Effect of sealing strategy on the temperature distribution and smoke spread behavior in inclined mine roadway: A numerical study

Sealing strategy is widely employed in coal mine fire extinguishing. To investigate the effects of sealing strategy on the temperature distribution, smoke back-layering length (SB-LL), and self-extinction time, the Fire Dynamics Simulator (FDS) is used to simulate the inclined roadway fires with the heat release rate (HRR) of 4 MW, roadway slopes (0 °, 5 °, 10 °, and 20 °) and sealing ratios (0%–100%). The relationship between the maximum temperature beneath the ceiling ( T C ) and sealing ratio ( θ ) and roadway slope ( α ) is analyzed by the dimensionless method. The results show that as the roadway slope increases, the maximum T C of the roadway fire decreases and its position continues to shift downstream, and the SB-LL becomes shorter. For small roadway slope, the weak stack effect is insufficient to stop smoke backflow. As the sealing ratio increases, the SB-LL and the maximum T C rise significantly, and the position continues to move to the fire source. For inclined roadway fires, the fire self-extinguishing requires a 100% sealing ratio, and the self-extinction time decreases with the increase of the roadway slope. This research has important theoretical and practical significance for the control of mine roadway fires.