Impact of air supply cessation time on thermal characteristics in coal mine dead-end roadway fires: An experimental study

Abstract

Following a fire incident in a coal mine dead-end roadway, shutting down the local ventilator can influence fire progression. This study delves into the impact of local ventilator shutdown time (i.e. air supply cessation time) on fire source combustion dynamics through small-scale experiments. Results indicate that the sudden cessation of air supply will prompt ghosting flame and even fire self-extinguishing. The ghosting flame emerges due to the uneven distribution of fuel vapor and oxygen concentrations, its moving direction is related to ventilation conditions and fire source combustion mode. And the burning time of the fire source after air supply cessation diminishes with increasing air supply cessation time and pool size but increases with higher ventilation velocities. Additionally, sudden cessation of air supply decreases smoke oxygen content and significantly elevates CO levels, particularly impacting ventilation-controlled fires. Moreover, this interruption leads to a substantial rise in smoke temperature, heightening fire risk. Thus, prudent closure of the local ventilator in dead-end roadway fires is recommended, particularly in scenarios of inadequate ventilation and prolonged combustion. These findings offer fresh insights into dead-end roadway fire behavior and furnish valuable guidance for firefighting and rescue operations in similar structures.

Keywords

• Coal mine dead-end roadway fire
• Air supply cessation time
• Fire behavior
• Thermal characteristics