近距离煤层群开采自燃危险区域划分及自燃预测

通过数值方法求解复合煤层采空区渗流、扩散和化学反应耦合的三维稳态数学模型，得到常温下采空区氧浓度及渗流速度场的分布.结合大型煤自然发火实验得到的煤自燃的下限氧浓度、上限漏风强度、极限浮煤厚度等参数及煤的实验自然发火期，划分出开采下部煤层时上部煤层煤柱及采空区自燃危险区域，再结合工作面推进速度，预测自然发火期.采用这种方法对东荣二矿采煤工作面顶部煤层煤柱进行自燃预测，得到进风侧的煤柱氧化升温区在距离工作面50~140 m处，回风侧在距离工作面50~85 m处，工作面推进速度大于1.6 m/d时，煤柱无自燃危险，工作面停止推进但正常通风38 d后，煤柱进风侧将首先发生自燃.

Determining spontaneous combustion danger zones and predicting spontaneous combustion during mining near-neighbored coal seams

A numeric algorithm was taken to solve coupled steady model of air flow, diffusion and chemical reaction in multi-layer neighbored coal seams and rocks, and oxygen concentration and flow velocity magnitude in different position was obtained. Oxygen concentration and flow velocity together with loose coal thickness were compared with their critic value obtained from large-scale coal spontaneous combustion experiment to determine spontaneous combustion danger zone. Connecting the result with velocity of the mining workface and the experimental spontaneous combustion duration, date of spontaneous combustion can be predicted. The method was employed to predict spontaneous combustion in coal pillar during mining the adjacent substrate coal in Dongrong No. 2 coalmine successfully. The result showed that self-heating zone lies in 50 - 140 m in the airflow inlet side and in 50 - 85 m in outlet side away from the workface in the coal pillar. If moving velocity of the workface is larger than 1.6 m/d, there is no danger of spontaneous combustion; while if the workface stopped to move but ventilation kept normal for 38 d, spontaneous combustion will take place in airflow inlet side of the pillar.