In order to solve the problem of serious slagging on heating surface of a supercritical 350 MW unit boiler in a power plant

field investigation was carried out from aspects of design

installation

operation and fuel. On the basis of preliminary conclusions

a test bench for simulating ash accumulation was built up and the experiments were carried out. The samples of ash accumulation were analyzed by SEM and XRD. The results show that

a coal in Xinjiang has a high tendency of ash accumulation

long-term co-firing the coal which easily slags is the main reason for the serious slagging of the boiler

and other items such as unreasonable air distribution mode

high oxygen operation and imbalance of primary to secondary air ratio during the boiler operation are the secondary cause. By optimizing the air distribution

reducing the oxygen content

strengthening the soot blowing and adjusting the ratio of primary to secondary air volume

the combustion intensity in the furnace was weakened

the flue gas temperature at the outlet of the furnace was lowered

and the slagging situation was greatly improved.