Experimental Study on Reducing NOx Emission of 300MW Coal-Fired Boiler with Burners in Front and Back Walls

Experimental study was carried on a 300MW swirling combustion pulverized coal firing furnace with put parts of tertiary air as over fire air to reduce NOx emission. The influence of boiler operational condition on the characteristics of NOx emission were studied, such as the content of O₂ at economizer exit, the proportion of the top tertiary air and mass flow of over fired air (OFA). Results show that the content of O₂ at economizer exit and the proportion of the top tertiary air have greater effect on boiler efficiency and NOx emission. It maintain the two parameters about 4% and 135t/h can inhibit NOx emission and have less influence on boiler efficiency; adjusting the opening of over fire air damper blow 60% can influence the NOx emission. After adjustment <;. The concentration of NOx emission concentration can control blow 800mg/Nm³. It could provide some technical gist for the same type of boiler.