In order to effectively prevent and control spontaneous combustion of residual coal in the goaf and reduce the waste of nitrogen caused by setting the position of nitrogen injection, 1303 fully mechanized coal caving faces of the Jinniu Mine are studied. By deploying a bundle tube monitoring system in the inlet air side and return air side of the goaf, changes in gas concentration in the goaf are continuously monitored. In addition, the distribution area for spontaneous combustion three-zone in the goaf is divided into heat dissipation zone, oxidized spontaneous combustion zone, and suffocation zone. Simulations from the COMSOL Multiphysics 5.3 software provide insight based on the three zones division standard of spontaneous combustion in the goaf. The gradual deepening of the nitrogen injection position into the goaf affects the lower limit of the oxidized spontaneous combustion zone significantly, but the impact on the upper limit of the oxidized spontaneous combustion zone is not obvious and is negligible. With regard to the width of the oxidized spontaneous combustion zone, it initially decreases followed by a gradual increase. Numerical calculations suggest the optimal nitrogen injection position is 40 m from the roof cutting line, with an oxidized spontaneous combustion zone width of 28 m. Based on the simulation analysis results, nitrogen injection controlling measures have been adopted for spontaneous combustion of residual coal in the goaf of the 1303 fully mechanized coal caving faces, and coal self-ignition in the goaf has been successfully extinguished.

中文翻译：

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综放工作面采空区自燃三区分布及注氮位置优化[J].

为有效防治采空区残煤自燃，减少因设置注氮位置造成的氮浪费，对金牛矿1303综放煤面进行了研究。通过在采空区进风侧和回风侧部署束管监测系统，持续监测采空区瓦斯浓度的变化。此外，采空区自燃三区分布区域分为散热区、氧化自燃区和窒息区。COMSOL Multiphysics 5.3 软件的模拟提供了基于采空区自燃三区划分标准的洞察力。采空区注氮位置逐渐加深对氧化自燃带下限影响显着，但对氧化自燃带上限影响不明显，可忽略不计。氧化自燃区的宽度先减小后逐渐增大。数值计算表明，最佳注氮位置为距顶板切割线 40 m，氧化自燃区宽度为 28 m。根据模拟分析结果，1303综放工作面采空区余煤自燃采取喷氮控制措施，成功扑灭采空区煤自燃。