[{"data":1,"prerenderedAt":72},["ShallowReactive",2],{"q-fire-108-1-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-108-1-火災學概要-040","fire-108-1-fire-science-040",108,1,40,"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：",{"A":16,"B":17,"C":18,"D":19},"無開口樓層燃燒","燃料控制燃燒","通風控制燃燒","悶燒","C",null,[],false,"本題考點：室內火災的兩種燃燒控制型態,關鍵在辨識燃燒速度是受燃料量限制還是受開口進氣量限制。\n【正解理由】室內火災進入最盛期後,可燃物大量裂解產生燃氣,此時燃燒所需空氣完全仰賴開口供應;當對外開口相對不足,空氣進入量成為瓶頸,燃燒速度即由通風量決定而非由燃料量決定,此狀態稱為通風控制燃燒。題幹敘述「燃料數量龐大、開口相對較少、燃燒速度因開口通風量而受限」正是此定義,故選 C。\n【逐項排除】\n(A) 無開口樓層是建築與消防法規上依開口面積比例所定的樓層分類用語,屬場所類別而非燃燒型態,層次與題意不符。\n(B) 燃料控制燃燒指空氣供應充足時,燃燒速度取決於可燃物的量、表面積與裂解速率,多見於火災初期成長期或室外開放空間,與題幹前提相反。\n(C) 通風控制燃燒即燃燒速度受開口進氣量所限的狀態,為最盛期典型型態,敘述正確,為本題應選者。\n(D) 悶燒是無火焰的表面燃燒,特徵為低溫、低氧、緩慢並產生大量煙粒,與最盛期燃料龐大、火勢猛烈的情境不同。\n【記憶點】看誰卡關:燃料不夠是燃料控制,空氣不夠是通風控制。","區劃空間火災的發展可分為初期成長期、閃燃、最盛期與衰退期四階段,燃燒控制型態的轉換恰與階段變化對應。成長期時燃燒面積小、室內空氣充裕,屬燃料控制;閃燃之後可燃物全面起火,需氧量暴增而開口面積固定,於是轉為通風控制;衰退期燃料消耗殆盡,又回復為燃料控制。\n\n量化上以開口因子描述通風能力,其形式為開口面積乘以開口高度的平方根,即 A 乘根號 H。經典的川越(Kawagoe)實驗指出,通風控制下木材類的燃燒速率約與開口因子成正比,常用關係式為每分鐘燃燒量約等於 5.5 乘以 A 乘根號 H(公斤每分鐘,A 以平方公尺、H 以公尺計)。由此可再推得火災持續時間約等於室內火載量除以該燃燒速率,這正是防火時效設計的理論起點。\n\n通風控制的實質後果是嚴重的不完全燃燒:氧氣不足使一氧化碳與未燃碳氫化合物大量累積,火焰常自開口向外噴出以取得空氣,室內則充滿高溫可燃燃氣。此時若突然增加開口,大量空氣湧入與蓄積燃氣混合並瞬間燃燒,即形成逆流(backdraft),其徵兆包括開口處黑煙脈動吸吐、玻璃燻黑帶油狀凝結物、無明顯火焰但高溫。\n\n易混淆概念對照:閃燃是燃料控制轉通風控制的轉捩現象,發生於氧氣尚足而燃氣累積達可燃濃度時;逆流則發生在已缺氧的通風控制階段,由外部供氧觸發。兩者的成因與發生時序相反,是本章最常設陷阱之處。悶燒又是另一路徑,屬多孔性固體的表面無焰燃燒,可長時間潛伏後轉為有焰燃燒。\n\n相關考點連結:同組概念常延伸至等值火災時間、火載量密度、開口部設置與排煙效果、以及消防搶救時開口選擇對火勢的影響等命題方向。",true,[28,32,36,40,44,48],{"webId":29,"stem":30,"number":31,"year":11,"session":12},"fire-108-1-fire-science-039","高壓氣體的爆炸界限，通常較常壓下為廣，爆炸上限也明顯提高，但下列何種氣體之爆炸範圍及爆炸上限在高壓下卻降低？",39,{"webId":33,"stem":34,"number":12,"year":35,"session":12},"fire-109-1-fire-science-001","已知辛烷的燃燒下限為 0.92（vol%），根據 Burgess-Wheeler 定理其燃燒熱約為多少？",109,{"webId":37,"stem":38,"number":39,"year":11,"session":12},"fire-108-1-fire-science-038","可燃物不藉由火焰或電器火花引起燃燒，在大氣中僅因受熱而引發燃燒的最低溫度稱為：",38,{"webId":41,"stem":42,"number":43,"year":35,"session":12},"fire-109-1-fire-science-002","三個面積分別為 0.20 m ，0.40 m ，0.60 m 之開口相互串聯時，其等效流動面積為何？",2,{"webId":45,"stem":46,"number":47,"year":11,"session":12},"fire-108-1-fire-science-037","下列有關 GHS 制度之說明，何者錯誤？",37,{"webId":49,"stem":50,"number":51,"year":35,"session":12},"fire-109-1-fire-science-003","依用戶用電設備設置規則及建築技術規則，下列避雷設置敘述何者錯誤？",3,[53,57,61,64,68],{"webId":54,"year":55,"stem":56,"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":58,"year":59,"stem":60,"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":62,"year":35,"stem":63,"number":13},"fire-109-1-fire-science-040","有關預混合火焰特性，下列敘述何者錯誤？",{"webId":65,"year":66,"stem":67,"number":13},"fire-107-1-fire-science-040",107,"下列何者並非長公路隧道火災之特性？",{"webId":69,"year":70,"stem":71,"number":13},"fire-106-1-fire-science-040",106,"下列何者會造成局部電阻值增加，而成為火災發生的原因？",1785123163440]