Flue gas denitration device using urea solution method

Abstract

The invention provides a flue gas denitration device using a urea solution method, which relates to flue gas denitration technology of a thermal power plant in the field of environmental protection. The device comprises a reactor which is connected with an upstream flue of an SCR reactor into an integral structure. The inside of the reactor is provided with a U-shaped rack pipe, one side pipe of the U-shaped rack pipe is a static mixer, and the upper end of the static mixer is an air inlet pipe communicated with the air. The other side pipe of the U-shaped rack pipe is an ammonia injection grid, and the top of the ammonia injection grid is a blind end. The bottom section of the U-shaped rack pipe is a decomposition chamber and one end of the decomposition chamber is provided with a nozzle spraying an atomized urea solution into the decomposition chamber. The decomposition chamber and the flue are arranged parallelly, the upper part of the decomposition chamber is positioned in the flue, and the lower part of the decomposition chamber is positioned outside the flue. Compared with the prior art, the device uses the heat of the flue gas to convert the urea solution into ammonia serving as a reducer of the SCR and realizes safe and economic denitration.

Description

technical field The invention relates to the flue gas denitrification technology of thermal power plants in the field of environmental protection, especially the direct removal of NO in flue gas by using urea solution in atmospheric treatment x installation. Background technique With the increasingly prominent environmental protection issues, the NO produced by coal-fired boilers in thermal power plants x The issue of emissions and ways to reduce them is rapidly attracting global attention. Among them, the selective catalytic reduction method SCR (Selective Catalytic Reduction) is the most widely used because of its high efficiency of removing NOx and the use of less reducing agent. In this method, ammonia (NH 3 ) is sprayed into the flue gas as a reducing agent, and under the action of a lower temperature and a catalyst, the NO x reduced to N 2 and H 2 O. Selectivity refers to NH 3 Selective, it only reacts with NOx, not with oxygen. Since the source of ammonia is ...

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Problems solved by technology

Since the source of ammonia is usually obtained by heating and gasifying liquid ammonia, as a dangerous chemical, liquid ammonia has safety hazards such as explosion and leakage during storage, transportation, and gasification, so its application is greatly restricted

Therefore, in places where public safety is of great concern, the pyrolysis method of urea solution is usually used to prepare ammonia, but this method usually consumes a large amount of fuel, which is very uneconomical, and the investment in urea pyrolysis equipment is relatively large

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