Life assessment for vintage boilers

Pertti Auerkari, Jorma Salonen, Stefan Holmström, Leila Laaksonen, Ulla McNiven, Olli Lehtinen, Sari Mäkinen, Ville Väänänen, Reino Nikkarila

    Research output: Chapter in Book/Report/Conference proceedingConference article in proceedingsScientific

    Abstract

    The high temperature sections of power and combined heat and power (CHP) boilers are designed for some de facto expected but finite life. Several significant damage mechanisms must be taken into account, particularly in superheaters and reheaters that are designed for creep but also suffer from thermal degradation, external erosion and corrosion, and internal steam oxidation that will gradually increase the metal temperature. As rising temperature tends to accelerate all damage mechanisms, major effects can be expected from the internal oxide growth. The feedback loop is taken into account in procedures to predict superheater life from known tube dimensions, time in operation, and other initial data. The oxide effect can be mitigated by internal cleaning, but in-service spallation of a relatively thick internal oxide can also become significant in old plants. Spallation can create problems but extends the tube life by keeping the wall cooler than with an adherent oxide. Examples are shown for boilers with more than 150 000 h of service.
    Original languageEnglish
    Title of host publicationBaltica VIII
    Subtitle of host publicationLife Management and Maintenance for Power Plants
    Place of PublicationEspoo
    PublisherVTT Technical Research Centre of Finland
    Pages78-89
    Volume2
    ISBN (Electronic)978-951-38-7594-7
    ISBN (Print)978-951-38-7593-2
    Publication statusPublished - 2010
    MoE publication typeB3 Non-refereed article in conference proceedings
    EventBALTICA VIII - International Conference on Life Management and Maintenance for Power Plants - Helsinki-Stockholm, Finland
    Duration: 18 May 201020 May 2010

    Publication series

    SeriesVTT Symposium
    Number265
    ISSN0357-9387

    Conference

    ConferenceBALTICA VIII - International Conference on Life Management and Maintenance for Power Plants
    CountryFinland
    CityHelsinki-Stockholm
    Period18/05/1020/05/10

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    Cite this

    Auerkari, P., Salonen, J., Holmström, S., Laaksonen, L., McNiven, U., Lehtinen, O., Mäkinen, S., Väänänen, V., & Nikkarila, R. (2010). Life assessment for vintage boilers. In Baltica VIII: Life Management and Maintenance for Power Plants (Vol. 2, pp. 78-89). VTT Technical Research Centre of Finland. VTT Symposium, No. 265