巷道中煤层阴燃状态的氧气体积分数梯度判别法

Volume Fraction Gradient Criterion of Oxygen in A Smoldering State of Coal Seam Roadway

为了研究巷道中煤层阴燃状态的判别方法,基于阴燃是氧控制反应的原理,根据通风阻力定律、风量平衡定律和Fick第一扩散定律,分别建立了煤层阴燃稳定传播与趋向熄灭时巷道中的O2体积分数方程,提出了用巷道中的O2体积分数梯度进行煤层阴燃状态的判别方法,即从巷道的自然风流区至热空气涡流区之间随着距自然风流区距离的增大,阴燃趋向熄灭时的O2体积分数梯度绝对值均是定值η,而阴燃稳定传播时的O2体积分数梯度绝对值呈现出大于η,等于η和小于η的下降趋势.借助巷道中煤层阴燃模拟实验装置,对上述判别方法进行了实验验证,实验测定出褐煤的η=90%/m.结果表明,巷道中煤层阴燃状态的O2体积分数梯度判别法是合理的.

In order to study the smoldering state criterion about the coal seam in roadway,we establish the equations of O2 volume fraction in the coal seam having a stable smoldering propagation and tending to extinction,respectively,based on the principle that smoldering is an oxygen control reaction and on the ventilation resistance law,air volume equilibrium law,and Fick＇s first law of diffusion.The O2 volume fraction gradient criterion to distinguish the coal seam smoldering state in roadway is proposed.With the increase of distance between the natural air flow zone and the hot air vortex zone of the roadway,the absolute value of O2 volume fraction gradient is a constant η when smoldering tends to extinction,while at the smoldering steady propagation,the absolute value of O2 volume fraction gradient shows a downward trend that is greater than η,equal to η,and less than η.With the simulation equipment that simulates coal seam smoldering in the roadway,the criterion is verified,that is,the η of lignite is 90%/m.The results show that the O2 volume fraction gradient criterion is reasonable about the roadway coal seam in smoldering state distinction.