A two-stage heat exchange flue gas recirculation system is adopted

The utility model relates to a flue gas recirculation system adopting two-stage heat exchange, which is designed for effectively controlling the temperature level of a hearth and inhibiting or preventing the hearth from coking. According to the utility model, a two-stage flue gas recirculation system for heat exchange is adopted; the device comprises a main flue arranged at a boiler flue gas outlet and connected with the main flue, a preheater, 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 dust remover is communicated with a recirculation flue; wherein the recirculating flue is communicated to a boiler furnace, an adjusting baffle device is arranged on the recirculating flue betweenthe recirculating fan and an air inlet of the boiler furnace, a flue gas bypass is arranged on the preheater, and a high-pressure economizer and a low-pressure economizer are arranged on the flue gasbypass for two-stage heat