Optimization of parameters to improve ventilation in underground mine working using CFD

Abstract

In underground mine, it is very important to maintain fresh and sufficient air in unventilated areas to maintain safe working environment for workers. To study the behaviour of air flow in underground mine, a T-shaped crosscut region of Bord and Pillar mining is considered for simulation in two different cases: without and with thin brattice positioning at crosscut region. Brattice is cost effective ventilation control device to deflect air into unventilated areas in underground mine. The ultimate objective is to find the best location and dimension of brattice across the crosscut region by which one can get maximum velocity at dead end. In this thesis, a computational fluid dynamics (CFD) and optimization algorithms are considered for maximizing the air flow at the dead end by placing a brattice at optimum location. Two different optimization algorithms: multi-objective genetic algorithm (MOGA) and non-linear programming of quadratic Lagrangian (NLPQL) optimization techniques were used in this study. ANSYS FLUENT software is used for CFD modeling at T-shaped crosscut region and computes the simulation result of air flow velocity at dead end. Optimization techniques are used for to optimize four input parameters; brattice position vertical and horizontal from the wall of crosscut region and width and length of brattice. The objectives for optimizations are to maximize the velocity at dead end and minimize the pressure drop in crosscut region. Comparison is carried out between crosscut region without and with a thin brattice using optimization techniques and found the best location and dimension of brattice. To increase the air flow velocity at dead end increases the safe working for workers and supply adequate air at working face.