Flue gas denitration reaction system

Abstract

The invention provides a flue gas denitration reaction system, belonging to the technical field of flue gas denitration. The flue gas denitration reaction system comprises a first ammonia spraying grid, a catalyst pre-reaction area, a second ammonia spraying grid and a catalyst main reaction area, wherein the first ammonia spraying grid, the catalyst pre-reaction area, the second ammonia spraying grid and the catalyst main reaction area are arranged in a flue in sequence along a flue gas flowing direction, the first ammonia spraying grid is connected with an inlet flue, and the catalyst main reaction area is connected with an outlet flue. Under the condition of keeping certain catalyst content and ammonia content, by separately arranging the catalyst pre-reaction area and the catalyst main reaction area and correspondingly matching the first ammonia spraying grid and the second ammonia spraying grid, the denitration efficiency is improved; the amount of ammonia escape caused by insufficient denitration reaction and uneven flow field distribution is reduced, and meanwhile the economical efficiency of the system is improved.

Description

technical field [0001] The invention belongs to the technical field of flue gas denitrification, and in particular relates to a flue gas denitrification reaction system. Background technique [0002] At present, SCR denitrification technology is widely used in flue gas denitrification technologies at home and abroad due to its mature technology. With the improvement of environmental protection standards, the requirements for flue gas denitrification efficiency are becoming more and more stringent. In addition to the optimization of the catalyst itself, another key factor in improving the denitrification efficiency of SCR is the mixing and reaction of ammonia and flue gas. At present, the SCR denitrification system needs to be based on the flue gas NO x The concentration and flow velocity distribution are used to adjust the amount of ammonia sprayed in each area of ​​the ammonia injection grid to ensure the required denitrification rate. However, due to the large amount of...

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Problems solved by technology

However, for the above-mentioned first patent, when there are large differences in the concentration of nitrogen oxides and ammonia in each zone, although the ammonia-nitrogen molar ratio in each zone can be evenly distributed, the amount of ammonia can also be adjusted according to the actual situation in each zone. Demand injection, but the corresponding catalyst loading is fixed, when the partition NO x Concentration exceeds the NO of the denitrification catalyst x When the load is on, it will still affect the denitrification efficiency of the system; and for the second patent, only the second layer mixer is installed alone without effective control of the ammonia injection area itself, so when the flue gas reaches the catalyst layer, the NH 3 and NO x There is still a concentration deviation, which makes the denitrification reaction insufficient, and there is a possibility that the already relatively uniform flow field of the flue gas will be broken again after the flue gas passes through the second layer mixer

[0006] It can be seen that due to the large volume of denitrification flue gas, the complex and changeable flow field, the NO x Concentration fluctuates frequently, there is still room for improvement by adjusting the amount of ammonia injection in the upstream and improving the denitrification efficiency of the system by increasing the mixing degree of the flow field in the downstream

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