煤层自然发火程度的精准判识与预警一直是煤自燃防控领域亟须解决的世界性难题，需构建煤自燃阶段精细划分和精准预警方法。通过建立煤自燃分级预警体系，实现煤层自然发火早期精准预报和主动防控，可有效防控煤层自燃或继发灾害的发生。现场采集工作面新鲜煤样，破碎混合成试验煤样，通过大型自然发火试验台模拟工作面煤层实际氧化升温环境，开展煤自然发火试验测试。进一步分析得到煤层自然氧化升温过程中各反应阶段指标气体产物体积分数和生成速率等数值随煤温的变化规律，确定了煤自燃反应各阶段的特征温度点位。通过试验数据比对分析，确定煤层氧化升温过程精细划分的判定指标（CO、O₂、C₂H₄、C₂H₆体积分数及φ(CO₂)/φ(CO)、Graham值、链烷比）随煤温变化的阈值区间。将煤自燃全过程精细划分成6个预警等级，并建立了较为完备的煤层自然发火分级预警体系，定量确定了各阶段的判定指标标准。结合工作面实例应用中分级预警体系的效益表现，验证了所构建预警方法对于矿井煤层自燃进程的预测预报，并采取相应防控措施抑制煤层火灾发展的可行性。研究成果可为矿井煤层自燃进程预测预报和主动防控工作提供借鉴。

The accurate identification and early warning of coal seam spontaneous combustion has always been a worldwide problem that urgently needs to be solved in the field of coal spontaneous combustion prevention and control. It is necessary to build a fine division of coal spontaneous combustion stage and accurate early warning methods. Through the establishment of a tiered early warning system for coal spontaneous combustion, the early and accurate prediction and active prevention and control of coal spontaneous combustion can be realized, and the occurrence of spontaneous combustion or secondary disasters can be effectively prevented. Fresh coal samples were collected from the working face on site, crushed and mixed into test coal samples, and a large-scale spontaneous combustion test bed was used to simulate the actual oxidation and heating environment of the coal seam in the working face, and the coal spontaneous combustion test was carried out. Through further analysis of the collected data, the change rule of the index gas product volume fraction and generation rate of each reaction stage in the process of natural oxidation and heating of coal seam with coal temperature was obtained, and the characteristic temperature points of each stage of coal spontaneous combustion reaction were determined. By comparing and analyzing the experimental data, the index gases of coal-oxygen reaction process (CO,O₂, C₂H₄, C₂H₆, φ(CO₂)/φ(CO), Graham, chain alkyl ratio)of the fine division of the coal bed oxidation heating process was determined, and the relationship between thresholds and coal characteristic temperature was obtained. The whole process of coal spontaneous combustion is finely divided into six early warning levels, and a relatively complete warning system for coal spontaneous combustion has been established, and the judgment standards at each stage have been quantitatively determined. Combined with the benefit performance of the hierarchical early warning system in the application of the field working face, it verifies the feasibility of the constructed early warning method for predicting and forecasting the spontaneous combustion process of coal seams in coal mines and adopting corresponding prevention and control measures to suppress the development of coal seam fires. The research results have important theoretical research value and practical guiding significance for the prediction and active prevention and control of coal spontaneous combustion in coal mines, which can further improve the safety of the mines, and guarantee the safety of the personnel working underground and realize the green mining of coal resources. 

0 引言

1 煤层自然发火试验

2 试验结果与分级预警

   2.1 煤层发火进程区间划分

   2.2 煤层发火特征温度点确定

   2.3 煤层自然发火分级预警体系建立

3 现场应用

4 结论