希臘火希臘火(flamethrower)+與石棉Asbestos3猛火油柜(flamethrower)

(c.a.1045AD)改變歷史的照片與改變歷史的發(fā)明HoytC.HottelPhanTh?KimPhúc潘金福改變歷史的橙劑（孟山都Mosanto）液體安全之提綱揮發(fā)(liquidfuelsafety)泄漏動(dòng)力學(xué)(forensicscience)點(diǎn)火與蔓延(hazardcontrol)揚(yáng)沸現(xiàn)象(boilover)液滴動(dòng)力學(xué)（dropletdynamics）水滅火動(dòng)力學(xué)(firepointtheory)7閃點(diǎn)什么是最低環(huán)境溫度，可以提供剛剛足夠的能量，讓液體表面的燃料濃度剛好可以達(dá)到支持閃燃的程度？由于液體表面的燃料濃度剛剛達(dá)到可燃限，所以點(diǎn)火過(guò)程會(huì)很快消耗那些位于可燃限附近的蒸汽，然后被高濃度的燃?xì)庀?，這一短時(shí)間的一閃即滅的點(diǎn)燃過(guò)程，被稱(chēng)作閃燃（flashfire）剛剛讓液體表面支持閃燃的環(huán)境溫度，稱(chēng)作閃點(diǎn)（flashpoint）閃點(diǎn)是液體表面存在燃爆風(fēng)險(xiǎn)的起點(diǎn)，因此對(duì)于液體燃料的存儲(chǔ)和運(yùn)輸過(guò)程的風(fēng)險(xiǎn)控制至關(guān)重要閃點(diǎn)必須用實(shí)驗(yàn)方法來(lái)測(cè)定液體燃料的危險(xiǎn)性隨溫度變化2025/6/269閃點(diǎn)的測(cè)量開(kāi)杯與閉杯測(cè)量結(jié)果美國(guó)NFPA30液體安全性的分類(lèi)FlammableIA–Flashpoint<73°F,boilingpoint<100°FFlammableIB–Flashpoint<73°F,boilingpoint>100°FFlammableIC–73°F<Flashpoint<100°FCombustibleII–100°F<Flashpoint<140°FCombustibleIIIA–140°F<Flashpoint<200°FCombustibleIIIB–Flashpoint>200°F在液體儲(chǔ)藏倉(cāng)庫(kù)中的應(yīng)用燃料分類(lèi)的地理要素由于地理位置的差異，英國(guó)采取不同的油品安全分類(lèi)系統(tǒng).揮發(fā)公式的來(lái)源RudolphClausius德國(guó)物理學(xué)家和數(shù)學(xué)家熱力學(xué)科學(xué)最重要的貢獻(xiàn)者之一第一次引入了熵的概念顯著影響了氣體和電力動(dòng)力學(xué)理論領(lǐng)域BenoitPaulémileClapeyron法國(guó)物理學(xué)家和工程師被認(rèn)為是熱力學(xué)的創(chuàng)始人有助于研究完美的氣體和均質(zhì)固體的平衡Clausius-Clapeyron方程的多種形式Clausius-Clapeyron方程的微分形式Clausius-Clapeyron方程的積分形式Clausius-Clapeyron方程Additional/

complementaryequationsTrouton’sruleDalton’slawRaoult’slaw

HeatofvaporizationattemperatureTMolecularweightBoilingpoint液面上的蒸汽分布紅外相機(jī)注視下的揮發(fā)過(guò)程常規(guī)災(zāi)害計(jì)算程序1.計(jì)算表面濃度2.用Trouton’srule計(jì)算揮發(fā)的焓值3.用Raoult’slawandDalton’slaw計(jì)算蒸汽分壓力4.找到點(diǎn)火的環(huán)境溫度or蒸發(fā)率估算Quintiere,Fundamentalsoffirephenomena,Wiley&sons,2006,pp.148

20例題1:基于低燃限的

最小點(diǎn)火環(huán)境溫度（閃點(diǎn)）估算甲醇在標(biāo)況（25Cand1atm）下的空氣中的最小點(diǎn)火溫度（閃點(diǎn)）:例題2：燃料的表面分布

學(xué)期結(jié)束，學(xué)生們希望喝點(diǎn)烈酒慶祝一下（ahottoddy）。他們有2inch高的烈酒杯，一半裝滿(mǎn)乙醇，放在微波爐內(nèi)。液體被加熱到50℃。假設(shè)蒸汽濃度在液體表面上方線(xiàn)性變化，乙醇的高低可燃限分別是3.3和19.0%（體積濃度）。計(jì)算酒杯中可以被點(diǎn)燃的區(qū)域。必要的數(shù)據(jù)，乙醇的汽化潛熱是840J/g，沸點(diǎn)是78C。hLhu例題03:從蒸氣壓到表面溫度SubstanceFormulaMWDhfkJmol-1

Dhc(lower)kJmol-1Dhc(lower)MJkg-1Cst(vol%)LFL(vol%)UFL(vol%)AIT(oC)inairFlashpoint(oC)Boilingpoint(oC)PvapatFP(atm)acetoneC3H6O58.08-249.41656.628.524.982.612.8465-18560.03622計(jì)算丙酮（acetone）的蒸氣壓達(dá)到0.036atm的環(huán)境溫度;;例題04:從表面濃度到表面溫度=>=>混合物的閃點(diǎn)液體燃料已知的一定是質(zhì)量濃度，首先需要轉(zhuǎn)換成摩爾濃度或體積濃度，這需要分子量和密度信息；在臨界溫度下，計(jì)算其飽和蒸氣壓；根據(jù)飽和蒸氣壓與摩爾濃度之乘積，就是蒸汽的分壓力；蒸汽分壓與環(huán)境壓力之比，就是蒸汽體積濃度；針對(duì)多種燃料，運(yùn)用勒夏特列定理，可以得到表面濃度是否達(dá)到低燃限的結(jié)果。如果表面濃度可燃，說(shuō)明液體閃點(diǎn)低于環(huán)境溫度，燃料屬于高風(fēng)險(xiǎn)的易燃燃料，需要特殊的安全處理措施?；旌衔锏陌踩怨浪悖?/2）混合物的安全性估算（2/2）燃料表面的蒸汽濃度（實(shí)驗(yàn)結(jié)果）27總結(jié)閃點(diǎn)是定義液體燃料點(diǎn)火潛力的單一重要的參數(shù)。閃點(diǎn)對(duì)應(yīng)于液體表面濃度達(dá)到LFL的環(huán)境溫度。閃點(diǎn)依賴(lài)于揮發(fā)過(guò)程，后者是克勞修斯-克拉佩龍方程決定的結(jié)果。28美國(guó)航空燃料簡(jiǎn)史萊特兄弟的發(fā)明為什么會(huì)成功？為什么他們的飛機(jī)會(huì)上天？通過(guò)活動(dòng)環(huán)節(jié)的天才組合增加了飛機(jī)的可控性（他們是自行車(chē)生產(chǎn)商）新發(fā)明的內(nèi)燃機(jī)具有緊湊高效的特征。利用了下列成果EtinenneLenoir,1860年發(fā)明第一款內(nèi)燃機(jī)N.A.Otto,KarlBenz,1876年發(fā)明四沖程內(nèi)燃機(jī)SamuelLangley,1896年發(fā)明蒸汽機(jī)馬達(dá)CharlesManley,1901年發(fā)明內(nèi)燃機(jī)馬達(dá)TWA800爆炸事件讓美國(guó)重新回顧燃料的安全性汽油的妙用DistilledproductfromtheprocessofmakingKeroseneforillumination.(economyandavailability)Distillant(gasoline)isusedtobedampedintoseaforsafetyreasons.Duringthefirstworldwar,theengineknock(Pinking)becameaproblemToavoidthisproblem,engineersusefuelsoflightspecificgravity.(Evaporability)燃料研究ChemicalcompositionsoffuelshadaprofoundeffectuponengineperformanceAtasinglecompressionratio,differencesinpowerdevelopmentwereminorThemoredetonationresistantthefuel,thehigherthecompressionratiothatcouldbeused,andtherefore,themoreefficientandpowerfultheenginecouldbe.32裂化問(wèn)題In1792,crackingwasusedinUKformakingilluminatinggas.1912,Burtonprocesscanmake35%gasolineoutofcrudeoil.Thecrackedfuelsgenerateresinousandgummymaterialinpipelines,causingcorrosionproblem.Theanti-knockpropertiesofcrackedfuelisnotappreciatedinthebeginning.Tetraethylleadisfoundtobegoodatresistingdetonationandoverheatingproblems.NavyintroducedTELin1926.1935,100octaneaviationgasolineintroducedinKleinpaper.33噴氣燃料MostofjetenginesdevelopedbeforetheendofworldwarIIutilizedordinarykeroseneasafuel.(Duetoavailability.Gasolineismilitarygoodsundercontrol.)Whittlehadconsidereddieselfuel,butkerosenewaschosenforflighttestingbecauseitslowfreezepoint.JP-1,aconventionallampburningkerosenewith-40Ffreezepoint.(1944)(Blowoutandreignitiondifficulties)JP-2,awide-cutfueltoexpandsupplies.(itsviscosityisunstable,riskofflammabilitybetween20and80Fatsealevel).JP-3andJP-41946,NACAevaluateFuelAandFuel-BFuelAislabeledasJP-3,withavailabilityof48%.FuelBisa100FflashpointkerosenesimilartoJP-1.Highvolatilityisabigproblemforenginesrunningat30,000feethigh.Finally,itisdecidedtolowerthevaporpressurefrom7psiato3psia,reducingevaporationlossesathighaltitudetoaverylowlevel.Thiswide-cutfuelisJP-4.35JP-4andJP-5JP-4istypicallycontains50to60%gasoline,andtheremainderiskerosene.Theprimaryadvantageofthewidecutisthegreatlyincreasedavailabilityoftheresultingfuel.USnavyuseaviationgasoline(JP-4)forturbojetaircraft.Soon,itlearnedthattheleadinthefuelwasattackingtheenginehotsectioncomponents.1952,“jetmix”,JP-5isdesignedwithahighflashpointkerosene.JP-5hasaminimumflashpointof140F,forship-boardsafetyreasons.Tomaximizeavailabilityofthisfuel,theNavyselectedamaximumfreezepointof-50F.Becausemissionisshort,whiletheseahasalargethermalmass(reservoir).JP-6Forsupersonicflight,JP-6wasdevelopedin1956.ItisakerosenebasedfuelsimilartoJP-5,butwithalowerfreezepointandimprovedthermalstability.JP-6’svaporpressureof0.5psiat100Fwasconsiderablylowerthanthe3psiofJP-4.JP-6’savailabilityis30%ofJP-4.U2JPTS(Thermallystablejetfuel)1956,withJFA-5(jetfueladditive5)37JP-7andJP-8SR-71,Mach-3speed,highheatofcombustion,paraffinsandcycloparaffins,JP-7,high-freezepoint(-46F)becauseofaerodynamicheating.CombatexperienceobservedduringtheVietnamwar,revealedthattheUSAFaircraft,usehighlightvolatileJP4hashighercombatlossesthanUSNaircraft,uselowervolatilityJP5.CrashdataindicatedthattheprobabilityofapostcrashfireforJP4isnearly100%,muchhigherthanwithakerosenefuelsuchasJP5orcommercialJetA.Ground-handlingdevice.JP-8wasdevelopedtoprovideasafer,kerosenebasedjetfuel(similartocommercialjetA-1)forAirForce.Itwasdevelopedtohaveadequateavailabilityandanacceptablefreezepoint(-47C).USAFuseJP-8forbattlefielduse.USNretainsJP-5astheshipboardfuelofchoice.JP-8+100Athightemperaturesthefueltendstobecomeunstableandprecipitatescarbonaceousmaterials.Oxygendissolvedinthefuelreactswithotherfuelcomponentstoformadditionalcarbonadoesmaterial.Fuelsystemandenginedesignersgenerallytrytorestrictthetemperatureoft