Benchmarking a 2018 Toyota Camry 2.5-liter Atkinson Cycle Engine with Cooled-EGR John J. Kargul, Mark Stuhldreher, Daniel Barba, Charles Schenk, Stanislav Bohac, Joseph McDonald, Paul DeKraker, Josh Alden (SwRI) NationalNational Center for Advanced TechnologyTechnology OfficeOffice of TransportationTransportation and Air Quality SAESAE 20192019-01-0249-01-0249 Office of Air and Radiation U.S.U.S. EnvironmentalEnvironmental Protection Agency A.PRIL9-11 2019 WCX DETROIT EPA’sEPA's AdvancedAdvanced TechnologyTechnology Testing andand DemonstrationDemonstration EPA’s National Vehicle and Fuel Emissions Laboratory – Part of EPA’s Office of Transportation and Air Quality in Ann Arbor, MI NVFELVFE isis proudproud to be an ISOI 0 certified andand ISOISO accredited lablab ISO 14001:2004 and ISO 17025:2005 NVFEL is a state of the art test facility that provides a wide array of dynamometer and analytical testing and engineering services for EPA’s motor vehicle, heavy-duty engine, and nonroad engine programs: • Certify that vehicles and engines meet federal emissions and fuel economy standards • Test in-use vehicles and engines to assure continued compliance and process enforcement • Analyze fuels, fuel additives, and exhaust compounds National Center for Advanced • Develop future emission and fuel economy regulations Technology (NCAT) • Develop laboratory test procedures • Research future advanced engine and drivetrain technologies (involving 20+ engineers – modeling, advanced technology testing and demonstrations) 2 2019-01-0249 A.PRIL9-11 2019 WCX DETROIT TopicsTopics 1.1. OverviewOverview ofof EPA’sEPA's EngineEngine BenchmarkingBene mar ·ng MethodMethod 2.2. KeyKey PointsPoints ofof InterestInterest for the Toyota A25AA25A-FKS-FKS o A25A-FKS - PFI and GDI Fuel Injector Systems o Percent Volume of EGR o Effective Expansion and Compression Ratios, Atkinson Ratios o Efficiency (BTE) o Comparison of Toyota’s 2018 Production & 2016 TNGA Development Engines 3.3. EPA’sEPA's Technical AnalysesAnalyses for FutureFuture EnginesEngines o Efforts to Validate EPA Concept Modeling o Toyota’s 2018 Production Engine versus EPA’s 2016 Future Concept Engine o Effects of Adding Partial and Full Cylinder Deactivation to 2018 Toyota A25A-FKS Engine 3 2019-01-0249 A.PRIL9-11 2019 EPA’sEPA's BenchmarkingBenchmarking MethodMethod WCX DETROIT Engine Setup Engine Tethering • The engine and its ECU were installed in an engine dynamometer Local Power Supply Chassis Signals test cell while the engine’s wiring harness was tethered to the Data ECU Acquisition Battery complete vehicle parked outside the test cell. System Charger Key Signals Test Cell Engine • A second engine is used in the test cell to keep vehicle intact for CAN Bus reference. Ground #1 AWG • Wiring connections/disconnects are made using vehicle connectors Ground Only at ECU and other major harness junctions. • Control engine load with pedal command. • Some signals have to be simulated such as transmission OSS, ABS wheel speed, etc. • Verifying proper operation o No check engine light o Makes rated load and power o Correct air fuel ratio o Verify combustion phasing with in cylinder pressure sensor 4 2019-01-0249 A.PRIL9-11 2019 EngineEngine ConnectedConnected toto DynoDyno viavia aa TransmissionTransmission WCX DETROIT To gather data for this benchmarking program, the engine was connected to the dynamometer via a GM 6L80 6-speed rear drive automatic transmission and torque converter, and drive shaft. There are several reasons an automatic transmission was used. 1. Minimize torsional vibrations. The transmission and torque converter have built in torsional damping. This allows low speed and high torque testing that could not be done with just a driveshaft connection. Transmission Input 2. The transmission is easily adapted to any engine. Transmission Output Inline Torque Sensor Inline Torque Sensor Assembly 3. The transmission gears selection and torque converter clutch are manually controlled. The gear ratios in overdrive allow a higher torque engine to be tested. 4. The transmission can be placed in neutral to allow idling and unloaded operation. 5. The transmission enables starting the engine with a production starter, Setup with transmission which is important when doing cold start testing. US ENVIRONMENTAL PROTECTION 5 AGENCY 2019-01-0249 A-PRIL9-11 TestTest DataData CollectionCollection andand AnalysisAnalysis 2019 WCX DETROIT Engine Test Phases 1)1) LowLow-Mid-Mid loadingloading Tested in steady-state operation at low to mid torque loads where the air-to-fuel ratio remains stoichiometric at speeds from 1000 to 5000 rpm. 2)2) HighHigh loadingloading Tested in transient operation at high torque loads where the air-to-fuel ratio will transition to enriched to protect the engine at speeds of 1000 to 5000 rpm. 3)3) IdleIdle-Low-Low loadingloading Tested in steady-state operation at low torque loads where the air-to-fuel ratio remains stoichiometric at speeds from idle to approximately 3000 rpm. Test Phases: D1. Low-Mid Load D2. High Load D3. Idle-Low Load 250 Test Phase Engine Operation Data Collection Data Processing 12 140kW 1 Low-Mid Approx. 30 sec. Steady-state Steady-state avg. a. 120kW w 8 :a 150 \ loading (stoichiometric) (wo/CVT) (using iTest) m 100kW BO kW 2 High 4 60kW Stab test Transient Transient Intervals -E z ----------- 40kW loading (stoich.→enriched) (wo/CVT) (using MATLAB) 2 -(ll 20kW ::,e- ++ 0 0 3 Idle-Low Approx. 30 sec. Steady-state Stead-state avg. ~ . ... __ _ ___ - -- - -10kW -•----- -20 kW -2 •----;--_~'°=-- ■ ----; -50 loading (stoichiometric) (with CVT) (using iTest) 1000 2000 3000 4000 5000 6000 Speed (RPM) US ENVIRONMENTAL PROTECTION 6 AGENCY 2019-01-0249 A.PRIL9-11 2019 WCX DETROIT TopicsTopics 1.1. OverviewOverview ofof EPA’sEPA's BenchmarkingBenchmarking Methodethod 2.2. KeyKey PointsPoints ofof InterestInterest for the Toyota A25AA25A-FKS-FKS o A25A-FKS - PFI and GDI Fuel Injector Systems o Percent Volume of EGR o Effective Expansion and Compression Ratios, Atkinson Ratios o Efficiency (BTE) o Comparison of Toyota’s 2018 Production & 2016 TNGA Development Engines 3.3. EPA’sEPA's Technical AnalysesAnalyses for FutureFuture EnginesEngines o Efforts to Validate EPA Concept Modeling o Toyota’s 2018 Production Engine versus EPA’s 2016 Future Concept Engine o Effects of Adding Partial and Full Cylinder Deactivation to 2018 Toyota A25A-FKS Engine 7 2019-01-0249 A.PRIL9-11 TestTest DataData CollectionCollection andand Analysis 2019 WCX DETROIT A25A-FKS - PFI and GDI Fuel Injector Systems • Toyota refers to the system as PFIPFI injector calibration data 30 PercentPercent portionportion ofof fuel “D-4S” and states that it uses Sl ope: 0.1424 rr,g / n s• ✓ kPa both direct injection (DI) and Offset : -2.0476 mg suppliedsupplied byby PFIPFI on Tier 2 FuelFuel fit Uncertainty: 0.1280 rtg port fuel injection (PFI) methods R2: 0.9924 250 together, and interchangeably, 12 200 to optimize engine performance i10 140 kW cc 120 kW and emissions. ll.. 8 O PFI Only-Single Injection w 150 O GDl&PFI-Singlelnjection ::a 100 kW o~~-~-~-~-~~-~-~-~ cc • Both PFI and GDI fuel injectors 6 o w • w w ~ m ~ ~ w 80 kW Injection Specifier ( ms- ✓ kPa) 100 systems are used at low loads, 4 60 kW zE while only GDI is used at high 50 Q) 2 ::, - 20 kW load. e- - 10 kW GDI injectorinjector calibration data ~ o o -10kW )I( )1()1( )I( • )I( )I( _.)(- --x -20kW For this test program, both the )I( )!____ Sl op e : -2 IC Offset: -50 )I( fit Uncertainty, PFI and GDI fuel injectors were Rl: 1000 2000 3000 4000 5000 6000 Speed (RPM) calibrated to determine the 30 relationship between injection 20 pulse width, injection pressure 15 10 O GDI ()rjy-Singlelnjeciion and fuel flow. + GDI Only-Mullipl1 lnjactions 0 GDl&PFI-Slnglelnjectlon 4 6 8 Injection Specifier( ms-JMPa) US ENVIRONMENTAL PROTECTION 8 2019AGENCY-01-0249 A.PRIL9-11 Test DataData CollectionCollection andand AnalysisAnalysis 2019 WCX DETROIT cEGR Measurement Hardware Original0 equipmentUI EGR manifoldI (bottom)) Fabricated EGR manifold, instrumented with flow versus fabricated and instrumentedinstrume ted EGR US ENVIRONMENTAL PROTECTION meter mounted on engine. AGENCY manifold (top). 9 2019-01-0249 A.PRIL9-11 TestTest DataData CollectionCollection andand AnalysisAnalysis 2019 WCX DETROIT TargetedTargeted PercentPercent OpeningOpening ofof EGREGR ValveValve && PercentPercent VolumeVolume ofof EGREGR 20182018 Toyota 2.52.5-liter-liter A25AA25A-FKS-FKS EngineEngine onon Tier 22 FuelFuel ECM Targeted EGR %Opening Measured EGR %Volume 25 0 250 Measured EGR %Volume 12 12 L ~ 10 200 L 140 kW &l 10 200 135 kW Q_ 120 kW w 8 0. 150 w 120kW ~ ;::;: 8 m 100 kW rn 150 6 105kW 80 kW 90kW 100 ~ 6 4 60 kW E E z 100 75 kW z 40 kW 60kW 50 (I) 4 2 ::J <D 0- 45 kW ::J 20 kW L er 10 kW ~ 50 L 0 0 2 30kW ~ -10 kW 15 kW -20 kW 7_5 kW -2 0 0 -50 1000 2000 3000 4000 500 0 6000 1000 2000 3000 4000 5000 6000 Speed (RPM) Speedl (RPM) Figure 18. Percent volume ofEGR as reported by EPA test cell measurements Figure 17. ECM's targeted percent opening of the EGR valve in the A25A­ of the A25A-FKS engine using the fabricated cEGR manifold shown in FKS engine, on Tier 2 fuel, (initial interval). Figure 8, on Tier 2 fuel. Measured peak value of 24.1% compares well with the 25% maximum EGR described by Toyota in SAE 2017-01-1021 10 2019-01-0249 Test Data Collection and Analysis A-PRIL9-11 est Data Collection and Analysis 2019 WCX DETROIT EffectiveEffective ExpansionExpansion andand CompressionCompression Ratios,Ratios Atkinson RatiosRatios 250 250 12 12 10 200 ~ 10 200 140kW i 140kW Figure 20. Effective ID Figure 19. Effective Compression Ratio in 0. 120kW (l_ 8 120kW w 8 w Expansion Ratio in the 150 ::;; 100kW :::;; 100kW the A25A-FKS engine, a:, ID A25A-FKS engine, on kW kW on Tier 2 fuel, 1 mm 100 100 Tier 2 fuel, 1 mm 4 60kW 4 60kW reference lift, (initial E E reference lift, (initial z z ------------ 40kW 50 40kW 50 interval).