Abstract: The coals from Hami and Zhundong areas of Xinjiang containing high concentration of alkali and chloride ions, are prone to cause severe contamination, slagging and corrosion in supercritical boilers, which will affect the operation security of the equipment. According to the quality of designed coal for one 660-MW supercritical boiler under construction and based on the operation experience of 300-MW boilers and the mixed coal firing tests carried out on a 3-MW test bed for coal combustion, an optimization scheme for the design and operation is proposed to control the furnace outlet flue gas temperature by enlarging the furnace, and improve the contamination, slagging and corrosion on the heating surfaces by installing more soot blowers and carrying out mixed coal combustion and combustion adjustment etc. It is expected that with these measures, the 660-MW supercritical boiler being constructed can safely burn the Hami high alkali metal coal up to 60% of its overall coal fuels, and the annual fuel costs will be reduced by 30 million yuan, which means a great improvement for the economic efficiency of the power plant so as to bring the power transmission from the west to the east into full play.

Key words: supercritical boiler, fouling, corrosion, slagging, design, operation