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 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/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/min, the tail gas control effect in the roadway is optimum. When L = 60 m and Q = 200 m/min, the ventilation mode in the roadway is mainly pressure-in ventilation. The high-volume-fraction NO region and the medium-volume-fraction NO region under this air volume are small.