摘要
瓦斯在采空区内运移造成工作面上隅角瓦斯超限是煤矿安全的重大隐患。为揭示采空区瓦斯运移规律,提出基于格子Boltzmann的非均质采空区瓦斯运移仿真方法。综放采场采空区是由非均质多孔介质组成的空间,大气和瓦斯混合气体在采空区的流动是非常复杂的具有层流、过度流和紊流的渗流运动。基于修正的Brinkman-Forch-heimer-Darcy定律,建立非均质采空区瓦斯运移的控制方程组。由于该方程组求解复杂,分别建立瓦斯渗流速度场和瓦斯浓度场的格子Boltzmann模型。通过格子Boltzmann模型的演化,实现采空区瓦斯运移的仿真。模拟实例表明,用该方法进行仿真可以得到任何时刻采空区内任意位置瓦斯和大气混合气休的流动速度和压力以及瓦斯浓度等数据,同时也可以得到采空区流线分布规律、速度变化规律、采空区压力的变化规律和采空区瓦斯运移规律。该方法能将时间、空间和系统行为结合起来,可在直观的条件下完成对地下煤矿采空区瓦斯运移态势的精确分析与模拟,可为揭示综放采场采空区上隅角瓦斯超限的原因提供一种新的方法。
The paper takes as its goal introducing an approach to the coal-mining gas migration simulation in heterogeneous goaf based on the lattice Boltzmann method. As is known, underground mining gas migration often results in the upper comer gas excessive and even coal-mining pit explosion. To explore the regularity of such gas migration, the present paper would like to provide a Lattice Boltzmann （LB） simulated model for such migration in heterogeneous goaf of full-mechanized coal mining working face. The goaf of full-mechanized coal mining face is an area that is filled with heterogeneous porous media and gas migration in it is complicated seepage movement in which the gas flow is done in laminar, transitional and turbulent manner. Studying the Brinkman-Forchheimer-Darcy amended law, this paper wishes to propose a control system which can reflect the characters of gas migration regularity in heterogeneous goaf of such coal mines. To make the complicated control system simple, we have established a LB model to simulate the gas seepage velocity field with another LB model constructed to simulate the gas concentration change. The simulation results we have gained by means of the two LB models can help to deduce many useful data, such as the gas migration speed, pressure and concentration in different cases and spots, which will enable the workers in-situ to control the gas migration law directly. The simulation results also present many laws, such as law of streamtrace distribution in goaf, law of speed, pressure and concentration, which will be useful for mine safety management. If this method can be used integratedly in combination with the data on time, space and system function together, the situation of gas migration can be better controlled so as to reduce and even eliminate unhappy coal-mine pit explosions and/or similar disasters.
出处
《安全与环境学报》
CAS
CSCD
北大核心
2009年第3期139-144,共6页
Journal of Safety and Environment
基金
教育部博士学科点专项科研基金项目(20070703009)
陕西省自然科学基金项目(007E217)
陕西省教育厅专项基金项目(077K076)
