自燃采空区注氮过程标志性气体分布特征研究

Study on sign gases distribution characteristic of spontaneous combustion goaf due to nitrogen-infusing

在高瓦斯自燃煤层采空区采取高抽加尾巷排放瓦斯的立体抽放方式时,为避免采空区发生自燃,对采空区进行注N2防火.以华晋焦煤有限责任公司沙曲矿15201工作面为例,在确定采空区自燃三带划分标准的基础上,通过埋管测试方法,研究采空区注N2前后采空区N2和O2分布状态,以及采空区N2运移规律.结果表明,注N2后,注入N2与采空区原有气体混合,气体在采空区漏风压与注N2压力共同作用下运移.N2影响区内O2体积分数下降,氧化带范围缩小,降低了工作面自燃的危险程度.为工作面优化注N2参数和提高注N2防灭火效果提供了参考.

In order to avoid coal spontaneous combustion occurred in the goaf, it is necessary to infuse nitrogen into the goaf when the tridimensional drainage manner, which includes an exalted and rear laneway, is used to the high-methane and spontaneous combustion coal seam goaf. As an example of 15201 working-face in Shaqu coalmine of Huajin coking coal Co. Ltd. , based on the confirmation of compartmentalization criterion of goaf spontaneous combustion three-zone and by means of a pipe-burying test method, the goaf nitrogen and oxygen distribution characteristic before and after nitrogen-infusing and nitrogen movement law have been investigated. It is indicated that the nitrogen mixes with goaf original gases after nitrogen-infusing, and the mixed gas moves together with the actions of air leak pressure and nitrogen-infusing pressure in the goaf. As oxygen concentration descend in the area influenced by nitrogen, the oxidation zone scope and the fatalness of coal spontaneous combustion in goaf have been reduced. It can provide reference bases for the optimization of nitrogen-infusing parameters and enhancing the effect of nitrogen-infusing fireproofing in other working-faces.