Computational Fluid Dynamics (CFD) Modeling of Pulverized Coal Combustion Processes in a 700 MW Wall Tangentially-Fired Boiler.

摘要

A computational fluid dynamic (CFD) model of a 700MW wall tangentially-firedfurnace of a coal fired power plant in Malaysia had been developed. The input data,such as coal feed rates, air flow rates and coal particle size are obtained from the plantdata. This paper presents coal combustion performance in terms of temperature andspecies distribution in the furnace. ANSYS FLUENT 14.5 was used for the simulation.The mathematical model for continuous phase is based on Eulerian description and forthe coal particles is based on stochastic Lagrangian description. A two dimensionalcombustor model is used in this study. For turbulence model, standard k-ε model wasused to describe the gas solid flows in the coal combustion. Non-premixed combustionand discrete phase model (DPM) had been selected for the simulation of coalcombustion. As a result of analysis, the maximum temperature was observed at 2720K. The species distribution of oxygen and carbon dioxide concentration are reasonablewith other studies. Pulverized coal combustion occurs immediately after coal and airwere mixed at high velocity and temperature. The high temperature was observed nearthe burner zone where devolatilization process occurs. Concentrations of oxygen andcarbon dioxide have reverse correlation. The results presented in this paper can enhancethe understanding of pulverized coal combustion. Besides that, it can be a baselinemodel to predict others parameters in the coal combustion process. Using this model,future study of pollutant emissions from coal combustion will be developed.