Author:Site Editor Publish Time: 2018-01-10 Origin:Site
What measures can reduce NOX emissions from circulating fluidized bed boilers?
1. Choose a reasonable bed temperature and bed temperature distribution. Depending on the type of coal used for combustion, under the premise of ensuring the combustion efficiency, the furnace bed temperature can be controlled at 850-900 ° C. Targeted measures are taken in the design of the boiler to make the bed temperature evenly distributed, eliminate local high temperature points and reduce nitrogen Oxide emissions.
2. Low oxygen burning. Depending on the type of coal used for combustion, under the premise of ensuring the combustion efficiency of the boiler, lower oxygen (excess air ratio) should be adopted as much as possible to suppress the formation of nitrogen oxides.
3 grade air supply. In the bed temperature controllable based on the use of a lower rate of primary wind, dense phase combustion zone is carried out in the fuel excess conditions, due to lack of air in a reducing atmosphere, nitrogen combustion intermediate products can not be further oxidized to NO , While being reduced to neutral N2, can effectively control the formation of nitrogen oxides. Secondary air into the dilute phase zone to complete the combustion process, both to ensure combustion efficiency and can effectively achieve low NOx combustion.
4. Control the amount of limestone added. As the limestone addition increases, the nitrogen oxide emission concentration increases accordingly, and excessive addition of limestone should be avoided.
5. Increase SNCR denitrification system. Although fluidized bed boilers use low nitrogen oxide combustion technology, to meet the ultra-low emission requirements, the newly built circulating fluidized bed boiler SNCR denitration system should be added to improve the regulatory capacity.