采空区场域自燃CO向工作面涌出的数值模拟

Numerical Simulation of CO Gushing to Working Face During Spontaneous Combustion in Goaf Field

针对采空区遗煤氧化产生的CO气体问题,建立了采空区自燃和CO释放与运移的数学模型.结合综放工作面实例,用有限元法求解得到了各量区域分布解,详细分析了采空区遗煤的自燃耗氧释放CO和CO绝对涌出量的一般规律.重点讨论了采空区瓦斯抽放、注氮等因素对CO的产生和涌出的量化影响;得到CO沿工作面回风边界涌出强度偏重于回风隅角,沿边界分布呈急剧衰减变化;指出控制遗煤自燃和控制CO生成两者一般是非同步的;单一的治理措施不能完全控制CO的生成,必须采取多手段综合防治.

The poisonous CO in the working face is mostly derived from the spontaneous combustion of remnant coal in goaf. A mathematical model was established, for spontaneous combustion and the release and movement of CO which generated frem coal oxygenation in goaf. Combined with instances of comprehensive mechanization and caving working faces, the regional distribution solutions of every variable were obtained by using finite element method. And the general role of CO release, and the absolute gushing quantity of CO were analyzed. The quantitative influences of some factors, such as goaf gas drainage and nitrogen injection, on the generation and gusing of CO were discussed emphatically. A conclusion is drawn that the gushing intensity of CO is greater at the return comer along the return boundary of working face, and the varying trend of the distribution along the boundary is sharp. It is pointed out that the control of the spontaneous combustion of remnant coal and the control of CO generation are usually not synchronous. Multi measures must be adopted to prevent and cure it synthetically.