土壤源热泵单U型埋管换热器短期运行换热分析

单U型管是当前土壤源热泵系统广泛使用的地下换热器形式,而地下换热器是地源热泵系统的重要组成部分。考虑U型管的实际形状,借助数学方法和数值分析软件,建立了地下垂直埋管换热器传热模型,并通过编程求解数学模型,得到了系统短期运行不同工况下埋管周围土壤的温度场分布情况。通过分析得出土壤导热系数、土壤比热、钻孔回填材料导热系数以及U型管间距的大小对埋管的换热性能具有直接影响。得出的结果可为合理设计地下埋管换热器提供参考。

Short-Term Operation Analysis of Heat Exchange on Single U-Tube Heat Exchanger of Ground Coupled Heat Pump

A single U--tube is the most common type of ground heat exchange in Ground Coupled Heat Pump(GCHP) system,and ground heat exchanger is an important component of the GCHP system.The real shape of U--tube was considered,and heat transfer model of underground vertical buried tube heat exchanger was built with math methods and numerical analysis software.The soil temperature distributions around the buried tube under different working conditions were solved by programming.The analysis shows that the thermal conductivity and specific heat of soil,the thermal conductivity of backfilled material in drilling and the distance between U--tubes have direct effect on the heat transfer performance of buried tubes.The results may provide guidance in the design of GCHP systems.