esp gas flow fundamentals

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


IntroductionIntroduction


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


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


ESP Field Testing

Field Testing Field Testing Velocity

Temperature

Pressure

Particulate

Chemical species

VelocityVelocity

TemperatureTemperature

PressurePressure

ParticulateParticulate

Chemical speciesChemical species


Physical Flow Physical Flow ModelingModeling


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


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


ESP Flow ModelingESP Flow Modeling


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


Gas Flow BalanceGas Flow Balance


Industry standard +/- 10% deviationIndustry standard +/Industry standard +/-- 10% deviation10% deviation

21 %35 %

26 %18 %

Percent of total mass flow through each chamber


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


ESP Gas ConditioningESP Gas Conditioning


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


Fabric Filter Flow ModelingFabric Filter Flow Modeling

Flow distribution

Flow balance between compartments

Pressure loss

Bag erosion

Thermal mixing

Ash deposition


Flow balance Flow balance between between compartmentscompartments


Bag erosionBag erosion




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



NOx NOx profile / mixingprofile / mixing

Ammonia injectionAmmonia injection


Large particle ash (LPA) Large particle ash (LPA) or or ““popcorn ashpopcorn ash”” capturecapture



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


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


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


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


Flow Modeling MethodsFlow Modeling Methods

Application to APC EquipmentApplication to APC Equipment

Other ApplicationsOther Applications


QuestionsQuestions


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


Power IndustryPower Industry


Fans

Ducts

Pulverizers

Windboxes

Furnaces

Air Heaters

Stacks

Turbines

Condensers

HRSGs

…

FansFans

DuctsDucts

PulverizersPulverizers

WindboxesWindboxes

FurnacesFurnaces

Air HeatersAir Heaters

StacksStacks

TurbinesTurbines

CondensersCondensers

HRSGsHRSGs

……


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””


Questions?Questions?


If you would like an electronic copy of this presentation, please contact Rob Mudry as follows:[email protected]. 734-525-0300

esp gas flow fundamentals

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