采空区石门负压对氧气浓度场影响的动态演变过程研究

为了研究采空区石门负压对采空区氧气场影响的动态演变过程,采用数值模拟方法构建了某矿综采工作面CFD模型并进行二次开发,模拟了瓦斯抽放石门位于采空区不同位置时采空区的氧气场分布。模拟结果表明:当瓦斯抽放石门位于煤自燃"三带"不同位置时,石门负压对采空区氧气浓度场具有不同影响,其中,石门位于散热带和自燃带范围时,石门负压会不同程度减小自燃带宽度,有效缓解采空区防治煤自燃压力;石门位于窒息带范围时,能缩小回风巷一侧自燃带范围,但由于石门负压导致采空区内部负压过高,工作面向采空区内漏风增加,使运输巷一侧自燃带范围急剧扩张,不利于运输巷一侧采空区防灭火工作。最后,将现场实测数据和模拟结果进行对比,证明了模拟结果的正确性。

Study on Dynamic Evolution Process of Negative Pressure Influence of Crosscut on Oxygen Concentration Field in Goaf

In order to study the dynamic evolution process of negative pressure influence of the crosscut on the oxygen concentration field in the goaf, the CFD model was developed with the data collected from the fully mechanized mining face of coal mine. The model was used to simulate the distribution of oxygen concentration field when the gas drainage crosscut is located at three different positions of the coal spontaneous combustion three zones in the goaf. The results show that when the gas drainage crosscut is located at different positions of the "three zones" of coal spontaneous combustion, the negative pressure of the crosscut has different effects on the distribution of the oxygen concentration field. When crosscut is located in heat dissipation zone and spontaneous combustion zone,the negative pressure of crosscut can reduce the range of spontaneous combustion zone to different extents, which can effectively alleviate the spontaneous combustion of coal. When the crosscut is located in the suffocating zone, it can reduce the range of the spontaneous combustion zone on the side of return air tunnel, but the range on one side of transportation roadway is expanding rapidly, which is not conducive to fire prevention work in goaf.Finally, the data measured by the on-site beam tube monitoring system are compared with the simulation result, which proves the correctness of the simulation results.