CFD simulation of multi-phase and multi-component diffusion of air-dust-gas in a fully mechanized mining face.

To explore the rule of airflow-dust-gas dispersion and interaction in a fully mechanized mining face, the airflow current vector, the dust trajectory, and the gas spatial distribution were numerically simulated by Fluent. The results show that under the influence of airflow, respiratory dust diffuses to the leeward side of each dust-producing point and footway space and forms a high-concentration (peak concentration 2000 mg/m3) dust mass at 2 m on the leeward side of the advancing support. Gas tends to accumulate near the coal cutter drum, the roof, and the return air corner of the mining face, and the peak concentration exceeds the lower limit of explosion. Near the rear drum of the coal cutter and at the advancing support, considering that the gas and coal dust concentrations are both high and dust and gas can reduce each other's explosion limit, serious gas and coal dust explosions are extremely likely to occur in the presence of a fire source, which may result in serious consequences. Therefore, the two areas can be regarded as key areas of gas and coal dust explosion prevention and control.