In view of the high temperature corrosion of water wall in a 330 MW tangentially-fired boiler firing high sulfur coal

a kind of self-developed anticorrosive and wear-resistant coating material was used to carry out supersonic arc thermal spraying on the water wall tube

and the flue gas components(O2

CO and H2 S) near the water wall were detected. The influence of oxygen content

the secondary air distribution(including burner surrounding air)

primary air volume

tertiary air volume

fineness of pulverized coal and other factors on the high temperature corrosion of water wall was analyzed. By optimizing the operation mode of the boiler

the concentration of reductive atmosphere near the water wall greatly reduced

especially the concentration of H2 S dropped from 0.030%～0.045% to below 0.030%

the reduce amplitude in some areas reached higher than 50%.Through the above comprehensive control

the water wall tubes and coatings in the burner area have not been replaced since the overhaul of the boiler in December 2016. The coatings of the water wall tubes were measured during the unit stopping. According to theoretical calculation

the service time of the coatings was about 3.41 years. It can ensure that the fire-facing side of the water wall tubes will not fail due to corrosion during an overhaul period.