Flue gas recirculation system based on bypass heat exchanger

The utility model relates to a flue gas recirculation system based on a bypass heat exchanger, and provides a better reheating steam temperature adjusting system for a secondary reheating boiler. Theutility model discloses a flue gas recirculation system based on a bypass heat exchanger. The device comprises a main flue arranged at a boiler flue gas outlet and connected with the main flue, wherein a preheater, a low-pressure economizer, an electric dust remover and an induced draft fan are sequentially arranged on the flue gas main pipeline; the flue gas main pipeline behind the electric dustremover is communicated with a recirculation flue; the recirculation flue is communicated to a boiler hearth; an adjusting baffle device is arranged on the recirculation flue between the recirculation fan and an air inlet of a boiler hearth, a cooling bypass is arranged on the preheater, a heat exchanger is arranged on the cooling bypass, and low-temperature smoke at an outlet of a unit low-pressure economizer system is a