chemistryandpropulsion(激光诊断)

Lecture10:TDLASApplicationstoEnergyConversion1.Introduction2.FuelinICengines–fuelandTAbsorptioncrosssectionvsgasolineblend3.H2OandTinslaggingcoalgasifier4.H2Ointransfercoalgasifier5.NOandCOincoal-firedboilerexhaust6.Futuretrends–energyconversionTransportcoalgasifierattheNationalCarbonCaptureCenterWilsonville,AL21.Introduction:TDLASisPracticalinHarshEnvironmentsUtilizeseconomical,robustandportableTDLlightsourcesandfiberopticsCanyieldmultipleproperties:species,T,P,V,&minreal-timeoverwideconditionsTto8000K,Pto50atm,Vto15km/sec,multiphaseflows,overcomingstrongemission,scattering,vibration,andelectricalinterferenceDemonstratedinharshenvironmentsandlarge-scalesystems:Aero-engineinlets,scramjets,pulsedetonationengines,ICengines,arcjets,gasturbines,shocktunnels,coal-firedcombustors,rocketmotors,furnaces….Potentialuseincontrolofpracticalenergysystems.CoalGasifier@UofUtahJeffries,PittsburghCoalConf,2011Coal-firedUtilityBoilerChao,ProcCombInst,2011IC-Engines@NissanJeffries,SAEJ.Eng,20102.FuelandTSensinginICEnginesw/TDLASCRFSandia,2006T&H2ONissan/PSI/SUSensor@UCBerkeley,2005T&H2ONissanNorthAmerica2007,Fuel&T3QuantitativeTDLASfirstrequirescrosssectiondata2.FuelandTSensinginICEnginesw/TDLASGasolinehasUnstructuredAbsorption&ManyBlendsAbsorptionspectrummeasuredwithFTIRStrongestabsorptioninregionofC-Hstretchingvibration4Opticalfrequencyincm-1defined:1/whereiswavelengthT=50C2.FuelandTSensinginICEnginesw/TDLASGasolineAbsorptionVarieswithTemperatureAbsorptioncrosssectionversustemperaturemeasuredwithFTIRStrongestabsorptioninregionofC-HstretchingvibrationPickonelaserfrequency(1)withlargeTdependencePickonelaserfrequency(2)withsmallTdependenceDeterminetemperaturefromabsorptionratioofselectedfrequencies5PremiumgradegasolineT=26CT=54CT=103CT=203CT=301CT=400CT=449CT=527C*Frequency[cm-1]2800290030003100010302040Absorption[m2mole-1]2=2951cm-11=2970cm-1Opticalfrequencyincm-1defined:1/whereiswavelength2.FuelandTSensinginICEnginesw/TDLASGasolineAbsorptionVarieswithBlendMeasured(FTIR)absorptioncrosssectionvarieswithblend28002900300031000204060Absorption[m2mol-1]Frequency[cm-1]6.3%Aromatic39%Aromatic6Twodifferentblendsofpremiumgradegasoline2.FuelandTSensinginICEnginesw/TDLASStanfordModelofGasolineAbsorptionCrossSection7TXTjjj,,51modelGasolineabsorptioncrosssectionmodel:DeterminecompositionofgasolineblendbyhydrocarbonclassFractionsofparaffin,olefin,aromatics,andoxygenatefromstandardtests(ASTMD1319&ASTMD4815)AssumeoxygenatesareethanolNormal-andiso-paraffinfractionbasedonfuelgradeDetermineabsorptioncrosssectionj(,T)forhydrocarbonclassEmpiricaldatabase(seeKlingbeiletal.,Fuel87(2008)3600)WeightedsumofjbymolefractionXjofeachhydrocarbonclassAbsolutemeasurementswithoutcalibrationusingthiscrosssection82.FuelandTSensinginICEnginesw/TDLASCrossSectionModelValidationExperiments21Gasolinesamplesmeasured(samplecollectionaugmentedbyChevron)SamplepoolcoversexpectedrangeofgasolinecompositionsCompositionvariationincrosssectionlargerthanx2attargetFTIRmeasuredcrosssectionsingoodagreementwithmodelpredictions100806040200CumulativeVolumeFraction[%]20151050SampleNumberAlkanesAromaticsOlefinsEthanolGasolineComposition500x1034003002001000ModeledCrossSection[cm2mole-1]500x1034003002001000MeasuredCrossSection[cm2mole-1]2951cm-12970.5cm-1450ºCComparisonbetweenmodelandexperiment2.FuelandTSensinginICEnginesw/TDLASGasolineSensorNeeds3-ColorLaserDifferencefrequencyoftwonear-IRlasersformid-IRoutputsThirdnear-IRlaserprovidestwomid-IRoutputsTwoMid-IRcolorsforsimultaneousfuelandTNIRcolorcanbeusedtoidentifyliquiddropletsoffuel2.FuelandTSensinginICEnginesw/TDLASOpticalAccessKeytoIn-cylinderFuelMeasurementsSU, Nissan, PSI collaborative project (2003‐2008)Measurefuelvstime(CA)closetosparkignition102.FuelandTSensinginICEnginesw/TDLASCrank-Angle-ResolvedGasolineAbsorptionHigh-quality,low-noisedataforentirecycleSensorprovidescycle-by-cyclestatisticsofF/AratioCriticalforunderstanding/controllingUHCemissionsNissanNorthAmerica(2007)Jeffriesetal.,SAEInternationalJournalofEngines,201011•Single-cycledatafromproductionengine2.FuelandTSensinginICEnginesw/TDLASColdStartFluctuationsCriticalforEmissionsControl•High-resolutiondataquantifieschangesinfuelloading•ProvidesnewtooltooptimizeMPI&DIGenginesPeakfuelatignitionfor400coldstartcycles12Part3:Sensorstooptimizecoalgasification13133.H2O&TinSlaggingCoalGasifier@UtahVisionforTDLASSensinginIGCCXXCoalOxygenorSteamOxygen/CoalRatioControlSensorforT&SyngasComposition34Fuel/airRatioControl1GasifierReactorCoreQuench2SyngasCleanupGasTurbineXXCoalOxygenorSteamOxygen/CoalRatioControlSensorforT&SyngasComposition34Fuel/airRatioControl1GasifierReactorCoreQuenchReactorCoreQuench2SyngasCleanupGasTurbineSensorforcontrolsignalstooptimizegasifieroutputandgasturbineinputTwoflowparametersconsidered:gastemperatureandsyngasenergyGastemperaturedeterminedbyratioofH2OmeasurementsForO2blownsystemsCO,CH4,CO2,andH2OprovidesyngasenergyWhereH2canbedeterminedbygasbalanceFourmeasurementstationsconsidered:spa