Analysis of temperature field of surrounding rock and influencing factors under the seasonal variation of air temperature at the entrance of roadway

In order to investigate the variation law of the temperature field of surrounding rock under the seasonal change of wind temperature at the roadway entrance and the influence of different physical parameters on the temperature field of surrounding rock, the heat conduction equation of the temperature field of surrounding rock was established according to the energy conservation law and Fourier law.The discrete element partition was carried out along the axial direction of roadway and radial direction of surrounding rock.The numerical solution of surrounding rock temperature field under the seasonal variation of wind temperature at roadway entrance was established by using the finite difference method.The C # program was compiled and the simulation research was carried out in Jining No.3 Coal Mine.The results show that under the seasonal variation of wind temperature at roadway entrance, the variation of surrounding rock temperature with the distance from the center of roadway has two zone distribution characteristics; the surrounding rock temperature at different depths in the radial direction changes seasonally and the variation range gradually decreases with the extension of the depth, the maximum or minimum temperature of deep surrounding rock lags behind that of shallow surrounding rock; the annual range of surface air temperature, mining depth and thermal diffusivity coefficient of rock has an important influence on the temperature field of surrounding rock, and the influence of air flow on the temperature field of surrounding rock is mainly manifested in the radial shallow surrounding rock.