A cyclone combustion boiler advanced air staged combustion denitrification system and method

Abstract

The invention discloses an advanced air staged combustion denitrification system and method for a cyclone combustion boiler. In view of the high emission of NOx pollutants in the cyclone combustion boiler itself, and the current key technologies, raw materials, and instruments for SCR flue gas denitrification in my country still need to be imported, and the technology itself requires expensive catalysts, and there is catalyst poisoning, replacement, and additional devices Unfavorable factors such as taking up space and taking up space lead to high operating costs, which greatly restricts its application. For this reason, the present invention proposes a cyclone combustion boiler advanced air staged combustion denitrification method and system, the denitrification efficiency is expected to be as high as 95%, not only can greatly reduce the NOx emission of the cyclone combustion boiler, but also compared with the SCR technology, eliminating the need for The use of expensive catalysts and the space occupied by flue gas denitrification devices have the advantages of low cost, simple equipment, and easy implementation of transformation.

Description

technical field [0001] The invention relates to an advanced air staged combustion denitrification method and system for a cyclone combustion boiler. Background technique [0002] Nitrogen oxides (NO x ) is one of the toxic substances in the exhaust gases of the chemical industry, defense industry, power industry, boilers and internal combustion engines. NO x The amount produced during fuel combustion is the largest, accounting for more than 30%, of which 70% comes from direct combustion of coal, and the fixed combustion source is NO x main source of emissions. [0003] In recent years, NO x More and more countries around the world pay more and more attention to the hazards of acid rain. It is not only one of the main reasons for the formation of acid rain, but also can produce a light blue toxic substance with carbon and oxygen compounds - nitro compounds after being irradiated by ultraviolet rays. It causes photochemical smog, which has a strong stimulating and damagin...

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Problems solved by technology

[0007] Such strict emission standards, for cyclone combustion boilers - boiler outlet NO x Emission concentration is usually 1200~1500mg / Nm 3 , to reach 100mg / Nm 3 Emission limit value, denitrification efficiency must be above 92% - the current SCR technology is simply impossible to achieve

Moreover, a large increase in the emission limit level requires a large increase in catalysts and reducing agents, making it more difficult to control ammonia slip during operation, and may cause problems such as boiler air preheater blockage that affect operational safety

When the unit is running at low load, the flue gas temperature is likely to be lower than the reaction window temperature of the denitrification catalyst, resulting in the failure of the SCR system to work normally, and it is difficult to meet the standard limit requirements

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