A kind of sncr denitrification system and denitrification method

Abstract

The invention discloses an SNCR denitrification system and a denitrification method, comprising a first nozzle group arranged in the middle and upper part of a furnace and / or a second nozzle group connected to a flue, an ammonia liquid tank, and a mixed vaporizer. The mixing vaporizer includes ammonia liquid pipe, steam pipe, Venturi mixing pipe and vaporizing gas pipe. A three-way structure is formed between the ammonia liquid pipe, the steam pipe and the vaporizing gas pipe. The nozzle pipe adopts a casing structure, including a denitrification agent inner pipe and a cooling sleeve. The front end of the denitration agent inner pipe is provided with a Venturi atomizing tube and a nozzle arranged at the outlet end of the Venturi atomizing tube. The steam under pressure is fed into the mixed vaporizer through the steam pipe, and a negative pressure is formed when passing through the Venturi vaporization pipe, so that the denitrification agent in the ammonia liquid tank is sucked into the Venturi vaporization pipe from the ammonia liquid pipe under negative pressure; the denitrification agent and steam Mixing and heat exchange are carried out in the Venturi vaporization tube, so that the denitrification agent is vaporized; the denitrification agent vapor is sent from the vaporization gas pipe to the nozzle, and sprayed into the flue gas to remove NOx in the flue gas. The invention has the advantages of good ammonia liquid mixing and atomization effects, high denitrification efficiency and the like.

Description

technical field [0001] The invention relates to an efficient SNCR denitration system and a denitration method, belonging to the technical field of combustion flue gas treatment. Background technique [0002] Nitrogen oxides (NOx) are one of the main pollutants in the atmosphere. In my country, fossil fuels account for a high proportion of primary energy consumption. As the public's awareness of environmental protection increases, the requirements for NOx emissions in flue gas are becoming more and more stringent. In order to meet the increasingly stringent emission standards, most coal-fired flue gas denitrification adopts SNCR-SCR combined denitrification system. SNCR (Selective Non-Catalytic Reduction) does not use a catalyst, which can save investment to a certain extent, but it needs to be set in the high temperature section. SCR (Selective Catalytic Reduction) uses a catalyst and has high efficiency, but the operating cost is high due to the need to update the cataly...

AI Technical Summary

Problems solved by technology

SCR (Selective Catalytic Reduction) uses a catalyst and has high efficiency, but the operating cost is high due to the need to update the catalyst

The reason why SNCR and SCR are often used in combination is mainly due to the low NOx removal efficiency of SNCR and the high ammonia slip

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