Meikuang Anquan (Aug 2024)
Study on the influence of air outlet form change of dust control air duct on dust transport in tunneling working face
Abstract
To study the impact of changes in the shape and quantity of dust control air duct vents on wind speed changes and dust transport in the main areas of the excavation tunnel, simulation calculations were conducted using FLUNET software for different shapes and spacing of control air vents, and corresponding cloud diagrams of wind speed and dust concentration changes were obtained for the 1.5 m high section in the tunnel and the section at different distances from the front end under corresponding conditions, as well as the wind speed and dust concentration change curves at the sampling points on the pedestrian side, verification was conducted in conjunction with the underground excavation roadway of Cuncaota Coal Mine. The research results show that under the conditions of a pressure extraction ratio of 1.2 and an axial and radial air outlet ratio of 1∶3, the dust control effect of the cylindrical control air outlet is better than that of the rectangular control air outlet and a single rectangular control air outlet. The dust concentration at the main position of the control air duct with the spacing of 750 mm is less than that at the corresponding position with the spacing of 500 mm; during the on-site verification process, under different air inlet conditions, the maximum dust reduction efficiency of the driver was 92.54%, with the dust concentration of 41.3 mg/m3. The maximum dust reduction efficiency at a distance of 5 m behind the first and second transfer points was 91.56%, with the dust concentration of 31.7 mg/m3. The dust control effect of 750 mm between the spacing of control air vents is better than that of 500 mm between the spacing of control air vents, which is consistent with the numerical simulation results.
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