turbocharged spark ignited direct injection a fuel economy
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Turbocharged Spark Ignited Direct InjectionA Fuel Economy Solution for the USJune 10, 2009
Paul WhitakerChief Technologist, Gasoline EnginesAVL Powertrain Engineering Inc.
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Micro PC Engines < 1,0 l
Small PC Engines1,0 - 1,5 l
Medium PC Engines 1,5 - 2,4 l
Large PC LDT / MDT
Truck
Variable Charge Motion
Variable Valve Lift2 / 3 Step
Variable Valve Lift Continuous
NA Homogeneous SIDI
TC Homogeneous SIDI
SIDI Stratified
Controlled Auto Ignition
CylinderDeactivation
Engines> 4 cyl
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Technology
New /current Mainstream:
General Market Trends:
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Global Gasoline Technology Trends
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0
8
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24
1000 2000 3000 4000 5000 6000Engine Speed [rpm]
BM
EP [b
ar]
220
240
260
280
300
320
340
360
BSF
C [g
/kW
h]
RON 95
MY 2005
t turb = 950°C
MY 2012+ VGT
SIDI + TurbochargingLow End Torque versus Mid / High Speed BSFC
MY 2010 DVCPMY 2007 I-VCP
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High Tumble for Turbo SIDIOctane and Faster Burn Rate Benefits with High Tumble Improves Full-Load Fuel Consumption
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Optical Engine Supports Turbo SIDI ProgramsExample: 1500 rpm Boosted Full Load Optimization
Optimized System
Fuel spray direction
Flame Images Good Injector: flame intensity
NO soot flames!
Air intake flow
HEAVY soot flames!
Base SystemLIF
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Engine Speed [rpm]
10
20
30
1000 2000 4000 6000
Full LoadState of art 2007
Enrichment RON 98
Enrichment
RON 95
Measures to reduce enrichment requirement:
• High RON fuels
• Higher temperature turbine (e.g.: 950°C 1050°C)
• Cooled external EGR
• Active exhaust gas cooling
Enrichment Requirement for Turbocharged Gasoline Engines
Full Load, Ultra High Performance Concepts
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Showing The Potential Of Turbocharged GDI
GDI-Turbo Concept Carfor low Fuel Consumption
5.0
5.5
6.0
6.5
7.0
7.5
8.0
8.5
NEDC l/100km160
165
170
175
180
185
190
195
200
NEDC g/km CO2
0.08
0.09
0.10
0.11
0.12
0.13
0.14
0.15
0.16
NEDC $/mile*
2.0L VW FSI
NEDC $/mile* based on $3.55/gallon for premium gasoline & $4.15/gallonultra low sulfur diesel – US average prices 22-APR-08
2.0L AVL t-GDI2.0L VW Diesel
FTP 75: 32 mpgHWFET: 50 mpg
160
180
200
220
240
260
280
300
320
340
6000
Engi
ne T
orqu
e -N
m
360
380
1000 2000 3000 4000 5000Engine Speed – rpm
AVL 2.0l Turbo SIDI
2.0l Turbo SIDI(Production)
Increased full load performance allows longer final drive ratio for improved fuel economy
Ethanol Turbocharged Direct Injection
05
1015202530354045
Lower Heating Value (MJ/kg)
26.842.5
2/3
0
5
10
15
20
25
30
35
Heat of Evaporation (kJ/MJ)
33.8
8.0
4x
Regular GasolineEthanol
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Multiple Injection Strategy for E100 Cold StartTurbo SIDI
Injector
Fuel pressure 4 bar
Large droplets
Wall film
Intake valve
Single Injection
After SOI
After EOI
Significantly reduced wall film
Small droplets
Fuel pressure 40 bar
After SOI
EOI
New Multiple Injection
Fuel Pressure 40 bar
No wall film
Small droplets
Minimised Piston Wetting
Last Injection Late
First Injection Early
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Turbo SIDI - Benefits of E85 on Full Load Operation
E85RON91
2.5%
30°CA
150 bar
950°C
25%
MBT
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Dual Fuel Strategy
E85 provides significant octane benefit with DI due to high latent heat of vaporization and high octane rating
Allows knock-free operation at high CR and high BMEP with very high thermal efficiency
but…Low E85 heating value is a disadvantage
Dual fuel strategy uses E85 DI only as required to eliminate knock in a high CR gasoline engine.
Combines high load E85 octane benefit with part load gasoline heating value advantage
Provides maximum leveraging of available ethanol
0
5
10
15
20
25
30
1500 2000 2500 3000 3500 4000 4500 5000
Engine Speed [rpm]
BM
EP [b
ar]
10% E85
25% E85
50% E85
70% E85
0
5
10
15
20
25
30
1500 2000 2500 3000 3500 4000 4500 5000
Engine Speed [rpm]
BM
EP [b
ar]
10% E85
25% E85
50% E85
70% E85
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Dual Fuel Optimized E85 Engine vs. CompetitorsCycle Simulation Results Medium Duty Truck
+ 530 mpg E85+ 860 mpg Urea
0
2
4
6
8
10
12
-25 -20 -15 -10 -5 0 5 10 15 20 25 30 35Metro Highway Fuel Economy Improvement (%)
Max
Gra
de in
6th
Gea
r at 6
5 m
ph (%
)
5.0l GTDI 91 RON5.0l GTDI FFV E855.0l Dual Fuel (gasoline mpg only)NA Gasoline Baseline 91 RONDiesel Target
Heating Value DisadvantageDownsizing/Downspeeding
Benefit
+3 Compression Ratio Increase, Advanced Combustion Phasing BenefitsGasoline Displaced By E85 At High Load
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Optical Engine - Split Injection for Catalyst HeatingComparison of Gasoline & E85 Flame Images
0
1001
100
FlameProbability
[%] Premixed Flame
Soot Flame
Gasoline DI
E85 DISignificantly
reduced smoke with E85
(oxygenated fuel) more calibration
freedom, increased efficiency
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Summary
Turbocharged SIDI is the most promising fuel economy technology for US:
Combines existing & proven technologies in a synergistic manner
Offers double digit fuel economy benefits
Much lower cost than diesel or hybrid
Can meet future emissions standards with inexpensive gasoline aftertreatment
Can be applied across an OEM’s entire engine portfolio in high volume
Provides benefits when operating on ethanol in Flex Fuel applications
Dual fuel (PFI gas + DI ethanol) concept new benchmark for SI fuel economy