Optimization of structural parameters and installation position of the wall-mounted air cylinder in the fully mechanized excavation face based on CFD and orthogonal design

In order to obtain the reasonable structural parameters and installation position of the wall-mounted air cylinder attached to the fully mechanized excavation face in coal mines, a scaled physical model was established based on the C103 fully mechanized excavation working face of Nahe Coal Mine of Baise Bailing Group in Guangxi Autonomous Region. The orthogonal design and the numerical simulation were combined to investigate the wind flow field and the distribution of dust concentration under different structural parameters and installation positions of the wall-mounted air cylinders. The results of orthogonal numerical tests showed that as the width (W) and the length (L) of the strip-shaped air outlet increased, the dust concentration cm in the breathing area of drivers first decreased and then increased. In addition, cm increased with the increase of the installation distance (D). The optimal dust-control effect of the wall-mounted swirling ventilation was achieved under the following condition: the width (W) and the length (L) of the strip-shaped air outlet were 0.05 m and 1.4 m, respectively, and the distance (D) between the wall-mounted air cylinder and the tunneling end was 5.6 m. Under this condition, the dust concentration at the driver's location was the lowest, and the dust-blocking efficiencies for both total dust and respirable dust were 92.14% and 94.08%, respectively. (C) 2019 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.