Effect of a Double-Machine Parallel Air Curtain on Wind Flow in an Underground Roadway of a Coal Mine

Abstract

In order to study the effect of a double-machine parallel circulation air curtain in intercepting wind flow in a mine roadway, the air curtain jet angle and full fan pressure were analyzed. Taking a metal mine roadway as the engineering background, Fluent numerical simulation technology was used to establish an equi-proportional physical model of the original roadway, and a K45-6 axial flow fan was selected to numerically simulate the flow field inside the original roadway, which was analyzed from three aspects: isolation pressure difference, air leakage volume and wind choke rate. The results show that when the full pressure of the fan is fixed, with an increase in the jet angle of the air curtain, the separation pressure difference and the wind choke rate show a trend of first increasing and then decreasing, and the air leakage volume shows a trend of first decreasing and then increasing. With an increase in the air curtain jet angle, the air curtain convergence gradually forms a complete air curtain, but when the air curtain jet angle continues to increase, the air curtain cannot effectively block the wind flow due to the transverse pressure from the roadway. When the jet angle is too small or the full pressure of the fan is too large, the phenomenon of induced air flow will occur, and the two-machine parallel air curtain will direct the air downstream of the roadway to upstream and no longer intercept the roadway air flow. After comprehensive analysis, the effect of wind control is obvious to set up a double-parallel air curtain in the roadway, and the optimal combination of the roadway air curtain is 30° for the full pressure blade of the fan and 30° for the jet angle.