Method for determining the Air Change Effectiveness of the auxiliary forcing ventilation system in underground mines using CFD software

Auxiliary forcing ventilation system is the most common air distribution system of the development headings in underground mines. This paper reports the development of numerical analysis for calculating the Air Change Effectiveness (ACE) of ventilation performance for auxiliary forcing ventilation system in underground mines. The methodology presented in this paper will be demonstrated through Computational Fluid Dynamics (CFD) modelling and calculated in accordance with ASHRAE F25-1997 methodology. Local age, Mean Age of Air (MAA) and ACE were calculated in three scenarios using CFD modelling to study the ventilation performance. ACE was calculated at locations in the development headings occupied space, based on the MAA from the same ventilation system parameters in three different scenarios. Simulation results indicate that ACE is influenced due to the involvement of objects in the development heading that can reduce the effective volume of the zone. This study provides some new ideas for measuring ACE which can provide better auxiliary ventilation system in underground mines. The proposed methodology could be applied as guidance for design and setup of auxiliary ventilation systems. Results from this CFD modelling will be used for extensive validation study which purpose will be to prove the accuracy of the methodology and, if necessary, to improve it.