High temperature corrosion in straw-fired power plants: Influence of steam/metal temperature on corrosion rates for TP347H

Melanie Montgomery, O Biede, OH Larsen

    Research output: Chapter in Book/Report/Conference proceedingArticle in proceedingsResearchpeer-review

    Abstract

    The corrosion in straw-fired boilers has been investigated at various straw-fired power plants in Denmark. Water/air-cooled probes, a test superheater and test sections removed from the actual superheater have been utilised to characterise corrosion and corrosion rates. This paper describes the corrosion rates measured for the TP347H type steel. The corrosion morphology at high temperature consists of grain boundary attack and selective attack of chromium. The corrosion rate increases with calculated metal temperature (based on steam temperature), however there is great variation within these results. In individual superheaters, there are significant temperature variations i.e. higher temperature in middle banks compared to the outer banks, higher temperature in leading tubes, which have a high impact on corrosion. In a single loop the assumption that heat uptake (and heat flux) is linear with respect to tube length is an oversimplification. It has been observed that corrosion is higher at certain areas of the loop, presumably due to the localised high heat flux. In addition, the corrosion rate was also seen to decrease from one year to the next, although steam temperatures were the same. The difference in the results could be traced back to a lower flue gas temperature on one side of the boiler. Although metal temperature is the most important parameter with respect to corrosion rate, flue gas temperature also plays an important role. Efforts to quantify the effect of flue gas temperature on corrosion rate are on going.
    Original languageEnglish
    Title of host publicationMaterials for Advanced power Engineering 2002
    EditorsJ.Lecomte-Beckers, M. Carton, F. Scubert, PJ Ennis
    PublisherForschungszentrum Jülich
    Publication date2002
    Publication statusPublished - 2002
    EventCOST proceedings - Liege
    Duration: 5 Nov 1829 → …

    Conference

    ConferenceCOST proceedings
    CityLiege
    Period05/11/1829 → …

    Cite this

    Montgomery, M., Biede, O., & Larsen, OH. (2002). High temperature corrosion in straw-fired power plants: Influence of steam/metal temperature on corrosion rates for TP347H. In J. L-B. M. C. F. S. PJ. E. (Ed.), Materials for Advanced power Engineering 2002 Forschungszentrum Jülich.