多层含水层中同井回灌地下水源热泵特性分析

The Analyses of Characteristic on Groundwater Heat Pump with Pumping & Recharging in the Same Well in Multilayer Aquifer

在适当简化了多层含水层和抽灌同井的基础上,分析了多层含水层中同井回灌地下水源热泵水力和热力特性。随着中间含水层竖向渗透系数的增加,抽、回水口降深绝对值减小,抽水和回灌相对容易;中间弱透水层厚度减小时,抽、回水口降深绝对值有所降低,但降低不明显;抽水流量增加,抽、回水口降深绝对值基本呈线性增加,从而增加抽水和回灌压力。中间弱透水层的存在,显著地降低了抽水温度降,大大增加了含水层热影响范围,即使弱透水层很薄,也能起到很好阻隔作用,在这种条件下井的出水温度对于流量的加大不敏感。因此在抽水和回灌允许的情况下,可以加大抽水流量,使井承担更大的负荷。

The hydrodynamic and thermal characteristic of Groundwater Heat Pump with Pumping & Recharging in the Same Well (GWHPPRSW) in multilayer aquifer was analyzed based on appropriately simplifying themultilayer aquifer and well with pumping & recharging together. With the increase of vertical permeability coefficient of the middle aquifer, the absolute values of pumping and injection drawdown were dropped, so pumping and injection was easier. With the decrease of the middle aquifer thickness, the absolute values of pumping and injection drawdown were dropped, but the decrease was not distinct. When the pumping flow increases, the absolute values of pumping and injection drawdown were increased linearly on the whole, so the pressure of pumping and injection was increased. For the existence of middle aquitard, the pumping temperature decrease was dropped remarkably, and the Thermal Effective Radius (TER) is lengthened consumedly. Even if the aquitard is very thin, the retard function is good, and the pumping temperature is not sensitive to the increase of pumping flow in this condition. So the pumping flow can be increased to burden more load with the permission of pumping and injection.