Combination materials for high temperature corrosion protection of boiler flue and its application

Abstract

The invention relates to a coating composite material for long-life high-temperature corrosion protection of boiler flue, which includes the first nickel-based self-fluxing alloy coating material, the second nickel-based self-fluxing alloy coating material, the third nickel-based self-fluxing alloy coating material, and the third nickel-based self-fluxing alloy coating material Coating materials, medium temperature and medium pressure composite coating materials, medium temperature sub-high pressure or sub-high temperature and sub-high pressure composite coating materials, high temperature and high pressure composite coating materials, cold sprayed glass fiber reinforced plastic coatings and polyurethane polymer coatings, each coating material can be used alone or in combination It is used to prepare high-temperature anti-corrosion coatings for different corrosion areas of boiler flues, and obtain high-temperature anti-corrosion boiler flues with equal lifespan. Using the above coating combination materials to prepare boiler flue high-temperature anti-corrosion coatings can accurately implement policies for specific boiler furnace types, and provide a cost-effective and equal-life corrosion protection method without reducing the service life, while maintaining the achievable process sex.

Description

technical field [0001] The invention belongs to the technical field of boiler flue anti-corrosion technology, and relates to a coating composite material for high-temperature anti-corrosion of boiler flue and its application. Background technique [0002] In the process of waste incineration, the boiler usually suffers severe high-temperature corrosion caused by chlorides, sulfides, alkali metals, etc. under high temperature conditions. Surface coating protection is the most commonly used protection method at present. It is mainly aimed at the heating surfaces of the "four tubes" of boilers such as membrane water walls of waste heat boilers and superheaters, reheaters, and economizers. Protection methods such as melting and surface deposition can inhibit or delay corrosion. Among them, thermal spraying is difficult to meet the requirements due to high porosity and low bonding strength; surfacing welding technology has been widely used and achieved good results, but it is be...

AI Technical Summary

Problems solved by technology

The heating surface area of ​​the "four tubes" in a general boiler can reach nearly a thousand or even several thousand square meters, and a general power station has at least two boilers. From this we can see that even a small power station needs tens of millions of anti-corrosion costs, which has brought huge costs to the enterprise. heavy financial burden

In fact, the interior of the boiler is divided into four flues, and the temperature of each flue has a large difference, and the corrosion rate of the high-temperature flue gas varies with the temperature. Even in the end, the occurrence rate of pipe bursts is often concentrated in some parts with the highest high-temperature corrosion rate. For these parts, it is often necessary to shut down the furnace for maintenance or cut and replace the pipes where local pipe bursts occurred. However, most of the other pipes can still be used safely for many years. Even when all the pipelines are scrapped as a whole, they are still basically intact, resulting in a large difference in the service life of each part

Therefore, this mode of using one method for unified protection of boilers not only makes the enterprise a heavy burden, but also causes a great waste of natural resources and energy

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