Under premise of satisfying boiler operation in Taishan Power Plant

the exhaust flue gas temperature has been enhanced through extracting a part of hot secondary air to inject into the cleaned flue gas after desulfurization

so as to reduce or eliminate the "gypsum rain".Through thermodynamics calculation

and comparing variation of parameters

such as the temperature of secondary air

the temperature of outlet flue gas from air preheater

and the temperature of inlet flue gas into platen superheater

etc.

a scheme of additionally installing the gas-gas heater(gghy)has been put forward.