Composite reducing type low NOx emission device suitable for power station boiler

Abstract

The invention relates to a composite reducing type low NOx emission device suitable for a power station boiler. The composite reducing type low NOx emission device comprises a coal water slurry generation mechanism, a coal water slurry pyrolytic reaction mechanism and a composite reducing type combustion device, wherein the coal water slurry generation mechanism has the function of treating coal powder into coal water slurry and is internally provided with a coal water slurry tank, the coal water slurry pyrolytic reaction mechanism has the function of pyrolysis generation of pyrolysis gas withreducing active components and is internally provided with a pyrolysis reactor and a cyclone separator, and the composite reducing type combustion device has the function of deeply reducing of NOx incombustion smoke. By adoption of high-speed separation air and the proper over fire air rate, the created oxygen content in the combustion area is smaller than 1%, the NOx generated low-oxygen area in combustion can be restrained, a composite spraying port is utilized for conveying pyrolysis gas generated through the coal water slurry pyrolytic reaction and internally containing reducing active components and ammonia into the area, the reducing reaction with NOx in smoke happens in the reducing atmosphere, the limitation of usage of a temperature window during NOx reducing through a conventional reducing agent is broken through, furnace interior efficient combustion and economical reducing are ensured, the NOx concentration in smoke is totally reduced, and NOx ultra-low emission of a coalpowder combustion furnace is achieved.

Description

technical field [0001] The invention relates to the technical field of boiler auxiliary facilities, in particular to a compound reduction low NOx emission device suitable for power plant boilers. Background technique [0002] NOx emissions from power plant boilers are one of the main sources of air pollution. In recent years, our country is increasing the intensity of environmental pollution control. For the flue gas emission of power plant boilers, the NOx emission concentration is currently being implemented to be less than 50mg / m 3 At present, the commonly used high-efficiency NOx reduction technologies mainly include selective catalytic reduction (SCR) technology and selective non-catalytic reduction (SNCR) technology. These two technologies mainly inject ammonia reducing agent into the flue gas Reduce NOx. However, SNCR technology has problems such as a narrow reaction temperature window and serious ammonia escape. SCR technology has disadvantages such as short cataly...

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Problems solved by technology

[0003] The purpose of the invention is to overcome existing power plant boilers and realize NOx3 There is a technical bottleneck problem in the low emission limit. To provide a composite reduction low NOx emission device that can break through the temperature window limit when ammonia reduces NOx, and at the same time realize high-efficiency, low-cost deep denitrification of power plant boilers

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