Numerical Simulation of Combustion Process under Different Tertiary Air Swirl Strength of HT-NR3 Burner

With a 600 MW supercritical swirl-opposed pulverized coal fired boiler serving as an object of study, this paper investigates the characteristics of pulverized coal particle trajectory, gas temperature at burner region, recirculation zone and flue gas temperature at the exit of furnace with Furnace software under different tertiary air swirl strength of HT-NR₃ burner. The simulated results indicate that pulverized coal mostly burned out in the space from middle burner area to overfire air area in swirl-opposed boiler. The side wall of boiler is scoured more seriously by pulverized coal under weak swirl strength. With the increasing of tertiary air swirl strength, the jet extended corner at exit of burners tends to be greater and the circulatory flow of high temperature flue gas is enhanced, it is advantageous to steady burning. Furthermore, the temperature at burner region is high enough to guarantee the pulverized coal fired rapidly and completely, which makes high burn out rate and low rate of flue gas carbon in dust.