In the process of exploiting geothermal energy by groundwater heat pump
(GWHP), the dynamic equilibrium of regional groundwater drawdown is the
basis for sustained operation of GWHP. In this paper, taking the GWHP
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 GWHP 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 1440m3/d 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.