地下水流动对埋地换热器影响的模拟研究

通过求解含水层中地下水流动的二维能量方程,分析了地下水流动对U型埋地换热器与周围土壤换热的影响,并与非含水层情况进行了比较。模拟结果表明,地下水流动显著影响埋地换热器周围的土壤温度场。与粘土层相比,埋地换热器在含水层内土壤温度变化较小,到达稳态时间较短。埋地换热器周围热作用半径,沿上游方向较小且很快达到稳态,而沿下游方向上的热作用半径基本与运行时间成正比关系。地下水流速越大,埋地换热器周围介质的平均温度越低,这有利于夏季排热工况。

Numerical study of the effects of groundwater flow on ground coupled heat exchangers

Base on the numerical solution for a two-dimensional energy equation of the groundwater flow in the aquifer, the effects of groundwater flow on U-shaped ground coupled heat exchangers (GCHE) were analyzed. Simulated results showed the effect the groundwater on the temperature field of the soil around the GCHE is obvious. Compared with the case in the clay layer, the temperature variation in the aquifer is small, reaching steady within a short time. The thermal effect radius of GCHE along the upstream is smaller than that of the downstream. Especially for the latter, the thermal effect radius is proportional to the operating time. The more rapid the groundwater flows, the lower the average temperature of the soil around the GCHE is, and this is helpful for the summer operation.