Variable-diameter ammonia spraying grid pipeline system, and SCR denitration device with same

Abstract

The invention discloses a variable-diameter ammonia spraying grid pipeline system, and an SCR denitration device with the same. The pipeline system comprises an ammonia supply pipeline and an ammoniaspraying pipeline, the ammonia spraying pipeline comprises a main tapered spraying tube, the ammonia supply pipeline is connected with the main tapered spraying tube, the main tapered spraying tube includes a plurality of main ammonia spraying tube sections, the calibers of the main ammonia spraying tube sections sequentially decrease from a close side of the ammonia supply pipeline to a far sideof the ammonia supply pipeline, and the adjacent main ammonia spraying tube sections are connected by a variable-diameter connecting tube. The SCR denitration device includes a gas mixer and an SCR reactor, and the outlet of the gas mixer is connected with the inlet of the SCR reactor; and the gas mixer includes the variable-diameter ammonia spraying grid pipeline system. The characteristic consistence of a flow field in the ammonia spraying grid pipeline with a flow field in a flue is achieved by designing the structure and the size of the pipeline.

Description

technical field [0001] The invention relates to the field of uniform mixing of selective catalytic reaction (Selective Catalyst Reactive, SCR) denitrification ammonia nitrogen, in particular to a variable-diameter ammonia injection grid pipeline system and an SCR denitrification device equipped with the pipeline system. Background technique [0002] SCR flue gas denitration technology is one of the most widely used flue gas denitrification technologies at present. It has the advantages of high denitrification efficiency, good selectivity, stable and reliable operation, etc. The structure of the inlet flue of the SCR system of domestic power plants has the characteristic of being inclined to one side or widening in the lateral direction, and has a 90° corner from horizontal to vertical. Inhomogeneity, especially in the 0-0.6m area of ​​the inlet flue wall near the boiler side, the flue gas flow rate changes sharply. To achieve uniform mixing of ammonia and nitrogen oxides in ...

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Problems solved by technology

There is another problem in practice: even if the opening of the ammonia injection branch control valve at the initial end on the ammonia injection main pipe is 100%, the flow rate in the branch pipe is not as large as when the ammonia injection branch control valve at the end is opened at 50% (different pipe diameter ratios , the situation may be slightly different), this is due to the shunt effect of the ammonia injection branch pipe on the ammonia injection grid main pipe, resulting in a gradual increase in the internal static distribution of the ammonia injection grid main pipe, which in turn causes the inconsistency of the flow distribution in the branch pipe

However, this patented solution can only achieve the effect of mixing the flue gas to a certain extent. Therefore, it is still necessary to improve the pipe structure of the ammonia injection grid to obtain a better mixing effect

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