Experimental Research And Numerical Simulation Of A Low NO_x Swirl Burner

With the rapid development of China’s economy and the gradually raise of living standards of our citizens, the air pollution problems get more and more attention of medias and audience; especially in recent years, most parts of China have been covered by thick haze for a period of time, it is aggravated the pressure to reduce emissions of the power industry. This paper describes the history and current status of the development of the low NOx swirl burner, and the outlet flow field characteristics as well as the correlation between it and high temperature corrosion on water wall has been studied by cold test through PDA (particle dynamics anemometry) system and simulated by FLUENT software.Velocities and root mean square (RMS) velocities, the shape of the recirculation zone, particle concentrations and particle diameter distribution near the burner outlet under different outer secondary air vane angles and different mass flow rate of the secondary air were obtained by experimental methods and the distribution of temperature, velocities, gas species and the concentration of the particles were clarified by simulating. Results from tests and simulations showed that there is an annular recirculation zone near the burner outlet, and the distribution of particles concentration is centre rich while outer zone lean. This distribution of particles contributes to the stability of the firing, as well as conducive the formation of reducing atmosphere to suppress the generation of NOx, however, simultaneously, this distribution of the particle concentration may go against carbon particle burning and contribute to the corrosion process in the boiler. Preliminary exploration has been done in this paper through experimental study and numerical simulation to solve the problem that how effectively eliminate or mitigate the water wall corrosion while keeping the NOx emissions low.