In order to solve the problem of slagging on heating surface of power plant boilers in the process of burning Zhundong coal

a scheme of spraying nano ceramic coating on slagging part of the heating surface was proposed. Based on the image analysis method

the contact angle between the coal ash melting droplet and the sample steel sheet as well as the element composition of the coal ash slag sample before and after the spraying were measured

and the influence mechanism of nano ceramic coating on the surface slagging of the sample steel sheet was analyzed. Moreover

the No.3 boiler of a 660 MW coal-fired power unit was sprayed using this scheme. The factors such as furnace slagging

boiler efficiency

furnace temperature

soot blower operation and NOx emission before and after the spraying were compared and analyzed. The results show that

the nano ceramic coating had a weakening effect on the adhesion of coal ash melting droplets

and could effectively isolate and protect the surface of the rigid substrate

which had a good anti slagging performance. After spraying the nano ceramic coating

the performance indexes of the boiler were obviously improved

the highest temperature of the water wall reduced from 670 ℃ to 526 ℃

the furnace temperature reduced by 30～60 ℃

the exhaust temperature decreased by 9.5 ℃

and the boiler efficiency increased by about 0.63%. The operation time of soot blower shortened by 58.2%

and the NO_x emission mass concentration reduced by 13.7%. This study shows that nano ceramic coating can solve the problem of furnace heating surface coking

which provides a certain guidance for slag prevention project of Zhundong coalfired boilers.