Numerical simulation research on arrangement of spray nozzles outside fully mechanized excavation face

Abstract

Aiming at the problem of poor spray continuity between the external spray nozzles of the wet dust removal system in the fully mechanized excavation face, the numerical simulation study of the nozzle arrangement was carried out. Firstly, by constructing a gas-liquid two-phase mathematical model, the velocity distribution and force state of the droplets are deduced; then, the geometric model of the fully mechanized tunnel is constructed, and based on the fluid dynamics analysis software Fluent, the state of the droplets in the wind-mist coupled flow field in the tunnel is calculated. Numerical simulations were carried out to study the effects of the number of nozzles and the position of nozzles on the physical properties of the droplets. The results show that the change of the number of nozzles has little effect on the distribution of small particle size droplets in the roadway, which are mainly distributed on the roadway wall and near the nozzle position. With the increase of the number of nozzles, the number of large-diameter droplets increases significantly, but the kinetic energy of each nozzle decreases and the diffusion distance shortens. When the spacing between the nozzles at the upper end of the spray rack is 80 mm, a more uniform and dense arc-shaped spray barrier is formed. The nozzles at the corner of the spray rack are arranged at a right angle for the best atomization uniformity. When the spacing is 110 mm, the distribution of droplets is the best.

Keywords

• fully mechanized excavation face
• wind and mist coupling
• number of nozzles
• droplet distribution
• nozzle arrangement