动态推进工作面采空区自燃规律的数值模拟

Numerical Simulation of the Spontaneous Combustion Laws in goaf of boost working face

基于非均质多孔介质中的连续性方程、多相气体渗流-扩散方程和综合传热方程,建立了工作面动态推进下的采空区遗煤自燃数值模型。结合实例条件,描绘了工作面开采推进过程中采空区内漏风流态、氧、CO、瓦斯和温度等分布状态及其动态过程。提出了工作面动态推进用各物理量分布后移的处理方法,使移动步距与时间动态过程相适应,实现了模拟计算在方法上的连续一体化。通过理论分析,发现采空区遗煤自燃与工作面推进速度呈指数关系,因而提高工作面推进速度能显著延长采空区内遗煤的自然发火期。

Based on the continuity equation, multiphase gas seepage - diffusion equation and synthesis heat transfer equation in heterogeneous porous media, a numerical model of spontaneous combustion of residual coal in goaf is established under the condition of working faces are being advanced dynamically. Based on an example, the distribution and dynamic procedure of air leakage seepage, oxygen, CO gas, methane and temperature in goaf during working face advancing are demonstrated. For the dynamic advance of working surface, the means of each physical quantity backward step and step is put forward, which can make the moving step suitable for time, so the continuity of simulating calculation is realized. Through theory analysis, it shows that the combustion of residual coal in goal has exponential relation with the speed of working face advancing, so increasing the advancing speed can retard obviously the spontaneous combustion of residual coal in goaf.