(1. School of Civil Engineering, Shaoxing University, Shaoxing 312000;2. International Scientific and Technological Cooperation Base for Geological Disaster Prevention of Zhejiang Province, Shaoxing 312000;3. Zhejiang Collaborative Innovation Center for Prevention and Control of Mountain Geologic Hazards, Shaoxing 312000)
Abstract:
Energy shield tunnels serve as critical underground structures for exploiting shallow geothermal energy, yet research on the influence of groundwater seepage on their heat exchange performance remains insufficient. To address this, a combined approach of model test and numerical simulation was employed to systematically investigate the effects of groundwater seepage velocity and flow direction on the heat exchange performance of energy shield tunnels. First, a similar experimental model was constructed to conduct model tests under five summer working conditions, clarifying the impact of groundwater seepage on the temperature distribution of heat exchange pipes and surrounding rock. The experimental results were then used to validate the accuracy of numerical simulations. Subsequently, 20 numerical simulation cases were performed under varying seepage velocities, flow directions, and seasonal conditions. The results demonstrate that the heat exchange performance of energy shield tunnels significantly improves with increasing groundwater seepage velocity. A smaller angle between the seepage direction and the tunnel axis enhances heat exchange efficiency. Under summer conditions, the temperature difference between the inlet and outlet of the heat exchange pipes is markedly greater than that observed in winter conditions.