Serious high-temperature corrosion occurred on water wall tubes in burner area of both two sides of No.1unit boiler in Hongshan Power Plant.Macro-examination and X-ray fluorescencs probe detection was performed on the corrosion products.The results showed that the corrosion products were loose

porous

fragile and easy to be exfoliated

and it mainly consisted of iron sulfide and iron oxide

indicating the corrosion was typical sulfide corrosion.Besides

the high-temperature corrosion theory was presented.Thus

some countermeasures were taken

such as strictly controlling the sulfur content in feed coal below 1%and the furnace outlet oxygen content within 3.0%to 3.5%

spraying protective layer for the water wall tubes in burner area

reasonably decreasing the coal fineness if the pulverizing system and steam temperature allowed

adjusting the over fire air volume

increasing the temperature of air and pulverized coal mixture at coal mill outlet as much as possible on the premise of ensuring the pulverizing system safety

regulating the opening degree of burners and each air door damper.After half year's operation

the high-temperature corrosion on water wall tube was probed to be controlled effectively.