Abstract
A three-dimensional numerical simulation is applied to a pulverized coal combustion field in a test furnace equipped with an advanced low-NOx burner called CI-α burner, and the detailed pulverized coal combustion characteristics are investigated. The numerical results are in general agreement with the measurements, and verifies that a recirculation flow is formed in the high-gas-temperature region near the CI-α burner outlet, and this lengthens the residence time of coal particles in this high-temperature region, promotes the evolution of volatile matter and the progress of char reaction, and produces an extremely low-O_2 region for effective NO reduction. The effect of the recirculation flow on the particle residence time is significant for the small particles with diameters less than 40μm. Regarding No emission mode, the efficiency factor of the conversion of char N to NO affects the total NO concentration in the downstream region after the injection of staged combustion air.
