Turbomachinery Laboratory, Texas A&M University Mechanical .

Turbomachinery Laboratory, Texas A&M UniversityMechanical Engineering DepartmentMICROTURBOMACHINERYApplicationsAugust 2014Luis San AndrésMast-Childs Professorhttp://rotorlab.tamu.edu

MICROTURBOMACHINERYJustificationDOE, DARPA, NASA interests range fromapplications as portable fuel cells ( 60 kW)in microengines to midsize gas turbines ( 400 kW) for distributed power and hybridvehicles.Meso-scale or MEMS turbomachinery ( 100 W)for Next Generation Land Warriors, Micro vehicles& robots, Portable electronic devices andsystems, Smart munitions

MICROTURBOMACHINERY as per IGTIDrivers:deregulation iability &efficiencyDistributed power(Hybrid Gasturbine & Fuel Cell),Hybrid vehiclesASME Paper No. GT2002-30404Honeywell, Hydrogen and Fuel Cells MeritReviewAutomotiveturbochargers,turbo expanders,compressors,Max. Power 250 kWattInternational Gas Turbine Institute

POWER RANGE 400 kWDistribute powerASME Paper No. GT2002-30404(Gas turbine &FuelCell Hybrid)Honeywell, Hydrogen and Fuel CellsMerit ReviewAuto engine andpart / rs/150hpcompressozr.pdf 100 Whttp://smarteconomy.typepad.com/smart economy/2006/09/microgas turbin.htmlPortable ElectronicDevicesKang, S., Ph D dissertation(Stanford Univ.)

MICRO GAS TURBINESCogeneration systems with high efficiencyMicroturbine Power Conversion Technology Review, ORNL/TM-2003/74. Multiple fuels (best iffree) 99.99X% Reliability Low emissions Reduced maintenance Lower lifecycle cost60kW MGTMANUFACTUREROUTPUT POWER (kW)Bowman25, 80Capstone30, 60, 200Elliott EnergySystems35, 60, 80, 150GeneralElectric175IngersollRand70, 250Turbec, ABB &Volvo100Hybrid System: MGT with Fuel Cellcan reach efficiency 60%Ideal to replace reciprocatingengines. Low footprint desirablesource: Dan Lubell, 2006 IJTC, Capstone Turbine Corportation

Capstone MicroTurbine Cooling finsNo gearbox or othermechanicalsRecuperatorLow scheduledFuel injectormaintenanceCombustionchamberOnly one movingpartNo coolants orlubricantsContaminant-freeexhaustCompact andlightweightSuper-low CO &TurbineNOXExhaust outputAir intakeGeneratorCompressorAir bearingssource: Dan Lubell, 2006 IJTC, Capstone Turbine Corportation

Capstone’s C30 EngineDiffuserOil-Free RadialBearingTurbineNozzleCompressorTurbineThrust RunnerOil-Free ThrustBearingOil-Free FoilBearings: 500 CProprietary bearingdesign and coatingThin Dense Chromejournals1.4 MDN (idle)3.1 MDN (full speed) 1.5 L/D1.6 psi static loadDemonstrated Life: 40k hours; 6kcycles and over 11Mhrs field lifesource: Dan Lubell, 2006 IJTC, Capstone Turbine Corportation

Expectation & Requirement Low cost – driven by materials Low maintenance – driven by design Long life – defined by the bearingsand materials Efficient – driven by design Fully integrated solutions – systemdesignsource: Dan Lubell, 2006 IJTC, Capstone Turbine Corportation

HYBRID GENERATION SYSTEMMCRC (molten carbonate fuel cell) MT generatorPressured, and Poweredby reformed fuel and airsupplied by compressorof MGTR&D Review of Toyota CRDL, 41Single-shaft gas turbine(max. 80 krpm)R&D Review of Toyota CRDL, 41

MTM in your neighborhoodMicroturbine Power Conversion Technology Review, ORNL/TM-2003/74.Cogeneration systemsHybrid Electric BusLow emissionFuel Cell-Microturbinehttp://jcwinnie.biz/wordpress/?p 2545Hybrid System : MGT with Fuel Cell canreach efficiency 60%Electricity-Heat total efficiency 90%.Reduces emissions of Carbon & otherair pollutantsSupports renewable energy goals

Compressor industrial applicationsSamsung Micro Turbo Mastercompressors feature gas foilbearings Pressures to 130 psig, power to0.13 MW Samsung line Turbo Master haspressure to 300 psig and power to2.4 MW. Runs on oil TPBs.11www.samsungtechwin.com, 2011

HSI Turbo blower packages (50-300 Hp)20-40% moreefficientwww.hsiblowers.comLow maintenanceLow noiseSmall footprintSee also www.neuros.comfor R&D and products in Korea12

ULTRA MICROTURBOMACHINERYMEMS MTMMeso-scale MTM Palm-size power source Brayton cycle Gas foil bearingsGT-2003-38866 Silicon wafer 1.2 Million rpm Thrust 0.1 N Spiral groove and hydrostaticwww.m-dot.com2007, Journal of Micromechanics andMicroengineering, Vol.17gas bearings100 Watt & lessSmall unmanned vehicles and to replacebatteries in portable electronic devices

Application of Meso/MEMS MTMRescueRobotMicro Gas TurbinePortable GeneratorPOWER DENSITY (MW/m3)5000http://www.robhaz.com/5005050.5Large ScaleCombustorhttp://www.m-dot.com/page8.htmlMicro Large ScaleMicro Solar CellLiSO2 olar .com/product/448 448.htmhttp://www.notebookrehttp://www.wir view.com/efly.com/1001000SIZE .htm

MEMS MTM at MITThrust: 11g (17 watts)Turbine inlet temp: 1600 KFuel burn: 16 gram/hrRotor Speed: 1.2 M rpmWeight: 2 gramsExhaust gas temp: 1243 KSource: GT2003-38866

Mesoscale MTM at Stanford 1997: DARPA – M-Dot projectPalm size gas turbine engine (thrust type)φ25 mm turbine, 400k rpmAll metal componentsRan a few minutes.Turbine blades melted!M-DOT micro-turbine engine1998: DARPA – M-Dot– Stanford – Carnegie Mellon projectReplace the inlet nozzle to improvespecific thrust density.· Inlet nozzle: major ceramic part. Tested in1,250 C gas· 7% performance (thrust/weight)improvement expected· Ceramic turbine built but not tested.Silicon nitride inlet nozzleand turbineFigures and text: Kang, S.,2001, Ph.D dissertation, Stanford Univ.& Personal communication with Kang, S.

MTM materials & fabricationFabricationMold SDM process3D Milling Mold SDM Precision 3D Milling MEMSGT2003- 38151DRIE processGT2003-38933GT2003-38866Materials & Reliability High temperature durability Light weightGT2004-53493

Available Bearing TechnologiesRolling element bearings Low temperatures Low DN limit ( 2 M) Need lubrication systemHerringbone grooved bearingNICH Center,Tohoku University Precision fabrication processAIAA 2004-4189PowerMEMS 2003 Low load capacity and stiffnessand little dampingGas Foil BearingGAS BEARINGS Oil-Free NO DN limit Low friction and power loss Thermal managementFlexure Pivot BearingAIAA-2004-5720-984GT 2004-53621

PV turbocharger systemA challenge!conventionalOil-BearingHoneywell Oil-LessBearing System(2007)Foil Bearingschosen

PV turbochargerMax. 240 krpmEngine oil TCCTW 100 gramBearings 5W-30 oil lubricatedT 150 C, 1.2 cPoise(d 6 mm, l 4 mm, c 0.012 mm,78.5 m/s)L 109 mm, D 45 mm, tip speed 589 m/sGas bearing TCCTW 230 gramair lubricated bearingsT 150 C, 0.0239 cPoise(d 25 mm, l 40 mmc 0.007 mm,412 m/s)

MTM – Needs, Hurdles & IssuesLargest power to weightratio,Compact & low # of partsHigh speedRotordynamics &(Oil-free) Bearings & SealingMaterialsReliability and efficiency,Low maintenanceExtreme temperature andpressureEnvironmentally safe (lowemissions)Lower lifecycle cost ( kW)Coatings: surface conditioning forlow friction and wearCeramic rotors and componentsManufacturingAutomated agile processesCost & numberProcesses & CyclesLow-NOx combustors for liquid &gas fuelsTH scaling (low Reynolds #)FuelsBest if free (bio-fuels)

Pressing challenges for gas bearing technologyintermittent contact anddamaging wear at startup & shutdown, and temporary rubs duringnormal operating conditionsCurrent research focuses oncoatings (materials),rotordynamics (stability) &high temperature (thermalmanagement)Need alow cost& longlifesolution!

Useful websitesNASA Oil-Free Turbomachinery ://www.eere.energy.gov/de/microturbines/Capstone micro turbinehttp://www.capstoneturbine.com/Mohawk Innovative Technology, Inc.http://www.miti.cc/MIT Gas Turbine Lab.http://web.mit.edu/aeroastro/www/labs/GTL/

1,250 C gas · 7% performance (thrust/weight) improvement expected · Ceramic turbine built but not tested. M-DOT micro-turbine engine Silicon nitride inlet nozzle and turbine Palm size gas turbine engine (thrust type) φ25 mm turbine, 400k rpm All metal components Ran a few minutes. Turbine blades melted! 1998: DARPA – M-Dot