1:20 PM - 1:40 PM
[3108-13-02] Study on a New Air Distribution System for Excavation Faces
Chairperson：小林 和弥（京都大学）
Keywords:Mine Ventilation, Excavation face, Dust, Methane, Simulation
Based on relevant field data, with traditional ventilation measures, the dust concentration may still exceed 300 mg/m3 and the local methane concentration in the tunnel may exceed 0.8 %. Therefore, based on the traditional ventilation method, a new ventilation system was designed, including an air distribution device and a dust removal fan, while effectively controlling both dust and methane. To effectively control dust and methane in a fully mechanized tunnel face, this study uses a research method that integrates numerical simulation and orthogonal testing to determine the optimal air distribution volume, positioning, and air outlet angle of the air distribution device.
The results show that Plans 1-5 (maintaining 50 % air volume) and 6-10 (maintaining 60 % air volume) do not create an efficient spiral axial air curtain directed toward the face. Therefore, there is still some return air at the exhaust outlet that moves to the rear of the tunnel. This phenomenon results in a large dispersion distance of dust and methane, possibly extending to the rear of the tunnel. Plans 11-15 (maintaining 70 % air volume), especially Plan 11 (70 %-10 m-0°), form a comparatively extensive radial and axial spiral air curtain. The synergistic effect of these two air curtains controls high concentration dust and methane within 5m of the work surface. At the operator's workplace, the dust concentration is less than 10 mg/m3 and the methane concentration is less than 0.5 %. There are cases where a relatively complete spiral air curtain can be formed in plans 16-25. However, due to the excessive air distribution volume in Plans 16-25, there is insufficient airflow from the pressure outlet to the working face. Therefore, the airflow velocity remains inadequate, resulting in ineffective dispersion of the dust concentration near the face and making accumulation more likely. As a result, the dust accumulation concentration may exceed 300 mg/m3. Based on the above analysis, it can be concluded that the optimal combination of parameters is Scheme 11 (air distribution volume 70 %, distance from pressure outlet 10 m, air outlet angle 0°). This scheme effectively controls the diffusion distance and concentration distribution of dust and methane, thereby effectively reducing the pollution in the tunnel.
The results show that Plans 1-5 (maintaining 50 % air volume) and 6-10 (maintaining 60 % air volume) do not create an efficient spiral axial air curtain directed toward the face. Therefore, there is still some return air at the exhaust outlet that moves to the rear of the tunnel. This phenomenon results in a large dispersion distance of dust and methane, possibly extending to the rear of the tunnel. Plans 11-15 (maintaining 70 % air volume), especially Plan 11 (70 %-10 m-0°), form a comparatively extensive radial and axial spiral air curtain. The synergistic effect of these two air curtains controls high concentration dust and methane within 5m of the work surface. At the operator's workplace, the dust concentration is less than 10 mg/m3 and the methane concentration is less than 0.5 %. There are cases where a relatively complete spiral air curtain can be formed in plans 16-25. However, due to the excessive air distribution volume in Plans 16-25, there is insufficient airflow from the pressure outlet to the working face. Therefore, the airflow velocity remains inadequate, resulting in ineffective dispersion of the dust concentration near the face and making accumulation more likely. As a result, the dust accumulation concentration may exceed 300 mg/m3. Based on the above analysis, it can be concluded that the optimal combination of parameters is Scheme 11 (air distribution volume 70 %, distance from pressure outlet 10 m, air outlet angle 0°). This scheme effectively controls the diffusion distance and concentration distribution of dust and methane, thereby effectively reducing the pollution in the tunnel.