Introduction  The low-temperature corrosion of the air preheater endangers the safety operation of the boiler in the power plant. It is necessary to analyze and compare the technical characteristics of different solutions of the low temperature corrosion about the air preheater in the coal-fired units.

  Method  The article focused on the low-temperature corrosion solution about air preheater. Two solutions which were steam-air heater system and hot air recirculation system were used to increase the cold end air temperature of air preheater by technical analysis and energy consumption analysis.

  Result  Steam-air heater system and hot air recirculation system have advantages. Although the initial investment of the steam-air heater system is relatively large, its system features have obvious advantages.

  Conclusion  The application of the steam-air heater system is more extensive for the low temperature corrosion problem of air preheater.