-acc symposium held on september 28 · mazda skyactiv-g engine with new boosting technology reiji...
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Mazda SKYACTIV-G Enginewith New Boosting Technology
Reiji Okita Mazda Motor Corporation
- ACC Symposium held on September 28 -
28, Sep. 2016
1. Mazda’s approach for environmental improvement
2. SKYACTIV-G Development Process
3. SKYACTIV-G 2.5L TC development
4. End message
CONTENTS
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3
Mazda’s Long-term Vision “Sustainable Zoom-Zoom“
© Mazda Motor Corporation │ Strictly Confidential │
Provide all the customers with driving pleasure, Also, Mazda considers the best contribution to the environment is to
incorporate superior and fairly valued technologies into every car modelrather than expensive eco technologies to limited models
a b c d e f g h i j
Vehicles
CO2
100%
0%
CO2
100%
0%a b c d e f g h i j
Vehicles
Small number
of expensive
eco-vehicles
Mazda’s approach
1. Mazda’s approach for environmental improvement
Why we believe so ?
1) Market forecast
2) Difference between Well-to-Wheel
CO2 emissions of EV and ICE
4© Mazda Motor Corporation │ Strictly Confidential │
CO2CO2
Well Tank Wheel
CO2CO2CO2CO2
Wheel
Tank to Wheel Well to Wheel
5
ICEInternal Combustion Engine
BEV
PHEV
・・・ GE/DE
1. Mazda’s approach for environmental improvement
250
200
150
100
50
0
202020102000 2030 2040 2050
Vehicle Sales Volume by regionRef. Marubeni Research Institute
Non-OECD
: Others
Non-OECD
: ASIA
OECD
Sales volume /year (m
illion)
Vehicle Sales by typeRef. BP Energy Outlook 2035
Most of power source of a car which will increase in future are internal combustion engines. It will not be possible to make a contribution for environment without improving internal combustion engines.
- Market forecast-
France IndiaEnglandItalyCanada USGermanJapan China
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0.5kg-CO2/kWh
1. Mazda’s approach for environmental improvement
- Well to Wheel -
We assume that global average of specific CO2 emission in electric power generation is 0.5kg-CO2/kWh
CO2排出原単位(発電端)の各国比較
Nuclear
Water
New energy, others
Well to Tank CO2 emission of Electricity(without transmission efficiency)
CO2
emis
sion
sby
bas
ic u
nit
Brea
kdow
n of
non
-fos
sil
ener
gies
0.37kg-CO2/L
Well to Tankof Fuel in Japan
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C car EV Real World Electricity Consumption : 21.2kWh/100kmC car SKYACTIV-G Real World Fuel Consumption: 5.2L/100km
Electricity Consumption and Fuel Consumption
A carB car
15%
30%
45%
0%
10 12 14 16 18 2010
12
14
16
18
20
22
24
26
28
30
Specific electricity consumption at NEDC (kWh/100km)
A car
B car
C car
21.2kWh/100km
Specific electricity consumption
at ADAC ECO test (kWh/100km)
C car average
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
1.4L
1.6L1.6L
1.2LI3 1.0L
1.4L
1.6L
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 I3
I.2L
1.2L
F/E at NEDC (L/100km)
15%
0%F/E ADAC ECO test
(L/100k)
- Well to Wheel -
1. Mazda’s approach for environmental improvement
5.2L/100km
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Well to Wheel CO2 emission 〜Mazda EstimateC car EVElectricity Consumption: 21.2kWh/100kmSpecific CO2 emission : 0.5 CO2-kg/kWh+ LCA considering Li-ion Battery: 1.0kg/100km
If the fuel consumption could be improved by 20%-30%, CO2 emission level of the vehicle powered by ICE could be equal to that of EV.
106 〜 116 CO2-g/km
C car SKYACTIV-GFuel Consumption : 5.2L/100km
148 CO2-g/km
20% - 30%
- Well to Wheel
1. Mazda’s approach for environmental improvement
(Well to tank + Tank to Wheel)
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Potential of the improvementWell to Wheel CO2 emission with ICE
Current efficiency of Tank-to-Wheel
� EV : 80%-90%
� ICE: max. 30% - 40%
1. Mazda’s approach for environmental improvement
There is still Large potential of improvement in ICE, also hybridization gives further improvement on ICE
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1. Mazda’s approach for environmental improvement
How do we let the aim accomplish ?“F/C improvement 20%〜30%”
CONTENTS
1. Mazda’s approach for environmental improvement
2. SKYACTIV-G Development Process
3. SKYACTIV-G 2.5L TC development
4. End message
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12© Mazda Motor Corporation │ Strictly Confidential │
2. SKYACTIV-G Development Process
Innovative High Thermal EfficiencyThe energy of the fuel is converted to power that
moves the vehicle.
� Improvement of driving force� Improvement of fuel economy� Decrease of poisonous substance in
exhaust gas
Maximize
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Effective work
Exhaust loss
Heat
En
erg
y B
ala
nce (
%)
Heat energy balance vs. load
0
20
60
80
100
20 40 60 80 100
Load (%)
40
Radiation, Misfiring loss
Cooling loss
Compression ratio
Specific heat ratio
Control factor
Combustion period
Combustion timing
Heat insulation
Pressure differenceb/w intake and exhaust
Mechanical loss
High-efficient Engine ← Minimize Losses
2. SKYACTIV-G Development Process
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2. SKYACTIV-G Development Process
Gasoline engine Diesel engine
Further reduction
LeanHCCI
adiabatic
Higher CR
LeanHCCI
Roadmap to the goal of ICE Distance to idealFar Close
Specific
heat ratio
Heat transfer
to wall
Compression ratio
Combustion
period
Control factors
Combustion
timing
Pressure diff.
Btw IN. & Ex.
Mechanical
frictionFurther reduction
friction reduction
More homogeneous
World lowest CR
TDC combustion
TDC combustion
World highest CR
friction reduction
Miller cycle 1
stste
p S
KY
AC
TIV
-G
1stste
pS
KY
AC
TIV
-D
2n
dste
p S
KY
AC
TIV
-G
2n
dste
p S
KY
AC
TIV
-D
3rd
ste
p=
Go
al
current current
Better mixing
Gasoline and diesel engines will look similar in the future.
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Alternative delivering torque higher than 400Nm on a large SUV is, V6 Natural Aspirated or Boosted I4 downsized.
Power Source for CD-SUV
TIME-LINE
TORQUE
Nm2.0L
2.0L/1.8L
1.3L
1.6L/1.5L1.5L
1.3L
2.5L
2.3L_T/C
3.7L_V6
200
400
Previous
Generation
New
Generation
2.5L
I4 Boostedor
HIGH CR NA
Inline four (4)
V6
3. SKYACTIV-G 2.5L TC development
CONTENTS
1. Mazda’s approach for environmental improvement
2. SKYACTIV-G Development Process
3. SKYACTIV-G 2.5L TC development
4. End message
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Scenario we selected I4 boosting,not V6 NA.
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18© Mazda Motor Corporation │ Strictly Confidential │
Compared to V6 3.7L, boosted I4 2.5L achieves:- 30% less mechanical friction with fewer cylinders (6 to 4) and less displacement
Mechanical Friction ~Calculation by Mazda
Effect of Downsizing V6 3.7L ⇒⇒⇒⇒ Boosted I4 2.5L
3. SKYACTIV-G 2.5L TC developmentAdvantage of I4 boosted
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Compared to the V6 3.7L, the boosted I4 2.5L achieves:- 30% less pumping loss with less displacement.
Effect of Downsizing V6 3.7L ⇒⇒⇒⇒ Boosted I4 2.5L
Pumping loss
3. SKYACTIV-G 2.5L Turbocharged (TC) Engine Development
Advantage of I4 boosted
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I4 boosted concept has superior mechanical friction and pumping loss, while it is inferior fuel efficiency due to lowered compression ratio, and acceleration response.
3. SKYACTIV-G 2.5L TC development
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P: pressure (kPa)
T: unburned gas temp. (K)
X_EGR:EGR ratio
Ignition delay
Livengood-Wu integral
3. SKYACTIV-G 2.5L TC development
Key issue to realize I4 boosted with high compression ratio is
Knocking Resistance Improvement
Evaluation Toolfor calculation of knocking resistance
22
3. Breakthrough Point to Realize I4 Turbocharging Concept
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To keep the advantage of I4 turbocharged engine for the mechanical friction and pumping loss, the compression ratio must be kept around 10.5.
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
0.5 1.0 1.5 2.0 2.5 3.0 3.5
LW
Inte
gra
l [-
]
Charging pressure [bar]
ε=13.0 ε=10.5
ε=9.0 ε=8.0
ε=7.0 ε=6.0
ε=5.0
LW integral value at BLD of 2.5L NA CR=13
ε=8
ε=10.5
Compression ratio setting
in the high load range
ε=6
((((2.5L)))) Displacement
2.5L TC
@2000rpm
ε=13
I4 2.5L
ε=10.5
BSFCImprovement
Anti-knocking technology
BS
FC
Mechanical Resistance
Pumping Loss
V6 3.7L
ε=13
V6 2.5L
ε=13
I4 2.5L
ε=13
I4 2.5L
ε=8
Maintain knock resistanceequivalent to NA
Compression ratio setting
in the light load range
Cascaded targets to realizecompression ratio, 10.5
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24© Mazda Motor Corporation │ Strictly Confidential │
The concept o improve knock resistance at high loads, encouraging “scavenging” for low speed and introducing EGR for mid/high speed.
3. SKYACTIV-G 2.5L TC development
ε=13
ε=10.5
ε=10.5
ε=10.5
EGR18%
EGR25%
(2.5L) ------ Displacement
@4000rpm
25
4. Setting Functional Targets and Appropriate Displacement
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“Scavenging” at low rpm/high load
The follows are necessities for the turbo charged 2.5L engines(CR 10.5/boost pressure 2.0bar) to ensure the knock resistance equivalent to 2.5L NA engines(CR 13.0) .- low rpm/high load : TDC Temp.Δ75K, BGR* 7.0% →2.5%
- mid/high rpm & high load: EGR ratio 18%
-75K
(2.5L) ------ Displacement
ε=10.5BGR 7.0%
ε=10.5BGR 2.5%
ε=10.5BGR 0.0%
ε=13.0Heavy knocking area
“EGR” at mid/high rpm & high load
EGR18%
Heavy knocking area
*: BGR = Residual gas ratio
@1500rpm
Specific Measures to achieve cascaded specific targets
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27© Mazda Motor Corporation │ Strictly Confidential │
Exhaust Pulsation of a Turbocharged Engine
For strong scavenging, a large gap of pressure and long overlap interval are necessary, while the boost pressure exceeding over exhaust gas pressure.
Pre
ssure
Crank angle
EVO
IVO
Boost Pressure
Exhaust pressure
OverlapInterval
Pre
ss
ure
Ga
p
High Pulsationmakes high boost
3. SKYACTIV-G 2.5L TC development
- Scavenging -
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Dynamic Pressure Turbo (DPT) Structure
To realize scavenging concept, 4-3-1 exhaust was adopted so that the volume of four exhaust passages are minimized evenly. Each passage is divided into primary and secondary in order to encourage turbine rotation and scavenging effect.
A-A cross section
B-B cross section
3. SKYACTIV-G 2.5L TC development
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Dynamic Pressure Turbo (DPT) Scavenging Effect
3. SKYACTIV-G 2.5L TC development
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Dynamic Pressure Turbo (DPT) effect at low/high engine rev.
3. SKYACTIV-G 2.5L TC development
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EGR gas is pulled through EGR outlet placed at down stream of the control valve,and brought to EGR cooler.
EGR pipe
DPT Control Valve
EGR Cooler
HP-Cooled EGR Passage
3. SKYACTIV-G 2.5L TC development
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Function of EGR Pipe Location
EGR passage does not disturb “scavenging” effect when it is required, but able to provide sufficient amount of EGR with transient accuracy.
Valve : Close
Low pressure
Low pulsation
Scavenging condition
& no EGR required
High pulsation
Pre
ssure
No Scavenging condition
& enough EGR required
Valve : Open
Pre
ssu
re
EGR pipeEGR pipe
EGR
Low rpm
High loadMid/High rpm
3. SKYACTIV-G 2.5L TC development
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Scavenging and EGR Area
SKYACTIV-G with DPT achieved to enable high scavenging under low engine speed, as well as introduce high amount of EGR in wider engine operation range, led significantly low fuel consumption performance.
3. SKYACTIV-G 2.5L TC development
Achievements
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35© Mazda Motor Corporation │ Strictly Confidential │
Reduction in Fuel Consumption
SKYACTIV-G 2.5L with DPT improves the fuel efficiency over a whole range.
3. SKYACTIV-G 2.5L TC development
36© Mazda Motor Corporation │ Strictly Confidential │
SKYACTIV-G 2.5L with DPT achieved significantly higher torque than predecessor from low engine speed under 91RON, as well as much shorter turbo lag.
Acceleration CharacteristicTorque Curve
3. SKYACTIV-G 2.5L TC development
37© Mazda Motor Corporation │ Strictly Confidential │
0
50
100
150
200
250
300
350
400
450
500
0 1000 2000 3000 4000 5000 6000 7000
Torq
ue [
Nm]
Engine Speed [rpm]
180km/h
200km/h
220km/h
240km/h 6th
100km/h120km/h
140km/h
160km/h
5th
100kW
110kW
120kW
V6 3.7L WOT
SKYACTIV-G 2.5T
WOT
2.3L TC WOT
SKYACTIV-G 2.5L with DPT λ=1 window
1
2
SKYACTIV-G 2.5L with DPT achieved wider range of λ=1 window, real-world fuel consumption has been improved by 30% from the predecessor model.
3. SKYACTIV-G 2.5L TC development
38
Summary
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Mazda 2.5L SKYACTIV-G Engine with “Dynamic Pressure Turbo” and “HP cooled-EGR” brought the following benefits:
2. Low fuel consumption at middle and high loads.
1. Acceleration response comparable to that of large-displacement naturally aspirated engine
3. The maximum torque of 420 Nm at low speed, 2000rpm
3. SKYACTIV-G 2.5L TC development
CONTENTS
39© Mazda Motor Corporation │ Strictly Confidential │
1. Mazda’s approach for environmental improvement
2. SKYACTIV-G Development Process
3. SKYACTIV-G 2.5L TC development
4. End message
� ICE has still enough potential to improve its thermal efficiency.
� Mazda continues to improve ICEperformance targeting to equalCO2 emission level as EV’s.
40© Mazda Motor Corporation │ Strictly Confidential │
Thank you for your kind attention