Diffusing mechanism analysis of reburning with natural gas to deoxidize NOx in the furnace

In order to examine the possibility of applying the new technology of reburning with natural gas to deoxidize NOx in the furnace, the fast-reaction model is adopted, which employs the SIMPLEC method to simulate the reacting and flowing processes taking place in a simplified reburning zone of a pulverized coal-fired unit. The results indicate that if diffusion is taken into account only, the NO concentration at a height equal to the depth of the furnace has been lowered to 0.02%. The NO concentration of the area above this height is below 0.02%. And the temperature in the reburning zone is still kept at a high level (1200°C), which is suitable for reducing the generation of NOx.