Pulverized coal fired boiler with ultralow nitric oxide emission

Abstract

The invention provides a pulverized coal fired boiler with ultralow nitric oxide emission, and belongs to the technical field of coal-fired power generation and environmental protection. The pulverized coal fired boiler comprises a hearth, a boiler burner, a boiler internal water-cooled wall heating surface, a screen type heating surface and a convection heating surface, wherein the boiler burner is provided with a reducing agent generating device and can generate CO which is the reducing agent; NO and CO carry out reduction reaction and flue gas denitration is implemented; the boiler burner comprises a low-nitrogen burner (LNB) and over fire air (OFA); by the low-nitrogen burner, deep air classification is implemented so as to reduce the original production of the NO; the molar ratio of the CO which is the reducing agent to the NO is adjusted by the over fire air (OFA); and catalyst layers are respectively adhered to the boiler internal water-cooled wall heating surface, the screen type heating surface and the convection heating surface along a smoke flowing direction, or independent catalyst layers are arranged on a tail-end flue. The pulverized coal fired boiler with ultralow nitric oxide emission is simple in structure and runs stably; denitration reaction can be finished without the aid of amino reducing agents, the denitration efficiency is high, and the denitration cost is reduced obviously; and the pulverized coal fired boiler with ultralow nitric oxide emission can be in different scale grades.

Description

technical field [0001] The invention belongs to the technical field of coal-fired power generation and environmental protection, and in particular relates to a pulverized coal boiler with ultra-low emission of nitrogen oxides. Background technique [0002] With the country's increasing emphasis on environmental protection, the control of pollutant emissions from thermal power plants is becoming more and more stringent. According to the "Coal Power Energy Conservation and Emission Reduction Upgrading and Transformation Action Plan (2014-2020)", the newly built coal-fired generating units in the central and eastern regions NO x Emissions must meet the emission limits of gas-fired units (50mg / m 3 ), ultra-low emissions will be the development trend of coal-fired power plants in the future. [0003] At present, the denitrification method of pulverized coal boiler mainly adopts low nitrogen combustion technology combined with selective catalytic reduction denitrification techno...

AI Technical Summary

Problems solved by technology

[0005] (1) It is necessary to arrange a catalyst layer in the flue at the tail of the boiler. The reconstruction project is difficult to construct, and the catalyst layer has body resistance, which affects the operating economy of the unit;

[0006] (2) The catalyst has a service life, and needs to be replaced regularly after deactivation, resulting in high follow-up costs, and it is difficult to regenerate and dispose of the deactivated denitrification catalyst, which is likely to cause environmental pollution;

[0008] (4) The denitrification reaction requires the use of an amino reducing agent, which has high operating costs and potential safety problems, and the amino reducing agent itself needs to consume a lot of energy in the production process, and it also pollutes the environment

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