Boiler water-cooled wall protecting device capable of preventing coking and high temperature corrosion

Abstract

The invention belongs to the field of low nitrogen discharge of boilers, and particularly relates to a boiler water-cooled wall protecting device capable of preventing coking and high temperature corrosion. The boiler water-cooled wall protecting device comprises water-cooled tubes, flat bars, a heat preserving boiler wall and an air line, small holes are formed in the flat bars which are welded together with the water-cooled tubes in a spacing manner to form a membrane water-cooled wall, an annular space is formed between the membrane water-cooled wall and the heat preserving wall, the upper and lower ends of the annular space are sealed to form a cavity, and the air line is mounted on the heat preserving boiler wall and communicated with the cavity. A boiler combustion air distribution mode is improved, coking and high temperature corrosion of the water-cooled wall are prevented, and high efficient combustion of coal dust and low nitrogen discharge are realized at the same time.

Description

technical field [0001] The invention belongs to the field of low-nitrogen discharge of boilers, and in particular relates to a boiler water wall protection structure for preventing coking and high-temperature corrosion. Background technique [0002] Coal occupies a dominant position in the energy structure of the world, especially China, but a large amount of nitrogen oxides are produced during coal combustion, resulting in severe acid rain and photochemical smog, hindering the sustainable development of the economy. In order to effectively reduce nitrogen oxide emissions, researchers have developed some low-nitrogen combustion technologies, such as low-nitrogen burners, air / fuel staging, overfired air, and flue gas recirculation. Among them, air staged combustion is a low-nitrogen combustion technology that is widely used at present. Its principle is to introduce part of the air required for combustion, generally called "separated burn-off air", from an appropriate distance...

AI Technical Summary

Problems solved by technology

[0003] However, while air staged combustion obtains the benefits of low nitrogen emissions, it also brings some "side effects", mainly as follows: First, the main combustion zone is a reducing atmosphere, with a large amount of hydrogen sulfide, carbon monoxide, hydrocarbon functional groups and unburned The exhausted coke and other reducing substances, the airflow is prone to deflection, and then strongly hits the water wall, resulting in coking and high-temperature corrosion of the water wall; secondly, air staged combustion achieves low nitrogen emissions, which often reduces the combustion efficiency of pulverized coal. Unable to achieve efficient pulverized coal combustion and low nitrogen emissions at the same time

For these existing problems, there is currently no effective solution, and some new combustion methods are still being explored

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