CFD Modelling of Ventilation, Dust and Gas Flow Dispersion Patterns on a Longwall Face

Abstract

Modern underground longwall mines are using large volume of ventilating airflow to maintain a working environment on longwall face and development heading. The design and effective management of ventilation flow on a longwall face is critical to the safety and productivity of the working place with due consideration of dust mitigation and gas emission dispersion. CFD models are developed to provide a better understanding of the ventilation airflow patterns on a typical longwall face extracting a medium-high seam. Results from the CFD models provide a clear visualization of airflow patterns as it enters from the maingate to the longwall, then passes the shearer along the face, before returning to the tailgate. Local recirculation and turbulence zones can be clearly identified where dust contamination and gas accumulation hazards could exist. Ventilation pressure drops along the face could also be estimated with the shearer and chock advance at different locations. Gas emission and dust generation from different sources on the longwall are modelled and their dispersion patterns predicted as the shearer cuts from tailgate to maingate. The use of wing brattices and curtains at different locations (maingate, maingate goaf entry and tailgate) and its effect on dust and gas dispersion are modelled to provide improved control and risk management on the longwall.