[{"data":1,"prerenderedAt":73},["ShallowReactive",2],{"q-fire-112-1-fire-science-035":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-035","fire-112-1-fire-science-035",112,1,35,"相較於氣體爆炸，一般的粉塵爆炸具有下列那種性質？",{"A":16,"B":17,"C":18,"D":19},"起火能量較低","起火溫度較低","爆炸壓力上升速率較低","破壞力較低","C",null,[],false,"本題考點：粉塵爆炸與氣體爆炸在起火條件、壓力上升速率與破壞形態上的差異。\n【正解理由】依燃燒學對非均相燃燒的通則，粉塵是固體顆粒懸浮於空氣中，火焰必須先加熱顆粒使其表面熱裂解或蒸發，釋出可燃氣體後才能與氧反應，這段熱傳與裂解要付出時間成本，使火焰傳播速度明顯慢於均相預混的氣體爆炸；壓力上升速率即單位時間內的壓力增量 dP／dt，是衡量爆炸猛烈度的指標，粉塵的火焰傳播既慢，該值自然較低，故選 C。\n【逐項排除】\n(A) 起火能量：粉塵的最小起火能量約在數十毫焦耳等級，遠高於可燃氣體的零點幾毫焦耳，並非較低。\n(B) 起火溫度：粉塵須先受熱裂解才生成可燃氣體，起火溫度高於同類可燃氣體，並非較低。\n(C) 正確：非均相燃燒使火焰傳播與壓力上升速率均較氣體爆炸緩和，這是粉塵爆炸的典型特徵。\n(D) 破壞力：粉塵爆炸燃燒持續時間長、總釋放熱量大，且壓力波會揚起沉積粉塵引發二次爆炸，破壞力不低於氣體爆炸。\n【記憶點】粉塵爆炸「難點燃、壓力升得慢，卻燒得久、破壞大」。","粉塵爆炸屬於非均相（多相）燃燒，與可燃性氣體的均相預混燃燒在機制上完全不同。氣體爆炸中燃料與空氣早已在分子尺度混合，一經引燃即以預混火焰速度傳播；粉塵爆炸則必須走完「顆粒受熱、表面熱裂解或蒸發、釋出可燃氣體、與氧混合燃燒、放熱再加熱鄰近顆粒」的連鎖過程，每一次傳播都要付出熱傳與裂解的時間，因此火焰傳播速度與壓力上升速率都比氣體爆炸緩和。工程上以爆炸指數 Kst＝(dP／dt)max×V^(1／3) 量化粉塵的爆炸猛烈度，V 為容器容積，同一粉塵須在相同體積基準下測得的值才具可比性。\n成立要件方面，氣體爆炸講可燃氣體、氧氣、點火源三要素，粉塵爆炸習慣講五要素，即三要素之外再加「粉塵懸浮成雲並達適當粒徑與濃度」與「相對密閉的空間」。粉徑愈細，比表面積愈大，最小起火能量與爆炸下限愈低；粉塵的爆炸下限以每立方公尺數十公克表示，與氣體以體積百分比表示的方式不同，這是常見的單位陷阱。\n易混淆對照可整理為三組：起火能量與起火溫度，粉塵高於氣體；壓力上升速率，粉塵低於氣體；燃燒持續時間與總釋熱量，粉塵大於氣體。特別要注意第一次爆炸的壓力波會把沉積於樑柱、管架、地面的粉塵重新揚起，形成濃度更高的粉塵雲而引發二次爆炸，這正是粉塵爆炸災損往往超過單次氣體爆炸的主因。\n延伸考點包括粉塵爆炸的防護方向（增濕、除塵、消除靜電、惰性化、爆炸洩放）、金屬粉塵遇水產生氫氣的危險，以及爆炸下限、最小起火能量與粒徑之間的定性關係。",true,[28,32,36,40,44,48],{"webId":29,"stem":30,"number":31,"year":11,"session":12},"fire-112-1-fire-science-034","對於具有分解爆炸性質的可燃性氣體，下列敘述何者錯誤？",34,{"webId":33,"stem":34,"number":35,"year":11,"session":12},"fire-112-1-fire-science-036","下列那一種措施有助於提高粉塵爆炸的防護作用以增加其安全性？",36,{"webId":37,"stem":38,"number":39,"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,{"webId":41,"stem":42,"number":43,"year":11,"session":12},"fire-112-1-fire-science-037","升高環境溫度對於環氧乙烷的分解爆炸有何影響？",37,{"webId":45,"stem":46,"number":47,"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":49,"stem":50,"number":51,"year":11,"session":12},"fire-112-1-fire-science-038","當外部風的風向不變而風速加倍時，對處於煙囪效應下的大樓而言，下列敘述何者正確？",38,[53,57,61,65,69],{"webId":54,"year":55,"stem":56,"number":13},"fire-113-1-fire-science-035",113,"某鑄造工廠因高溫鋁水洩漏，遇水引發爆炸，此為何種爆炸？",{"webId":58,"year":59,"stem":60,"number":13},"fire-111-1-fire-science-035",111,"下列何者為乾粉最主要滅火原理？",{"webId":62,"year":63,"stem":64,"number":13},"fire-110-1-fire-science-035",110,"面對廚房油鍋起火燃燒，下列何項應對動作的風險最大？",{"webId":66,"year":67,"stem":68,"number":13},"fire-109-1-fire-science-035",109,"有關引火性液體的敘述，下列何者正確？",{"webId":70,"year":71,"stem":72,"number":13},"fire-108-1-fire-science-035",108,"為避免液化石油氣儲槽因外圍起火燃燒，一時無法撲滅而發生 BLEVE 現象，可採取之防救策略下列何者正確？",1785129966625]