陕西煤炭

以南家咀煤矿14501回顺掘进工作面为研究对象，利用数值模拟和现场试验相结合的方法，对比分析了自然泄放和钻墙抽采2种模式下的煤壁瓦斯涌出特征。数值模拟研究结果表明，自然泄放状态下，煤壁瓦斯涌出量随暴露时间增加呈指数衰减趋势，且煤层瓦斯压力越高，相同暴露时间内的瓦斯涌出衰减越明显；钻墙截流抽采作用下，煤壁瓦斯涌出量随抽采时间增加呈指数衰减趋势，且煤层瓦斯压力越高，相同抽采时间内的瓦斯涌出衰减越明显；对比2种模式下的煤壁瓦斯涌出规律发现，抽采50 d左右时的煤壁瓦斯涌出量相对于自然暴露情况降低了24%。通过现场观测2种模式下的煤壁瓦斯涌出量与巷道瓦斯浓度变化规律，自然泄放状态下的巷道口瓦斯浓度达到0.38%,而在钻墙截流抽采作用下的巷道口瓦斯浓度迅速衰减；抽采至5 d时，巷道口瓦斯浓度降低至0.29%,表明钻墙抽采对工作面瓦斯截流效果显著。

Taking the 14501 return airway excavation working face of Nanjiazui Coal Mine as the research object, the gas emission characteristics of coal wall under two modes of natural emission and drilling wall extraction were compared and analyzed by the method of numerical simulation and field test.The numerical simulation results shown that the gas emission of coal wall decreased exponentially with the increase of exposure time under natural emission conditions.The higher the gas pressure of coal seam, the more obvious the gas emission attenuation at the same exposure time.Under the action of drilling wall intercepting extraction, the gas emission decreased exponentially with the increase of extraction time, and the higher the gas pressure in coal seam, the more obvious the gas emission attenuation during the same extraction time.By comparing the gas emission of coal wall under the two modes, it was found that the gas emission amount at about 50 days of extraction was reduced by 24% compared with the natural emission.According to the field test result of coal wall gas emission and roadway gas concentration under the two modes, the gas concentration at the roadway entrance reached 0.38% in the state of natural emission, while the gas concentration at the roadway entrance decreased rapidly under the action of drilling wall intercepting extraction.The gas concentration decreased to 0.29% when the extraction reached 5 days, indicating that drilling wall extraction had a significant effect on the gas intercepting of the working face.