煤层群开采自燃“三带”分布规律及防灭火技术研究

为防止近距离煤层群工作面回采后相邻采空区气流互通引起采空区遗煤自燃,以李家壕煤矿31114综采工作面为工程背景,采用现场实测结合数值模拟的方法,对本煤层进风侧、回风侧及上覆采空区氧浓度分布规律进行测定,依据氧浓度分布规律划定了本煤层采空区自燃“三带”分布范围,并给出了工作面安全回采的最小推进度。同时,利用Fluent软件模拟得到煤层群开采上覆采空区氧浓度分布规律,划定了上覆采空区火灾重点防治区域,该区域位于工作面后方50m范围内的上邻近层工作面遗留煤柱,依据遗留煤柱破碎漏风易发火的特征,提出采用地面封堵、隅角封堵、遗留煤柱注浆相结合的综合防灭火技术。

Study on distribution law of "three zones" of spontaneous combustion in Coal Seam Group Mining and fire prevention and extinguishing measures

In order to prevent the spontaneous combustion of residual coal in goaf caused by the interworking of air flow in adjacent goaf after mining of close coal seam group working face. Taking the 31114 fully mechanized mining face of lijiahao coal mine as the engineering background, the oxygen concentration distribution law on the inlet side and return side is measured by using the method of field analysis and numerical simulation. According to the oxygen concentration distribution law, the distribution range of "three zones" of spontaneous combustion in the goaf of the mining layer is delimited, and the minimum advance degree of safe mining in the working face is given. At the same time, the distribution law of oxygen concentration in the overlying goaf of coal seam group mining is simulated by FLUENT software, the key prevention and control area of fire in the goaf of the upper adjacent layer is delimited, and the comprehensive fire prevention and extinguishing measures combining ground plugging, corner plugging and grouting at the position of residual coal pillar are proposed.