Rapid corrosion of ND steel heat exchange tubes in waste-to-energy plants’ GGHs – what are some effective ways to prevent this corrosion?
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The figure below shows the corrosion condition of the ND steel heat exchange tubes in a GGH at a power plant after half a year of use. As can be seen from the figure, the fins are damaged and have become brittle. Usage conditions: Temperature 90~140 degrees ； Medium: the flue gas resulting from waste incineration. Let’s take a look and see if there are any good solutions.
To address the rapid corrosion problem of ND steel in the heat exchange tubes of waste-to-energy plants, the following methods can be considered to prevent corrosion: 1. Use more corrosion-resistant materials: Materials such as high-chromium steel or nickel-based alloys can be used in place of ND steel, as they possess better corrosion resistance. 2. Add an anti-corrosion coating: Apply a high-temperature and corrosion-resistant coating to the surface of the heat exchange tubes, such as fluoroplastic coatings or ceramic coatings. 3. Optimize flue gas purification: Add more effective purification steps before the flue gas enters the heat exchanger, in order to remove or reduce the concentration of corrosive substances such as sulfur and chlorine. 4. Improve operation and maintenance management: Regularly inspect and maintain the heat exchange tubes, and promptly identify and address issues that may cause corrosion, such as abnormal temperatures or fluid leaks. 5. Use corrosion inhibitors: Add corrosion inhibitors to the medium to reduce the corrosion rate. Through the above measures, the corrosion of heat exchange tubes can be effectively slowed down or avoided. .
Epoxy-coated carbon steel can be used, as well as 2205 duplex steel.
Is it better to use H fins? Has anyone encountered this before?
For GGH flue gas heat exchangers, glass-lined heat exchange tubes are the best choice; Chongqing Luohuang Power Plant uses them – I’m not sure about the corrosion situation there