Aiming at the problems of slagging and high temperature corrosion of water wall in a 1 000 MW ultra-supercritical double tangential boiler, the mechanism of slagging and high temperature corrosion of boiler was analyzed by X-ray diffraction (XRD) and X-ray fluorescence (XRF).The results show that the presence of sodium and calcium in coal reduces the ash melting point of coal, causing boiler slagging. Sulfide-type high temperature corrosion is the main type of high temperature corrosion of the boiler. Through coal blending optimization and air distribution adjustment, the coal quality feeding into the furnace and the air distribution mode of the burner were optimized. The results show that selecting low-sulfur and low-slagging coal for blending can effectively alleviate the problem of slagging in the furnace. The increase of the total air volume of the boiler and the reasonable adjustment of the secondary air distribution of the burner can effectively reduce the concentration of the reducing atmosphere in the furnace, and alleviate the problem of high temperature corrosion in the furnace. The prediction results of boiler corrosion tendency by numerical simulation method show that the high-temperature corrosion should be further prevented in the hot corner area of the furnace by adding adherent wind or water wall spraying.
