Circulating fluidized bed boiler capable of realizing ultra-low emission of nitrogen oxide and SO2

Abstract

The invention discloses a circulating fluidized bed boiler capable of realizing ultra-low emission of nitrogen oxide and SO2, and solves the problem that indexes of nitrogen oxide and carbon dioxide emitted by an existing circulating fluidized bed boiler cannot be further reduced. Two cyclone separators in a traditional circulating fluidized bed system are changed into one cyclone separator, a cross section of the cyclone separator is greatly increased, so that a whole-journey path of spiral descending of high-temperature ash particles is substantially increased, kinetic energy is greatly reduced after the ash particles with particle size of 20-100 micrometers spirally fall and touch the bottom of a returning box, the high-temperature ash particles cannot rebound and raise and circularly enter a hearth to be mixed with fire coal and intake air, fire coal coating rate of the high-temperature ash particles is increased, and nitrogen oxide and carbon dioxide produced by the fire coal in aburning process are reduced fundamentally.

Description

technical field [0001] The invention relates to a coal-fired boiler, in particular to a circulating fluidized bed boiler which can greatly reduce the emission of nitrogen oxides and SO2. Background technique [0002] The coal-fired circulating fluidized bed boiler is mainly composed of the furnace, the separator, and the heating surface in the tail shaft flue. The boiler with this structure is generally provided with two smoke outlets symmetrically at the rear of the furnace. The smoke outlets are respectively connected with a cyclone separator. The cyclone separator is a cylindrical cylinder. A conical transition body is connected to the bottom end of the cylindrical cylinder body. The return pipe arranged vertically in the direction is connected with a return box at the bottom end of the return pipe, and a return pipe is also arranged on the return box, and the other end of the return pipe is connected with the bottom of the furnace; the circulating fluidized bed boiler T...

AI Technical Summary

Problems solved by technology

[0005] The invention provides a circulating fluidized bed boiler capable of realizing ultra-low emissions of nitrogen oxides and SO2, and solves the technical problem that the indicators of nitrogen oxides and carbon dioxide emitted by existing circulating fluidized bed boilers cannot be further reduced

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