Coal mine dust is a critical hazard that can trigger explosions and cause pneumoconiosis, thereby severely threatening mine safety and occupational health. Although long-forcing and short-exhausting ventilation are commonly adopted in long-distance heading faces, their parameters are often determined empirically, leading to suboptimal dust control efficiency. This study utilizes numerical simulations via FLUENT to investigate dust migration patterns under five key ventilation parameters in the 2-2 Upper Coal Working Face of the Xintai Taigemiao Mining Area. The results reveal a zonal distribution of dust: a high-concentration accumulation zone within 0–15 m, a medium-concentration transition zone between 15 and 35 m, and a low-concentration settling zone beyond 35 m. Diffusion rates vary significantly across zones under different ventilation settings. The optimized parameters for the 20 m2 cross-section roadway in this study include: exhausting duct set 0.3 m from the return-side wall, exhausting inlet at a distance of 4 m (0.9√A, A is the roadway cross-sectional area) from the face, forcing inlet at 20 m (4.5√A) from the face, duct installation height of 0.75 times the roadway height, and a forcing-to-exhausting air volume ratio between 1.2 and 1.6. Compared with the non-optimized scheme, this configuration reduces the average dust concentration in the breathing zone (1.2 m height) by up to 62.3%, and restricts 85% of the high-concentration dust within 0–15 m from the heading face, effectively suppressing dust dispersion to the rear roadway. This study provides a quantitative reference and theoretical strategy for engineering applications of dust prevention in similar large-section long-distance heading faces within the scope of numerical simulation.
Fully mechanized coal mining is a key method of coal extraction. As mining intensity increases, dust pollution in fully mechanized mining faces has become increasingly severe, significantly hindering the coal industry‘s alignment with the “Healthy China” strategy. To address the prominent dust pollution and the inefficiency of current spray dust suppression methods, this study proposes a combined spray dust suppression system. Using the Taigemiao mining area—where the coal dust exhibits hydrophilic characteristics—as a case study, we investigate the system’s spray flow field characteristics via numerical simulation. The results indicate that activating the shearer‘s external nozzles increases the airflow velocity near the shearer to 4 m/s, with the droplet concentration at the breathing zone height peaking at 28,786 mg/m3. Furthermore, activating the inter-support spray-induced dust removal device boosts the airflow velocity to 15.8 m/s, generating negative pressure at the dust suction inlet and forming a high-concentration droplet zone near the coal wall. During the operation of the combined system, the droplet distribution is characterized by “three high-concentration areas” and “post-nozzle attenuation.” The optimal droplet proportion reaches 93.81%, maintaining an appropriate velocity within the efficient dust capture range. Overall, the dust capture efficiency of the combined system is significantly superior to that of a single spray system.