温度分层环境下火灾烟气羽流上升高度公式分析

*:20060111:,,,:(50476023);(2004BA803B034);(2005037561):10096094(2006)04009306*方俊1,疏学明2,袁宏永2,张永明1,沈兆武3(1,230027;2,100084;3,230027):,,,Morton,,,,,Morton:;;;Morton;;:TK121;TU972+.4:A0,,,,,,,,,,,,,,,,,,[1,2],,,1995,Heskestad[3]366m366m244m,,,Morton[4]1956,,CO2,25%,2000NFPA92B[5],MortonHeskestad,2,,,CFD,,1,,,,,;,,,[6]Zmax=3.8B1/40N-3/4(1)B0,m4/s3;NBruntVaisl,HzB=Aa-agudA(2)a,kg/m3;,kg/m3;g,98m/s2;u,m/s;A,m2,B0=u0r20a0-0a0g(3)u0,m/s;r0,m;a0,kg/m3,;0,kg/m3,,B0=gQc/a0CpTa0Qc,kW;Cp,J/(kg!K);Ta0[7],KN=-ga0dadZ1/2(4)B0=gQc/a0CpTa0a=0.003484P/Ta(1),Zmax=5.54Q1/4c(dTa/dZ)-3/8(5)Zmax,m;Ta,K;936420068安全与环境学报JournalofSafetyandEnvironmentVol.6No.4Aug,2006Z(5)HeskestadNFPA92B,,(5)(1)27∀2,12m12m2m:,,,,,,,,,,,,15,,30cm,,,,3DS18B20(-10~120#C,∃05∀),20cm,8,15cm,1s,A55,,,,,LDV,,WEINBERGERSPEEDCAMProLt,100/s,,00001s0001m,,30cm,,,1Fig.1Schematicplanoftheexperimentalsetup(a)t=19418s,Z=0(b)t=22484s,Z=0071m(c)t=25550s,Z=0137m(d)t=30149s,Z=0242m226∀Fig.2Smokeplumewithoutlettemperatureof26∀94Vol.6No.4安全与环境学报6430cm,,,,2()21,,,,,,,2,,,,1,,,20s,,6min,,,,2,30s,B0(3),,1,10,4abcde,15cm,ABCDE,3cmacCE,2112,4,2,25cm223FDS(FireDynamicSimulator,20),MaQuintiereFDS,,,[8],100∀,,,,,,,,,,,,4412,234,5,265,,,,,,,,31)Stage1,,,,,,2)Stage2,,11Table1Initialoutletconditionsandthermalenvironmentsofscheme1/∀/∀/(m!s-1)/(10-5m4!s-3)/Hza18022250052111080451b175250130417460485c18123125051214050447d17530063059742650485e18530063066740480596A175195018009860498B17624713033353510509C18525625024133570629D19129125030760850652E18123875024132052022Table2Initialoutletconditionsandtemperatureenvironmentsofscheme2/∀/∀/(m!s-1)/(10-5m4!s-3)/Hz12425485010536290620224254701224104054632556640133713306214245056301306039056612447420135759073822447280131740606449520068,:Aug,20063()()Fig.3Typicalexperimental(up)andsimulatedcontour(down)ofcottonwicksmokeinastratifiedenvironment5()()Fig.5Axialandambienttemperaturesinuniform(up)andstratifiedenvironments(down)4()()Fig.4Typicalexperimental(up)andsimulatedcontour(down)ofdieseloilsmokeinastratifiedenvironment6Fig.6Axialvelocitiesofcottonwickanddieseloilsmokeinthesameoutletandstratificationconditions,,,,,,3)Stage3,,,(1),278426~8,22,,,,,96Vol.6No.4安全与环境学报6471Fig.7Experimentalandintegralheightsofcottonwickanddieseloilsmokeinscheme1Heskestad,,25%,,100%,,,,,,(3)(1),,k1=a0-0(smoke)a0-0(air)1/4(6),Dai[9],,,,,,,,Morton,,6~62,,30cm,,,-1/3,k2=(Z-Z0)/d0Z0,d0,,Z0=02,(1)(5)(7)(8)Z%max=k13.8B1/40N-3/4+k2d0(7)Z%max=k15.54Q1/4cdTadZ-3/8+k2d0(8)k11,(7),22,3482Fig.8Experimentalandintegralsmokeheightsofcottonwickanddieseloilsmokeinscheme23Table3Maximumheightsandcorrectionfactorsofcottonwicksmokeofscheme1and2/m/mHmax/mk1k2a0015085039813011b0015095042313514c0015082040512763d0015102052813275e0015085044712687(1)A003065027911237B0031058911370C00308041011301D003085046311291E0030850466112781002507804221119220025083047911164(2)30025081049911044400250920514113454Table4Maximumheightsandcorrectionfactorsofdieseloilsmokeofschemes1and2/m/mHmax/mk1k2a001507503980753011c001507404050802763(1)C00306904090731301E00307504660791278100250630446078112(2)2002507004900821219720068,:Aug,200634,1,2k2!d030cm,,51),,2),,,3),,,4),References():[1]MOWRERFW.Enclosuresmokefillingrevisited[J].FireSafetyJ,1999,33:93114[2]CHOWWK,LIYZ,CUIE,etal.Naturalsmokefillinginatriumwithliquidpoolfiresupto16MW[J].BuildingandEnvironment,2001,36:121127[3]HESKESTADG.Fireplumebehaviorintemperaturestratifiedambients[J].CombustionSciandTech,1995,106:207228[4]MORTONBR,TAYLORG,TURNERJS.Turbulentgravitationalconvectionfrommaintainedandinstantaneoussources[C]//ProceedingsoftheRoyalSocietyofLondon.London:TheRoyalSociety,1956,234:123[5]NFPA.Guideforsmokemanagementsystemsinmalls,atria,andlargeareasNFPA92B2000[R].NationalFireProtectionAssociation,Quincy,MA,2000[6]FANGJun(),SHUXueming(),YUANHongyong(),etal.Solutionofintegralequationsandexperimentalanalysisoffiresmokeplumesinstablylinearlythermallystratifiedenvironments[J].EngineeringScience(),2004,1(6):3743[7]FANWeicheng().Guideoffirescience()[M].Wuhan:HubeiScienceandTechnologyPress,1993[8]MATG,QUINTIEREJG.Numericalsimulationofaxisymmetricfireplumes:accuracyandlimitations[J].FireSafetyJournal,2003,38:467492[9]DAIZ,TSENGLK,FAETHGM.Velocity/mixturefractionstatisticsofround,selfpreserving,buoyantturbulentplumes[C]//PORTLANDOR,PETERSONRB,EZEKOYEOA,etal.NationalHeatTransferConference,Proceedings,30thCombustionandFireResearch.HeatTransferinHighHeatFluxSystems.Gaithersburg,MD:NIST,1995:1933AnalysisoftheincreasingequationoffiresmokeplumesintemperaturestratifiedambientFANGJun,SHUXueming,YUANHongyong,ZHANGYongming,SHENZhaowu(1StateKeyLaboratoryofFireScience,UniversityofScienceandTechnologyofChina,Hefei230027,China;2CenterforPublicSafety,TsinghuaUniversity,Beijing100084,China;3DepartmentofModernMechanics,UniversityofScienceandTechnologyofChina,Hefei230027,China)Abstract:ThepresentpaperhasdoneaninvestigationandanalysisofthemovementsofsmolderingcottonwicksmokeandflamingdieseloilsmokeplumesinatemperaturestratifiedambientinasmallscaleenvironmentthroughexperimentalmeasurementsandCFDsimulatio