[{"data":1,"prerenderedAt":73},["ShallowReactive",2],{"q-fire-113-1-fire-science-040":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-113-1-火災學概要-040","fire-113-1-fire-science-040",113,1,40,"有關複燃之敘述，下列何者錯誤？",{"A":16,"B":17,"C":18,"D":19},"相對於閃燃，複燃現象發生的機率較少","複燃的發生原因是熱量累積過多","複燃可能發生在成長期或衰退期","複燃現象所釋放的能量常造成門窗的破壞","B",null,[],false,"本題考點：複燃（backdraft）之成因與發生條件，並與閃燃（flashover）作區辨。\n【正解理由】複燃是通風受限空間的火災產物：開口不足使氧氣被消耗殆盡，火焰縮小甚至轉為無焰悶燒，但室內仍維持高溫並持續熱裂解，累積大量一氧化碳等未燃可燃氣體；一旦門窗破壞或開口被打開，新鮮空氣瞬間灌入，混合氣落回燃燒範圍而急速爆燃。其觸發關鍵是氧氣突然補充，而非熱量單純累積過多；熱量累積使室內可燃物同時起火者為閃燃，兩者成因不同，故選 B。\n【逐項排除】\n(A) 複燃須同時具備缺氧蓄積未燃氣體與突然供氧兩個條件，成立門檻高於閃燃，發生機率確實較少，敘述正確。\n(B) 把複燃成因寫成熱量累積過多，是誤植閃燃的成因，敘述錯誤。\n(C) 通風受限之火災在成長期即可能因缺氧轉為悶燒，衰退期亦常維持高溫低氧狀態，兩階段都可能發生複燃，敘述正確。\n(D) 複燃伴隨急遽膨脹的壓力波與由開口噴出的火球，常造成門窗破壞，敘述正確。\n【記憶點】閃燃看熱、複燃看氧：一個是熱到全面起火，一個是開門送氧引爆。","複燃又譯回燃，英文為 backdraft，與閃燃同為室內火災的急遽現象，但成因與觸發條件完全不同，是本科最常出現的對照題型。\n閃燃屬燃料控制型火災走向全面燃燒的過程：室內可燃物持續燃燒，上部熱煙層溫度與輻射熱通量不斷升高，當熱煙層溫度約達攝氏五百至六百度、地板面輻射熱通量約達每平方公尺二十千瓦時，室內尚未起火的可燃物同時到達引燃溫度而全面起火，火災由成長期進入最盛期。其前兆是滾燃現象、熱煙層下降與輻射熱急升，關鍵變數是熱。\n複燃則屬通風控制型火災的產物：氧氣被消耗到無法維持有焰燃燒，室內轉為悶燒，但高溫仍使可燃物持續熱裂解，累積的一氧化碳等未燃氣體濃度遠高於爆炸上限，暫時無法燃燒；一旦開口打開，新鮮空氣灌入使混合氣落回燃燒範圍，便在極短時間內爆燃，伴隨壓力波與自開口噴出的火球，門窗因而破壞。其前兆包括門縫呈現吸氣與吐氣交替的脈動、黑煙自縫隙間歇噴出、窗玻璃被油污染成黃褐色並出現熱裂紋，關鍵變數是氧。\n兩者的對照可記成：閃燃看熱、複燃看氧；閃燃出現在成長期末，複燃在通風受限的成長期或衰退期都可能發生。也因為複燃需要缺氧蓄積與突然供氧兩個條件同時成立，其發生機率低於閃燃。另一個易與複燃混淆的名詞是煙氣爆炸：可燃煙氣流入相鄰尚未起火的空間並冷卻蓄積，遇到火源後引燃，其觸發條件是點火源而非開口供氧，發生位置也常不在起火室內，與複燃須靠新鮮空氣灌入的機制不同。延伸考點多集中在前兆辨識、火災成長四階段的配合，以及通風控制與燃料控制兩種燃燒型態的轉換時機。",true,[28,32,36,40,44,48],{"webId":29,"stem":30,"number":31,"year":11,"session":12},"fire-113-1-fire-science-039","有關於液化石油氣之性質與事故發生之處置原則，下列敘述何者錯誤？",39,{"webId":33,"stem":34,"number":12,"year":35,"session":12},"fire-114-1-fire-science-001","火場中輻射為熱傳遞主要的方式之一，輻射熱之性質及其計算的方式下列何者錯誤？",114,{"webId":37,"stem":38,"number":39,"year":11,"session":12},"fire-113-1-fire-science-038","惰性氣體滅火藥劑 IG541 的組成分不包括下列何者？",38,{"webId":41,"stem":42,"number":43,"year":35,"session":12},"fire-114-1-fire-science-002","建築物火災成長過程中有關衰退期的敘述何者錯誤？",2,{"webId":45,"stem":46,"number":47,"year":11,"session":12},"fire-113-1-fire-science-037","主成分為碳酸氫鉀的乾粉滅火藥劑不適用下列何種火災？",37,{"webId":49,"stem":50,"number":51,"year":35,"session":12},"fire-114-1-fire-science-003","下列有關儲槽火災之敘述何者錯誤？",3,[53,57,61,65,69],{"webId":54,"year":55,"stem":56,"number":13},"fire-112-1-fire-science-040",112,"已知距離光源 2 公尺處的減光率為 20%，則當與光源的距離加倍時，其減光率約為多少%？（提示：log(80)≒ 1.903，log(64)≒ 1.806）",{"webId":58,"year":59,"stem":60,"number":13},"fire-111-1-fire-science-040",111,"沾有油類之毛巾，集中堆置於塑膠籃而產生自然發火，其原因為下列何者？",{"webId":62,"year":63,"stem":64,"number":13},"fire-110-1-fire-science-040",110,"常見吸入火場中的煙霧而中毒者，其最主要之原因即為吸入太多的一氧化碳（CO），一氧化碳往往是火場的致命殺手，其濃度達多少時可以讓人在 1 分鐘內死亡？",{"webId":66,"year":67,"stem":68,"number":13},"fire-109-1-fire-science-040",109,"有關預混合火焰特性，下列敘述何者錯誤？",{"webId":70,"year":71,"stem":72,"number":13},"fire-108-1-fire-science-040",108,"建築物火災進入最盛期時，燃料數量龐大，但因對外開口相對較少的情況下，燃燒速度因開口通風量而受限，此現象稱為：",1785129966408]