transfer and Energy Conservation,Ministry of Education, Beijing University of Technology, Beijing 100124, China School of Energy Power and Mechanical Engineering,North China Electric Power University,Baoding 071003, Hebei, China)
出处
《北京工业大学学报》
CAS
CSCD
北大核心
2017年第6期949-955,共7页
Journal of Beijing University of Technology
基金
北京市科技计划资助项目(D141100002714001)
关键词
双U型埋管换热器
Fluent软件
热阻
double U-tube geothermal heat exchanger
Fluent software
thermal resistance
