The emission and migration of gas in the longwall gobs are closely linked to the temperature field formed by the oxidation and exothermic behavior of coal. This work conducted gas adsorption and desorption experiments on coal particles and obtained the relationship between gas desorption rate and temperature. Additionally, the coupling relationship between multi-physical fields, including the air flow, gas and oxygen concentration, air and solid temperature has been improved. On this basis, a coupled model for gas and coal spontaneous combustion was constructed. The distribution characteristics of the gas concentration field and solid temperature field before and after extraction in gob were simulated. The optimal extraction point position was determined at 38 m from the working face, 25 m on the return air side, and a height of 11 m with an extraction negative pressure of −6 kPa. The results show that: The gas desorption rate exhibits an exponential relationship with temperature, and the coefficient and exponential factor in the exponential equation are and . The gas concentration in the gob and upper corner before extraction is high, and there is also a high-temperature area on the air intake side. After extraction, the gas concentration in the upper corner decreased from 2.94% to 0.366%, which is lower than the critical value of 0.8%. At the meanwhile, the maximum temperature only increased by 3.36 °C. Based on the field's verification, the monitoring value of gas concentration in the upper corner is 0.253%, which reduces the danger of gas in the upper corner while controlling the heating of residual coal. This work can provide basic support for the prevention and control of gas disasters in gobs.

中文翻译：

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长壁采空区煤氧复合作用下瓦斯涌出与抽采数值研究

长壁采空区瓦斯的涌出和运移与煤的氧化放热行为形成的温度场密切相关。本工作对煤颗粒进行瓦斯吸附和解吸实验，得到瓦斯解吸速率与温度的关系。此外，空气流量、气体和氧气浓度、空气和固体温度等多物理场之间的耦合关系也得到了改善。在此基础上，建立了瓦斯与煤自燃耦合模型。模拟了采空区采采前后瓦斯浓度场和固体温度场的分布特征。最佳抽采点位置确定为距工作面38 m、回风侧25 m、高度11 m，抽采负压为-6 kPa。结果表明：气体解吸速率与温度呈指数关系，指数方程中的系数和指数因子分别为 和 。回采前采空区及上角瓦斯浓度较高，进风侧也存在高温区。抽采后，上角瓦斯浓度由2.94%下降至0.366%，低于临界值0.8%。与此同时，最高温度仅上升了3.36℃。经现场验证，上角瓦斯浓度监测值为0.253%，在控制余煤加热的同时，降低了上角瓦斯危险性。该工作可为采空区瓦斯灾害防治提供基础支撑。