Abstract: Rotary air preheater is heat exchange equipment widely used in large and mediumsize power boiler at the rear. The fatal shortcoming of the equipment is high air leakage factor. The leakage air not only influences the thermal efficiency of boiler and the supply of air flow, but also increases the power consumption of the draft fans, and this leads the increase of both grass and net coal consumption rate. Ten of ideas for prevention and control of air leakage of air preheater were proposed in this paper.

Key words: air preheater, mechanism of air leakage, sealing structure, prevention and control of air leakage