Numerical Study on Airflow Distribution Law in 8 m Large Mining Height Fully-mechanized Face

This paper is based on the field practice of fully mechanized mining face with 8 m mining height in Bulianta Coal Mine of Shendong Company. Combined the mining space with the mining equipment space, the analysis shows that the main influencing factors of airflow field are entity obstruct, and the CFD numerical model is established, the flow characteristics and distribution law of airflow field in the fully mechanized mining face with large mining height are revealed. Numerical simulation shows that the air flow field has obvious changes in the working area of coal mining machine from 15 m in front to 30 m in the rear. Both the coal cutting side and the pedestrian side have the tendency of wind speed rising first and then decreasing, then rising again and then decreasing gradually until the average wind speed of the working face. The wind speed above the coal mining machine is generally increased. The higher the distance from the coal mining machine, the higher the wind speed in the coal cutting side. Meanwhile, the air flow mainly flows along the roof and coal wall. The maximum wind speed reached 2.2 m/s at the end of the downwind side of the coal machine, the average wind speed increased by 67% at cutting coal side, and the pedestrian side by 33%, it shows that the airflow is mainly longitudinal diffusion and horizontal diffusion is complementary if the wind flow is blocked by obstacles at fully mechanized mining face with 8 m mining height.