Li, Jinghai

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Engineering Conferences International

Refereed ProceedingsThe 12th International Conference onFluidization - New Horizons in FluidizationEngineeringEngineering Conferences International Year 2007PRESENTATION SLIDES: AnalyticalMulti-Scale Methodology for FluidizationSystems - Retrospect and ProspectJinghai LiInstitute of Process Engineering Chinese Academy of Sciences,Beijing, jhli@home.ipe.ac.cnThis paper is posted at ECI Digital Archives.http://dc.engconfintl.org/fluidization xii/12911---- from a simple idea to industrial applicationJinghai Li, Wei Ge, Jiayuan Zhang, Shiqiu GaoWei Wang, Ning Yang, Qicheng Sun & Jian GaoNational Key Laboratory of Multi‐phase Complex SystemsInstitute of Process Engineering, Chinese Academy of SciencesP. O. Box 353, Beijing 100080, P. R. ChinaAnalytical Multi-Scale Methodology for FluidizationMay 15,  2007Fluidization XII2StrategyConclusionChallengeVerificationSolutionExtensionApplicationLimitationProgress CFD IndustryFuture3Challenge41. Structure HeterogeneityAxial / RadialLocal52. State MultiplicityCo-existenceWith slight change of operation conditionAt a critical conditionJump Change (choking)63. Scale-up EffectUnder the same operating conditions 1Li: Analytical Multi-Scale Methodology for Fluidization SystemsPublished by ECI Digital Archives, 200727Heterogeneityinfluence4. Critical influence of structural changes on transport and reactionSame Number of particlesGas flow rateVolume of unitCd = 0.032 CdoCdo Cd =15.4 CdoOrientationinfluence8CD= 18.6 CD= 5.43Meso-scale clustersStructural influences on transport propertiesCD= 2.85LocalLocal &Radial9Interface：CDi<10Dense-phase:CDc≈105Dilute-phase:CDf≈100Drag coefficients in different phasesStructural influences on transport propertiesInterdependent10Challenge: Spatial-temporal Multi-Scale StructureKey/Focus: Correlation and inter-dependence between different scalesHow to formulate?What is the mechanism?What happens at meso-scale?11Strategy12Average     Multi-Scale dclInterface：Particle-fluid compromiseDense-phase:Particle-dominatedDilute-phase:Fluid-dominatedMulti-PhysicsLinear       Non-linearReductionism Holism HeterogeneityDependence between scales2The 12th International Conference on Fluidization - New Horizons in Fluidization Engineering, Art. 129 [2007]http://dc.engconfintl.org/fluidization_xii/129313Complex systemResolutionScale 1Scale 2 Scale n…...With respect to scalesDescription of individual scalesModelingNo correlation between scalesDescriptive 14Complex systemResolutionScale 1Scale 2 Scale n…...With respect to scalesDescription of individual scalesModelingCorrelativeCorrelation between scales  Closure without stabilityLower scaleHigher scale15Complex systemResolutionDescription of individual scalesMech. 1 ……Mech. 2 Mech. kWith respect to dominant mechs.Identification of extremum tendencies of each dominant mechanisms and their compromiseStabilityModelingCorrelation between scalesScale 1 Scale 2 Scale n…...With respect to scalesAnalytical (Variational) Closure with stability condition 16Insufficiency of conservation equations:Cluster-scaleParticle-scale:in dense-phaseStability  ?6 equationsDilute phaseGas velocity       UcSolid velocity      UdcVoidage εcVolume fraction   fCluster diameter dclGas velocity        UfSolid velocity      UdfVoidage εf8 VariablesDense phasein dilute-phase17Compromise between dominant mechanismsCompromiseParticle-dominatedε = minParticle-fluid compromisingWst = min|ε =minFluid-dominatedWst = minparticle fluid( )ststWN = = min1 - ε ρ18Stability ?Physical Concept of EMMS ModelStability Condition:Wst = min |ε= min Nst =minEMMSmodelOperating ConditionsCompromisebetween dominant mechanismsCorrelation between scales6 equationsDilute phaseGas velocity       UcSolid velocity      UdcVoidage εcVolume fraction   fCluster diameter dclGas velocity       UfSolid velocity      UdfVoidage εf8 VariablesDensephaseEnergy-minimization multi-scaleCluster-scaleParticle-scale:in dense-phaseIn dilute-phase3Li: Analytical Multi-Scale Methodology for Fluidization SystemsPublished by ECI Digital Archives, 2007419Mathematical Formulationmax23456( )1 1(( ) (1 )( ) 0( ) (1 )( ) 0( ) /(1 ) 0( ) (1 ) 0( ) (1 ) 0( )p p mfp mfmfp p mst mfp fc c i i c p ff f f p ff f i i c cp pf pcg f cclU Ud U gUN UF m F f m F f gF m F gF m F m F f m FF U U f U fF U U f U fF dεε ερ ερ ρε ρ ρε ρ ρ− + ⋅− −− +−= + − − − == − − − == + − − == − − − == − − − =⎡ ⎤⎢ ⎥⎣ ⎦= −XXXXXX1)10fmfgε ⋅−=To find：X={ Udc ,Uc , εc, f , dcl , Udf,  Uf,  εf }Minimizing：(1- )ststWN ε ρ=s.t.  Fi(X)=020Summary of the strategy:Applying the multi-scale method to study the stability condition of complex systems by analyzing the compromise between dominant mechanisms and correlation between different scales.21ProgressVerificationSolutionExtensionApplicationLimitation22Idea model method software industryPetroChinaSINOPECBaosteelCFDTwo-phaseTurbulenceThree phaseGranular flowEmulsionFoamNano-structureCatalysisBiological systemCompromiseTo be studied :StudyingStudied1984 1987 1994 1999To be generalizedRoadmap:2004Nst = min verifiedExtensionMathematicsPhysicsNst=min verification &Upgrading23Whether or not ? If yes, why?VerificationNst = min ?24Equilibrium: Max. EntropyLinear: Min. Entropy ProductionVerificationNon-linear: No theoryavailableImpossiblePossible: Discrete simulationNon-EquilibriumStability criterionFluidization4The 12th International Conference on Fluidization - New Horizons in Fluidization Engineering, Art. 129 [2007]http://dc.engconfintl.org/fluidization_xii/129525Pseudo-ParticleSolid particleFluid (Pseudo-particles) Micro-scale descriptionMacro-scale phenomena ParticlesGas      Pseudo-particles Objective StrategyGe & Li: CFB5, 1996;   Chem. Eng. Sci., 58, 2003, 156526Generating meso-scale structure with    micro-phenomena:1024 particles1024 CPUs + PPMMa et al., Chem. Eng. Sci., 61(21), 2006, 7096270 1 2 3 4 5 6 7123456789101112    Nst  (J/(kg.s))Time (s)1.5 2.0 2.5 3.0 3.5 4.0 4.5123456789101112    Nst  (J/(kg.s))Time (s)1.5 2.0 2.5 3.0 3.5 4.0 4.5123456789101112    Nst  (J/(kg.s))Time (s)0 1 2 3 4 5 6 7123456789101112  Nst  (J/(kg.s))Time (s)Li et al., China Particuology, 2005, 3, 290-295.Region D Region Gmin(1 )ststpWN ε ρ= =− ( )1 (v) 1 (v) v min(1 )st stVN N dVεε= ⋅ ⋅ − =− ⋅ ∫Nst min was verifiedFluid Particle-Fluid Systems Region DRegion GLocal (micro-scale) structure:Point A & BMeso-scale structure:Region DEMMS model       Radial EMMS modelGlobal (macro-scale) structure:Region GglobalcompromisePoint A Point Bst=W minε =mintemporal compromise(at any single point)regional compromisestW =spatial compromise(at any single instant)min→ minstN → minstN28Solution291988, Non-linear optimization program(difficult to use)1998, Analytical solution(complicated)2002, Complete solution(simple and available from internet):searching in the parameter spaceSolutionsNst=minεcεf8 variables   6 equationshttp://pevrc.ipe.ac.cn/emms/emmsmodel.php3From complicated to simple300.0 0.2 0.4 0.6 0.8 1.00.50.60.70.80.91.0εc(εf-εc)/(εmax-εc)min0.0 0.2 0.4 0.6 0.8 1.00.50.60.70.80.91.0minεc(εf-εc)/(εmax-εc)Dense onlyDense/Dilute Coexistence Dilute only0.0 0.2 0.4 0.6 0.8 1.00.50.60.70.80.91.0 minminεc(εf-εc)/(εmax-εc)Ug=3.4m/sNst=0.747(blue)~1(red)two roots at right top and right bottom? Local structural parameters ? Regime diagram? Choking definition? Radial and axial distribution5Li: Analytical Multi-Scale Methodology for Fluidization SystemsPublished by ECI Digital Archives, 2007631Extension to 6 different systems32ViscosityInertiaWv , Wte fluctuating Wv / Wte min75 100 125 150 1750.00000.00040.00080.0012    75 100 125 150 1750.000040.000060.00008    temporal compromise (at any point)spatial compromise(at any instant)Time stepWνWte50 100 150 200 250 300 3500510152025    Time stepWWteνminWWteν →Point APoint BRegion GRegion GPoint A & B Region GExtension 1: Turbulent FlowminWν →maxWte →Compromise between Viscosity and Inertia33ViscosityNsurf+turb fluctuating Nsurf+turb minPoint A & B Region GsurfNturb=surfRegion Gminst surf turbN N N= + →N min=minTemporal Compromise(at any  point)N =Spatial compromise(at any instant)minGasPoint APoint BRegion GSurface tensionminsurfN →minturbN →Extension 2: Gas-Liquid Bubbly FlowCompromise between movement tendencies of bubbles and liquid34Extension 3: MicroemulsionLipophileHydrophileminOHE →minWTE →3x105 4x105 5x105202530    3x105 4x105 5x105182430    minOHE =minWTE =minOHE =minrepulse WT OHE E E= + →2.0x105 4.0x105300400500    Region C Point ARegion CPoint Btemporal compromise(at any single point)spatial compromise(at any single instant)Point A & B Region CEWT , EOH fluctuating Erepulse minDenotationsH: Hydrophile group (red) T: Lipophile group (blue) W: Water (green) O: Oil (yellow)Compromise Between Hydrophile and Lipophile35Extension 4: Granular FlowStream a dominantHa , Hb fluctuating Ha+Hb minFaFbPoint A & B Region GRegion G200 300 4000.5000.5040.5080.512HatPoint B200 300 4000.5000.5040.5080.512HbPoint AHa=minHb=minHa=mintemporal compromise(at any single point)spatial compromise(at any single instant)Ha+Hb min( )Ha+HbRegion G200 400 600 8000.5000.5040.5080.512tFbStream b dominantCompromise Between Two Streams of Granular Flow36ES , Eμ fluctuating Es/Eμ min9000 10000 11000 120001820222426E s / E μTime step9000 10000 11000 120001820222426E s / E μTime step0 5000 10000 150001020304050E s/EμTime stepPoint A & B Region GRegion GLiquid Point APoint Btemporal compromise(at any single point)spatial compromise(at any single instant)Region GSurface energyViscous dissipationminsE →minEμ →Extension 5: Foam DrainageCompromise Between Surface Energy and Viscosity6The 12th International Conference on Fluidization - New Horizons in Fluidization Engineering, Art. 129 [2007]http://dc.engconfintl.org/fluidization_xii/129737Interfacial potentialtends to minimumFlow dissipation tends to minimumCompromiseExtension 6: Nano Gas-liquid FlowCompromise Between  Interfacial potential and ViscosityminS →minrϕ →382. Dominant mechanismsCompromise Definition  aH --- potential a bH --- potential bCompromise Compromise Compromise Compromise Compromise Definition  Definition  Definition  Definition  Definition  ( )ba minmin  HH ==te =max( min) WW =νteW --- turbulent dissipation Wν --- viscous dissipation st min( min)W ε ==stW --- volume specific energyconsumption for transporting andsuspending particles ε--- local voidage of the identified areasurfturb min( min)  NN ==turbN --- dissipation liquid in the turbulent surfN --- surface dissipation s min( min)  EE μ ==Eμ --- viscous dissipation sE --- surface energy OHWT min( min) EE ==WTE --- lipophilic potential OHE --- hydrophilic potential Compromise Definition  r S min( min) ϕ ==rϕ --- dissipation associated with the transportation of unit amount of kinetic energy across unit length S --- surface energy in the system1. SystemsCrossflow of granular materialsGas-solidsystemTurbulentflowEmulsion FoamdrainageTurbulentgas-liquidflowNanogas-liquidpipe flow3. Local extremumexistence indicationNoNoNoNoNoNoNoexistence indication4. Global extremumYesYesYesYesYesYesYesSummary:39Gas-solid systemTurbulenceGas-liquid system Granular flowEmulsionFoam drainageGenerality?Compromise between dominant mechanismsParticle Fluid     ViscosityInertiaSurface tensionViscosityStream AStream BHydrophileLipophileSurface energyViscous dissipation……Extremum tendency of mechanism 1 Extremum tendency of mechanism 2 40Complex systemResolutionDescription of individual scalesApplication verification modificationMech. 1 ……Mech. 2 Mech. kWith respect to dominant mechs.Identification of extremum tendencies of each dominant mechanisms and their compromisestabilityModeling Correlation between scalesScale 1 Scale 2 Scale n…...With respect to scalesAnalytical Multi-scale Methodology41Mathematical model of complex systems in general — Multi-objective variational problemEj (X)　Ek (X)mins.t.  Fi(X)=0,  i=1, 2, ……, mX = { x1, x2, ……, xn } J. Li et al., Chem. Eng. Sci., 2003, 58, 521- 535.…42Applications in CFD7Li: Analytical Multi-Scale Methodology for Fluidization SystemsPublished by ECI Digital Archives, 2007843Computer capacity: dramatic increase1985：Vax 11/780  106 flops 107 times2005:  Dawning 4000  1013 flops44FLUENT 2OrthogonalFLUENT 4StructuredFLUENT 5TetrahedralFLUENT 6.3PolyhedralAdapted from  T. Gessner et al., WCCM 2006, Fluent Inc. & Fluent User ManualsVOFK -ε KTGF SGS2006199919961983DPM + LESMesh improvementConstitutivemodelsCFD computation capability: gradual progress45WhyComputation capability is far behind computer capacity?Whatis the key problem?46Heterogeneity in a control volume !47FLUENTCFXPHOENICSCurrentSoftwaresEMMSProblem: average  CDMissing meso-structureCD  considering structure48Two-fluid models…Local parameters Cd for local cells…Start FinalMulti-scale CFD:Average approachEMMSStructure parameters & accelerationN. Yang et al., Chem. Eng. J.,  2003, 96, 71- 80.8The 12th International Conference on Fluidization - New Horizons in Fluidization Engineering, Art. 129 [2007]http://dc.engconfintl.org/fluidization_xii/129949Reproduced meso-scale structuresCFX CFX + EMMS Fluent Fluent + EMMSWang, et al., Chem.Eng.Sci., 62, 2007, 208Yang, et al., Chem.Eng.J.,96, 2003, 7150Solid output flux0 5 10 15 20 25 30020406080100120  ExperimentalSimulationOutput solid flux (kg/m2s)EMMS+CFDTime (s)0 5 10 15 20 25 30020406080100120 ExperimentalSimulationOutput solid flux (kg/m2s)Empirical correlations+CFDTime (s)CFX Only CFX + EMMS51Coexistence of dilute and dense regions in a CFB riser024681 00 .6 0 .7 0 .8 0 .9 1 .0 V o id a g eHeight (m)02468100.7 0.8 0.9 1.0 VoidageHeight (m) A BCFX Only CFX + EMMS CFD + EMMSYang, et al., Ind. Eng. Chem. Res., 43, 2004, 5548 Gidaspow & coworkers, Chem. Eng. Sci., 61, 2006, 554452Regime transition: Choking prediction ExperimentsSimulation Wang, et al., Chem.Eng.Sci., 62, 2007, 81453Flow in each gridSpatial & temporalInterface: UDFsEMMS/GlobalEMMS/MatrixEMMS/Axial…….Software(registered)CFD + EMMS: software developmentCodesCommercial5442EMMS软件包物性参数结构参数操作条件参数总体分布26新型计算流体力学方法CFX onlyCFX +EMMS0 5 10 15 20 25 30020406080100120 ExperimentalEMMSWen & Yu/ErgunOutlet solid flux (kg/m2 s)Time (s)Chem. Eng. J. 2003, 96: 71-80I&EC Res. 2004, 43: 5548-5561Computation platformEMMS CFD+EMMS Particle Method………PPM DPD SPH 计算与通信部分  DEM MaPPM粒子类 作用函数类数据结构元胞列表＋邻居列表 区域分解动态负载平衡 通信模式组织管理类 通信类 辅助类库………… 算   法………… 边界类MPI STL Loki AUTOCAD CAD 图形转换 边界条件处理 粒子生成 等区域分解等负载分解构形 前处理 数据分割MD 粒子 方法  粒子方法通用软件平台的总体结构http://pevrc.ipe.ac.cn/emms/emmsmodel.php39Li: Analytical Multi-Scale Methodology for Fluidization SystemsPublished by ECI Digital Archives, 20071055Software — EMMS EMMS software package at website (http://pevrc.ipe.ac.cn/emms/emmsmodel.php3)EMMS software package for calculating the axial and radial distribution of solid concentration, solid velocity and gas velocity in CFBInput InterfaceOutput Interface56Input windowOutput figuresSoftware — EMMS+CFDOutput tables57Applications to industries58Bayer: Pressure profile in boilerb) EMMS calculation c) On site plant data printouta) CFB boilerpressure pressureheightheight59SINOPEC Stage 1 :MIP (max. iso-paraffins) process  Shade of color: concentrationNovel FCC RiserHeight: 40 mDiameter 1∼3.5 mDetermine design parameterDiametervelocityInventory 60SINOPEC Stage 2 :Further optimization of MIP process10The 12th International Conference on Fluidization - New Horizons in Fluidization Engineering, Art. 129 [2007]http://dc.engconfintl.org/fluidization_xii/129116198 orifices 169 orifices 390 orificesSINOPEC: the influence of orifice number62Arc-shaped Basin-shaped Cone-shapedSINOPEC: the influence of distributor shape63Upright outlet Sideward outletSINOPEC: the influence of outlets640 5 10 15 20 25 3005001000150020002500 modeling measurementPressure drop (Pa/m)Height (m)0.00 0.05 0.10 0.15 0.20 0.25 0.300.30.40.50.60.70.80.91.0 modeling measurementRelative solid concentrationRelative distance from the wallSINOPEC: CFB Boiler (Wuhan) 65Before optimizationAfter optimizationPetroChina: slurry bed loop reactor 66Zhang et al. (2004), Ind. & Eng. Chem. Res. 43: 5521.Baosteel: Simulation of ore preparation for11Li: Analytical Multi-Scale Methodology for Fluidization SystemsPublished by ECI Digital Archives, 20071267Applicationsin future68Common focus of chemistry and process engineeringRelative importance69StructureFunctionPropertiesReactionTransferChemistryChemicalEngineering70Structure of Apatite SphereH. Zhang et al., Chem. Mater., 2005, 17, 5824-5830Reaction -dominated CompromiseDiffusion-dominatedQingshan Zhu’s group, Institute of Process Engineering, CASStructure of Cu2OReaction controlDiffusion controlCompromise71Multi-scale mass transferShdynamicShstaticShdilute ShdenseMeso-scaleMicro-scaleMulti-scaleStructure-dependent Sh72Comparison between CFD computation and experiments (Ouyang et al., 1995, AIChE J.)c/c 0r/r0Averaged flow & averaged mass transferMulti-scale flow &Averaged mass transfer Multi-scale flow multi-scale mass transferc/c 0r/r0c/c 0r/r0c/c 0r/r0c/c 0r/r0c/c 0r/r012The 12th International Conference on Fluidization - New Horizons in Fluidization Engineering, Art. 129 [2007]http://dc.engconfintl.org/fluidization_xii/1291373Limitations & Difficulties74Limitation of the EMMS model:Stability Condition:Wst = min |ε= min Nst =minEMMS model6 equationsUgpspGU ρ=Operating ConditionsInterface：Particle-fluid compromiseCDi<10Dense-phase:Particle-dominatedCDc≈105Dilute-phase:Fluid-dominatedCDf≈100Dilute phaseGas velocity       UdcSolid velocity      UcVoidage εcVolume fraction   fGas velocity      UdfSolid velocity     UfVoidage εf8 VariablesDense phaseCluster diameter dclCompromisebetween dominant mechanismsCorrelation between scales75Applicability of stability conditionNo, at local pointYes, at big volumehow big  volume ?Nst=min ?          760 10 20 30 40 50 60 700.05.0x10-41.0x10-31.5x10-32.0x10-32.5x10-3  σ Nst   L/DABCDFGE77Two-fluid: Constitutive modelMulti-scale: Cluster diameterDiscrete:  Micro-mechanismsNo best !But all useful !Individual               Integration !!78Focus: Spatio-temporal multi-scale structureUmbrella: Complex systems Methodology: Multi-scale methodTool: Computer simulation HighlightsNano-technology Material scienceSystems biologyConclusions13Li: Analytical Multi-Scale Methodology for Fluidization SystemsPublished by ECI Digital Archives, 20071479AcknowledgementNSFC (Natural Science Foundation of China)MOST (Ministry of Science and Technology)CAS (Chinese Academy of Sciences)ETH (Swiss Federal Institute of Technology)AvH (Alexander von Humboldt Foundation)Financial support Prof. Mooson Kwaukand Coworkers80Thank you !14The 12th International Conference on Fluidization - New Horizons in Fluidization Engineering, Art. 129 [2007]http://dc.engconfintl.org/fluidization_xii/129

PRESENTATION SLIDES: Analytical Multi-Scale Methodology for Fluidization Systems - Retrospect and Prospect

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PRESENTATION SLIDES: Analytical Multi-Scale Methodology for Fluidization Systems - Retrospect and Prospect

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