Method and device for preventing membrane water wall type boiler from high-temperature corrosion and coking

Abstract

The invention discloses a method and a device for preventing a membrane water wall type boiler from high-temperature corrosion and coking. The method comprises the following steps of uniformly arranging a plurality of hood-type nozzles in an area, which corresponds to a main hearth combustion area, on the sidewall of the water wall of the boiler; arranging a sidewall bellows for providing an air source for all the hood-type nozzles on the outer wall of the sidewall of the water wall of the boiler; leading out a part of secondary air from the main air duct of the boiler to be fed into the sidewall bellows; ejecting the part of secondary air in parallel by clinging to the inner wall of the sidewall of the water wall of the boiler and via the plurality of hood-type nozzles, and forming a wall-clinging air protective film on the inner wall of the sidewall of the water wall of the boiler, so as to prevent the boiler from high-temperature corrosion and coking. The device mainly comprises hood-type nozzles arranged on the sidewall of the water wall of the boiler, wherein a plurality of ejection ports are uniformly designed in one end of each hood-type nozzle stretching in the boiler along a peripheral direction. The design is simple in structure and the process is economic; moreover, the occurrences of the phenomena of large-area high-temperature corrosion and coking of the water wall, which are caused by the wall-clinging combustion of pulverized coal are reduced with a remarkable effect, the safety of the sidewall of the water wall of the boiler is effectively ensured, and overhaul cost is decreased.

Description

technical field [0001] The invention relates to the technical field of boiler combustion, in particular to a method for preventing high-temperature corrosion and coking of a membrane-type water-cooled wall boiler and a device thereof. Background technique [0002] During the operation of coal-fired boilers, avoiding high-temperature corrosion of water-cooled walls is a prerequisite for safe, economical and stable operation of power plant boilers. In the boiler with the front and rear walls opposed to combustion, because a large amount of pulverized coal particles enter the furnace for combustion, a large amount of pulverized coal is likely to burn near the two side walls of the furnace, resulting in serious reduction near the water-cooled walls on both sides of the boiler. atmosphere, resulting in large-area high-temperature corrosion and coking of the water wall of the boiler. Especially with the increasingly stringent environmental protection requirements of thermal power...

AI Technical Summary

Problems solved by technology

However, after many years of practical application of this method, it is found that this kind of air leakage is directly vertical to the water-cooled wall into the furnace, and it is impossible to form a wind film on the surface of the water-cooled wall.

At the same time, the air volume of the leaked air cannot be controlled, which leads to a decrease in the combustion efficiency of the boiler and affects the economical efficiency of the boiler operation.

[0007] In the past 20 years, in the furnace type with the front and rear walls facing each other, all kinds of measures to prevent high-temperature corrosion of the side wall water-cooled wall have not been successful.

In particular, Zhundong coal, which contains a large amount of sodium, potassium and alkali metals, has been widely used in recent years, and the combustion of boilers is more likely to cause serious high-temperature corrosion and coking of water-cooled walls.

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