基于煤层注氮技术的防止煤自燃与火灾的应用技术研究

Research on applied technology of preventing spontaneous combustion and fire of coal based on nitrogen injection technology of coal seam

长壁采空区常规注氮由于冷却功能效果不佳,往往不能达到预期的防火效果,为此,提出了冷却注氮防止采空区煤自燃的技术方案和相应的深部冷却设备系统,并对采空区煤炭自燃多物理场耦合模型进行了模拟,使其适用于注氮工况。结果表明:冷却氮气进入采空区可显著降低高温区温度约5℃,有效降低采空区煤炭自燃的发生风险;氮气注入模拟结果与现场数据吻合较好,验证了氮气注入模型的准确性;采空区存在注氮点的最优位置,该点位能最大程度地抑制煤炭自燃。

Conventional nitrogen injection in longwall gob often fails to achieve the expected fire prevention effect due to its poor cooling effect.Therefore,a technical scheme for preventing spontaneous combustion of coal in gob by cooling nitrogen injection and a corresponding deep cooling equipment system were proposed,and a multi-physical coupling model for spontaneous combustion of coal in gob was simulated to make it suitable for nitrogen injection.The results show that cooling nitrogen into the goaf can significantly reduce the temperature of the high temperature area by about 5℃,and effectively reduce the risk of spontaneous combustion of coal in the goaf.The simulation results of nitrogen injection agree well with the field data,which verifies the accuracy of the nitrogen injection model.There is an optimal position of nitrogen injection point in the gob,which can inhibit coal spontaneous combustion to the greatest extent.