Prediction and thermal characterizes of ventilation-controlled fire in coal mine dead-end roadway: An experimental investigation

Ventilation conditions can significantly affect the fire behavior of dead-end roadway fires. Due to the unique characteristics of coal mine dead-end roadways, fires in such environments are prone to transition into ventilation-controlled fires, presenting a significant threat to mine production and personnel safety. In this study, several small-scale experiments were used to investigate the thermal characteristics and critical conditions for ventilation-controlled combustion in dead-end roadway fires. The findings show that the flame range, flame length, smoke temperature, and fuel mass loss rate are significantly higher in ventilation-controlled fires than in fuel-controlled fires. Lower ventilation velocities lead to an earlier transition to ventilation-controlled combustion and higher mass loss rates. Besides, a prediction model for dead-end roadway fires based on fuel-to-air equivalent ratio is proposed to forecast the combustion type. The critical fuel-to-air equivalence ratio for the occurrence of ventilation-controlled fires is 0.08–0.11. In addition, the oxygen volume fraction in the downstream smoke of the fire source will stabilize at about 2 % and 15 % in ventilation-controlled fires and fuel-controlled fires, respectively. When the combustion changes from fuel-controlled to ventilation-controlled combustion, the CO yield will rise rapidly. Moreover, when the ventilation velocity is lower than the critical ventilation velocity, combustion often transitions to ventilation-controlled combustion. The outcomes of this research offer a novel perspective into the fire behavior of dead-end roadways, offering valuable guidance for firefighting and rescue operations in similar structures.