Numerical Simulation And Structure Optimization Of A New Pulverized Coal Burner

The pulverized coal burner is a equipment which respectively puts the coal-air mixture (a coal burning wind) supplied by the coal preparation system and the secondary air needed to the chamber in a certain density and speed to realize the stable ignition and combustion in a state of suspension . The pulverized coal burner is the main component of the pulverized coal furnace combustion equipment, and it can burn fully, improve the working conditions and reduce labor intensity, etc.With saving energy and environmental protection more and more valued, pulverized coal burner is required high combustion efficiency and low pollutants discharge. This paper focuses on the basic research of combustion principle, structural optimization of the internal and external systems of the burner, combustion process, burning numerical simulation and burning experiment.A more accurate analysis and calculation of the new pulverized coal burner's flow field characteristics are done with numerical calculation method.A novel pulverized coal burner was designed based on two phase stochastic separation model and flow structure theory. Numerical simulation was developed on flow fluid characteristics of combustion by gas phase used Eulerian method and coal particle phase adopted Lagrangian method, it puts high emphasis to investigate the influence of combustor structure, particles diameter , air matching ratio on temperature, velocity, oxycarbide and combustion efficiency. The results show that temperature rises with particle diameter increasing, however, the minor particle diameter perform high temperature. Turbulent motion and mixing degree between the gas-particle phase is enhanced owing to secondary swirl air injection, and it can protect high temperature corrosion, alleviate the degree of inwall slagging by adopting direct-flow tertiary air. Moreover, to verify the effectiveness of the proposed novel kiln burner, hot- condition experimental study was performed, it shows a good agreement between simulation and experimental results.