[{"data":1,"prerenderedAt":73},["ShallowReactive",2],{"q-fire-112-1-fire-science-030":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-112-1-火災學概要-030","fire-112-1-fire-science-030",112,1,30,"滅火藥劑的供給率關乎火災初期的滅火成敗、滅火時間與藥劑使用量，下列敘述何者錯誤？",{"A":16,"B":17,"C":18,"D":19},"供給率需高於界限供給率始可滅火","供給率越大則滅火藥劑所需必要量越低","供給率越大則滅火時間越短","燃燒面積越大則界限供給率越高","B",null,[],false,"本題考點：滅火藥劑供給率與界限供給率的關係，題目問錯誤敘述。\n【正解理由】依滅火藥劑供給率的基本關係，單位面積、單位時間所投入的藥劑量必須大於界限供給率，冷卻與窒息的速率才能勝過火災的產熱速率與藥劑破壞速率而完成滅火。藥劑必要量等於供給率乘以滅火時間，供給率增大雖能縮短滅火時間，但實驗曲線顯示必要量隨供給率呈先下降、通過最低點後再回升的形狀，存在一個最經濟供給率，並非越大越省。故選 B。\n【逐項排除】\n(A) 供給率必須高於界限供給率才可能滅火，這正是界限供給率的定義，敘述正確。\n(B) 把必要量說成供給率越大就越低並不正確，必要量對供給率呈先降後升、具有最低點的關係，為本題應選項。\n(C) 供給率越大，單位時間投入的冷卻與窒息能力越強，滅火時間確實越短，敘述正確。\n(D) 燃燒面積越大，火焰對藥劑的熱回饋、藥劑流失與破壞的比例升高，界限供給率隨之提高，敘述正確。\n【記憶點】供給率要「夠大」才滅得掉，但「越大越省」不成立，藥劑總量有一個最低點。","界限供給率又稱臨界供給率，指恰好能把火勢壓制到滅火的最小單位面積供給率。它的物理意義來自一個平衡：藥劑投入火面後，一部分被火焰熱回饋消耗（水汽化、泡沫破泡、藥劑分解），一部分才真正發揮冷卻、窒息或抑制作用。當供給率低於界限值，投入的藥劑全被火焰破壞，火勢不會衰減，滅火時間趨於無限大；只有超過界限值，超出的部分才形成有效滅火能力，滅火時間才會隨供給率上升而縮短。\n藥劑必要量的曲線是本題的關鍵。必要量等於供給率乘以滅火時間，供給率剛超過界限值時滅火時間極長、必要量很大；供給率提高後滅火時間急速縮短，必要量隨之下降；但供給率再往上加，滅火時間的縮短幅度趨於平緩，未參與滅火即流失、溢流的藥劑比例卻上升，必要量因而回升。整條曲線呈谷形，谷底所對應者即最經濟供給率，也是設計上追求的平衡點。\n影響界限供給率的因素可整理成三類：燃料性質（沸點低、燃燒熱高、極性溶劑會破泡者，界限供給率高）、火面規模（面積越大、火焰輻射回饋越強，界限供給率越高）、以及投射方式與環境（風速、投射角度、藥劑到達率）。這也說明同一種藥劑對不同火災類型的適用性差異。\n易混淆的名詞要分清：供給率是「單位面積單位時間投入量」，必要量是「整場火災的總投入量」，放射時間則是「設備能持續放射的時間」，三者互為乘除關係但概念不同。本考點常與泡沫滅火設備的放射量與放射時間、二氧化碳滅火設備的設計濃度與放射時間一起出題，考的都是同一組「率、量、時間」的換算邏輯。",true,[28,32,36,40,44,48],{"webId":29,"stem":30,"number":31,"year":11,"session":12},"fire-112-1-fire-science-029","有關重油油槽發生火災時可能產生的大規模沸溢（boilover）現象，下列敘述何者錯誤？",29,{"webId":33,"stem":34,"number":35,"year":11,"session":12},"fire-112-1-fire-science-031","在長寬高為10×10×4 公尺的密閉空間中以高壓式二氧化碳作為滅火防護設備。若欲將空間中的氧氣濃度降至 15%以下以達到鈍化效果，至少應加入多少立方公尺的二氧化碳？",31,{"webId":37,"stem":38,"number":39,"year":11,"session":12},"fire-112-1-fire-science-028","下列那一種前期現象比較可能因後續的消防滅火或救援作為而引發複燃？",28,{"webId":41,"stem":42,"number":43,"year":11,"session":12},"fire-112-1-fire-science-032","將大塊的木頭切碎為小片的木屑時，下列敘述何者錯誤？",32,{"webId":45,"stem":46,"number":47,"year":11,"session":12},"fire-112-1-fire-science-027","下列何種措施於室內發生火災時有助於防止或延緩閃燃的發生？",27,{"webId":49,"stem":50,"number":51,"year":11,"session":12},"fire-112-1-fire-science-033","當防火門兩側的壓力差加倍時，其透過門縫所流出的氣體體積流率有何變化？",33,[53,57,61,65,69],{"webId":54,"year":55,"stem":56,"number":13},"fire-113-1-fire-science-030",113,"有關煙控分析中「等效流動面積」的定義，下列敘述何者正確？",{"webId":58,"year":59,"stem":60,"number":13},"fire-111-1-fire-science-030",111,"下列對高樓逃生通道設計原則的描述，何者錯誤？",{"webId":62,"year":63,"stem":64,"number":13},"fire-110-1-fire-science-030",110,"某建築物火場產生大量煙霧，正向煙囪效應在中性帶以上 10 公尺處的壓力差為 12 Pa，若建築物內、外的溫度差不變，請問中性帶以上 20 公尺處的壓力差為何？",{"webId":66,"year":67,"stem":68,"number":13},"fire-109-1-fire-science-030",109,"海龍替代滅火藥劑中，下列何者在大氣之滯留時間最久？",{"webId":70,"year":71,"stem":72,"number":13},"fire-108-1-fire-science-030",108,"下列何種措施，可以防止由大樓窗口噴出的火焰向上層延燒？",1785129966594]