Influence of mixed ventilation on particulate-gas diffusion and distribution of diesel engine exhaust in fully mechanized excavation face

Tail gas emitted by underground trackless rubber wheel cars poses a serious threat to the health and safety of underground workers. To effectively reduce the tail gas concentration of a comprehensive excavation face, this study adopted a numerical simulation method to investigate the influence of air suction volume Q and distance L between trackless rubber wheel cars and headfaces on the diffusion law of diesel particulate matter, CO, and NO x under long suction and short pressure ventilation. The results showed that under the condition of L = 20 m, the trackless rubber wheel car is closer to the suction air duct. At this point, when Q = 600 m 3 /min, the tail gas control effect in the roadway is optimum. In addition, under the condition of L = 40 m, the trackless rubber wheel car is in the middle of the roadway. At this point, when Q = 300 m 3 /min, the tail gas control effect in the roadway is optimum. When L = 60 m and Q = 200 m 3 /min, the ventilation mode in the roadway is mainly pressure-in ventilation. The high-volume-fraction NO x region and the medium-volume-fraction NO x region under this air volume are small.