Temperature Distribution of Coal Mine Tunnel Fire During Dynamic Sealing Process: A Numerical Study

Implementing a sealing measure on both ends of the mine tunnel fire is an important approach for fire extinguishing. In order to explore the effect of different sealing velocities on the temperature distribution of mine tunnel fire during dynamic sealing, a series of full-scale mine tunnel fire models were built using Pyrosim, and Fire Dynamics Simulator (FDS) was carried out to investigate the smoke temperature beneath the tunnel ceiling in symmetrical sealing on both ends. The results show the sealing method led to a substantial increasement of the mine tunnel ceiling temperature when the HRR was relatively small (2 MW). And with the acceleration of the sealing velocity, the time to reach the maximum temperature was earlier. However, the HRR was greater than 6 MW, the sealing velocities have less impact on the maximum ceiling temperature. Due to dynamic sealing of the mine tunnel fire with natural ventilation conditions, the ceiling temperature expressed an exponential decay along the longitudinal direction. Meanwhile, with the increase of the HRR, fire extinguishing time was generally advanced. When the sealing velocity was relatively slow, the maximum ceiling temperature exhibited a hysteresis, and the temperature of outside the sealing wall declined slowly. The research has great significance for mine tunnel fire control and rescue.