A CFD analysis of equipment fires in an underground development heading for improved auxiliary ventilation design.

Abstract

Abstract: This study investigates the intricacies of equipment fires in a blind development heading of an underground mine using computational fluid dynamics (CFD). A series of fire dynamic simulations (FDS) were conducted for various ventilation velocities in the main airway, and with different distance between the auxiliary ventilation duct outlet to the blind working face. The impacts of the ventilation velocity in the main airway, and separation distance between the duct outlet to the blind face on temperature distribution and smoke spread mechanism were investigated. The findings indicate that the distance of the auxiliary ventilation duct outlet to the working face has a strong impact on the smoke stratification beneath the airway ceiling. The high-velocity flow from the auxiliary duct leads to turbulent eddies characterized by high levels of fluctuating vorticity near the working face, and the extent of the turbulent region increases as the distance between the working face and the duct outlet increases. This implies that lesser distance between the duct outlet to the working face is safer to mitigate smoke dispersion due to fires in the blind face of an underground heading. Similarly, the ventilation velocity in the main airway was observed to influence the smoke back layering length although, the influence on fire smoke gas temperature in the blind heading was found to be negligible. The insight from this study will aid the future design and installation of auxiliary mine ventilation duct in the underground development heading with the aim of minimizing smoke dispersion and enhancing safe evacuation of personnel in the event of a fire emergency.

Highlights: Numerical analysis of a large mining equipment fire is evaluated using CFDAuxiliary ventilation duct has a strong impact on fire-induce smoke stratificationHigh-velocity flow from auxiliary duct induces turbulent eddies near the blind faceTurbulent eddies prevent fire smoke stratification which hinders safe evacuation.