Numerical simulation of turbulent flow in complex geometries used in power plants

Performance degradations or improvements of coal-fired power stations depend on effective functioning of pulveriser equipment and combustion efficiency of furnaces in boilers. The function of a pulveriser is to grind the lumped coal: and transfer the fine coal to the furnace for efficient combustion. However, the presence of several solid objects inside the mill, flow of air and particles takes turn around from inlet to outlet. The flow simulation process involves the geometrical modelling, grid generation and particle trajectories for the given flow conditions, and has been investigated to understand the flow path in grinding chamber, separator and classifier. The behaviour of turbulent air flow motion with fly ash particle paths on Lagrangian scale in computational domain are obtained through CFD/CAD software packages. The understanding developed with reference to recirculation flows in the inlet duct, non-uniform flow over the height of bowl mill and unequal flow at exit, provides valuable insights to designers for optimisation of components for better efficiency. (C) 2002 Published by Elsevier Science Ltd.