寸草塔二矿31110工作面采空区自燃“三带”及标志气体临界值研究

Research on spontaneous combustion"three zones"and the critical values of indicator gases in the 31110 working face of the Cuncaota NO.2 Coal Mine

基于采空区煤炭自燃理论,通过现场观测、数值模拟等手段开展了自燃“三带”分布范围研究,计算了工作面的安全推进速度,基于煤样程序升温气体产物的实验数据,优选了31号煤层的自然发火标志气体,并对国能神东煤炭集团有限责任公司寸草塔二矿31110综采工作面自然发火临界值进行了计算分析。研究结果表明,31110工作面采空区自燃“三带”分布近似呈现“L”型,柔模墙支护主运巷道一侧的氧化带宽度(214 m)明显大于辅运巷道侧采空区氧化带宽度(79 m);31110工作面的安全推进速度为4.76 m/d,正常平均推进速度为11.88 m/d,可以满足安全开采的需求;优选了CO、C_(2)H_(4)和C_(2)H_(2)作为衡量31110采空区自燃不同阶段的标志气体,采空区上隅角CO气体浓度临界值为41.54×10^(-4)%,回风流中CO气体浓度临界值为4.15×10^(-4)%,并据此建立了31110工作面自然发火分级预警响应及防灭火治理技术管理体系,为31110工作面煤自燃火灾早期预测预报和防治工作提供了依据。

Basing upon the theory of coal spontaneous combustion in goaf,the distribution range of the"three zones"of spontaneous combustion was studied through on-site observation,numerical simulation and other methods,and the safe advancement speed of the working face was calculated.Basing upon experimental data of gas products generated by coal sample program heating,the natural ignition marker gas of coal seam 31 was the best selection,and the critical value of spontaneous combustion in the 31110 fully mechanized mining face of Cuncaota NO.2 Coal Mine of China Energy Shendong Coal Group Co.,Ltd.was calculated and analyzed.The research results show that the"three zones"distribution of spontaneous combustion approximately presents an"L"shape in the goaf of the 31110 working face,the width of the oxidation zone(214 m)on the side of the main transport roadway supported by the flexible formwork wall is significantly larger than that on the side of the auxiliary transport roadway in the goaf(79 m),the safe advance speed of the 31110 working face is 4.76 m/d,and the normal daily average advance speed is 11.88 m/d,which meets the requirements of safe mining.CO,C_(2)H_(4),and C_(2)H_(2)were selected as significant gases to measure the different stages of spontaneous combustion in the 31110 goaf,the critical concentration of CO in the upper corner of the goaf is 41.54×10^(-4)%,and the critical concentration of CO in the return airway is 4.15×10^(-4)%.A management system for fire classification warning response and fire prevention and control technology for 31110 working face was established,which providing a basis for early prediction and prevention of coal spontaneous combustion fires in the 31110 working face.