Double-bypass flue structure of boiler tail flue

The invention discloses a double-bypass flue structure of a boiler tail flue, and belongs to the technical field of boilers. The invention aims to solve the problem that high-temperature furnace flue gas in a tail flue of a power station boiler cannot be subjected to denitration flue gas temperature heating and heat exchange with heat exchange equipment at the same time to improve the primary air temperature. The system comprises a denitration smoke temperature heating bypass flue and a heat exchange bypass flue, one end of the denitration smoke temperature heating bypass flue and one end of the heat exchange bypass flue are respectively communicated with a boiler tail flue, and the other end of the denitration smoke temperature heating bypass flue and the other end of the heat exchange bypass flue are communicated with an original denitration inlet flue; a flue closing baffle I and a flue adjusting baffle are sequentially arranged on the denitration smoke temperature heating bypass flue in the flowing direct