Heat transfer elements of preheater on boiler with SCR denitrification equipment were blocked by ammonium bisulfate(ABS).Large amount of ammonia escaping caused by excessive ammonia injection in SCR equipment or it's local area was considered as the main reason.Thus

comprehensive retrofit for heat transfer elements of preheater with bad operation effect should be conducted

combining with decreasing the exhaust gas temperature or air leakage rate.Meanwhile

the heat transfer element for cold segment of air preheater should be made of Corten steel

for the low sulfur content coal

or high outlet integrated temperature.