Low-nitrogen combustion process of circulating fluidized combustion boiler

Abstract

The invention relates to a low-nitrogen combustion process of a circulating fluidized combustion boiler. Coal water slurry is fed into a boiler furnace of the circulating fluidized combustion boiler to be used as fuel, staged combustion of the fuel is conducted, primary air is fed from the bottom of the boiler furnace, secondary air is fed from the side wall of the boiler furnace, high-temperatureflue gas in the furnace is subjected to solid-gas separation before entering a flue, and solid particles obtained through separation are returned into the boiler furnace for circulation combustion. The modes of coal water slurry combustion, staged combustion and solid particle circulation combustion are comprehensively adopted, the combustion efficiency of the boiler can be improved, and nitrogenoxides generated by the combustion process can be reduced.

Description

technical field [0001] The invention relates to the technical field of boiler combustion, in particular to a low-nitrogen combustion process for a circulating fluidized combustion boiler. Background technique [0002] As we all know, the nitrogen oxides generated by boiler combustion are very harmful. They are the main components of acid rain and photochemical smog, and nitrogen oxides can also destroy the ozone layer, which in turn leads to excessive ultraviolet rays and harms the human body. [0003] Therefore, the country has imposed strict restrictions on the emission of nitrogen oxides, resulting in a variety of methods and technologies for removing nitrogen oxides. The most common is the Selective Catalytic Reduction (SCR) denitrification method after the furnace. The efficiency is high, but its equipment cost and operating cost are also high; another common way is to use low temperature and staged combustion in the furnace to achieve partial denitrification and select...

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Problems solved by technology

[0002] As we all know, the nitrogen oxides generated by boiler combustion are very harmful. They are the main components of acid rain and photochemical smog, and nitrogen oxides can also destroy the ozone layer, which in turn leads to excessive ultraviolet rays and harms the human body.

[0003] Therefore, the country has imposed strict restrictions on the emission of nitrogen oxides, resulting in a variety of methods and technologies for removing nitrogen oxides. The most common is the Selective Catalytic Reduction (SCR) denitrification method after the furnace. The efficiency is high, but its equipment cost and operating cost are also high; another common way is to use low temperature and staged combustion in the furnace to achieve partial denitrification and selective non-catalytic reduction (Selective Non-Catalytic Reduction SNCR) denitrification in the furnace In this method, the coal particles are directly burned. The disadvantage of this method is that the temperature in the furnace is low, which leads to the low combustion efficiency of the boiler, and the SNCR equipment at the flue gas outlet still needs to be expensive. the cost of

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