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Flow Distribution Influences onFlow Distribution Influences onAir Pollution Control Equipment Air Pollution Control Equipment
PerformancePerformanceRobert Mudry, P.E.Vice President – EngineeringAirflow Sciences [email protected]
WPCA Seminar – AmerenMay 31 – June 1, 2006
Robert Mudry, P.E.Robert Mudry, P.E.Vice President Vice President –– EngineeringEngineeringAirflow Sciences CorporationAirflow Sciences Corporationrmudryrmudry@@airflowsciencesairflowsciences.com.com
WPCA Seminar WPCA Seminar –– AmerenAmerenMay 31 May 31 –– June 1, 2006June 1, 2006
11Airflow Sciences Corporation
OutlineOutline
IntroductionFlow Distribution Analysis TechniquesApplication to Air Pollution Control Equipment• ESP• FF• SCR• FGD
Other ApplicationsConclusionsQuestions
IntroductionIntroductionFlow Distribution Analysis TechniquesFlow Distribution Analysis TechniquesApplication to Air Pollution Control EquipmentApplication to Air Pollution Control Equipment•• ESPESP•• FFFF•• SCRSCR•• FGDFGD
Other ApplicationsOther ApplicationsConclusionsConclusionsQuestionsQuestions
22Airflow Sciences Corporation
IntroductionIntroduction
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Why is Flow Distribution Important to APC Equipment?• Performance
Flow uniformityChemical species injectionAsh capture / build-up
• Operating costsPressure dropErosionCorrosion
Applications• Design of new equipment• Retrofit of existing equipment• Solving operational or maintenance issues
Why is Flow Distribution Important to APC Equipment?Why is Flow Distribution Important to APC Equipment?•• Performance Performance
Flow uniformityFlow uniformityChemical species injectionChemical species injectionAsh capture / buildAsh capture / build--upup
•• Operating costsOperating costsPressure dropPressure dropErosionErosionCorrosionCorrosion
ApplicationsApplications•• Design of new equipmentDesign of new equipment•• Retrofit of existing equipmentRetrofit of existing equipment•• Solving operational or maintenance issuesSolving operational or maintenance issues
OutlineOutline
Introduction
Flow Distribution Analysis Techniques• Field Testing• Computational Fluid Dynamics (CFD)• Physical Flow Modeling
Application to APC Equipment
Other Applications
Conclusions
Questions
IntroductionIntroduction
Flow Distribution Analysis TechniquesFlow Distribution Analysis Techniques•• Field TestingField Testing•• Computational Fluid Dynamics (CFD)Computational Fluid Dynamics (CFD)•• Physical Flow ModelingPhysical Flow Modeling
Application to APC EquipmentApplication to APC Equipment
Other ApplicationsOther Applications
ConclusionsConclusions
QuestionsQuestions
44Airflow Sciences Corporation
ESP Field Testing
Field Testing Field Testing Velocity
Temperature
Pressure
Particulate
Chemical species
VelocityVelocity
TemperatureTemperature
PressurePressure
ParticulateParticulate
Chemical speciesChemical species
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Physical Flow Physical Flow ModelingModeling
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Pros• Easy flow visualization• Ash buildup analysis• Touch & feel benefit• Gas injection possible
Cons• “Cold” flow• Geometric simplification• Scaled (incl perforated plate)• Longer schedule & more $$ than CFD model• Harder to make design changes (serial)
ProsPros•• Easy flow visualizationEasy flow visualization•• Ash Ash buildupbuildup analysisanalysis•• Touch & feel benefitTouch & feel benefit•• Gas injection possibleGas injection possible
ConsCons•• ““ColdCold”” flowflow•• Geometric simplificationGeometric simplification•• Scaled (Scaled (inclincl perforated plate)perforated plate)•• Longer schedule & more $$ than CFD modelLonger schedule & more $$ than CFD model•• Harder to make design changes (serial)Harder to make design changes (serial)
Computational Fluid Dynamics (CFD) Computational Fluid Dynamics (CFD) ModelingModeling
Pros• Thermal effects considered• Full scale• Lower $$ and time than physical model• Liquid & gas injection possible• Easy to make changes• Design runs done in parallel
Cons• Geometry is “virtual”• Bulk effects of small geometry modeled• Ash dropout & reentrainment prediction issues• Require high-end computers
ProsPros•• Thermal effects consideredThermal effects considered•• Full scaleFull scale•• Lower $$ and time than physical modelLower $$ and time than physical model•• Liquid & gas injection possibleLiquid & gas injection possible•• Easy to make changesEasy to make changes•• Design runs done in parallelDesign runs done in parallel
ConsCons•• Geometry is Geometry is ““virtualvirtual””•• Bulk effects of small geometry Bulk effects of small geometry modeledmodeled•• Ash dropout & Ash dropout & reentrainmentreentrainment prediction issuesprediction issues•• Require highRequire high--end computersend computers
77Airflow Sciences Corporation
OutlineOutline
IntroductionFlow Distribution Analysis TechniquesApplication to APC Equipment• ESP• FF• SCR• FGD
Other ApplicationsConclusionsQuestions
IntroductionIntroductionFlow Distribution Analysis TechniquesFlow Distribution Analysis TechniquesApplication to APC EquipmentApplication to APC Equipment•• ESPESP•• FFFF•• SCRSCR•• FGDFGD
Other ApplicationsOther ApplicationsConclusionsConclusionsQuestionsQuestions
88Airflow Sciences Corporation
ESP Flow ModelingESP Flow Modeling
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Flow distribution
Flow balance between cells
Pressure loss
Thermal mixing
Gas conditioning
Ash deposition
Flow distributionFlow distribution
Flow balance Flow balance between cellsbetween cells
Pressure lossPressure loss
Thermal mixingThermal mixing
Gas conditioningGas conditioning
Ash depositionAsh deposition
ESP Velocity DistributionESP Velocity DistributionUniform velocity within collection region
Industry standards• ICAC• % RMS
deviation
Uniform velocity within collection regionUniform velocity within collection region
Industry standardsIndustry standards•• ICACICAC•• % RMS % RMS
deviationdeviation
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Gas Flow BalanceGas Flow Balance
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Industry standard +/- 10% deviationIndustry standard +/Industry standard +/-- 10% deviation10% deviation
21 %35 %
26 %18 %
Percent of total mass flow through each chamber
1212Airflow Sciences Corporation
Pressure DropPressure DropGeneral goal: • Minimize DP
Methods• Vanes• Duct contouring• Area management
General goal: General goal: •• Minimize DPMinimize DP
MethodsMethods•• VanesVanes•• Duct contouringDuct contouring•• Area managementArea management
Flow
Ductwork redesign saves 2.1 inches H2O over baseline
ESP Temperature StratificationESP Temperature Stratification
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ESP Gas ConditioningESP Gas Conditioning
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Modify ash resistivity• SO3, ammonia, others
Alter gas density, viscosity• Humidification
Modify ash Modify ash resistivityresistivity•• SOSO33, ammonia, others, ammonia, others
Alter gas density, viscosityAlter gas density, viscosity•• HumidificationHumidification
Low SO3 Concentration
High SO3Concentration
SO3 Concentration
Temperature
Res
istiv
ity
5 ppm SO3
Humidification gone awry
Ash DepositionAsh Deposition
Drop out
Re-entrainmentDrop outDrop out
ReRe--entrainmententrainment
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Fabric Filter Flow ModelingFabric Filter Flow Modeling
Flow distribution
Flow balance between compartments
Pressure loss
Bag erosion
Thermal mixing
Ash deposition
Flow distributionFlow distribution
Flow balance Flow balance between between compartmentscompartments
Pressure lossPressure loss
Bag erosionBag erosion
Thermal mixingThermal mixing
Ash depositionAsh deposition
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SCR Flow ModelingSCR Flow Modeling
Flow distribution
Thermal mixing
NOx profile / mixing
Ammonia injection
Pressure loss
Large particle ash (LPA) or “popcorn ash” capture
Ash deposition
Flow distributionFlow distribution
Thermal mixingThermal mixing
NOx NOx profile / mixingprofile / mixing
Ammonia injectionAmmonia injection
Pressure lossPressure loss
Large particle ash (LPA) Large particle ash (LPA) or or ““popcorn ashpopcorn ash”” capturecapture
Ash depositionAsh deposition
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SCR Flow DistributionSCR Flow Distribution
Velocity profile• At AIG• At SCR inlet• At AH inlet
Directionality• At SCR inlet
Velocity profileVelocity profile•• At AIGAt AIG•• At SCR inletAt SCR inlet•• At AH inletAt AH inlet
DirectionalityDirectionality•• At SCR inletAt SCR inlet
1818Airflow Sciences Corporation video
SCR Thermal MixingSCR Thermal Mixing
SCR low load operation with economizer bypass
CFD model to design mixer using full scale operating conditions
Physical model tracer gas tests to confirm design
SCR low load SCR low load operation with operation with economizer bypasseconomizer bypass
CFD model to design CFD model to design mixer using full scale mixer using full scale operating conditionsoperating conditions
Physical model tracer Physical model tracer gas tests to confirm gas tests to confirm designdesign
553 ° F825 ° F
630 ° F
Without mixer, ∆T = ±83 °F
With mixer, ∆T = ±15 °F
1919Airflow Sciences Corporation video
SCR Ammonia InjectionSCR Ammonia Injection
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Tracer gas in physical model
Species tracking in CFD
Tracer gas in physical Tracer gas in physical modelmodel
Species tracking in CFDSpecies tracking in CFD
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SCR Large Particle Ash CaptureSCR Large Particle Ash CaptureComplicated aerodynamic properties• Light weight• Unique drag coefficient• Random rebound
CFD modeling to predict:• Gas velocity patterns• LPA particle paths• Hopper capture efficiency• Pressure loss• Erosion potential
Complicated aerodynamic Complicated aerodynamic propertiesproperties•• Light weightLight weight•• Unique drag coefficientUnique drag coefficient•• Random reboundRandom rebound
CFD modeling to predict:CFD modeling to predict:•• Gas velocity patternsGas velocity patterns•• LPA particle pathsLPA particle paths•• Hopper capture efficiencyHopper capture efficiency•• Pressure lossPressure loss•• Erosion potentialErosion potential
FGD Flow ModelingFGD Flow Modeling
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Flow distributionWater droplet behaviorPressure loss Ash deposition
Flow distributionFlow distributionWater droplet behaviorWater droplet behaviorPressure loss Pressure loss Ash depositionAsh deposition
OutlineOutline
Introduction
Flow Modeling Methods
Application to APC Equipment
Other Applications
Conclusions
Questions
IntroductionIntroduction
Flow Modeling MethodsFlow Modeling Methods
Application to APC EquipmentApplication to APC Equipment
Other ApplicationsOther Applications
ConclusionsConclusions
QuestionsQuestions
2323Airflow Sciences Corporation
Power IndustryPower IndustryVirtually every component of a power plant can be modeled that involves flow (air, gas, liquid, steam, particulate), heat transfer, combustion, or chemical reaction
Virtually every component of a power plant can be modeled Virtually every component of a power plant can be modeled that involves flow (air, gas, liquid, steam, particulate), heat that involves flow (air, gas, liquid, steam, particulate), heat transfer, combustion, or chemical reactiontransfer, combustion, or chemical reaction
EnvironmentalEnvironmentalParticulate CaptureParticulate CaptureNOxNOxSOx SOx CEMsCEMs
PerformancePerformanceHeat RateHeat RateCapacity Capacity Pressure LossPressure LossCombustionCombustionInstrumentationInstrumentation
MaintenanceMaintenanceFoulingFoulingPluggagePluggageErosionErosionCorrosionCorrosionVibrationVibration
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Power IndustryPower Industry
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Fans
Ducts
Pulverizers
Windboxes
Furnaces
Air Heaters
Stacks
Turbines
Condensers
HRSGs
…
FansFans
DuctsDucts
PulverizersPulverizers
WindboxesWindboxes
FurnacesFurnaces
Air HeatersAir Heaters
StacksStacks
TurbinesTurbines
CondensersCondensers
HRSGsHRSGs
……
ConclusionsConclusions
Gas flow patterns have significant impact on the performance of air pollution control equipment
Analysis and design tools include field testing and flow modeling
CFD and physical modeling are applied to a wide range of equipment “from the fan to the stack”
Gas flow patterns have significant impact on Gas flow patterns have significant impact on the performance of air pollution control the performance of air pollution control equipmentequipment
Analysis and design tools include field testing Analysis and design tools include field testing and flow modelingand flow modeling
CFD and physical modeling are applied to a CFD and physical modeling are applied to a wide range of equipment wide range of equipment ““from the fan to the from the fan to the stackstack””
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Questions?Questions?
2727Airflow Sciences Corporation
If you would like an electronic copy of this presentation, please contact Rob Mudry as follows:[email protected]. 734-525-0300