掘进巷道瓦斯分布数值实验研究

Numerical Experiment of Methane Distribution in Developing Roadway

根据局部通风流场特点确定适合矿井局部通风掘进巷道工作面瓦斯与风流质量交换的数学模型,在近壁面使用标准壁面函数法解决近壁面的流动,在湍流充分发展区,使用RNG k-ε双方程湍流模型;讨论考虑巷道支护的情况下壁面粗糙度的影响,确定矿井掘进工作面局部通风模型网格划分的方法、掘进头瓦斯涌出的边界条件;利用计算流体力学(CFD)软件Fluent对掘进工作面的风流与瓦斯的混合过程进行了模拟;得出不同瓦斯涌出量情况下掘进巷道工作面风流分布和瓦斯浓度的分布规律。研究表明:瓦斯涌出量和风速对流场分布有影响,随着瓦斯涌出量的增大和风速的降低,瓦斯对流场的影响越来越明显。

The mathematical model for mass transfer between airflow and methane in working face of developing roadway with local ventilation was established based on the study of the airflow pattern and char- acteristics of the local ventilation. Mesh partition method for local ventilation model was analyzed and the influence of roughness factor of airway surface on simulation results was studied. The boundary conditions to describe the methane emission on roadway surface were analyzed. The Fluent software, a commercial CFD（Computational Fluid Dynamics ） one, was used to simulate the mass transfer process between the airflow and the emitted methane in working face with forced local ventilation by taking RNG k - ε two-equation model. The airflow patterns and methane distributions in working face with local ventilation were obtained when methane was emitted from the head of working face at different rates. The study shows that gas emission rate and airflow speed have influence on the airflow field. With the increasing of gas emission rate or the decreasing of airflow speed, the influence of gas emission on airflow field becomes more and more significant.