Distribution characteristics of temperature field in deep roadway and numerical simulation of ventilation and cooling in Jiaojia Gold Mine

In order to solve the high temperature damage occurs in the deep roadways of Jiaojia Gold Mine and understand the influence of different ventilation conditions on the temperature and velocity fields in deep roadways, based on obtaining the overall distribution of the ground temperature field in the middle sections of - 580 m and - 670 m, by using CFD numerical simulation, the distribution characteristics of the temperature field and velocity field in the two areas under natural ventilation conditions were calculated. For the -670 m middle section, by adding a forced ventilation system, the cooling effect of different ventilation conditions on the roadway was simulated. The results indicate that, the geothermal gradient in the study area ranges from 3. 0 ℃ / hm to 3. 2 ℃ / hm, categorizing it as a geothermal anomaly area. The original rock temperature in the middle section of -580 m has exceeded 30. 4 ℃, and the temperature of the roadway is 29. 3 ℃ . Heat damage has begun to emerge. Under natural ventilation conditions, the average temperature at the -670 meter middle section of the tunneling working face is 33. 4 ℃, which is relatively high. After the addition of the forced ventilation system, the air supply volume and air supply temperature were altered. When the air supply temperature was decreased by 5. 0 ℃, the average temperature of the working face dropped by 4. 7 ℃, and the cooling degree reached 18. 5%. When the air supply temperature was kept constant and only the air supply volume was changed, it had a negligible impact on the temperature and wind speed of the tunneling face.