Drainage type SCR denitration urea direct injection system

Abstract

The invention relates to an SCR denitration urea direct injection system in the thermal power industry, and concretely relates to a drainage type SCR denitration urea direct injection system. The system comprises mixing units connected with urea spray guns in a one-to-one correspondence manner; each mixing unit comprises an introduction cavity, four distribution pipes and four injection cavities; the outlet of each introduction cavity is correspondingly connected with the inlets of the four injection cavities through the four distribution pipes respectively; each mixing unit is connected to the downstream outlet of each urea spray gun through the inlet end of the introduction cavity of the mixing unit; and the section of the flue corresponding to one mixing unit is a 4a * 4b rectangle, and a and b are unit lengths of the length and the width of the section of the flue respectively. The urea pyrolysis product spraying uniformity can be effectively improved, the problem of non-uniform ammonia nitrogen existing in a urea direct spraying system is solved, and the system has the advantages of being simple in principle, reliable in effect, easy to manufacture and install and the like and has good application and popularization value.

Description

technical field [0001] The invention relates to an SCR denitration urea direct injection system in the thermal power industry, in particular to a drainage type SCR denitration urea direct injection system. Background technique [0002] The denitrification system of thermal power plants consumes a lot of ammonia, and its ammonia area is generally a major hazard. In recent years, the National Energy Administration has issued several documents to promote the implementation of liquid ammonia to urea projects in thermal power plants. Some provincial and municipal governments have issued documents to speed up relevant transformation work. At present, the most widely used technical routes for converting liquid ammonia to urea are urea pyrolysis and urea hydrolysis, both of which have the problems of complex systems and high investment costs. Relatively speaking, the urea direct injection pyrolysis technology, which directly injects urea solution into the SCR inlet flue for pyrolysi...

AI Technical Summary

Problems solved by technology

However, the general number of spray guns in the urea direct injection scheme should not be too many, which will make it difficult to meet the technical requirements for the uniformity index of ammonia injection, which also has a negative impact on the popularization and use of urea direct injection technology

[0003] In view of the above problems, the current commonly used method is often to install a large number of mixing devices downstream, which is difficult to guarantee the mixing effect and increases the resistance more

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