An Engine System Approach to Exhaust Waste Heat Recovery - EERE

DisclaimerThe work described in this presentation, conducted under the Caterpillar / DOE cooperativeresearch agreement, was conducted by the Technology and Solutions Division (T&SD) ofCaterpillar Inc. The cooperative research described in the presentation was done to evaluate proofof-conceptfor technologies that meet EPA 2010 on-highway emissions with the potential to improvepeak brake thermal efficiency by 10%. Cursory consideration was given to which technologies mayhave some ability to be commercialized by the engine divisions of Caterpillar which havecommercialization responsibility.The process to validate technologies as commercially viable was not in the scope of the program,nor was it undertaken. Commercialization aspects such as cost/benefit analysis, reliability,durability, serviceability and packaging across multiple applications were only considered at acursory level. Until such analysis is completed,any attempt to imply commercial viability as a resultof the material in this presentation is not justified.Copyright: ©2010 Caterpillar Inc. All Rights ReservedTrademark: CAT, CATERPILLAR, their respective logos, “Caterpillar Yellow” and the “Power Edge” trade dress, aswell as corporate and product identity used herein, are trademarks of Caterpillar and may not be used withoutpermission.Caterpillar Non-Confidential

AGENDA• EWHR Program Objectives, Timeline, Scope• Technical Developments• Summary and ConclusionsCaterpillar Non-Confidential

Program ObjectiveDevelop components, technologies, and methods torecover energy lost in the exhaust processes of aninternal combustion engine and utilize that energy toimprove engine thermal efficiency by 10% (i.e. from ~42% to ~46% thermal efficiency) No increase in emissions rate No reduction in power density Compatible with anticipated aftertreatmentCaterpillar Non-Confidential

Program TimelineProgram Phases Per ContractEND OFPROGRAMDefineRoadmapPhase 120052006ValidateroadmapPhase 220072008Mid-ProgramSystem DemoPhase 320092010Continue developmentof promisingtechnologies Originally planned as a 5 Phase Program Truncated to 3 Phases – migration to Supertruck Final program report Technologies developed Key results & lessons learnedCaterpillar Non-Confidential

An integrated system solutionto waste heat recoveryA/CEngine C15ApproachBrakePowerPort Insul.(0.5%)Numbers in ( ) indicate % increase inthermal efficiency from this componentPiping(0.5%)Intercooling(1.3%)HP Turbine(2.0%)HP CompI/CHP TurbStackStrategy OptimizationLP CompLP TurbAmbientCGIHECoolerDPFCGIBaseline C1515.2L On-Highway Truck EngineLPL (low pressure loop) configurationStack Recovery*(4.0%)Compressors(0.7%)LP Turbine(1.0%)•Turbocompound or bottoming cycle: supplementsengine power via electrical or mechanicalconnection to flywheelCaterpillar Non-Confidential

• “System” SolutionProgram Philosophy– Modular; “Best” elements can be carried to production• Production-Viable Technologies– Cost, Packaging, Manufacturing• Broad Emissions Architecture Applicability– Viable for HPL, LPL, or non-EGR solutions– Compatible w/ AftertreatmentCaterpillar Non-Confidential

AGENDA• EWHR Program Objectives, Timeline, Scope• Technical Developments• Summary and ConclusionsCaterpillar Non-Confidential

Technical Progress – HP Turbine +2%Target: + 2% Engine Thermal Efficiency:• + 8% Turbine Stage Efficiency• Improved Exhaust Pulse UtilizationRND Gen1 vs Baseline Radial HPHP Turbine Efficiency TargetTurbine-Mech Eff, T-S, (%)0.840.820.80.780.760.740.720.70.682%Bslntarget0.6 0.65 0.7 0.75 0.8Velocity Ratio, U/CPeak efficiency shiftrequired for +2% enginethermal efficiencyTechnologies• RND turbine• Mixed Flow turbineCaterpillar Non-Confidential

Technical Progress – HP Turbine +2%Technology 1 – Radial, Nozzled, Divided (RND) Turbine• High efficiency turbine wheel• Nozzled and divided turbine housingGas Stand Test Results0.85000.8000Turbine Aero efficiency (T-S)0.75000.70000.65000.60000.55000.50000.45000.40005%Imperial College Test DataRND TurbineBase Turbine0.4000 0.5000 0.6000 0.7000 0.8000 0.9000 1.0000 1.1000Velocity ratio, U/C+• + 5-6% turbine efficiency• Full map width benefitsCaterpillar Non-Confidential

Technical Progress – HP Turbine +2%Technology 1 – Radial, Nozzled, Divided (RND) Turbine• High efficiency turbine wheel• Nozzled and divided turbine housingOn-Engine Test Results: Single-stage turbo HPL EGR engineBSFC BSFC - % ∆ - Improvement RND vs Base Radial with RND TurbineTurbine3000.0Response Testing3.5+402500.02000.0Engine LoadLOAD1500.01000.0500.03.01.72.22.21.31.01.61.10.40.0900 1100 1300 1500 1700 1900 2100SPEEDEngine Speed2.5TIME (sec)Response Time33521.510.530% improvement in response00800 1000 1200 1400 1600 1800 2000Engine SpeedENGINE SPEED (rpm)BslnRND30252015105Peak Smoke Opacity, %SmokeCaterpillar Non-ConfidentialDurability testing underway• Successful completion of nozzle ring thermal cycle test

Technical Progress – HP Turbine +2%Technology 2 – Mixed Flow Turbine• Nozzle-less, divided volutefirst-passGas Stand Test Results0.8500radialmixed flowTurbine Aero efficiency (T-S)0.80000.75000.70000.65000.60000.55000.50000.45000.40005%Imperial College Test DataMixed Flow TurbineBase Turbine0.40000 0.50000 0.60000 0.70000 0.80000 0.90000 1.00000 1.10000Velocity ratio, U/C• + 2-3% turbine efficiency• Efficiency peak at lowerU/C a improved exhaustpulse utilization• + 5-6% efficiency atlower U/CCaterpillar Non-Confidential

Technical Progress – HP Turbine +2%Technology 2 – Mixed Flow Turbine• Nozzle-less, divided volutefirst-passradialmixed flowOn-Engine Test Results: Series turbo LPL EGR engineBSFC BSFC - % ∆ Improvement - Mixed Flow vs with Radial Mixed HP Flow Turbine Turbine1800.01600.01400.01200.0Engine LoadEngine LOADLoad1000.0800.0600.0400.0200.00.01.31.51.43.11.31.10.42.6-0.2-0.1-0.6900 1100 1300 1500 1700 1900 2100Engine SPEEDSpeedEngine Speed• 1 to 1.5% fuel economybenefit at low and mid speedrange where exhaust pulseenergy is significantDevelopment of mixed-flow,nozzled, divided turbine isunderwayCaterpillar Non-Confidential

Technical Progress – LP TurbineTarget: + 1% Engine Thermal Efficiency:• + 6% Turbine Stage Efficiency+1%Technology 1 – High Efficiency Axial Turbine• +6% turbine efficiency verified – analysis, test• Packaging concerns w/ series turbosTechnology 2 – High Efficiency, Nozzled, Radial Turbine• Minimal impact on response – design freedomGas Stand Test Results0.84Gas Stand Turbine EfficienciesTurbine-Mechanical Eff, T-STurb-Mech Eff, T-S0.820.80.780.760.740.720.7EWHR LP2%BSLN LP0.680.65 0.7 0.75 0.8 0.85 0.9• + 4% peak turbine efficiencyCaterpillar Non-ConfidentialVelocity Ratio, U/CVelocity Ratio, U/C

Technical Progress – CompressorsTarget: + 0.7% Engine Thermal Efficiency:• + 2.5% Compressor Stage Efficiencies+0.7%HP Technology – Highly backswept wheel w/ vaned diffuserGas Stand Test Results2.82.62.42.2Pressure Ratio21.81.60.820.810.80.780.760.720.740.660.62• efficiency 1-1.5% > production• ½ of target achieved0.71.41.210.1 0.15 0.2 0.25 0.3 0.35 0.4Caterpillar Non-ConfidentialFlow

Technical Progress – Stack Recovery+4%Target: + 4% Engine Thermal Efficiency• Stack recovery on baseline LPL engine• Turbocompound downselected• Brayton Cycle investigated – packaging challengesEngine Simulation ResultsPeak Torque Conditions7.0%6.0%Technologies• Mechanical TurbocompoundBSFC Benefit5.0%4.0%3.0%2.0%1.0%0.0%85% Transmission Efficiency90% Transmission Efficiency95% Transmission Efficiency0 5 10 15 20 25 30Backpressure (kPa)• Electrical TurbocompoundCaterpillar Non-Confidential

Technical Progress – Stack RecoveryTarget: + 4% Engine Thermal Efficiency• Stack recovery on baseline LPL engineTechnology 1 – Mechanical Turbocompound+4%• Robust, high-efficiency bearing is challenge• Developed power turbine gas stand test method• Detailed shaft motion measurements• Test Conditions• 5 bearing systems• Speeds from 25-60krpm• Gas Stand Test Results• < 0.002” shaft motion• 80-84% aero efficiency0.0020.0010.0-0.001-0.00250krpmGas StandInstrumentationCaterpillar Non-ConfidentialShaft Motion Results

Technical Progress – Stack RecoveryTarget: + 4% Engine Thermal Efficiency• Stack recovery on baseline LPL engineTechnology 2 – Electrical Turbocompound• Two concept designs developed / analyzed• Concept 1: Generator in front of compressor• Rotordynamic / packaging challenges• Concept 2: Generator between wheelsCaterpillar Non-Confidential0.002• Thermal management challenges• Concept 2 analysis results 0.001• Generator efficiencies > 96%0.0• Peak rotor stress acceptable• Peak stator temperature acceptable-0.001• Peak magnet temperature acceptable• Bending critical speed acceptable-0.00250krpmDevelopment Ongoing: TSB-Funded ProgramGas StandRe(x)Shaft Radius, inches< >43210-1-2-3-4Shaft11Motor / Generator5 10 153rd Critical Speed (87 krpm)20 25+4%CompressorInstrumentation3035 400 2 4 6 8 10 12Axial Location, inches45Shaft147Turbine

Summary-0.4%• Effect of lowercomponentefficienciesStack Recovery(4.0%)Port Insul.(0.5%)PipingIntercooling(0.5%)(1.3%)Strategy OptimizationHigh Eff.HP Turbine(2.0%)-0.7%• Used RND turbine• Mixed Flow ND will improve-0.5%• HP compressor ~ ½ ofgoal achieved• No change yet to LP compressor* Turbocompound or Bottoming CycleCompressors(0.7%)“Mid-Program” Proof-of-Concept Demo*High Eff.LP Turbine(1.0%)Thermal Eff.ImprovementDesign point demo - target: +9.0%Design point demo - achieved: +7.0%*Not commercially validated-0.4%• Used radial turbine map(better packaging vs axial)“Virtual” Demo:Engine Simulationusing measuredcomponentperformance mapsCaterpillar Non-Confidential

Port Insul.(0.5%)Piping(0.5%)SummaryIntercooling(1.3%)Stack Recovery(4.0%)Strategy OptimizationHigh Eff.HP Turbine(2.0%)Without theseelements, value ofturbocompound isjust 2%* Turbocompound or Bottoming CycleCompressors(0.7%)High Eff.LP Turbine(1.0%)“Mid-Program” Proof-of-Concept Demo*Thermal Eff.ImprovementDesign point demo - target: +9.0%Design point demo - achieved: +7.0%“Virtual” Demo:Engine Simulationusing measuredcomponentperformance maps*Not commercially validatedCaterpillar Non-Confidential

Caterpillar Thanks:AcknowledgementsBarber-Nichols Inc.ConceptsNRECHoneywellImperial CollegeOak Ridge National LabTurbo SolutionsElectric turbocompound design consultingTurbomachinery design consulting & optimization.Turbomachinery design consulting,component procurement and integration.Gas stand testing of advancedturbomachinery componentsOn-engine testing of advancedturbomachinery componentsTurbomachinery design consulting &optimization.Caterpillar Non-Confidential

Caterpillar Thanks:Acknowledgements• Department of Energy• Gurpreet Singh• John Fairbanks• DOE National Energy Technology Laboratory• Carl MarondeCaterpillar Non-Confidential