Both the gasoline and diesel engines will be winners

Transcription

1 Both the gasoline and diesel engines will be winners 26th International AVL Conference «Engine & Environment» Mitsuo Hitomi Mazda Motor Corporation 1

2 Contents Target for ICE powered vehicles Improving thermal efficiency of ICEs Status of gasoline and diesel engines: Technological issues Thermal efficiency improvement Will ICE vehicles catch up with EVs? Conclusions 2

3 Target for ICE powered vehicles Forecast of world annual vehicle sales volume Automobile stocks by region Salesvolume/year billi ( on) Hybridvehicle belongstoicefamily, nottoevfamily. HEV InternalCombustionEngine EV PHEV Salesvolume/year billi ( on) Non-OECD : Others Non-OECD : ASIA OECD Calendaryear 2035 Ref.MarubeniResearchInstitut e Calendaryear It is impossible to improve environments without improving ICEs. 3

4 Target for ICE powered vehicles 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. 4

5 Target for ICE powered vehicles 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) F/E at NEDC (L/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 I30.9L 1.2L 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 5

6 Target for ICE powered vehicles 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 6

7 Target for ICE powered vehicles 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. 7

8 Target for ICE powered vehicles Fuel cost / year 500 Assumption: 14,000km mileage/year 1.55 Euro/L Euros/kWh Average mileage /year 400 Country Mileage/year (km) Vehicle age (years) Target F/E in C car with ICE powered vehicle in terms of CO2 Japan United States England Germany France 9,896 18,870 14,720 12,600 5,84 8,30 6,20 6,75 14,100 7, Ref.)Report from investigative commission on c lean diesel passenger car growth future prospect EVequivalentCO2inCcar L/100km Fuel economy (km/l) 4L/100km(25km/L) for C car =560L/14000km 868 Euros 21kwh/100km for C car =2940kwh/14000km 838 Euros 4L/100km of real-world fuel economy can be a target for customers. 1L/100km 8

10 Improving thermal efficiency of ICEs Energy losses of ICE 100 Heat Energy Balance vs. Load Radiation, Misfiring loss Control factors Compression ratio Heat Energy Balance (%) Exhaust loss Cooling loss Pumping loss Specific heat ratio Combustion period Combustion timing Heat transfer to wall 20 0 Mech. friction loss Effective work Load (%) Pressure difference between In. & Ex. Mechanical friction Fuel economy improvement=loss reduction All fuel economy improving technologies involve these 7 factors. 10

11 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. 11

13 Status of gasoline and diesel engines Gasoline Light load:2000rpm IMEP290kPa Heat balance analysis Unburned loss 20.8 Cooling loss 21.2 Diesel Exhaust loss Indicatedwork(gross) (gross) Thermal efficiency 40.8% 42.8% Compression ( Expansion) ratio Specific heat ratio(λ,g/f) Combustion period λ:1,g/f:17 75 λ:2.8,egr ratio:57%,g/f:63 40 Combustion timing Heat transfer to wall LIC 13

14 Status of gasoline and diesel engines Gasoline Middle load:2000rpm IMEP940kPa Heat balance analysis Unburned loss Diesel 16.0 Cooling loss 15.9 Exhaust loss Indicated work (gross) Thermal efficiency Compression ( Expansion) ratio Specific heat ratio(λ,g/f) Combustion period Combustion timing Heat transfer to wall 41.3% 42.8% λ:1,g/f:15 λ:1.6,egr ratio:35%,g/f:

15 Status of gasoline and diesel engines Improvement approaches Gasoline Shorter combustion period in light-and-mid load ranges Diesel Shorter combustion period in light-and-mid load ranges Lean burn Homogeneous learn burn Heat insulation + higher compression ratio Heat insulation + higher compression ratio 15

17 Thermal efficiency improvement Effect of fast burn at low load Gasoline 2000rpm IMEP: 290kPa λ:1,g/f:17 Diesel λ:2.8,egr ratio:57%,g/f:63 Base(75deg) Base(40deg) In the light load range, the effect of shortening the combustion period is two times greater in gasoline engines than in diesel engines. 17

18 Thermal efficiency improvement Effect of fast burn at high load Gasoline λ:1,g/f: rpm IMEP: 940kPa Diesel λ:1.6,egr ratio:37%,g/f:33 Base(50deg) Base(75deg) In the high load range, the effect of shortening the combustion period is almost the same between gasoline and diesel engines. 18

19 Thermal efficiency improvement Effect of homogeneity in diesel 2000rpm CR:14 Combustion timing:mbt Combustion period:30deg IMEP: 290kPa λ:2.8 EGR ratio:57% (2zone 0D-calc.) (2zone 0D-calc.) Diesel stratified mixture Homogenous mixture IMEP940kPa λ:1.6 EGR ratio:37% Homogenous mixture Frequency (in combustion area) 3D CFD IMEP=940kPa In-cylinder average Excess air ratio IMEP=290kPa IMEP=290kPa In-cylinder average IMEP=940kPa 1/Φ<1; 2 zone combustion 1/Φ>1; 2 zone combustion until oxygen consumed then Oxygen fed from air zone Φ=1 Stratified Homogeneous Zone image Fuel molecule Oxygen molecule Thermal efficiency improvement is possible to some degree with an enhancement of homogeneous air and fuel mixture during fuel combustion. 19

20 Thermal efficiency improvement Effect of heat insulation 0.7 Gasoline 2000rpm IMEP290kPa Combustion timing:mbt Combustion period:30deg 0.9 Diesel Homogeneous EGR ratio:57% Heat transfer to wall halved ε λ λ λ λ CR 50% heat insulation improves thermal efficiency by approx. 10 % for both the gasoline and diesel engines. CR 20

21 Thermal efficiency improvement Effect of heat insulation 0.75 Gasoline 2000rpm IMEP940kPa Combustion timing:mbt Combustion period:30deg 0.95 Diesel Homogeneous EGR ratio:37% λ Heat transfer to wall halved λ CR Effects of heat insulation on thermal efficiency in the high load range are almost equal to those in the light-and-mid load ranges. CR 21

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

23 Thermal efficiency improvement Walk of efficiency improvement Gasoline (GE) Middle load:2000rpm IMEP940kPa Diesel (DE) GE: 50deg Combustion period DE: 75deg λ=1 GE: Homo. Specific heat ratio DE: λ=1.6 Strat. Compression raio GE: 14 DE: GE: Wall heat transfer Base DE: Intake valve close GE: DE: 85deg 36deg 30deg λ=1.6 Homogeneous deg ABDC In the mid-and-high load ranges, there is room for improving thermal efficiency by approx. 40% for both the diesel and gasoline engines. 23 λ=4 λ=4 λ=1 λ=2 λ= *GE λ=2 λ=4 λ=4

25 Will ICE vehicles catch up with EVs? Indicated Specific Fuel Consumption g/kwh 1 st step SKYACTIV λ=1 area Target for 2 nd step Boosted lean burn Target for 3 rd step IMEP (kpa) Targeted ISFC improvements Light-and-mid load: 30% in the 2 nd step & 40% in the 3 rd step High load rang : 10% in the 2 nd step under λ=1. 20% in the 2 nd step & 35% in the 3 rd step under boosted lean burn 25

26 Will ICE vehicles catch up with EVs? Brake Specific Fuel Consumption Target for Mazda 3 5.2L/100km 3.8L-4.2L/100km around 25% fuel consumption reduction required 100g/kwh 32% 1 st step SKYACTIV 40% 20% 34% 12% 30% λ=1 area Boosted lean-burn Target for 2 nd step Target for 3 rd step BMEP (kpa) It seems possible for ICEs to attain a 25% fuel economy improvement, which is the target to to attain the EV level CO2 26

27 Will ICE vehicles catch up with EVs? Comparison of thermal efficiency improvement during driving 60 Engine Efficiency [%] MotorandBatteryEficiency 1 st step 2 nd step 3 rd step [%] [km/h] VehicleSpeed Time [sec] ICE vehicles will be able to attain the CO2 level of EVs based on mode simulation. Efficiency improvement for EVs is nearing its limit. 27

29 Conclusions Approach to reduce CO2 emissions Gasoline Diesel Light-and mid load Lean burn + fast burn + high More homogeneous lean burn + compression ratio HCCI high compression ratio Mid-and-high load Lean burn +high compression More homogeneous lean burn + ratio high compression ratio + fast burn Heat insulation + high compression ratio Enabler Technologies to mix fuel and air quickly.

30 Conclusions 1. The annual volume of auto sales in the world will approximately double by 2050 mainly because of increasing sales volume in non-oecd countries. 2. In order for ICE vehicles to attain the well-to-wheel CO2 level of EVs, approx. 25 % improvement in real-world fuel economy is required. 3. If both the gasoline and diesel engines achieve more homogeneous leanburn, heat insulation and high compression ratio, it is possible for them to attain the CO2 level of EVs. Questions for you Despite the fact that lean burn is required to drastically improve thermal efficiency, do you still think that downsizing engines have a future? Even though the much electricity is generated by coal-fired power plants, will you continue to advance the zero CO2 scheme of electricity? 30

31 Thank you for your attention!