Numerical modelling for improved underground-mine ventilation systems

Diesel engine is commonly used in the underground mining heavy vehicle. However, particle emissions from combustion engine have been declared to be a serious concern for the human health as well as the environment. Diesel engines are one of the most important sources of particulate and NOx emissions which consumes significant amount of oxygen which is dangerous for the mine workers as they will receive insufficient oxygen supply. Therefore, we need to design a proper ventilation system so that adequate oxygen can be supplied and keep the hazardous gas or ultrafine particles concentration as an allowable level in the mining tunnels. The main objective of this study is to find a high concentration area in the mining tunnel and propose and examine various ventilation strategies to control the concentration level to ensure health and safety, work efficiency and cost related to energy consumption. The well-established computational fluid dynamics (CFD) approach has been carried out to investigate the airflow, particle tracing and the position of the ventilation system. A three dimensional unsteady model is developed in this study for an underground mine tunnel with heavy vehicle is in operation. The commercial CFD software, ANSYS 15 (CFX) has been used for the numerical simulation. An Eulerian-Lagrangian approach is used to respectively model the main flow and particules' trajectories.