Against the rotating characteristics,low temperature corrosion ash deposition performance and outlet gas temperature distribution rule of the rotary air preheater,it suggests non-balance heat exchanger be added at the air preheater inlet and the flue duct be divided into several small ones.By properly reducing the inlet gas temperature of each small flue duct,the boiler exhaust temperature becomes equilibrium and decreases on a whole.Finally,the boiler exhaust temperature can be reduced and the boiler effic...