At present

due to the small cross-sectional area of the furnace

short flame spread distance and partial overlap of the tangentially-fired boiler in industry

the local high temperature area is large and the thermal NO_x generation is high. In this paper

based on the principle of nitrogen reduction of coal-fired boiler

the thermal NO_x generation is controlled through the technical route of low NO_x burner + over burning air(OFA) + flue gas recirculation(FGR). At the same time

the commercial software Fluent is used to simulate and test the 75 t/h tangentially-fired boiler. The results show that

the low nitrogen gas burner can reduce the NO_x generation by 25%～30%

the burnout air system can reduce the NO_x generation by 20%～25%

and the flue gas recirculation system can reduce the NO_x generation by 60%～70%. By using this technology

the NO_x generation of tangentiallyfired boiler can be controlled from 400 mg/m3 to less than 80 mg/m3

and the emission reduction effect is remarkable. The research results provide a technical reference for gas-fired boilers with high NO_x production.