Numerical study on smoke temperature distribution of cable fires in bifurcated coal mine roadways

Cable fires in coal mines can interrupt mining operations and threaten the safety of underground personnel. In order to study the temperature distribution of cable fires in bifurcated roadways, 14 cases with different heat release rates, longitudinal ventilation velocities and bifurcation angles were simulated using FDS. The results show that the maximum excess ceiling temperature in the main roadway increases with the heat release rate and decreases with ventilation velocity, while remaining unaffected by the bifurcation angle; a prediction model for the maximum excess ceiling temperature of the cable fires in main roadway was proposed. The maximum excess ceiling temperature in the branch roadway increases with heat release rate and bifurcation angle, initially increasing and then decreasing with ventilation velocity; a maximum excess ceiling temperature prediction model for branch roadway cable fires incorporating bifurcation angle was developed adopting dimensional analysis theory. The longitudinal temperature decay rate in downstream sections of both the main and branch roadways decreases with increasing ventilation velocity at lower wind speeds, and the corresponding temperature attenuation models were established. At higher wind speeds, regularly discontinuous breakpoints were observed in the main roadway, and the points of the maximum temperature rise in the branch roadway were shifted.