地下水渗流对单U形地埋管埋深的影响

为解决因埋深过大而引起的竖直地埋管换热器换热效果不佳的问题,根据黄土高原地区的地质条件,建立轴向岩土分层的单U形地埋管换热器数值模型.通过数值模拟,分别研究了改变含水层厚度、地下水渗流速度和地下水位线高度对地埋管换热性能的影响,并提出了以典型含水层厚度来确定地埋管最佳埋深的方法.结果 表明:当实际含水层的厚度不超过典型含水层厚度时,地埋管最佳埋深的位置为实际含水层底部;反之,地埋管最佳埋深的位置为典型含水层底部;随着渗流速度的减小,典型含水层厚度先增大后趋于不变,在渗流速度为1×10-6 m/s时达到最大值30 m;地下水位线的提高对典型含水层厚度没有影响,但提高了典型含水层的位置,使得最佳埋深变小.

Influence of groundwater seepage on the buried depth of single U-tube heat exchanger

In order to solve the problem of negative heat transfer effect caused by excessive buried depth of vertical ground heat exchanger, a numerical model of single U-type ground heat exchanger with axial rock-soil body stratification was established according to the geological conditions in loess Plateau area. Through numerical simulation, the influence of changing the aquifer thickness, the seepage velocity, and the height of the water table on the heat transfer performance of the ground heat exchanger is analyzed, and a method to determine the optimal buried depth of the exchanger based on the typical aquifer thickness is proposed. The results show that when the actual aquifer thickness does not exceed the typical aquifer thickness, the optimal buried depth of ground heat exchanger is the bottom of the actual aquifer. On the contrary, the optimal buried depth is the bottom of typical aquifer. With the decrease of seepage velocity, the thickness of typical aquifer first increases and then tends to remain unchanged, reaching a maximum of 30 m when the seepage velocity is 1×10-6m/s. The increase of the groundwater table has no effect on the thickness of the typical aquifer, but it increases the location of the typical aquifer, making the optimal buried depth smaller.#$NL