According to actual operational of a 600 MW unit boiler air preheater

in order to improve coal quality variations and low-load conditions

it proposes a series of retrofit measures.Performance indicators such as air leakage rate of the air preheater

flue gas temperature

hot air temperature

and flue gas and air side resistance are tested after the renovation.After testing

compared with before the renovation

the air leakage rate of the A-side and B-side air preheaters meets the requirement of less than 4%

the decrease in flue gas temperature meets the requirement of not less than 4 ℃

and the decrease in primary air resistance meets the guarantee value requirement of greater than 0.5 kPa

The renovation effect achieved the expected results

which effectively improving the safety and economy of the air preheater and the entire unit operation.It can provide reference for other power plant boiler air preheater reconstruction.