基于欧拉多相流模型的流化床煤气化过程三维数值模拟

第38卷第3期2008年5月东南大学学报(自然科学版)JOURNALOFSOUTHEASTUNIVERSITY(NaturalScienceEdition)Vol38No3May2008王小芳金保升钟文琪(,210096):以欧拉多相流模型为基础,气相采用k-湍流模型,固相采用基于颗粒动理学理论封闭模型,引入传热传质煤热解气化过程反应模型,建立了流化床煤气化过程的三维数理模型,该模型同时考虑了稠密气固流动和相内相间的化学反应.对直径022m的流化床煤气化炉不同操作参数下的气化过程进行了三维数值模拟,获得了气化炉内气化产物的组分分布温度分布及化学反应速率变化规律.模型的计算结果与实验结果进行了比较,结果表明:数值模拟与实验吻合较好,最小相对误差仅为1%左右,最大相对误差为20%左右,平均相对误差小于14%.:流化床煤气化;欧拉模型;颗粒动理学理论;3D数值模拟:TF538:A:1001-0505(2008)03-0454-073DnumericalsimulationoncoalgasificationinfluidizedbedbasedonEulerianmultiphasefluidmodelWangXiaofangJinBaoshengZhongWenqi(SchoolofEnergyandEnvironmen,tSoutheastUniversity,Nanjing210096,China)Abstract:BasedontheEulerianmultiphasefluidmode,l3Dnumericalmodelswereestablishedtosimulatethecoalgasificationinfluidizedbed.Thegasphasewasmodeledwithk-turbulentmodelandtheparticlephasewasmodeledwithkinetictheoryofgranularflow.Submodelsincludingheattransfermode,ltransfermode,lspeciestransportmodelandchemicalreactionmodelwereaddedtoconsiderthedensegas-solidflowandchemicalreactionsinfluidizedbedcoalgasifier.Coalgasifica-tionsinafluidizedbedcoalgasifierwithdiameterof022mweresimulated.Compositionprofilesofgasproduc,ttemperaturedistributionofgasphaseandchemicalreactionratesunderdifferentop-eratingconditionswereobtained.Simulatedresultswerecomparedwithexperimentalvalues.There-sultsshowthatnumericalsimulationsareinwellagreementwiththeexperiments.Theminimumre-lativeerrorofsimulationtotheexperimentisonly1%,themaximumrelativeerrorisabout20%andthemeanrelativeerrorislessthan14%.Keywords:fluidizedbedcoalgasification;Eulerianmode;lkinetictheoryofgranularflow;3Dnu-mericalsimulation:2007-11-20.:(1982),,;(),,,,[e-mail].:(863)(2006AA05A103).:,,.[J].:,2008,38(3):454-460.,,,;..,,,,,[1]..:-.-,,,,,[2].,[3].vanWachem[4],Benyahia[5],Zhong[2],,.,.:Watanabe[6]Grbner[7],-.,.Yu[8],,,Ocampo[9].,.Yu[8],,,.,.111k-;,[2,10].11.1连续方程t(gg)+(ggg)=Sgs(1)t(ss)+(sss)=Ssg(2),,.,,S,[8]Ssg=-Sgs=Mccc(3),M,.,,,,1g=RTpNi=1YiMi(4),Yi,Mi.112动量方程1)t(ggg)+(gggg)=-gpg+ggg-(g-s)+g+SgsUs(5),Us;;g,:=34CDgsg-sds-265gg081502sggd2s+175gsg-sdsg08(6)CD=044Res100024Res(1+015Re0687s)Res1000(7)Res=ggg-sdsg(8)g=g[g+(g)T]-23g(g)I(9)g=gl+Cgg2/(10),g;gl;Cggk2/.2)t(sss)+(ssss)=-sps+ssg+(g-s)+s+SsgUs(11),ps;s,ps=ss[1+2g0s(1+e)](12)g0=351-ss,max1/3-1(13)t(ss)+(ss)s=23[(-psI+s):s+()-s+s+Dgs](14)455第3期王小芳,等:基于欧拉多相流模型的流化床煤气化过程三维数值模拟s=3(1-e2)2ssg04ds-s(15)s=-3(16)Dgs=dss418gd2ss2g-s2(17)=150sds384(1+e)g01+65(1+e)g0s2+22ssdsg0(1+e)(18)s=(-ps+ss)+s[s+(s)T]-13(s)I(19)s=432ssdsg0(1+e)(20)s=342ssdsg0(1+e)+10sds961+45sg0(1+e)2(21),g0;,;s;s;Dgs;;s;s.113能量方程,:t(ggHg)+(ggvgHg)=(gTg)+hgs(Tg-Ts)+SgsHs(22)t(ssHs)+(ssvsHs)=(sTs)+hsg(Ts-Tg)+SsgHs(23),H,,h;SH.H=jYjHj(24),,g=jXjjjXjij(25),Xjj;ij=1+ij12MjMi14281+MiMj12(26)hsg=6kgsgNusd2s(27)Nus=(7-10g+52g)1+07Re02sPr13+(133-24g+122g)Re07sPr1312:;,,,;.121煤热解反应动力学模型,:Cs++H2O+(28)n1CO2+n2CO+n3CH4+n4H2(29),i(i=1,2,,4)..1970Badzioch,[11].Kobayashi[12]:Ck1(1-Y1)S1+Y1V1Ck2(1-Y2)S2+Y2V2(30)dcdt=-(k1+k2)c(31)dvdt=dv1+dv2dt=(Y1k1+Y2k2)c(32),S1,S2;Y;V;c;v;k1,k2Arrhenius:k1(2)=A1(2)exp-E1(2)RTs(33)[12]:A1=0.2s-1,A2=13s-1,E1=0.1046kJ/mol,E2=0.1674456东南大学学报(自然科学版)第38卷kJ/mol,Y1=03,Y2=10.122气固非均相反应模型O2,H2OCO2,.,;.[8]rc=6Vckcdspi(34),Vc;pi;kc,kc=1ka+1kd-1(35),ka=ATnsexpERTs;kd=ShDgsMcRTsds.Sh=2+0654Re12Sc13;Dgs=83410-6T175p.123气体均相反应模型/,Arrhenius,2,rc=min(ra,re)(36)ra=kaTzCnACmB(37)re=vi,rMw,iAkminminRYRvR,rMw,R,BPYPNjvj,rMw,j(38),ka=Aexp-ERT;C;n,m;A,B,405.1.1[13-14]/(Pa-1s-1)znm(39)ka,1=596Tpexp(-1800/Ts)(42)ka,4=101015exp(-16000/Tg)kmol-075m225K15s-10.01.00.5(40)ka,2=20827exp(-18036/Ts)(43)ka,5=51591015exp(-3430/Tg)kmol-15m45K15s-1-1.51.51.0(41)ka,3=633exp(-14051/Ts)(44)ka,6=35521014exp(-15700/Tg)kmol-1m3Ks-1-1.01.01.0(45)ka,7=2.78103exp(-1510/Ts)kmol-1m3Ks-10.01.01.0(45)ka,8=1.04906105exp(-5478/Ts)kmol-1m3Ks-10.01.01.013,O2,CO2,H2O,CO,H2,CH4N2,i,[11]t(gYg,i)+(gYg,ivg)=-Jg,i+Ri+Si(39),Jg,ii,;Ri;Si.Fick:Jg,i=-gDi,m+tSctYg,i(40)14[9],1.,,..1(:mm),,,.064,()10m,048[8].Ocampo[9][9],23.457第3期王小芳,等:基于欧拉多相流模型的流化床煤气化过程三维数值模拟2/%/%MAVw(FC)w(C)w(H)w(O)w(N)w(S)Qdw/(MJkg-1)dp/mm/(kgm-3)2615418541753541561804296950621250:w.3/%/(kgh-1)/(kgh-1)/(kgh-1)//(H2)(CO2)(N2)(CH4)(CO)1801944642284196314406462134997280219464208558531931603708410943802844636882664814867154129580:.2,(2).,.22,,1%,20%,14%.,,.,,CO2H2,CO.:C+H2O(2-)CO+(-1)CO2+H2,[15].,12,,,,.Ocampo,:CaCO3+SO2+12O2CaSO4+CO2(41)CO2CO+H2OH2+CO2,CO+H2OH2+CO2,,CO,H2.,,.2.13(x=0).:,Cs,CO2,,CsCH4,CO2;CH4,,,,CH4,,O2,;,,,,,CO,CO2H2.2243(x=0).:Cs,.Cs-O2Cs-H2O,Cs-CO2.,,Cs-O2,,,,,,Cs-H2O,Cs-CO2,[11].,,458东南大学学报(自然科学版)第38卷,Cs-O2,,,,,Cs-O2,Cs-H2O,Cs-CO2.,.Cs-H2O,Cs-CO2,Cs-H2O,Cs-CO2.3(x=0)30122m2m.k-E,,,459第3期王小芳,等:基于欧拉多相流模型的流化床煤气化过程三维数值模拟,,,.,,,.,,,,.4Cs(References)[1],,,.[J].,2004,19(3):252-256.ZhouHongcang,JinBaosheng,ZhongZhaoping,eta.lExperimentalstudyofcoalpartialgasificationinafluid-izedbed[J].JournalofEngineeringforThermalEner-gyandPower,2004,19(3):252-256.(inChinese)[2]ZhongWenq,iZhangMingyao,JinBaosheng,eta.lThree-dimensionalsimulationofgas/solidflowinspou-tfluidbedswithkinetictheoryofgranularflow[J].Chi-neseJournalofCh