To solve the problem of excessive air leakage from the four-compartment air preheater

a fourcompartment rotary air preheater of a 1 000 MW power plant is used as the study object to investigate the thermal characteristics

rotor thermal deformation and air leakage of the air preheater

by combining theoretical analysis with numerical simulation. The numerical simulation results show that

for every 1% increase in air leakage rate of the 1 000 MW unit

the heat transfer efficiency of air preheater will be reduced by 1.13%

and the power plant will consume 3 604 tons of standard coal more on average per year. There are large temperature gradients in the axial and circumferential directions inside the air preheater

and most of the corrosion and deposition areas are distributed in the low temperature section. There are large differences in rotor thermal deformation during different operating conditions of the air preheater

and the maximum thermal deformation occurs on the secondary air side. It is necessary to make corresponding adjustments according to the thermal deformation characteristics of different positions of the rotor when setting the sealing system.