The problems existing in air preheater of boiler equipped for unit no.2 in Zhanjiang Electric Power Co Ltd

namely low reliability of the sealing control system

abrasion and aging of some sealing components

and high air leakage rate in the air preheater etc.

for these

a retrofit scheme

including retrofit of simulating compartments on the rotor

redesign and replacement of the fixed sectorial plates

and the radial plates used for axial seal

and replacement of radial and axial sealing strips etc.

has been put forward.After implementation

the measured air leakage rate in air preheaters at A and B side of the boiler for unit no.2 under condition of 250 MW load

are 4.92% and 5.59% respectively;and under condition of 300 MW load

the measured air leakage rate in air preheaters on A and B side of said boiler are 3.17% and 3.64% respectively

boasting remarkable effectiveness.