The Numerical Simulation Of Reformedlow-nitrogen Burning Boiler Of 300MW

Nowadays,air staged combustion technology is widely used because of its particular advantages among low-NOx reform technology in coal-fired boiler. This paper focused on the tangentially fired boiler of 300 MW and analyzed the impact of the low-nitrogen reform on the flowing, burning and emission capacity of the boiler by numerical calculation method. The final result complied well compared with the local metrical data.Futhermore, we had fully investigated the combustion and NOx emission under different operation conditions after the reform in order to reduce the content of nitrogen as well as improve the boiler efficiency, and the results was meaningful for the relevant research and project.We used analog calculation to the boiler under the rated operation condition and compared the result with the experimental data. which matched well. The reform measurements are listed in details as follows: we removed the second wind vents and set a three-layer burning wind vent in the main area of combustion. The boiler capacity was numerical calculated, and the result showed perfect combustion capacity of the boiler after reform and the NOx emission was reduced greatly. In the meanwhile, the carbon content of the ash and the boiler efficiency changed little, which reached our initial expectation.Finally, we simulated the variation operation conditions of the boiler including air velocity of the burning wind, excess air coefficient and the pivot angle of the burning wind vents.It proved that the increase of the air velocity of the burning wind ? and reducing of the air velocity in the main area of combustion will improve the reducing property and decrease the formation of NO and NOx emission of boiler. However this reform reduced the burn-out rate of coal and improved the ash content. Additionally, the increase of pivot angle of the burning wind vents suppressed the concentration of NOx, which was opposite with the burn-out rate of coal. The result from the boiler reform approach would provide better insight to planners and operators in the field of boiler reform project.