Simulation Study of SNCR Denitrification Lance Setting for Coal-Fired Chain Grate Hot Water Boiler

To effectively control the emission of NOx, this paper takes a 46MW coal-fired chain grate hot water boiler as the research object and uses FLIC coupled with FLUENT software to simulate the effects of SNCR denitrification gun settings on denitrification efficiency and ammonia escape. FLIC software was used for the simulation of grate solid-phase combustion, and the simulation results were imported into FLUENT software as boundary conditions for the simulation of furnace combustion, and a systematic simulation study was carried out on the arrangement of the spray gun, the spraying speed, and the atomization angle. It was found that: eight lances were set up in the horizontal direction of the furnace to make the flow field of the denitrifying agent in the furnace uniform, and the lances were arranged in two layers in the vertical direction, and the denitrification efficiency reached a maximum of 49.83% when the spraying speed was $35 \mathrm{~m} / \mathrm{s}$, the atomized particle size was $200 \mu \mathrm{~m}$, and the atomizationanglewas30.The denitrification efficiency was improved by $2.82 \%$ compared to the conventional settings such as a number of lances 8, incident velocity of $20 \mathrm{~m} / \mathrm{s}$, atomization angle of 20°, and atomized particle size of $200 \mu \mathrm{~m}$. The research in this paper provides a theoretical basis for the setup of SNCR denitrification engineering guns for coal-fired chain furnaces, which is of great reference significance.