The effect of jet velocity ratio on aerodynamics of rectangular slot-burners in tangentially-fired furnaces

In a typical coal-fired power station boiler ignition and combustion of coal are largely controlled by burner aerodynamics, hence the geometry of the burner plays an important role in achieving stable combustion, high burnout of fuel, low production of pollutants and control of fouling. Current practice in pulverized coal fired boilers is to use either swirl burners or tangentially-fired slot-burners. The later system has been adopted for boilers in Victoria firing brown coal. To obtain a better understanding of the overall combustion process, it is important to investigate the aerodynamics of the jet development from these burners. Computational Fluid Dynamics (CFD) is an effective tool to investigate aerodynamics of the burners, and this paper presents the results of CFD simulations of several slot-burner models based on real geometries used in coal-fired power stations in Victoria. The CFD software CFX-5 has been used for this study. The effect of the primary to secondary jet velocity ratio for different burner geometries has been investigated and the validation of the numerical results has been carried out by comparison with the available measured data