[{"data":1,"prerenderedAt":73},["ShallowReactive",2],{"q-fire-107-1-fire-science-033":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-033","fire-107-1-fire-science-033",107,1,33,"燃燒時若生成的熱與散失的熱保持平衡，燃燒溫度保持均勻之燃燒為下列何者？",{"A":16,"B":17,"C":18,"D":19},"定常燃燒","定壓燃燒","定體積燃燒","定質量燃燒","A",null,[],false,"本題考點：燃燒現象依「熱平衡是否維持」所作的分類,即定常燃燒與非定常燃燒的區別。\n【正解理由】燃燒過程中若單位時間的產熱量等於向外的散熱量,系統達成熱平衡,火焰形狀、燃燒速率與溫度都不再隨時間改變,這種穩定狀態稱為定常燃燒,蠟燭、瓦斯爐與開放空間中穩定燃燒的油盤皆屬之;反之產熱大於散熱時溫度持續攀升,即為非定常燃燒,是建築物火災成長期的典型型態。題幹所述「生成熱與散失熱保持平衡、燃燒溫度保持均勻」正是定常燃燒的定義,故選 A。\n【逐項排除】\n(A) 正確:以產熱與散熱平衡、燃燒狀態不隨時間變化為要件,完全符合題意。\n(B) 錯誤:定壓燃燒指燃燒在壓力維持不變的條件下進行,屬熱力學過程條件,與熱是否平衡無關。\n(C) 錯誤:定體積燃燒指容積固定的密閉條件,燃燒時壓力與溫度反而急遽上升,通常屬非定常。\n(D) 錯誤:燃燒學並無「定質量燃燒」這一正式分類,是本題用來誘答的自創名詞。\n【記憶點】定常看熱平衡,定壓定容看熱力學條件,兩組概念不要混在一起。","燃燒現象的分類有好幾條軸線,考試最常混淆的就是把不同軸線的名詞放在同一組選項裡誘答。依熱平衡分,可分為定常燃燒與非定常燃燒:前者產熱與散熱相等,火焰穩定、溫度均勻,是燃燒器具設計追求的狀態;後者產熱大於散熱,熱量不斷蓄積,溫度與燃燒速率一路上升,建築物火災的成長期、密閉容器內的爆炸性燃燒都屬之。依燃料與空氣混合方式分,則有預混燃燒與擴散燃燒;依固體燃燒型態分,有蒸發燃燒(如硫、萘)、分解燃燒(如木材、塑膠)、表面燃燒(如木炭、金屬)與自我燃燒(如硝化纖維素,分子內自帶氧)。\n定常與非定常的理論基礎可用熱爆炸的產熱與散熱曲線理解:產熱量隨溫度呈指數上升,散熱量隨溫度呈近似線性上升,兩線相交時系統穩定,即定常燃燒;當散熱條件變差(蓄熱良好、堆積過厚、環境溫度升高)使兩線僅相切甚至不相交,溫度便持續攀升而失控,這正是自然發火與非定常燃燒的成因,也解釋了為何堆積的油布、廢棉紗與農產副產物容易自燃。\n易混淆對照:定壓燃燒與定體積燃燒描述的是壓力或容積的邊界條件,常出現在內燃機循環的討論中;定常與否描述的是時間上的穩定性,兩者不同層次。\n定常燃燒在火災工程上也有實用意義:油盤火與燃燒器火源在達到穩定後,質量損失速率趨於定值,熱釋放率也隨之固定,因此可作為實驗與火災模擬的標準火源;建築物火災則因蓄熱與可燃物依序捲入而長期處於非定常狀態,必須以成長曲線描述,兩者的分析方法完全不同。\n延伸考點:同一批概念會以「自然發火的條件」「蓄熱與散熱的平衡」「燃燒的四要素與燃燒型態分類」等形式出現,作答時先辨識題目問的是哪一條分類軸線,即可避開誘答。",true,[28,32,36,40,44,48],{"webId":29,"stem":30,"number":31,"year":11,"session":12},"fire-107-1-fire-science-032","下列何者並非防火區劃構件構造之性質？",32,{"webId":33,"stem":34,"number":35,"year":11,"session":12},"fire-107-1-fire-science-034","建築物火災發生後，若火勢由局部火災擴散至全面火災之短時間現象稱為？",34,{"webId":37,"stem":38,"number":39,"year":11,"session":12},"fire-107-1-fire-science-031","下列何者並非造成電氣火災的原因？",31,{"webId":41,"stem":42,"number":43,"year":11,"session":12},"fire-107-1-fire-science-035","描述火勢大小之物理量為下列何者？",35,{"webId":45,"stem":46,"number":47,"year":11,"session":12},"fire-107-1-fire-science-030","固體燃料火焰延燒最快的方式為下列何者？",30,{"webId":49,"stem":50,"number":51,"year":11,"session":12},"fire-107-1-fire-science-036","下列何項不是閃燃發生之條件？",36,[53,57,61,65,69],{"webId":54,"year":55,"stem":56,"number":13},"fire-111-1-fire-science-033",111,"執行危害性化學品災害搶救指導原則（HAZMAT），下列有關區域管制（Zoning）敘述何者錯誤？",{"webId":58,"year":59,"stem":60,"number":13},"fire-110-1-fire-science-033",110,"當一小爆炸發生時，其壓力波將全廠之粉塵揚起，再被隨後而至之燃燒引爆所引起之全廠性爆炸，此現象為何？",{"webId":62,"year":63,"stem":64,"number":13},"fire-109-1-fire-science-033",109,"乙醇之燃燒化學反應式為下列何者？ 9 3",{"webId":66,"year":67,"stem":68,"number":13},"fire-108-1-fire-science-033",108,"電氣火災中，下列何者為積污導電現象？",{"webId":70,"year":71,"stem":72,"number":13},"fire-106-1-fire-science-033",106,"設有一儲存倉庫使用混凝土及磚塊所築成，該倉庫長 10 m、寬 7 m、高 3.5 m。可燃物（以木材為主）總重 2100 kg，總表面積為 300 m2，倉庫內有一開口寬 1.8 m、高 2 m，試問火災持續時間最長為多少？",1785123163815]