Influence of different pumping and recharging schemes on regional groundwater drawdown in groundwater heat pump project: A case in Anhui Fuyang People’s Hospital

Abstract

In the process of exploiting geothermal energy by groundwater heat pump, the dynamic equilibrium of regional groundwater drawdown is the basis for sustained operation of groundwater heat pump. In this paper, taking the groundwater heat pump project of Fuyang People?s Hospital in Anhui, China as an example, a mathematical model is established and numerical simulation is carried out based on the hydrogeological conceptual model by using MODFLOW software. In addition, considering the pattern of same direction recharge, the intersect recharge, and the ratio of 90% and 100% reinjection, respectively, the area change of the drawdown funnel caused by the groundwater heat pump project and the recovery of the water level after the system stopped operation are analyzed. The results show that the funnel area of the pumping well under the 90% recharge ratio is greater than that of the 100% recharge, while the operation result of recharge well is opposite in the most adverse situation of the system with a production volume of 1440 m3 per day and continuous operation for 4 months. Furthermore, with the same reinjection ratio, the funnel area of the same direction recharge mode is larger than that of the intersect recharge mode in both pumping wells and recharge wells, and increases with the decrease of drawdown. Moreover, with the increase of recharge amount, while the water level of recharge well rises, there is a certain supplement and balance to the water quantity of the pumping well.