地源热泵U型管地下换热器的数值模拟

Computer Simulation of the U-tube Ground Heat Exchanger for GSHP

通过改进现有二维传热模型建立准三维传热模型,模拟U型竖直埋管地下换热器的运行工况．模型引入换热功率函数作为边界条件,对单个线热源到区域中心距离提出新的计算方法,运用有限体积法求解．通过与实验结果比较,模型结果可以满足工程精度的要求,并且给出U型管内流体温度分布情况以及钻孔深度对U 管两支管之间的热短路的影响．

This paper established a 3D heat transfer model to simulate the running state of the vertical U-tube ground heat exchanger（GHE）, which introduced the heat exchange function as the boundary condition for the inlet of the U-tube. The author proposed a new method to calculate the distance between individual line heat source and the district center, and derived the solution by finite volume method. The model can meet the requirement for the engineering precision by comparison between numerical and experimental results. Furthermore it presented the temperature distribution of the fluid inside the U-tube, and also analyzed the effects of the depth of borehole on thermal interference between the U-tube two legs.