Flue gas denitration device

Abstract

The invention discloses a flue gas denitration device. The flue gas denitration device comprises a flue gas inlet (301), an inlet connecting flue (3), a denitration reactor (4), an outlet connecting flue (5) and a flue gas outlet (501), which are sequentially communicated. An ammonia injection grid (302) and an inlet flue guide vane (303) are arranged on the inlet connecting flue (3). A rectification device (401) and a catalyst (402) are sequentially arranged along the flowing direction of a flue gas in the denitration reactor (4). An outlet flue guide vane (502) is arranged on the outlet connecting flue (5). The flue gas inlet (301) is communicated with a high-temperature air preheater (102). The flue gas outlet (501) is communicated with a low-temperature economizer (104). A baffle plate (2) is arranged between the high-temperature air preheater (102) and the low-temperature economizer (104) to isolate the high-temperature air preheater (102) from the low-temperature economizer (104). The flue gas inlet (301) and the flue gas outlet (501) are positioned on the two opposite sides of the connecting flue (5) respectively, and are at the same height. About 2 / 3 of an interface space can be reduced, investment cost is greatly reduced, the shutdown time of a boiler is shortened, and influence on normal production is avoided.

Description

technical field [0001] The invention relates to a flue gas denitrification device, and is especially suitable for an SCR flue gas denitrification device used for removing nitrogen oxides in flue gas in small and medium pulverized coal boilers (410t / h and below). Background technique [0002] China is a country where coal is the main energy source. Coal accounts for 75% of primary energy, of which more than 84% is used through combustion. Nitrogen oxides (NOx) in the exhaust gas released by coal combustion are the main atmospheric pollutants. one of the sources of pollution. Selective Catalytic Reduction (SCR) is the most common and effective method for removing nitrogen oxides in boiler exhaust gas, and is widely used in various industrial devices. The main principle is to use ammonia as a reducing agent, mix it with air and spray it into the flue upstream of the SCR denitrification reactor, and react with the nitrogen oxides in the flue gas under the action of the catalyst...

AI Technical Summary

Problems solved by technology

[0007] In order to meet the above-mentioned height space requirements for denitrification, it is usually difficult to rely on simple interstage space compression, and usually requires relatively large adjustments to the rear heating surface, such as replacing all heat exchange elements of the economizer or air preheater with heat exchangers. Elements with higher thermal efficiency can compress the space as much as possible under the same heat transfer conditions, or move part of the heating surface to the outside of the boiler to make room for space. No matter what kind of transformation method, the investment is huge and the furnace needs to be shut down for a long time , affecting normal production; on the other hand, the above-mentioned transformation methods all need to re-calculate the boiler's thermal power, and will more or less affect the operating parameters and status of the existing boiler

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