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建立了瓦斯抑制条件下顶煤自燃数学模型,并给出了模型中各方程的边界条件、初始条件及各参数的确定方法,利用Fluent软件对给定条件下的极限平衡区顶煤自燃过程进行了模拟研究.模拟结果显示,靠近进风巷的顶煤升温较快;随着时间延长,高氧浓度区域逐渐向顶煤内部扩展;顶煤内瓦斯浓度梯度减小,最高瓦斯浓度降低.通过对模拟数据分析得出,顶煤升温过程为加速过程,内含瓦斯明显延长了顶煤的自然发火期;供风量对顶煤自然发火期影响不大,但对顶煤高温区中心点位置的影响较大;自然发火期与其耗氧速度存在负指数函数关系.
The mathematical model of spontaneous combustion of top coal under gas containment was established. The boundary conditions, initial conditions and parameters of each model in the model were given. By using Fluent software, the spontaneous combustion process of top coal under the given conditions was carried out The simulation results show that the top coal near the air inlet is heated rapidly and the area with high oxygen concentration gradually expands into the top coal within time. The gas concentration gradient in the top coal decreases and the maximum gas concentration decreases. The analysis of simulation data shows that the top coal heating process is an acceleration process. The internal gas obviously prolongs the natural ignition period of the top coal. The supply air volume has little effect on the natural coal firing period, but for the top coal in the high temperature zone The influence is greater; there is a negative exponential function between the spontaneous combustion period and the oxygen consumption rate.