[{"data":1,"prerenderedAt":73},["ShallowReactive",2],{"q-fire-111-1-fire-science-023":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-111-1-火災學概要-023","fire-111-1-fire-science-023",111,1,23,"建築物起火後，對於防止火焰由下層窗戶往上層延燒，下列敘述何者錯誤？",{"A":16,"B":17,"C":18,"D":19},"窗戶「寬度\u002F高度」之值愈小，火焰愈容易向上層延燒","增加側壁高度","減少室內可燃物量","設置突出屋簷","A",null,[],false,"本題考點：火災由下層開口噴出後沿外牆向上層延燒的機制，以及開口形狀與外牆構造對延燒的影響。\n【正解理由】開口噴出火焰的貼牆程度取決於開口的寬高比。寬度除以高度的值愈小，代表開口是縱長型的窄高窗，噴出氣流集中、向外動量大，兩側又容易捲入空氣，火焰會往外前伸而離開牆面；反之寬度除以高度的值愈大的橫長型開口，火焰噴出後容易貼附外牆上升，才是向上層延燒風險高的形狀。題目要選錯誤者，(A) 把方向講反，故選 A。\n【逐項排除】\n(A) 敘述錯誤，為本題應選者：寬高比值愈小的縱長型開口，火焰反而較易脫離牆面，向上層延燒的危險並非愈高。\n(B) 增加上下層開口之間的側壁（窗間牆）高度，可拉長火焰爬升到上層開口的路徑並阻隔輻射，屬有效對策，敘述正確。\n(C) 減少室內可燃物量會降低熱釋放率，噴出火焰長度隨之縮短，向上延燒的能力下降，敘述正確。\n(D) 突出屋簷或水平遮板可把上升火焰往外撥離牆面，使其不直接舔到上層開口，屬常見的防止上層延燒手法，敘述正確。\n【記憶點】橫長開口火焰貼牆，縱長開口火焰前伸。","由開口噴出的火焰能否舔到上層開口，取決於噴出火焰的長度、貼牆程度與上下層開口之間的阻隔。開口寬高比是關鍵形狀參數：橫長型開口氣流薄而寬，兩側捲入的新鮮空氣相對少，火焰缺乏往外推的動量，會沿外牆表面貼附上升，最容易延燒到正上方；縱長型開口噴出氣流集中而厚，向外動量大、兩側捲風充分，火焰前伸離牆，反而不易貼牆上竄。這個結論來自建築防火的燃燒實驗，並非直覺可得，是本題的命題價值所在。\n外牆側的對策沿著同一個力學邏輯展開：上下層開口之間留設足夠高度的窗間牆，等於拉長火焰要爬升的距離，火焰在途中被捲入的冷空氣稀釋降溫，抵達上層開口時已不足以引燃；在開口上方設突出的屋簷或水平遮板，則是直接把上升氣流往外撥開，強迫火焰脫離牆面。兩者一個延長路徑、一個改變方向，實務上常在同一棟建築併用。\n另一條路是從火源端下手：室內可燃物量與其燃燒特性決定熱釋放率，熱釋放率決定噴出火焰的長度與溫度，可燃物量減少，火焰自然短而弱，這也是內部裝修材料受到規範的理由之一。\n相關考點連結：向上延燒屬同一棟建築的垂直延燒問題，與棟距不足時經由輻射引燃鄰棟的水平延燒要分開記憶；後者關心的是輻射熱通量與距離平方成反比，前者關心的是噴出火焰的形狀與貼牆行為。同一組觀念也常延伸考「防止延燒的三個著力點」：減少燃料、阻隔路徑、改變火焰方向。\n定性與定量的分寸也值得留意：本題四個選項都停在定性層次，考的是機制方向而非具體公式，作答時只需判斷每個對策究竟是讓火焰爬升路徑變長、讓火焰方向偏離牆面，還是讓火源本身變小；(A) 之所以是唯一錯誤，正因為它宣稱的方向與燃燒實驗的結論相反。另需注意，噴出火焰的長度會隨室內熱釋放率增大而增長，玻璃一旦全面破裂使開口擴大，原本足夠的窗間牆高度也可能不再足以阻斷，這是評估既有建築物垂直延燒風險時最常被忽略的一環。",true,[28,32,36,40,44,48],{"webId":29,"stem":30,"number":31,"year":11,"session":12},"fire-111-1-fire-science-022","連棟式木造建築物引發火災，消防隊射水同時拆除未受火勢波及的房屋，請問其採取的滅火方法係下列何者？",22,{"webId":33,"stem":34,"number":35,"year":11,"session":12},"fire-111-1-fire-science-024","下列何者非影響建築物中煙霧流動與蔓延的主要因素？",24,{"webId":37,"stem":38,"number":39,"year":11,"session":12},"fire-111-1-fire-science-021","下列有關熱量傳遞的敘述，何者正確？",21,{"webId":41,"stem":42,"number":43,"year":11,"session":12},"fire-111-1-fire-science-025","近來消防機關大力推行安裝住宅用火災警報器，其安裝位置在天花板或牆壁上緣，主要考量因素為何？",25,{"webId":45,"stem":46,"number":47,"year":11,"session":12},"fire-111-1-fire-science-020","下列對於燃燒要素的敘述，何者錯誤？",20,{"webId":49,"stem":50,"number":51,"year":11,"session":12},"fire-111-1-fire-science-026","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？",26,[53,57,61,65,69],{"webId":54,"year":55,"stem":56,"number":13},"fire-113-1-fire-science-023",113,"根據 Burgess-Wheeler 定理，若丙烷的燃燒下限為 2.2%，其燃燒熱約為多少 kcal\u002Fmole？",{"webId":58,"year":59,"stem":60,"number":13},"fire-112-1-fire-science-023",112,"在最小發火壓力以上，可燃性氣體的最小發火能量，會隨著下列那一種條件改變而下降？",{"webId":62,"year":63,"stem":64,"number":13},"fire-110-1-fire-science-023",110,"請問 2 公斤的氫氣（H2）完全燃燒，所需要的理論空氣量為多少公斤？",{"webId":66,"year":67,"stem":68,"number":13},"fire-109-1-fire-science-023",109,"若要看清某一物體，該物體與其背景間有一定之對比度。對比度之計算：C=(B\u002FB0)-1，有關對比度下列何者正確？",{"webId":70,"year":71,"stem":72,"number":13},"fire-108-1-fire-science-023",108,"乙醇在閃火點時的飽和蒸汽壓為 25 mmHg，則乙醇在常壓下的燃燒下限約為何？",1785129966820]