[{"data":1,"prerenderedAt":73},["ShallowReactive",2],{"q-fire-107-1-fire-science-026":3},{"subject":4,"subjectSlug":5,"subjectKicker":6,"subjectShort":7,"question":8,"related":27,"sameNumber":52,"hasEssay":26},"火災學概要","fire-science","火災學 · Fire Science","火災學",{"id":9,"webId":10,"year":11,"session":12,"subject":4,"number":13,"stem":14,"options":15,"answer":20,"answerNote":21,"images":22,"imagesPending":23,"lawTimestamp":11,"explanation":24,"explanationDeep":25,"freq":12,"indexable":26},"fire-107-1-火災學概要-026","fire-107-1-fire-science-026",107,1,26,"在火勢擴大的過程中，下列那一現象並非成長期的常見特徵？",{"A":16,"B":17,"C":18,"D":19},"煙層變厚","火焰延燒","材料自燃","火場溫度增加","C",null,[],false,"本題考點：室內火災各階段的特徵辨識，重點在區分成長期與閃燃後最盛期的現象。\n【正解理由】室內火災依序分為初期、成長期、最盛期與衰退期。成長期的定義是燃燒仍受燃料控制、火勢由起火物逐步向周邊可燃物擴展，此時熱釋放率上升、上層熱煙層增厚下降、室溫持續攀高。至於室內未直接接觸火焰的材料同時被輻射熱加熱到自行起火，那是閃燃發生時與其後最盛期的現象，代表火災已越過成長期，故選 C。\n【逐項排除】\n(A) 煙層變厚：燃燒生成的煙持續累積於天花板下並逐漸下降，是成長期的典型現象。\n(B) 火焰延燒：火由起火物向鄰近可燃物擴展，正是成長期得名的原因。\n(C) 材料自燃：室內可燃物受上層熱煙輻射而同時起火，屬閃燃與最盛期的特徵，並非成長期常見現象，為本題答案。\n(D) 火場溫度增加：熱釋放率隨延燒面積擴大而升高，上層煙氣與室溫隨之上升，屬成長期的固有特徵。\n【記憶點】成長期是「一處燒到多處」，閃燃後才是「全室同時燒」。","區劃火災的時間歷程可用熱釋放率對時間的曲線來理解。初期以起火物本身的燃燒為主，熱釋放率低、室溫接近常溫，此時滅火最容易；進入成長期後，火焰向鄰近可燃物擴展，熱釋放率常以 Q＝αt² 的型態增長（α 依火災成長速率分為慢速、中速、快速、極快速四級），上層熱煙層形成並逐漸增厚下降；當上層煙氣溫度累積到約 500 至 600℃、或地板面接受的輻射熱通量達到約 20 kW\u002Fm² 時，室內尚未起火的可燃物幾乎同時被引燃，即為閃燃；其後進入最盛期，燃燒受開口供氧支配轉為通風控制，火焰由開口噴出、溫度最高、對建築結構破壞最烈；可燃物耗盡後熱釋放率下降而進入衰退期。\n判斷題的關鍵在於把「逐步擴展」與「同時起火」分開：成長期的燃燒面積是一點一點長出來的，閃燃則是瞬間的全面性轉變，兩者常以「材料自燃」「全面燃燒」「開口噴出火焰」等字眼作為分界線索。\nt² 成長曲線的四級成長速率也常入題：以熱釋放率達到 1055 kW 所需時間區分，極快速約 75 秒、快速約 150 秒、中速約 300 秒、慢速約 600 秒，成長係數 α 隨之改變。可燃物型態決定落在哪一級，例如堆疊的塑膠製品與泡棉家具偏極快速，木製家具偏中速，這也解釋了為何同樣面積的空間，火載量組成不同時抵達閃燃的時間可以差上好幾倍。\n易混淆概念對照：閃燃（flashover）是成長期到最盛期的轉捩，缺的是熱；複燃（backdraft）發生於缺氧蓄積後的突然供氧，缺的是氧；滾燃（rollover）則是天花板下未燃氣體被引燃的滾動火舌，屬閃燃前兆。此外，通風控制與燃料控制的分界通常也落在閃燃前後，成長期屬燃料控制、最盛期屬通風控制，這組對應關係常與本題同時命題。",true,[28,32,36,40,44,48],{"webId":29,"stem":30,"number":31,"year":11,"session":12},"fire-107-1-fire-science-025","下列何者並非複燃（backdraft）發生之原因？",25,{"webId":33,"stem":34,"number":35,"year":11,"session":12},"fire-107-1-fire-science-027","下列何者並非高科技廠房火災之特性？",27,{"webId":37,"stem":38,"number":39,"year":11,"session":12},"fire-107-1-fire-science-024","容易著火之燃料具下列何種特性？",24,{"webId":41,"stem":42,"number":43,"year":11,"session":12},"fire-107-1-fire-science-028","下列何者並非古蹟火災防護之特性？",28,{"webId":45,"stem":46,"number":47,"year":11,"session":12},"fire-107-1-fire-science-023","熱傳導之熱流動方向為何？",23,{"webId":49,"stem":50,"number":51,"year":11,"session":12},"fire-107-1-fire-science-029","下列何者並非學校實驗室火災之特性？",29,[53,57,61,65,69],{"webId":54,"year":55,"stem":56,"number":13},"fire-111-1-fire-science-026",111,"一公克水完全汽化成水蒸氣，溫度 327℃水蒸氣體積為 V1，溫度 727℃水蒸氣體積為 V2，則 V2\u002FV1 值？",{"webId":58,"year":59,"stem":60,"number":13},"fire-110-1-fire-science-026",110,"易燃性氣體受到壓縮後溫度會有升高的狀況發生，可能會發火導致火災的發生，此現象為何？",{"webId":62,"year":63,"stem":64,"number":13},"fire-109-1-fire-science-026",109,"閃燃發生時間之影響因素中，通風為其中之一項，請問：A0(H0)1\u002F2 的通風因子公式中，A0 與 H0 各代表何意？",{"webId":66,"year":67,"stem":68,"number":13},"fire-108-1-fire-science-026",108,"乙炔加壓後容易產生分解爆炸，為避免此現象，乙炔鋼瓶常利用浸泡何種溶劑之多孔性物質，使乙炔溶解於其中，防止分解爆炸？",{"webId":70,"year":71,"stem":72,"number":13},"fire-106-1-fire-science-026",106,"有一家用延長線，欲連接電子鍋、熱水瓶及微波爐，耗電功率分別為 550 W、1100 W 及 2200 W，請問該延長線至少應具多大之容許電流？（家用電壓為 110 V）",1785123163739]