Aiming at solving the problem of high temperature corrosion of water wall after low nitrogen combustion transformation of 700 MW tangentially-fired boiler burning high sulfur coal

this paper proposes a solution of low nitrogen transformation combined with wall adhering air technology.In this solution

three layers/12 pieces nearwall air is added to increase the volume fraction of oxygen in reducing area near the water wall

thus to reduce the volume fraction of CO and H_2S

and decrease the quantity of corrosive medium scouring the water wall surface.Numerical simulation method is used to optimize the near-wall air angle.When the near-wall air angle is 60°

the volume fraction of H_2S near the water wall is the lowest

that is

the volume fraction of H_2S near the water wall in the reducing region

the main combustion region and the cold ash bucket region are 4.04×10~(-5)

8×10~(-5) and 26×10~(-5)

respectively.At the same time

the water wall temperature decreases

which can prevent overtemperature of the water wall effectively and slow high temperature corrosion of the water wall.The numerical simulation results are in well agreement with the experimental results

indicating that the near-wall air angle of 60°can effectively solve the high temperature corrosion of water wall in low nitrogen combustion reform of high sulfur coal boiler.