2015 ERC Symposium Mitsuo Hitomi Mazda Motor Corporation

Transcription

1 Mazda s Approach for Developing Engines from a Perspective of Environmental Improvement 2015 ERC Symposium Mitsuo Hitomi Mazda Motor Corporation

2 Contents Improving thermal efficiency of ICEs Goal of SKYACTIV engines SKYACTIV engines: 1 st step SKYACTIV engines: Next step Investigation results of boosted downsizing engines and future strategy for engine displacement

3 Improving thermal efficiency of ICEs Energy losses of ICE Heat Energy Balance (%) Heat Energy Balance vs. Load Radiation, Misfiring loss Exhaust loss Cooling loss Pumping loss Mech. friction loss Effective work Load (%) Control factors Compression ratio Specific heat ratio Combustion period Combustion timing Heat transfer to wall Pressure difference between In. & Ex. Mechanical friction Fuel Economy Improvement=Loss reduction All technologies for improving fuel economy must overcome these seven controlling factors. 3

4 Improving thermal efficiency of ICEs Roadmap to the goal of ICE Far Distance to ideal Close Control factors Current Gasoline engine Diesel engine Current Compression ratio World highest CR Higher CR World lowest CR Specific heat ratio Combustion period Combustion timing Heat transfer to wall Pressure diff. Btw IN. & Ex. Miller cycle 1 st step SKYACTIV-G Lean HCCI Lean HCCI 2 nd step SKYACTIV-G Adiabatic 3 rd step=goal 2 nd step SKYACTIV-D Adiabatic More homogeneous 1 st step SKYACTIV-D Better mixing TDC combustion TDC combustion Mechanical friction Friction reduction Further reduction Further reduction Friction reduction Gasoline engine and diesel engine will look similar in the future. 4

5 Contents Improving thermal efficiency of ICEs Goal of SKYACTIV engines SKYACTIV engines: 1 st step SKYACTIV engines: Next step Investigation results of boosted downsizing engines and future strategy for engine displacement

6 Goal of SKYACTIV engines Specific CO2 emissions of electric power generation (kg CO2/kWh) After 2011 big earthquake in Japan France Canada Japan Italy UK Germany USA China India Specific CO2 emission from electric power generation is assumed to be 0.5kg-CO2/kWh. 6

7 Goal of SKYACTIV engines Fuel consumption reduction target for ICE powered vehicle in real world C car average 21.2kWh/100km B car A car 45% 30% 15% 0% A car B car C car Specific electricity consumption at NEDC (kwh/100km) Electric power consumption of C car in the real world: 21.2kWh/100km. Fuel consumption of Mazda 2L C car in the real world: 5.2L/100km *Source : ADAC EcoTest NEU ab März L 1.6L 1.6L 1.4L I3 1.0L 1.4L 1.2L 1.4L 1.6L I2 0.9L 1.4L I3 1.0L 1.4L 1.2L Note I3 I30.9L1.2L I.2L I3 I.0L 1.4L 1.6L 2.0L A 1.8L 1.6L 1.2L 1.4L 1.2L Mazda3 2.0L SKYACTIV G F/E at NEDC (L/100km) 7

8 Goal of SKYACTIV engines Fuel consumption reduction target for ICE powered vehicle in real world Average Mazda3 2.0L = 5.2L/100km Well to Wheel_CO2 (g/km) Target; 4L/100km 21.2kwh/100km =C car in the real world 4.2L/100km 3.8L/100km 4L/100km 3L/100km LCA considering just Li ion Battery manufacturing 2 ton (minimum estimation ever found)co2 for 20kWh battery Lifetime mileage assumed 200,000km Specific CO2 emission of electric power generation kg/kwh Target for Mazda 3 5.2L/100km 4L (3.8L-4.2L)/100km Around 25% fuel consumption reduction required 8

9 Goal of SKYACTIV engines Real-world CO2 emissions (In Japan) Evaluation condition: Weighted average of results of below 3 tests, considering Japanese ambient temperature distribution in a year 1. JC08 Hot ambient temperature 25 air conditioner 25 AUTO 2. JC08 Hot ambient temperature 37 air conditioner 25 AUTO 3. JC08 Cold ambient temperature 7 air conditioner 25 AUTO Average energy consumption = JC08H 25 -((JC08H 25 -JC08H 37 )*0.2+(JC08H 25 -JC08C 7 )*0.3)/4 Well to Wheel co2 [g co2/km] Comparison of well to wheel CO2 Discrepancy=26% B car 1.3L JC08 mode 57 B car BEV Discrepancy=39% Fuel economy of internal combustion engines needs to be reduced by approx. 26%((126-93)/126=0.26) to attain the EV-level CO2 emissions. 9

10 Contents Improving thermal efficiency of ICEs Goal of SKYACTIV engines SKYACTIV engines: 1 st step SKYACTIV engines: Next step Investigation results of boosted downsizing engines and future strategy for engine displacement

11 SKYACTIV engines: 1 st step Roadmap to the goal of ICE Far Distance to ideal Close Control factors Current Gasoline engine Diesel engine Current Compression ratio World highest CR Specific heat ratio Combustion period Combustion timing Heat transfer to wall Pressure diff. Btw IN. & Ex. Miller cycle 1 st step SKYACTIV-G 2 nd step SKYACTIV-G 3 rd step=goal 2 nd step SKYACTIV-D 1 st step SKYACTIV-D Mechanical friction Friction reduction The most distinctive feature of 1 st step gasoline engine is world highest compression ratio. 11

12 SKYACTIV engines: 1 st step Full load Performance SKYACTIV-G 2.0L 圧縮比 =14 CR=14 20Nm 15% improved to current 2.0L Torque (Nm) EU B 2.0L former2.0l GE Competitors scatter band 95RON Engine Speed (rpm) Improve low- and-mid end torque in spite of a high compression ratio and achieve superior driving 12 12

13 SKYACTIV engines: 1 st step Compression ratio vs. RON SKYACTIV G(4 2 1) 91RON CR=13 SKYACTIV G(4 2 1) 95RON CR=14 Torque (Nm) former DI 91RON CR=11.2 former PFI 91RON CR=10 20Nm Engine Speed (rpm) Performance enhanced together with high compression ratio 13

14 SKYACTIV engines: 1 st step BSFC A 2.0LDI T/C 1500rpm Brake specific fuel consumption(g/kwh) 50g/kWh SKYACTIV-G 2.0L C Downsizing D 2.0L B2.0L DI lean burn E2.0L DI BMEP(kPa) SKYACTIV-G surpasses competitors all new engines including 30% downsized engines in fuel efficiency. 14

15 SKYACTIV engines: 1 st step BSFC vs. CR 1500rpm BSFC (g/kwh) 50g/kwh old PFI CR=10 old DI CR=11.2 SKYACTIV-G(4-2-1) 91RON CR=13 SKYACTIV-G(4-2-1) 95RON CR= BMEP (kpa) SKYACTIV-G made a large improvement in performance over conventional engines. 15

16 Contents Improving thermal efficiency of ICEs Goal of SKYACTIV engines SKYACTIV engines: 1 st step SKYACTIV engines: Next step Investigation results of boosted downsizing engines and future strategy for engine displacement

17 SKYACTIV engines: Next step Roadmap to the goal of ICE Far Distance to ideal Close Control factors Current Gasoline engine Diesel engine Current Compression ratio World highest CR Higher CR World lowest CR Specific heat ratio Combustion period Combustion timing Heat transfer to wall Pressure diff. Btw IN. & Ex. Miller cycle 1 st step SKYACTIV-G Lean HCCI Lean HCCI 2 nd step SKYACTIV-G Adiabatic 3 rd step=goal 2 nd step SKYACTIV-D Adiabatic More homogeneous 1 st step SKYACTIV-D Better mixing TDC combustion TDC combustion Mechanical friction Friction reduction Further reduction Further reduction Friction reduction Gasoline engine and diesel engine will look similar in the future. 17

18 SKYACTIV engines: Next step Walk of efficiency improvement Light load: 2000rpm IMEP290kPa Gasoline (GE) Diesel (DE) Combustion period Specific heat ratio Compression raio Wall heat transfer 40 GE: DE: GE: DE: GE: DE: GE: DE: 75deg 40deg Intake valve close GE: 93deg ABDC DE: λ=1 30deg Homogeneous Base Base 0.5*GE Homogeneous λ=2.8 λ=2.8 λ=4 Stratified 36deg ABDC There is room for improving thermal efficiency in the light load range: Approx. 30% for diesel engines Approx. 40% for gasoline engines 18

19 SKYACTIV engines: Next step Brake Specific Fuel Consumption Target for Mazda 3 5.2L/100km 3.8L 4.2L/100km around 25% fuel consumption reduction required 32% 100g/kwh competitors 0 20% 40% 12% 34% 30% Boosted lean burn BMEP (kpa) 1 st step SKYACTIV Target for 2 nd step Target for 3 rd step It seems possible for ICEs to attain a 25% fuel economy improvement, which is the target to to attain the EV-level CO2 19

20 SKYACTIV engines: Next step Hybridization requirement on electric device capacity Regenerative energy just delivers10-30% of vehicle driving energy BSFC Regenerative energy at deceleration Motor drive Electricity generated by engine Actual efficiency Motor drive Electricity generated by engine Energy flow motor battery loss loss Engine best efficiency point generator engine loss BMEP (kpa) 900 Motor drive using electricity generated by engine = Large battery and large motor required 20

21 SKYACTIV engines: Next step Hybridization requirement on electric device capacity Where motor drive electricity generated Brake energy at deceleration by engine Motor drive Motor drive BSFC Current Hybrid Motor drive 2 nd step engines BMEP (kpa) 900 When Mazda s next-generation engines are hybridized, small-sized motor and battery are sufficient enough to power engines. 21

22 Contents Improving thermal efficiency of ICEs Goal of SKYACTIV engines SKYACTIV engines: 1 st step SKYACTIV engines: Next step Investigation results of boosted downsizing engines and future strategy for engine displacement

23 Investigation results of boosted downsizing engines Prediction of BSFC BSFC (g/kwh) rpm 95RON 2.5L NA ε=13 1L T/C ε=6 1L T/C ε= Torque (Nm) 4000rpm 95RON 2.5L NA ε=13 1L T/C ε=6 1L T/C ε= Torque (Nm) At low load, 1L boosted engine with usual CR=10 shows better BSFC than 2.5L NA, but at mid. and high load, 2.5L engine shows much better BSFC than 1L boosted engine.

24 Investigation results of boosted downsizing engines Mode fuel distribution map NEDC FTP Downsizing is favorable for NEDC-mode fuel economy 24

25 Investigation results of boosted downsizing engines Real world fuel economy *Source : ADAC EcoTest NEU ab März L 2.0L A 1.8L Boosted D/S 1.2L 2 or 3 cyl or cyl. deactivation 1.2L 1.6L 1.0L 1.6L 1.4L 1.4L 1.2L 0.9L 1.4L 1.4L 1.6L 1.0L 1.2L 1.2L 1.4L I.2L 0.9L Mazda6 2.0L SKYACTIV-G I.0L Mazda3 2.0L SKYACTIV-G Mazda3 2.0L SKYACTIV-G 1.6L 1.4L CX-5 2.0L SKYACTIV-G 1.6L F/E at NEDC (L/100km) SKYACTIV engines are better than boosted downsizing engines in the real world fuel economy.

26 Investigation results of boosted downsizing engines Comparison between 2L SKYACTIV and 1L and 1.4L boosted D/S 1500rpm 95RON SKYACTIV cylinder deactivation 1L D/S 1L D/S BSFC (g/kwh) SKYACTIV current 1.4L D/S w/ cyl. Deact. SKYACTIV planned imp. 1.4L D/S w/ cyl. Deact Torque (Nm) 2L SKYACTIV engine can be superior to 1.4L boosted D/S engine with a cylinder deactivation system, and 1L 3 cylinder boosted D/S engine in all operational ranges.

27 Investigation results of boosted downsizing engines Comparison between 2.5L SKYACTIV and 1L and 1.4L boosted D/S 1.0L D/S 1.4L D/S w/ cyl. Deact. SKYACTIV 2.5L w/ cyl. Deac. 1.0L D/S 1.4L D/S w/ cyl. Deact. SKYACTIV 2.5L w/ cyl. Deac. Even 2.5L SKYACTIV engine can be superior to 1.4L 4-cylinder boosted D/S engine with a cylinder deactivation system, and 1L 3 cylinder boosted D/S engine in all operational ranges.

28 Investigation results of boosted downsizing engines Cost Turbocharger Base engine (Direct Injection) Boosted D/S Strengthened piston,con-rod, crankshaft, block, head Intercooler & piping SKYACTIV-G Electric VCT exhaust Boosted downsizing engines require extra expensive devices.

29 Excess air ratio vs. thermal efficiency Indicted thermal efficiency (%) Future strategy for engine displacement Target of lean burn IMEP 900kPa 600kPa 300kPa 2000rpm CR=14 Combustion duration= Excess air ratio NOx vs. excess air ratio High load Expanding Λ>2.2 is required for the compatibility of both efficiency and no NOX after-treatment NOxEI NOxEI Light Load Excess air ratio BMEP (kpa) BMEP (kpa)

30 Future strategy for engine displacement Lean burn capable area against displacement BSFC (g/kwh) rpm Λ= L turbo CR=10 λ=1 Λ=1 EGR 1L turbo CR=10 lean 2.5L NA CR=13 λ=1 2.5L NA CR=13 lean Λ=1 EGR Torque (Nm) Large Disp. NA can enlarge lean-burn area wider than boosted downsizing. Boosted Upsizing for wide lean-burn area is recommendable

31 Examination of fuel economy

32 Examination of fuel economy Average mileage /year Country Japan United States Mileage/year (km) 9,896 18,870 Vehicle age(years) 5,84 8,30 England Germany 14,720 12,600 6,20 6,75 France 14,100 7,50 Ref.)report from investigative commission on c lean diesel passenger car growth future prospect July 2008 Averaged mileage/year is somewhere between 10,000 and 15,000 km. (US excluded.)

33 Examination of fuel economy Real world fuel economy (US) Midsized cars Fuel economy (mpg) COMBI CITY HWY 1 Ford Fusion SE Hybrid Toyota Camry Hybrid XLE Volkswagen Passat TDI SE Hyundai Sonata Hybrid Mazda6 Sport Nissan Altima 2.5 S (4 cyl.) Honda Accord LX (4 cyl.) Chevrolet Malibu Eco Toyota Camry LE (4 cyl.) Hyundai Sonata GLS Subaru Legacy 2.5i Premium Chevrolet Malibu 1LT Toyota Camry XLE (V6) Honda Accord EX L (V6) Consumer report Honda Civic Hybrid Volkswagen Jetta Hybrid SE Volkswagen Jetta TDI Mazda3 i Touring sedan COMPACT CARS Overall mpg = 29 or higher Fuel economy (mpg) COMBI CITY HWY Chevrolet Cruze Turbo Diesel Mazda3 i Grand Touring hatchback Toyota Corolla LE Plus Ford Focus SE SFE Volkswagen Jetta SE (1.8T) Nissan Sentra SV Honda Civic EX Hyundai Elantra GLS Dodge Dart Rallye Fuel economy of HEV is superior, however,

34 Examination of fuel economy Fuel cost / year 5000 assuming 19,000km /year gasoline price; 3.8$/gallon Mid size cars =250$/year Compact cars =237$/year Mid size conventional 1150 Mid size HEV mpg Average drive cannot payoff the price increase by HEV by superior fuel economy

35 Summary We created roadmaps toward the ideal ICE and are steadily advancing developments accordingly. We introduced the world s highest compression ratio into the gasoline engines at the first step. We believe that our approach is more reasonable than the boosted downsizing approach from a perspective of real-world fuel economy and cost. We believe that hybrid-level fuel economy is achievable with just improving ICE technologies and that EV-level CO2 emissions is also achievable with improved ICE and simple hybrid technologies. We believe that the EV-level of well-to-wheel CO2 emissions is achievable with approx. 25% improvements from that of the current SKYACTIV. Once EVs have held a large share of the market, tremendous amount of electricity will have to be generated. As a result, EVs will be unable to obtain benefits from the current electric price due to the electric price increase. We regard large engine displacement as a cost free turbocharger, and plan to maximize its advantage and increase engine displacement. If expensive technologies which only improve fuel economy are offered to our customers, they cannot pay off high vehicle prices. Therefore, we continuously offer technologies together with additional values, such as driving pleasure. 35

36 Thank you for your attention!