Freezing of coal in the underground storage of a power plant

J. Sipilä (Corresponding Author), Pertti Auerkari, Stefan Holmström, J. Itkonen, K. Aaltonen

    Research output: Contribution to journalArticleScientificpeer-review

    3 Citations (Scopus)

    Abstract

    A coal freezing incident in the underground coal storage of the Salmisaari power plant in Helsinki represents a unique risk factor in terms of the contributing mechanisms. Filling with subzero temperature coal in winter froze silo drains with seepage water, resulting in its leakage into the silo to form large lumps of icy coal that blocked the fuel discharge system. Compared to any previous experience with freezing of coal in transport or storage, including closed storage silos, the unexpected direction of heat transfer from storage wall to coal means an additional challenge in its mitigation, for example, by application of freeze conditioning agents. To assess the accompanying risk and options, the strength of the frozen coal has been modelled from the expected behaviour bounded by the extremes of moisture content. Based on this strength model and realistic distributions of the input variables, a Monte Carlo analysis has been used to assess the expected strength of frozen coal under the local winter climatic conditions. The results suggest that the strength of frozen coal in the discharge hoppers is typically strong to render immediate remedial action tedious and thus explain the challenge to the plant operation.
    Original languageEnglish
    Pages (from-to)38-42
    Number of pages4
    JournalCold Regions Science and Technology
    Volume79-80
    DOIs
    Publication statusPublished - 2012
    MoE publication typeA1 Journal article-refereed

    Fingerprint

    underground storage
    Freezing
    freezing
    power plant
    Power plants
    Coal
    coal
    Coal storage
    Hoppers
    Monte Carlo analysis
    Leakage (fluid)
    Seepage
    winter
    risk factor
    conditioning
    drain
    leakage
    Moisture
    heat transfer
    moisture content

    Keywords

    • Coal
    • freezing
    • ice
    • silo
    • strength model
    • underground storage

    Cite this

    Sipilä, J. ; Auerkari, Pertti ; Holmström, Stefan ; Itkonen, J. ; Aaltonen, K. / Freezing of coal in the underground storage of a power plant. In: Cold Regions Science and Technology. 2012 ; Vol. 79-80. pp. 38-42.
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    title = "Freezing of coal in the underground storage of a power plant",
    abstract = "A coal freezing incident in the underground coal storage of the Salmisaari power plant in Helsinki represents a unique risk factor in terms of the contributing mechanisms. Filling with subzero temperature coal in winter froze silo drains with seepage water, resulting in its leakage into the silo to form large lumps of icy coal that blocked the fuel discharge system. Compared to any previous experience with freezing of coal in transport or storage, including closed storage silos, the unexpected direction of heat transfer from storage wall to coal means an additional challenge in its mitigation, for example, by application of freeze conditioning agents. To assess the accompanying risk and options, the strength of the frozen coal has been modelled from the expected behaviour bounded by the extremes of moisture content. Based on this strength model and realistic distributions of the input variables, a Monte Carlo analysis has been used to assess the expected strength of frozen coal under the local winter climatic conditions. The results suggest that the strength of frozen coal in the discharge hoppers is typically strong to render immediate remedial action tedious and thus explain the challenge to the plant operation.",
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    author = "J. Sipil{\"a} and Pertti Auerkari and Stefan Holmstr{\"o}m and J. Itkonen and K. Aaltonen",
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    Freezing of coal in the underground storage of a power plant. / Sipilä, J. (Corresponding Author); Auerkari, Pertti; Holmström, Stefan; Itkonen, J.; Aaltonen, K.

    In: Cold Regions Science and Technology, Vol. 79-80, 2012, p. 38-42.

    Research output: Contribution to journalArticleScientificpeer-review

    TY - JOUR

    T1 - Freezing of coal in the underground storage of a power plant

    AU - Sipilä, J.

    AU - Auerkari, Pertti

    AU - Holmström, Stefan

    AU - Itkonen, J.

    AU - Aaltonen, K.

    PY - 2012

    Y1 - 2012

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    AB - A coal freezing incident in the underground coal storage of the Salmisaari power plant in Helsinki represents a unique risk factor in terms of the contributing mechanisms. Filling with subzero temperature coal in winter froze silo drains with seepage water, resulting in its leakage into the silo to form large lumps of icy coal that blocked the fuel discharge system. Compared to any previous experience with freezing of coal in transport or storage, including closed storage silos, the unexpected direction of heat transfer from storage wall to coal means an additional challenge in its mitigation, for example, by application of freeze conditioning agents. To assess the accompanying risk and options, the strength of the frozen coal has been modelled from the expected behaviour bounded by the extremes of moisture content. Based on this strength model and realistic distributions of the input variables, a Monte Carlo analysis has been used to assess the expected strength of frozen coal under the local winter climatic conditions. The results suggest that the strength of frozen coal in the discharge hoppers is typically strong to render immediate remedial action tedious and thus explain the challenge to the plant operation.

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