Computational study on fumace process in a multi-burner boiler of pulverized coal fired tangentially at four corners

Abstract

Aiming at the optimization of the operation condition, a general numerical method for calculating pulverized coal combustion in a full-scale furnace fired tangentially at four corners is adopted. “κ-ɛ” turbulence model is used for the gas phases and a stochastic approach based on the Lagrangian technique is used for particle phases. Two-competing reactions model for the coal devolatilization and PDF (the probability density function) method for the combustion of the gas phases are employed. In the numerical simulations, assuming the air distribution of second port level is of pagoda, waist drum and uniform type. The results show that pagoda type air distribution is advantageous to ignition and smooth combustion of pulverized coal, and suitable to inferior coal combustion in practice. In the present furnace, the igniting distance at 1st and 3rd corner is longer than that at 2nd and 4th corner. The results from numerical calculations are in good agreement with those of observed in practice.

Keywords

power station boiler / combustion of pulverized coal / numerical simulation