Abstract: In order to investigate the influence of temperature in deep coal mining area on coal seepage and pore fracture structure deformation, 3D CT reconstruction technology and ANSYS were used to simulate the process of conjugate heat transfer and thermal deformation of coal microstructure respectively. The conjugate heat transfer simulation results show that water that was initially injected into the 80℃ coal wall at 20℃ was heated to 37.13℃ when it flows out. The temperature of the coal gradually decreases along the wall facing the fluid center. Pore fracture structure has an important influence on the velocity and the temperature of the flow along the flow direction. When the connected cross-section porosity is large, the flow speed is slow, the fluid heats up quickly, and the solid temperature decreases. On the other hand, when the connected cross section porosity is small, the flow speed is fast, the fluid temperature rises slowly, and the solid temperature rises. The thermal deformation simulation results show that the deformation is proportional to the distance from the constraint surface. When the deformation near the constraint surface is small, and the direction is pointed to the pore fracture space. While if the deformation at a place that is far away from the constraint surface is large, the deformation direction is diverging outward. Moreover, the existence of the cracks will increase the deformation, the deformation difference between the different pore or crack structures will also increases with the increasing temperature.

Key words: coal, 3D CT reconstruction, conjugate heat transfer, cross-section connected porosity, thermal deformation