Abstract:

At initial stage of boiler startup (before grid connecting)，the temperature rise of boiler heating surface has to be controlled, the superheater surface temperature has to be controllable， and superheat steam temperature should be controlled.Large piece of oxide scale will fall off because of large variation of superheater temperature or overtemperature. The fallen oxide scale will block the superheater within one week after the boiler startup,which could cause overtemperature and tube burst. Disengaging the boiler feed water lowflow protection and controlling the feed water flow between 350~574t/h can effectively solve the problem of frequent burst pipe in boilers.

Key words:

supercritical boiler, feedwater flow, superheater explosive, oxide scale