Both the gasoline and diesel engines will be winners · Both the gasoline and diesel engines will be winners ... I2 0.9L I3 I.0L I3 0.9L 1.4L I3 1.0L 1.2L ... Intake valve close GE:

Both the gasoline and diesel engines will be winners

Mitsuo HitomiMazda Motor Corporation

26th International AVL Conference« Engine & Environment »

1

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






Conclusions

3It is impossible to improve environments without improving ICEs.

Forecast of world annual vehicle sales volume

Calendar year

Internal CombustionEngine

HEV

PHEVEV

0

Sales volume /year (

billi

on)

0.5

1.0

1.5

2.0

2010 2015 2020 20302025

Hybrid vehicle belongs to ICE family, not to EV family.

Ref. Marubeni Research Institute

2035

2.5

2.0

1.5

1.0

0.5

0

202020102000 2030 2040 2050

Automobile stocks by region

Non-OECD: Others

Non-OECD: ASIA

OECD

Calendar year

Sales volume /year (

billi

on)


After 2011 big earthquake in Japan

0.97

0.80

0.520.470.450.430.39

0.170.09

(kg-CO2/kWh)1.2

1.0

0.8

0.6

0.4

0.2

0France Canada Japan Italy UK Germany USA China India

0.52

Specific CO2 emission from electric power generation is assumed to be 0.5kg-CO2/kWh.

Specific CO2 emissions of electric power generation

4


A carB car

C car average15%

30%

45%

0%

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

10 12 14 16 18 2010

12

14

16

18

20

22

24

26

28

30

Specific electricity consumption at NEDC (kWh/100km)

3

4

5

6

7

3 4 5 6 7

I2 0.9L

I3 I.0L

I3 0.9L

1.4L

I3 1.0L

1.2L

1.4L

A 1.8L1.6L

1.4L1.6L1.6L

1.2LI3 1.0L

1.4L1.6L

1.2L

1.6L

2.0L

1.4L

1.6L

1.4L

*Source : ADAC EcoTest NEU ab März 2012

1.4L

1.2L

Mazda3 2.0L SKYACTIV-G

Note I3I.2L

1.2L

F/E at NEDC (L/100km)

A car

B car

C car

5

Target for ICE powered vehiclesFuel consumption reduction target for ICE powered vehicle in real world

21.2kWh/100km

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.00

20

40

60

80

100

120

140

Specific CO2 emission of electric power generation kg/kwh

Wel

l-to-

Whe

el_C

O2

(g/k

m)

4L/100km

3L/100km

Average

21.2kwh/100km=C car in the real world

Fuel consumption reduction target for ICE powered vehicle in real world

LCA considering just Li-ion Battery manufacturing2 ton (minimum estimation ever found)CO2 for 20kWh batteryLifetime mileage assumed 200,000km

Mazda3 2.0L = 5.2L/100km

Target for Mazda 3 5.2L/100km 4L (3.8L-4.2L)/100km

Around 25% fuel consumption reduction required

3.8L/100km

6


4.2L/100kmTarget; 4L/100km

Comparison of well-to-wheel CO2

Wel

l-to-

Whe

elco

2[g

-co2

/km

]

B car 1.3L B car BEV

126

93 93

57Discrepancy=39%

Discrepancy=26%

1. JC08 Hot ambient temperature 25℃ air conditioner 25℃ AUTO2. JC08 Hot ambient temperature 37℃ air conditioner 25℃ AUTO3. JC08 Cold ambient temperature -7℃ air conditioner 25℃ AUTO

Real-world CO2 emissions (In Japan)Evaluation condition: Weighted average of results of below 3 tests, considering Japanese ambient temperature distribution in a year

0

50

100

150

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


Average energy consumption = JC08H 25℃－（（JC08H 25℃－JC08H 37℃）*0.2+（JC08H 25℃－JC08C -7℃）*0.3）/4

JC08 mode

4000

5000

3000

2000

1000

00 10 20 30 40 50 60 70 80 90 100

EV equivalent CO2 in C car

Fuel cost / year

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.

Fuel economy (km/L)

Assumption: 14,000km mileage/year 1.55 Euro/L 0.285 Euros/kWh

Country

JapanUnited States

EnglandGermany

France

Vehicle age（years）

9,89618,87014,72012,600

5,848,306,206,75

14,100 7,50Ref.）Report from investigative commission on c lean diesel passenger car growth・future prospect

Mileage/year (km)

Target F/E in C carwith ICE powered vehicle in terms of CO2

Average mileage /year


8

4L/100km 1L/100km

Contents






Conclusions

9

Energy losses of ICE

Fuel economy improvement＝Loss reductionAll fuel economy improving technologies involve these 7 factors.

Effective work

Exhaust loss

Hea

t Ene

rgy

Bal

ance

(%)

Heat Energy Balance vs. Load

0

20

60

80

100

20 40 60 80 100Load (%)

40

Radiation, Misfiring loss

Cooling loss

Control factors

Pressure difference

between In. & Ex.

Mechanical friction

Specific heat ratio

Heat transferto wallPumping loss

Mech. friction loss

Combustionperiod

Combustion timing

Compression ratio

10


Gasoline engine Diesel engine

Further reduction

LeanＨＣＣＩ

Adiabatic

Higher CR

LeanＨＣＣＩ

Roadmap to the goal of ICE Distance to idealFar Close

Specificheat ratio

Heat transferto wall

Compression ratio

Combustion period

Control factors

Combustiontiming

Pressure diff.Btw IN. & Ex.

Mechanicalfriction

Gasoline engine and diesel engine will look similar in the future.

Adiabatic

Further reduction

Friction reduction

More homogeneous

World lowest CR

TDC combustion

TDC combustion

World highest CR

Friction reduction

Miller cycle 1stst

ep S

KYA

CTI

V-G

1stst

ep S

KYA

CTI

V-D

2ndst

ep S

KYA

CTI

V-G

2ndst

ep S

KYA

CTI

V-D

3rd

step

=Goa

l

Current Current

Better mixing


11

Contents






Conclusions

12

13

Specific heat ratio（λ，G/F）Combustion period 40

Indicated work(gross)

DieselGasoline

Exhaust loss

Cooling loss

Unburned loss

Heat balance analysis

40.8

34.7

20.8

42.8

33.5

21.2

Thermal efficiencyCompression ( Expansion) ratio

Combustion timing

Heat transfer to wall LIC


14 14 λ：1，G/F:17 λ：2.8，EGR ratio：57%，G/F:63

75

40.8% 42.8%

Light load： 2000rpm – IMEP290kPa

Status of gasoline and diesel engines

14

Gasoline Heat balance analysis


Exhaust loss

Cooling loss

Unburned loss

41.3

39.3

16.0

42.8

40.6

15.9

75

14 14

λ：1，G/F:15 λ：1.6，EGR ratio：35%，G/F:3350

41.3% 42.8%

Specific heat ratio（λ，G/F）Combustion period

Thermal efficiencyCompression ( Expansion) ratio

Combustion timing

Heat transfer to wall

DieselMiddle load： 2000rpm – IMEP940kPa


Shorter combustion periodin light-and-mid load ranges

Shorter combustion period in light-and-mid load ranges

Lean burn Homogeneous learn burn

Heat insulation + higher compression ratio

Heat insulation + higher compression ratio

Improvement approaches

DieselGasoline


15

Contents






Conclusions

16

17

Effect of fast burn at low load

In the light load range, the effect of shortening the combustion period is two times greater in gasoline engines than in diesel engines.


λ：1，G/F:17

Gasolineλ：2.8，EGR ratio：57%，G/F:63

Diesel

Base（75deg）30deg＠MBT Base（40deg）30deg＠MBT

40.341.9

42.8 43.5

2000rpm – IMEP: 290kPa

18

Effect of fast burn at high load

In the high load range, the effect of shortening the combustion period is almost the same between gasoline and diesel engines.


λ：1.6，EGR ratio：37%，G/F:33λ：1，G/F:15

DieselGasoline

Base（50deg）30deg＠MBT Base（75deg）30deg＠MBT

41.0

43.2 42.845.2

2000rpm – IMEP: 940kPa

Effect of homogeneity in diesel 2000rpm CR：14 Combustion timing：MBT Combustion period：30deg

1/Φ<1; 2 zone combustion1/Φ>1; 2 zone combustion until oxygen consumed then Oxygen fed from air zone

Diesel stratifiedmixture

Homogenous mixture

(2zone 0D-calc.)

Homogeneous

Φ=1Zone image

Fuel moleculeOxygen molecule

Stratified

Homogenous mixture

(2zone 0D-calc.)

IMEP: 290kPa λ：2.8 EGR ratio： 57%

IMEP940kPa λ：1.6 EGR ratio： 37%

Thermal efficiency improvement is possible to some degree with an enhancement of homogeneous air and fuel mixture during fuel combustion.

3D CFD

Excess air ratio

IMEP=290kPa

IMEP=940kPa

IMEP=940kPaIn-cylinder average

IMEP=290kPaIn-cylinder average

Freq

uenc

y (in

com

bust

ion

area

)

19


50% heat insulation improves thermal efficiency by approx. 10 % for both the gasoline and diesel engines.

Effect of heat insulation

20


Gasoline

ελ

λ

Diesel

CR

λλ

Homogeneous EGR ratio： 57%

CR

2000rpm – IMEP290kPaCombustion timing：MBT Combustion period：30deg

Heat transfer to wall halved

0.7 0.9

0.35 0.35

Effects of heat insulation on thermal efficiency in the high load range are almost equal to those in the light-and-mid load ranges.

Effect of heat insulation

21

Gasoline Diesel

CR CR

Homogeneous EGR ratio： 37%2000rpm – IMEP940kPa

Combustion timing：MBT Combustion period：30deg

λλ


Heat transfer to wall halved

0.75 0.95

0.375 0.375

There is room for improving thermal efficiency in the light load range:Approx. 30% for diesel engines Approx. 40% for gasoline engines 22

Light load： 2000rpm – IMEP290kPaWalk of efficiency improvement


Combustion period GE:DE:

Specific heat ratioGE:

DE:

Compression raio GE:DE:

Wall heat transfer GE:DE:

Intake valve close GE:DE:

93deg ABDC36deg ABDC

Base ← ← ←Base ← ← ←

40deg 30deg ← ← ←

Homogeneous

Stratified

←←

Homogeneous←

14 ← ← 20 30

←λ=1

λ=2.8 λ=2.8 λ=4

0.5*GE

40

45

50

55

60

Gasoline (GE) Diesel (DE)

75deg

←←

←←

←←

←←

Middle load： 2000rpm – IMEP940kPa


Walk of efficiency improvement

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

Combustion period 50deg75deg

Specific heat ratioλ=1

Homo.

Strat.

Compression raio 14

Wall heat transfer Base

λ=1.6

Intake valve close GE:DE:

GE:DE:

GE:DE:

GE:

DE:

GE:DE:

85deg36deg 36deg ABDC

30deg

Homogeneous

20 30

λ=1.6 λ=1.6

λ=4

λ=4

λ=1 λ=2

λ=2

λ=4

λ=4

←

←

←←←

←

←

←←←

← ←

←

←←

← ←

←

←← 0.5*GE

40

45

50

55

60Gasoline (GE) Diesel (DE)

←←

←← ← ←←

Contents






Conclusions

24

Indicated Specific Fuel Consumption

Targeted ISFC improvements Light-and-mid load: 30% in the 2nd step & 40% in the 3rd step High load rang : 10% in the 2nd step under λ＝1.

20% in the 2nd step & 35% in the 3rd step under boosted lean burn 25

0 200 400 600 800 1000 1200IMEP (kPa)

180

240

260

280

120

140

100g/kwh

λ=1 area Target for 2nd step

Target for 3rd step

1st step SKYACTIV

Boosted lean burn


It seems possible for ICEs to attain a 25% fuel economy improvement, which is the target to to attain the EV level CO2

Brake Specific Fuel Consumption

26

Target for 2nd step

100g/kwh

0

Target for 3rd step

200 400 600 800 1000BMEP (kPa)

32%

40%20%

34%

12%

30%

1st step SKYACTIV

λ=1 area

Boosted lean-burn


Target for Mazda 3 5.2L/100km 3.8L-4.2L/100kmaround 25% fuel consumption reduction required

Will ICE vehicles catch up with EVs?Comparison of thermal efficiency improvement during driving

20

30

40

50

60[%

]

Engine Efficiency

020406080

100120

580 680 780 880 980 1080 1180

[km

/h]

Time [sec]

Vehicle Speed

1st step

2nd step

3rd step

60

70

80

90

100

[%]

Motor and Battery Efficiency

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

Contents






Conclusions

28

DieselGasolineLight-and–mid load More homogeneous lean burn +

high compression ratioLean burn + fast burn + high compression ratio HCCI

Approach to reduce CO2 emissions

Mid-and-high load More homogeneous lean burn + high compression ratio + fast burn

Enabler Technologies to mix fuel and air quickly.

Conclusions

Lean burn +high compression ratio

Heat insulation + high compression ratio

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?

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 lean-burn, heat insulation and high compression ratio, it is possible for them to attain the CO2 level of EVs.

Conclusions

30

Questions for you

Thank you for your attention!

Both the gasoline and diesel engines will be winners · Both the gasoline and diesel engines will be winners ... I2 0.9L I3 I.0L I3 0.9L 1.4L I3 1.0L 1.2L ... Intake valve close GE:

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