摘要
为了得出U型通风方式下采空区风流流场及瓦斯分布规律,建立了U型通风方式的三维物理模型。在将采空区渗透率设定为连续性分布的条件下,运用Fluent软件对采空区压力分布、风流流场及瓦斯分布情况进行了数值模拟。模拟得出了与实际情况相接近的工作面及采空区压力分布,在此基础上分析了采空区风流流场及瓦斯分布规律。结果表明:漏入采空区深部的风流与深部涌出的瓦斯汇聚流向采空区顶部,之后风流沿着顶板流向靠近工作面区域的采空区,并回转形成涡流,风流从顶板向下流动,流向工作面;沿采空区走向方向、工作面倾向方向及采空区顶板方向,瓦斯体积分数总体上都是不断增大。
The paper is to pursue a numerical simulation for the airflow and the gas distribution regulation in the goaf of mechanized working face. For this purpose, we have established a 3-d physical model of U-shape ventilation trend. So far as we know, the permeability rate has a significant influence on the airflow field and gas distribution, which is likely to enable us to set the goaf permeability as a continuity distribution mode closer to the actual ventilation situation than the uniform distribution and segmented uniform distribution. It is on the above idea that we have worked out a numerical simulation model for the pressure distribution, airflow field and the gas distribution in the goaf via a software Fluent. Furthermore,since the differential pressure of the working face plays an important part in leakage of goaf, the leakage rate may also have an important influence on the gas distribution in the goaf, which leads to the necessity to find the reasonable pressure distribution regularity for the research of the airflow field and gas distribution in the goaf. Starting from this need, we have first of all worked out the regularities of the airflow field and the gas distribution model in the goaf. The research results can be stated in the following way： （1） Part of the airflow from working face in the goaf may come back to the working face via the returning air side; （2） Another part of the airflow is turned to the deep side of the goaf which converges with the gas from the depth of the goaf; （3） The converging airflow would flow to the top of the goaf, and, then, turns to the part of the goaf close to the working face along the roof and forms the eddy current; （4） At this moment, the eddy airflow current is likely to flow concurrently downward the working face along with the x axis, namely oriented towards the direction of the goaf; （5） While the gas concentration of goaf has been constantly increasing on the whole, the increased gradient of the gas concentration in the deep side of the goaf turns to be larger than that of the goaf near the working face; （6） In the direction of y axis, that is, the direction from the north to the south of the working face, or, from the wind inlet to the back air side, the gas concentration of the goaf is supposed to be constantly increasing, too; and, （7） Then, in z axis direction, the gas concentration of the goaf would bring about a layer phenomenon from the floor to the roof of the goaf, which also tends to be constantly increasing, too.
出处
《安全与环境学报》
CAS
CSCD
北大核心
2013年第2期164-168,共5页
Journal of Safety and Environment
基金
国家自然科学基金项目(51174079)
高等学校博士学科点专项科研基金项目(20104116110001)
关键词
矿山安全
数值模拟
渗透率
瓦斯浓度
流场分布
mine safety
numerical simulation
permeability
gasconcentration
airflow field distribution
