Fire prevention and extinguishing technology for fully mechanized top-coal caving mining in Yuanbaowan Coal Mine

Aiming at the spontaneous combustion prevention and control requirements of the No. 9 coal seam in Yuanbaowan Coal Mine, a dynamic model of oxygen concentration gradient diffusion and temperature variation in the goaf was established based on multi-physics coupling theory. Through Fluent simulations, a multi-factor sensitivity analysis was conducted on the evolution characteristics of oxygen concentration under three conditions: upper and lower corner sealing, lower corner nitrogen injection, and the combined action of nitrogen injection and sealing. A multi-source fusion monitoring system, dynamic pressure-balancing ventilation regulation in open areas, continuous nitrogen injection into the goaf, and inhibiting foam coverage were integrated to construct a three-dimensional fire prevention and extinguishing system for the fully mechanized top-coal caving face, forming a combination of fire prevention and extinguishing technologies with regional adaptability.