放射熱のフィードバックを受けるウレタンブロック間の延焼拡大メカニズムに関する研究 Experimental Study on Fire Spread between Polyurethane Foam Blocks Exposed to Radiation Feedback

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Abstract

上部に煙層が形成される空間において,直線状に3 個配置したウレタンブロック間の延焼拡大実験を行い,延焼時間,発熱速度,放射熱流束,煙層温度を測定した。天井高さおよびウレタンブロック間の離隔距離をパラメータとし,9 通りの実験を行った。中央のウレタンブロックに点火後,両側のウレタンブロックに延焼した。延焼時間は天井高さが低くなるほど小さくなり,これは天井が低くなるほど点火したウレタンブロックの鉛直面の燃え下がりが早くなることと対応している。また,天井が低くなるほど,煙層からの予熱の影響により延焼したウレタンブロックの発熱速度は急激に増加し,その最大値は自由空間で燃焼した場合の3 倍程度となった。

Model scale experiments on fire spread between spaced three urethane foam blocks under smoke layer were conducted. Time to fire spread between blocks, mass loss rate of urethane foams, heat flux and smoke layer temperature were measured. The ceiling height and separation distance between specimens were varied. When the separation distance was small fire spread was occurred by flame touching. When the distance was large, it was occurred by piloted ignition. Times to fire spread were decreased as the ceiling heights are decreased because downward vertical flame spread rate of urethane foam ignited at first, which increase radiation heat flux to the adjacent urethane foam, were increased. Heat release rate calculated by mass loss rate of urethane foam ignited secondary increased considerably when the ceiling height is low. Because flame spread rate on horizontal and vertical surface were increased by the high surface temperature at the time for a fire to spread. For this reason the maximum heat release rates were almost three times of those of urethane foam measured in an open air in earlier study.

Journal

  • Bulletin of Japan Association for Fire Science and Engineering

    Bulletin of Japan Association for Fire Science and Engineering 67(1), 9-16, 2017

    Japan Association for Fire Science and Engineering

Codes

  • NII Article ID (NAID)
    130007404346
  • NII NACSIS-CAT ID (NCID)
    AN0018688X
  • Text Lang
    ENG
  • ISSN
    0546-0794
  • NDL Article ID
    028195561
  • NDL Call No.
    Z16-105
  • Data Source
    NDL  J-STAGE 
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