Ken Pendlebury. Director, Gasoline Engines Ricardo UK Ltd. Sponsors

Transcription

1 Ken Pendlebury Director, Gasoline Engines Ricardo UK Ltd Sponsors

2 Gasoline Engines in an Electrified World CENEX LCV September 2017 Ken Pendlebury, Director, Technical Consultants, Ricardo

3 A decade of change We are already experiencing major change and disruption in this decade, which will influence the optimum future powertrain strategy 3

4 Key Market Drivers Key drivers for electrification are CO2 legislation and potential zero emissions cities Overview of key market drivers for electrification for Europe Many cities throughout Europe are facing challenges to comply with EU standards for air quality. Local authorities are expected to be increasingly rigorous in introducing zero emission zones (ZEZs). Some countries are considering banning the sale of ICE vehicles in the future European fleet average CO2 target 95g/km from 2021, g/km from 2025 Air Quality Fiscal Incentive Fuel Economy / CO2 Privileges Pollutant Emissions Infra-structure Availability Recycling Public Awareness Euro 6 limits enforced from Sep2014. Move to WLTP and Real Driving Emissions (RDE) being introduced in 2017 with Euro 6d Safety Performance Personal Mobility Consumers expectations are for EVs to have ranges much greater than their typical week day driving distances Source: EMLEG, European Commission, ACEA Incentives for electrically charged cars are available in many EU countries, such as tax reductions and exemptions in Austria or Germany or. bonus payments in France and UK Cost Some local authorities offer privileges such as free parking for EVs By 2025 EU member states will be required to provide electric charging infrastructure to meet demand but only in densely populated areas Increasing public awareness of emissions and air quality issues due to media coverage, for example VW Dieselgate 4

5 Is there a future for the gasoline engine There is, however, a consensus that the ICE will remain important beyond 2030 A range of predictions exist but it is generally believed that the ICE will be fitted to a large proportion of vehicles beyond 2030, it is not clear what technology these engines will contain Ricardo view: more than 40% xevs by 2030 (BEV 20%, PHEV 12% & HEV 12%) Ricardo view: up to 25% xevs by 2025 (BEV 15%, PHEV 8% & HEV 2%) Assuming CO2 targets achieved via improvements in ICE-based vehicles and hybridisation Assuming breakthrough in energy storage cost reduction and major infrastructure investments for re-charging 5

6 New gasoline combustion technologies A wide variety of technologies are being pursued to improve thermal efficiency A number of primary efficiency paths are being pursued initially as an alternative to electrification Technology Ricardo Activity Lean combustion Volcano SGDI Ricardo LBDI Lean-G Technology Ricardo Activity Miller cycle Cylinder deactivation Water Injection Variable compression ratio Ultra high efficiency gasoline engine Magma concept Gomecsys simulation and test 6

7 Gasoline Technology Developments High efficiency engines Bolt on Technologies A number of complimentary technologies can be used to further enhance efficiency Technology Ricardo Activity Waste heat Recovery Turbochargers 2500 rev/min 8 bar BMEP EGR EGR responses: HP and LP EGR Configurations Response (2500 rev/min, 8 bar BMEP - Fixed VGT position) 1.8 Technology Pressure Ratio (total) P2/P1 1.7 Ricardo Activity LP EGR (Cooled) HP EGR (Cooled) Cooled LP EGR compressor operating point for 25% EGR rate 1.6 Increasing HP EGR rate 1.5 Increased compressor efficiency for LP EGR system Volts electrification Air Flow (lbs/min) TITLE: PROPRIETARY NOTICE This document contains proprietary information, and such information may not be disclosed to others for any purpose, or used for manufacturing without written permission. GT17 C224(49) 50 Trim EI55 0,42 A/R PART NUMBERSCLEARANCES(in)COMMENTS: Wheel: Axial: Hsg: Radial: 'Z' Line-up: B/plate: N phy Nc Diff exit width: EI = DE = Garrett Engine Boosting Systems T1c / 545 W* W T1c /545 P1c / TEST No:ie122s DATE: 7-SepCELL No: REV: Turbo compounding ADEPT, HYBOOST, APU 7

8 Is there a future for the gasoline engine What are the potential charecteristics of new gasoline engines While it is accepted that most vehicles will have gasoline engines by 2030, the characteristics of those engines are dependent on external factors Higher battery cost, limited charging infrastructure Micro Hybrid Mild Hybrid Series Hybrid Full Hybrid Low cost high efficiency limited operating point ICE High efficiency wide operating range ICE PHEV REEV BEV Low battery cost, improved charging infrastructure 8

9 At Ricardo the Magma engine concept has been developed to meet the needs for conventional high efficiency ICE Main Targets Components of the Magma engine concept Boosted downsized gasoline engine Central injector combustion system Power 140kW Torque 275Nm Efficiency 40% Capacity 1.5l Specific rating 100kW/l BMEP 24bar High geometric compression ratio (13:1) Miller cycle early intake-valve closing (EIVC) strategies Increased maximum boost pressure, delivered by turbo-supercharging Electro hydraulic valvetrain offers greater potential Stoichiometric and lean combustion are both possible 9

10 Controlling combustion knock remains the core challenge The geometric compression ratio of 13:1 has been selected as the highest optimum before the negative effects of surface area-to-volume ratio (S/V) begin to dominate (at conventional B/S ratio) 15 DI gasoline engines 14 Compression ratio Magma target 13 Charge Air Cooler Effective CR is reduced by Miller cycle valve event strategies Waste-gate Clutch Bypass 30 Peak BMEP [bar] 10

11 High compression ratio Miller cycle engines encompass a spectrum of technology approaches A range of different technologies and objectives are encompassed by the Miller Cycle bracket Engine Nissan HR12DDR VW EA211 evo Audi EA888 Gen 3B Ricardo Magma Swept volume [L] Compression ratio BMEP at 2000 rev/min [bar] Peak BMEP [bar] Variable valvetrain DVVT DVVT (CDA) CPS CPS or CVVL Valve event strategy LIVC EIVC EIVC EIVC Supercharger Variablegeometry turbo Fixed-geometry turbo Turbosupercharging Specific power [kw/l] Boosting system 11

12 Comparison of BSFC between the baseline 2.0 L4 engine and the Magma 1.5 L3 at the same torque Baseline 2.0 L4 400 Magma 1.5 L3 BSFC [g/kwh] 350 Downsizing from a 2.0 to a 1.5 litre engine increases the fuel consumption benefits % -5.2% -21.8% -10.6% -6.3% -7.1% Engine speed [rev/min] Torque [Nm] 12

13 Vehicle simulation for drive-cycle fuel consumption predictions Ricardo V-SIM drive-cycle simulation for a D-segment passenger car with 6MT FTP % WLTC -12.5% Without downsizing, the WLTC benefit is 6.3% and the FTP75 benefit is 7.5% 13

14 The target for the xev engine is best thermal efficiency Performance targets are modest (including low speed torque) as the engine will always be combined with heavy electrification Ultra High Efficiency Gasoline Engine Targets Torque [Nm] Power [kw] / Thermal efficiency [%] Main Targets Power 140kW 70kW Torque 275Nm 160Nm Efficiency 40% 45% Capacity 1.5l 1.5l Specific rating 100kW/l 46kW/l BMEP 24bar 14bar Engine Speed 14

15 Engine geometry is critical to achieving benefits at high CR Long stroke engine design minimises heat losses at very high compression ratio For square engine there is little benefit in raising compression ratio above 13:1 Penalty of additional heat loss from increased surface to volume ratio As bore/stroke ratio reduces, very high compression ratio provides a benefit through reduced surface to volume ratio Target for bore/stroke ratio of Target compression ratio of ~17:1 Source: Ricardo 15

16 High compression ratio will lead to increased combustion knock Aggressive EIVC/LIVC strategy (Miller cycle) cam timings will reduce end of compression temperature, reducing combustion knock Charge Air Cooler Optional Water Injection Reduce compression in-cylinder through Miller cycle cam timing (EIVC or LIVC) Performance is recovered through additional compression in turbocharger Intercooling of charge air reduces temperature at end of compression Peak engine performance is reduced from Magma engine EGR Valve Key is that we accept significant engine compromise to improve efficiency and reduce cost EGR Cooler 16

17 Simulation results for Magma xev gasoline engine Efficiency Walk for xev Engine In reality it is difficult to isolate these benefits as they are interdependent technologies BTE [%] Key Technologies Bore / Stroke Ratio - Lean homogenious combustion - Central longitudinal DI injection - 17:1 compression ratio - Water injection - No mechanically driven ancillaries 17

18 Advanced gasoline and mild hybridisation offer diesel levels of fuel consumption at potentially lower price WLTC CO2 Benefit +48v 48V P0 Product On-Cost ( ) engine has no incremental cost 18

19 Summary There are a wide range of predictions for the future powertrain strategies but all analysis suggests that >70% of vehicles at 2030 will have an internal combustion engine 40~43% Thermal efficiency The type of engine will depend on the cost of batteries and cost of advanced gasoline concepts. Ricardo are developing two engine types that will fulfill Mild and full hybrid requirements High efficiency Miller cycle engine potentially with lean operation, advanced valvetrain and advanced boosting combined with low voltage electrification The Ultra High efficiency (>45%) gasoline engine with very limited operating range and performance which will be used in series hybrid or as range extender engine >45% Thermal efficiency >50% With waste heat recovery It is likely that both of these engine types will become common and the mix will be determined by total propulsion system cost and usage profile 19

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