Study on coupled heat transfer and seepage in large sparsely fractured surrounding rocks in deep underground spaces

It is essential to research coupled heat transfer and seepage in fractured surrounding rocks in deep underground spaces to design proper ventilation and air conditioning systems for deep underground spaces. The heat transfer theory and discrete network seepage models were used to establish a 3-D unsteady coupling model for large sparsely fractured surrounding rocks in deep underground spaces. Using COMSOL Multiphysics simulation software, the temperature fields of the surrounding rock matrix and fracture water were obtained. Furthermore, the influences of the seepage velocity and the fracture aperture on the fracture water temperature field were discussed. The results of the numerical simulations showed that the characteristics of the fractures have an important impact on the temperature field of a large sparsely fractured surrounding rock. The numerical simulation results were basically in accordance with the experimental results.