Research And Retrofitting On High Temperature Corrosion Of Water-cooled Wall Of Dagang 328.5MW Utility Boiler

To solving Dagang power plant #3, #4 units serious high temperature corrosion that takes place after altering to burn highly sulphuric Yangquan anthracite coal, with #3 boiler cold air dynamic field experiment, wall atmosphere measuring analysis and pertinent changing coal numerical simulative calculation, check out D cape burner actual fixing angle deviation from the design value, the design tangential circle diameter is over big; deeply analyze the mechanism and main cause of high temperature sulphur corrosion and chlorin corrosion of the water-cooled wall tube in highly reductive atmosphere and certain temperature condition; and with changing to use Datong soft coal less sulphuric than Yangquan coal, reconstruct the combustion system, adopt the "powder in air" type horizontal thick-thin burner, reduce the tangential circle radius. The experiment and actual measurement show that the reconstruction can ensure the boiler water-cooled wall surface's average oxygen content in high temperature corrosion area not lower than 1.5% in different load warm operation mode, reductive atmosphere near wall is basically eliminated and the problem of water-cooled wall high temperature corrosion is solved very well.Zhang Xinliang (Power Engineering)Directed by Prof. Yan Weiping...