Efficient and energy-saving circulating fluidized bed boiler

The utility model discloses an efficient and energy-saving circulating fluidized bed boiler. A vertical upward flue (10) is arranged at the rear part of a vertical downward flue (9), an outlet of a hearth (5) is communicated with an inlet at the upper end of the vertical downward flue (9), a smokestack (3) for improving the tangential flow velocity of flue gas is arranged between the vertical downward flue (9) and the vertical upward flue (10), a high-temperature separator is arranged in the vertical upward flue (10), the upper end of an outlet of the vertical upward flue (10) is connected with a superheater (8), the lower parts of the vertical downward flue (9) and the vertical upward flue (10) are provided with an ash pit (1), and the ash pit (1) is provided with a material return port (2) communicated with the hearth (5). The efficient and energy-saving circulating fluidized bed boiler disclosed by the utility model has a good separation effect and high thermal efficiency, occupies a small area, and is con