Low-nitrogen combustion device for fluidized bed boiler

Abstract

The invention relates to a low-nitrogen combustion device for a fluidized bed boiler. According to the principle of oxynitride generation, through coupling of air staging and recycled flue gas staging technologies, a combustion area with three stages of the strong reducing property, the weak reducing property and oxidability is formed in the height direction of a hearth, meanwhile, the combustion intensity of a dense-phase area of the hearth is remarkably alleviated, the combustion temperature of the dense-phase area of the hearth is controlled, the distribution uniformity of the overall temperature of the hearth is improved, and generation of temperature type oxynitride is restrained; and meanwhile, generation of fuel type oxynitride is greatly lowered, and generated oxynitride can be restored into nitrogen.

Description

technical field [0001] The invention belongs to the technical field of fluidized bed combustion, and relates to a low-nitrogen combustion device for a fluidized bed boiler. Background technique [0002] Fluidized bed combustion is a new type of boiler combustion technology that has emerged in the past two decades. It has the advantages of wide fuel adaptability, high combustion efficiency, large load variation range, and relatively low nitrogen oxide emissions. It is the main furnace type of clean coal combustion technology today. , are widely used in coal-fired industry and thermoelectric fields. However, with the increasingly severe environmental pressure, the state has stricter requirements on environmental protection emission standards. In December 2015, the three ministries and commissions of the State Council issued the "Comprehensive Implementation of Coal-fired Power Plants Coal power plants need to achieve ultra-low emissions before 2020, and the eastern region nee...

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Problems solved by technology

But so far, there are relatively few research reports on the use of low-nitrogen combustion technology for fluidized bed boilers. Although most fluidized bed boilers, especially circulating fluidized bed boilers, have adopted relatively simple air classification technology, the early stage is not enough for environmental protection. Attention, when designing and manufacturing fluidized bed boilers, we only pay attention to the fluidization characteristics of the fluidized bed material layer, focus on boiler combustion efficiency, pursue boiler thermal efficiency, and even overload operation and other traditional design concepts, resulting in deviations in the primary air distribution ratio in actual operation. Large, the air staging effect is not obvious, resulting in low staging combustion effect

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