[{"data":1,"prerenderedAt":73},["ShallowReactive",2],{"q-fire-107-1-fire-science-012":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-012","fire-107-1-fire-science-012",107,1,12,"下列何者並非容易悶燒材料之特性？",{"A":16,"B":17,"C":18,"D":19},"多孔","易產生焦化層","容易悶燒之材料亦容易自燃","閃火點低","D",null,[],false,"本題考點：悶燒(smoldering)的發生條件與材料特性,以及「閃火點」其實是液體參數。\n【正解理由】悶燒是固體在無焰狀態下的表面氧化放熱反應,反應速率受氧氣擴散控制,因此材料必須多孔讓氧氣滲入內部,受熱後又能形成焦化層以隔熱蓄熱,使反應區維持在氧化溫度。閃火點是可燃液體蒸氣與空氣形成可燃混合氣、遇火源閃燃的最低溫度,描述的是液體先蒸發再有焰燃燒的行為,與多孔固體的無焰悶燒無關,故選 D。\n【逐項排除】\n(A) 多孔是悶燒的必要條件,孔隙同時提供氧氣通路與絕熱效果,使反應熱不易散失,泡棉、鋸屑、棉織品皆屬此類。\n(B) 焦化層形成後兼具隔熱與蓄熱作用,把熱留在反應區,是悶燒能長時間持續而不熄滅的關鍵特性。\n(C) 易悶燒的多孔材料散熱面積相對小、蓄熱能力強,堆積時容易因內部發熱累積而自燃,此敘述與悶燒材料特性相符。\n(D) 閃火點低是可燃液體的性質,液體受熱先蒸發、以有焰燃燒為主,不會留下焦化層,並非悶燒材料特性,為本題應選者。\n【記憶點】悶燒三特徵是「多孔、會碳化、易自燃」;閃火點是液體的事,和悶燒沾不上邊。","悶燒是無焰的表面氧化反應,氧氣直接在固體表面與孔隙內和碳化物反應,速率受氧氣擴散限制,因此傳播極慢——典型悶燒鋒面推進速度是每秒零點零幾毫米的量級,遠低於有焰燃燒,卻可以持續數小時甚至數日;一旦條件改變,例如開門送入新鮮空氣,就可能瞬間轉為有焰燃燒。這正是火災調查中「起火時間遠早於發現時間」的常見成因,也是深夜住宅火災傷亡偏高的原因之一。\n容易悶燒的材料有共同結構特徵:多孔而低密度,氧氣得以滲入;受熱裂解後留下含碳固體殘渣而非完全汽化;導熱度低,反應熱不易散失。聚氨酯泡棉、棉花、鋸屑、稻草、香菸、活性碳與纖維板都符合。相對地,熱塑性塑膠受熱先熔融滴落、可燃液體受熱先蒸發,兩者都不形成焦化層,自然無從悶燒。\n易混淆概念對照:閃火點是液體蒸氣可被引燃的最低溫度,著火點(燃點)是移去火源後仍能持續燃燒的溫度,自燃溫度則是無外來火源即自行起火的溫度。悶燒對應的是蓄熱自燃這一組,與閃火點分屬不同體系。多孔材料大量堆積時,因體積增加而散熱面積相對縮小,內部熱量出不去,常在遠低於自燃溫度的環境中,靠氧化或微生物發熱長時間累積而起火——稻草堆、廢紙堆與含油抹布自燃都是這個機制。\n相關考點:悶燒常與一氧化碳生成量合併命題。供氧不足使不完全燃燒比例上升,悶燒產生的一氧化碳濃度明顯高於旺盛的有焰燃燒,這是密閉空間悶燒特別致命的原因,也是題目常拿來與「通風控制型火災」對照的地方。另一個延伸方向是偵測:悶燒階段幾乎沒有火焰與明顯溫升,定溫式與差動式探測器不易動作,靠的是大量微小煙粒子,因此偵煙式探測器對悶燒的早期偵測明顯有利,這組對照在警報設備的範圍也會考。",true,[28,32,36,40,44,48],{"webId":29,"stem":30,"number":31,"year":11,"session":12},"fire-107-1-fire-science-011","在高科技無塵室作業中，下列敘述何者不是避免人員帶靜電產生危害之處理方式？",11,{"webId":33,"stem":34,"number":35,"year":11,"session":12},"fire-107-1-fire-science-013","假設大氣中氧氣容積為 21%，現在一密閉空間（體積為 V）內，有三分之一體積（V\u002F3）為惰性氣體時（壓力仍為一大氣壓），該空間內氧氣濃度為多少%？",13,{"webId":37,"stem":38,"number":39,"year":11,"session":12},"fire-107-1-fire-science-010","下列有關二氧化碳滅火劑之敘述，何者錯誤？",10,{"webId":41,"stem":42,"number":43,"year":11,"session":12},"fire-107-1-fire-science-014","我國在 106 年實施 A1、A2、A3 新式火災認定方式，下列有關 A2 火災認定之敘述，何者錯誤？",14,{"webId":45,"stem":46,"number":47,"year":11,"session":12},"fire-107-1-fire-science-009","要做好火災預防工作，從理論觀點上，可由火災預防之「3E 政策」著手，下列敘述何者不屬於「3E 政策」項目？",9,{"webId":49,"stem":50,"number":51,"year":11,"session":12},"fire-107-1-fire-science-015","有一火場之消光係數為 2 m-1，請問發光物體之能見度為多少公尺？",15,[53,57,61,65,69],{"webId":54,"year":55,"stem":56,"number":13},"fire-111-1-fire-science-012",111,"密閉空間燃燒中天花板會向地面放射大量輻射熱促進地面可燃物燃燒速度，此現象為何？",{"webId":58,"year":59,"stem":60,"number":13},"fire-110-1-fire-science-012",110,"根據 NFPA265 對閃燃現象（flashover）之定義，下列敘述何者錯誤？",{"webId":62,"year":63,"stem":64,"number":13},"fire-109-1-fire-science-012",109,"下列常見之乾粉滅火藥劑敘述何者正確？",{"webId":66,"year":67,"stem":68,"number":13},"fire-108-1-fire-science-012",108,"建築物之中性帶高度受室內溫度、室外溫度及上下開口的影響，下列敘述何者錯誤？",{"webId":70,"year":71,"stem":72,"number":13},"fire-106-1-fire-science-012",106,"凡不能與氧化合之物質均非可燃物，例如氦（He）、氖（Ne）、氬（Ar）等氣體。但氮（N2）可與氧化合，亦被視為非可燃物，是因為其反應過程具何因素？",1785123163577]