Fluidized-bed boiler

Abstract

The invention provides a fluidized-bed boiler, which comprises a fluidized-bed combustion chamber. The bottom of the fluidized-bed combustion chamber is provided with a wind chamber of a wind distributor, and the fluidized-bed combustion chamber is communicated with a blower; combusted flue gas of the combustion chamber is exhausted from a chimney through an induced draught fan; the outlet of the induced draught fan is connected with a flue gas recirculation tube which is respectively communicated with the fluidized-bed combustion chamber and the wind chamber; an upper layer wind adjusting valve is arranged between the flue gas recirculation tube and the fluidized-bed combustion chamber; an upper layer fan is arranged between the upper layer wind adjusting valve and the combustion chamber; an air draft pipe with an air regulating valve is arranged between the upper layer fan and the upper layer wind adjusting valve; upper layer wind is formed by the air and flue gas; the blower is connected with an air-flue gas mixing chamber; the other end of the mixing chamber is communicated with the flue gas recirculation pipe through a flue gas secondary fan and a flue gas secondary regulating valve; and the upper part of the mixing chamber is communicated with the air chamber to form one-time wind. The fluidized-bed boiler has the advantages of improving the utilization rate of fuel, reducing the emission of pollutants, and having higher desulphurization efficiency and wide application of coal fuel.

Description

technical field [0001] The invention relates to the technical field of a boiler combustion device, in particular to a fluidized bed boiler with a flue gas recirculation device. Background technique [0002] The existing fluidized bed boiler structure includes a boiler body provided with a fluidized bed combustion chamber. The bottom of the combustion chamber is provided with an air distribution plate with a hood. The hood communicates with the primary air blower through the air chamber. The blower will Compressed air enters the combustion chamber through the air chamber and air cap, and the combustion flue gas in the boiler body passes through the heating component from the upper end of the cyclone separator, and then is led to the chimney by the induced draft fan through the dust collector to be discharged. One side of the fluidized bed combustion chamber communicates with a fuel tank. [0003] At present, during the operation of domestic small and medium-sized fluidized b...

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Problems solved by technology

[0003] At present, during the operation of domestic small and medium-sized fluidized bed boilers, the phenomenon of insufficient primary air volume and slag leakage of the air distribution plate often occurs due to wear and tear of components and reduced sealing performance of pipelines, which also causes large amount of return material and separation from the cyclone The secondary combustion of the unburned matter in the return pipe of the boiler; moreover, at present, a large number of domestic small and medium-sized fluidized bed boilers still have a low desulfurization rate, and these defects restrict the internal mass transfer and heat transfer of the existing fluidized bed boilers effect, as well as the function of the furnace charge returning to the furnace, thus affecting the boiler output and economic benefits, and causing excessive emissions of pollutants

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