U型埋管换热器换热性能的解析解法

Analytical Method for Heat Transfer Performance of U-tube Ground Heat Exchanger

以钻孔壁为界,将U型埋管的换热区域划分为内外两个部分。对于钻孔外的土壤部分,通过圆柱热源模型建立了非稳态分析解模型;对于钻孔内部,考虑到流体温度的沿程变化以及两管之间的热干扰,利用能量平衡原理建立了稳态分析解模型。内外两部分之间通过钻孔壁温耦合连接。

Seeing the borehole wall as the boundary,the heat transfer area of U-tube will be classified into inside part and outside part.For the soil part outside the drilling,non-steady state solution model will be used through the Cylindrical Source Theory.For the inside part,steady state model will be used through the Energy Balance Theory,considering the changes of fluid temperature along the way and the thermal influence between the two pipes.The inside part and outside part are combined with the temperature of borehole wall directly.