浅埋藏近距离煤层群开采煤炭自燃防治理论与技术基础研究

In order to study the deformation characteristics and crack evolution law of coal rock and coal pillar, leakage mechanism of coalseams, criterion of coal spontaneous combustion and comprehensive fire prevention technique, the technological means of laboratory experiments, theoretical analysis, numerical simulation and field combined tests would be adopted in the item. Through the above research, the deformation, migration and destruction features of the overlying coal and rock and coal pillar are clarified. The leakage power characteristics and leakage passage formation mechanism of panel-mining and mining-surface are made clear. And then the coupling rule about crack evolution of coal rock and coal pillar and the leakage airflow field is revealed. The characteristics of oxygen supply channel and oxygen delivery capacity under the gas extraction and pumping is analyzed by the numerical simulation. Then the disaster-causing mechanism that coal spontaneous combustion was induced under the influence of the gas extraction/pumping is revealed. The microscopic law and macroscopic effect of coal spontaneous combustion of close distance coal seam group with shallow burying is obtained through comprehensive analyzing the perturbing effect between coal spontaneous combustion and crack evolution of coal rock, air leakage characteristics, gas extraction and pumping. Next, the interpretation model of high-temperature area in goaf on the basis of the reflection characteristics of the electromagnetic field is established. The criterion and early warning technique of the dangerous high-temperature area caused by coal spontaneous combustion is structured by the lithologic detection of the electromagnetic field and the index gases. At last the fire prevention system of coordinated control which is priority to inorganic fire material combining the methods of the pressure balancing ventilation and the spray resistance change is studied. Through the above research work, the item has important theoretical and practical significance for the safety and efficient mining of close distance coal seam group with shallow burying.

通过实验室实验、理论分析、数值模拟与现场综合试验等手段，系统开展煤岩及煤柱变形特征与裂隙演化、煤层间漏风机制、煤自燃危险区域判定准则与综合防治技术等方面的研究。阐明上覆煤岩体及煤柱变形、运移和破坏特征，厘清采区-采区、采区-地表漏风动力特征及漏风通道形成机制，揭示煤岩裂隙演化与漏风流场的耦合规律。模拟分析瓦斯抽采及抽水影响下供氧通道及供氧能力的变化特征，揭示瓦斯抽采/抽水诱导煤自燃的致灾机理。综合分析煤岩裂隙演化、漏风特征、瓦斯抽采及抽水对煤自燃的扰动效应，获得浅埋藏近距离煤层群煤自燃微观规律与宏观效应。建立大地电磁场岩性反射特性的采空区高温解译模型，构建基于大地电磁场岩性探测和煤自燃指标气体协同反演煤自燃危险区域的判定准则和采空区煤自燃预警技术。研究并建立以无机灭火材料灭火为主，以均压通风、喷雾阻化为辅的综合防灭火体系，为实现浅埋藏近距离煤层群安全高效开采提供科学支撑和技术保障。

煤炭依然是我国国民经济发展的主要能源]。2016年，煤炭在我国一次能源生产和消费结构中的比例分别达到76.2%和69.1%。然而，我国煤矿井下生产潜在危险因素较多，灾害形势依然严峻。煤矿百万吨死亡率与国外主要产煤国家相比，差距仍很大。“十二五”期间，全国816 处重点煤矿中，有煤层自燃倾向的矿井占54.9%，统计自然发火期在3个月以内的矿井占50%以上[5]，每年因自燃形成的火灾近400次，煤自然氧化形成的火灾隐患近4000次，仅我国北方煤田火区累计烧毁的煤炭已达42亿吨以上。. 为了满足我国国民经济高速发展对煤炭的需求，近年来相继建成了一批大型、特大型矿井，而且这些矿井大部分分布在我国的北方煤田，如神华集团的神东矿区、乌达矿区、宁煤矿区、中煤能源平朔井工矿区、大同矿区等北方煤田,这些矿区目前的赋存条件大部分属于浅埋藏近距离煤层群开采。在煤自燃防治方面，浅埋藏近距离煤层群开采与中、深部赋存煤层开采条件相比，其工作面具有与地面漏风严重、煤层自燃危险性高等特点。.因此，为保障浅埋藏近距离煤层群开采的高产高效矿井的安全生产，系统全面地研究覆煤岩变形特征及裂隙发育规律，并在此基础上研究采空区漏风机制及煤自燃规律，构建煤自燃危险区域判定准则及防治技术，将有助于浅埋藏近距离煤层群开采高产高效工作面采空区煤自燃的综合控制与治理，对高产高效矿井安全生产具有重要的理论意义和实用价值。. 项目研究揭示了浅埋藏近距离煤层群开采过程中上下覆煤岩层裂隙发育、贯通及破断特征，阐述二次采动影响下采区-采区、采区-地表漏风通道形成的机制、上覆煤岩层裂隙场演化与漏风场的耦合作用关系；研究采空区漏风机制及煤自燃规律，瓦斯抽采/抽水过程诱导采空区遗煤氧化自燃的致灾机理，分析二次采动、煤岩裂隙发展发育及漏风特征对浮煤自燃氧化的扰动影响效应；构建浅埋藏近距离煤层群煤自燃危险区域判定准则和理论表征体系，提出了煤自燃隐蔽火源预测预警及综合防治技术，为浅埋藏近距离煤层群开采提供安全保障。