Excellence in Automotive R&D
Reducing the particulate emission numbers in DI Gasoline EnginesKody Klindt, IAV Automotive Engineering Inc.
22
Overview
1. Motivation
2. Particle Formation and Measurement
4. Applying Calibration Measures to a GDI Concept
5. Summary
3. Process Description
33
Overview
1. Motivation
2. Particle Formation and Measurement
4. Applying Calibration Measures to a GDI Concept
5. Summary
3. Process Description
4
Russia
Currently: Euro 42014: Euro 5
Currently: Euro 2Currently: ADR79/02 (Test
method Euro 4)
AustraliaSouthern Africa
Currently : Euro 3, Euro 4 Beijing07/2010: Euro 4
China
Currently: Euro 2 / Euro 3 (Delhi)04/2010: Euro 3 / Euro 4 (Delhi)
India
Currently: J-LEV 2010Green Car Label
2013: J-LEV 2013
Japan
Currently: US10Tier 2 / LEV 2
2013: LEV 3
Currently: Euro 52011: Euro 5+2014: Euro 6North America
Europe
Currently: Proconve L5 (Basis: Euro5)
2013/14: Proconve L6
Brazil
4
MotivationLimit Values for Particulate Emissions
EU6 and LEV3 limit values for particulate emissions under discussion
EU 4 EU 5 EU 5+ EU 6
2005 09/2009 09/2011 09/2014
PM [mg/km]
Diesel 25 5 4.5 4.5
GDI - 5 4.5 4.5
PN [1/km]Diesel - - 6*1011 6*1011
GDI - - - 6*1011 (?)
LEV 2 LEV 3
2007 2013
PM [mg/ml]
DieselGDI 10 3 (?)
5555
Partikelmasse Euro 6 = 4,5
Par
tikel
anza
hl [#
/km
]
Partikelmasse [mg]0 1 2 3 4 5 6 7 8
MotivationPresent range of DI gasoline engine
Broad distribution
of particle mass
and
particle number
with different
production
concepts
EU6 particle mass limitPM = 4,5 [mg/km]
Particle mass [mg/km]
Parti
cle
num
ber *
1012
[1/k
m]
EU
6 pa
rticl
e nu
mbe
r lim
itP
N =
6*1
011[1
/km
]0
2
4
6
8
7 8651 2 3 40
66
Overview
1. Motivation
2. Particle Formation and Measurement
4. Applying Calibration Measures to a GDI Concept
5. Summary
3. Process Description
77
Particle Formation and MeasurementSoot formation mechanisms
Acetylenemolecules
Aromatic rings
Kernels
Coagulation
Primary sootparticulate
Agglomeration
3D branchedchains
H–C C–H≡
HC in hot atmosphere with O2deficiency
Fuel Film onPiston Head
Fuel Film on Combustion chamber roof
and spark plugLiquid fuel tothe injector
Fuel droplets in the flame front and rich mixture
zones
Fuel fromFire land
Global rich mixture: Catalyst heating, Acceleration enrichment, Rich region in engine map
88
HORIBAMEXA 1000 SPCS
Particle sizemin - max
23 nm -2500 nm5 nm -
1000 nm
Effective range
0 – 3x108 #/cm3
2.4x103 – 1012
dN/dlogDp/cm3
-
38
Sampling rate
1 Hz
10 Hz
PMP conformity
yes
no
Size group
CAMBUSTIONDMS 500
Particle Formation and MeasurementParticle number measuring systems
Condensation particle counter Electric mobility classification
5 10 100 1000nm
dN/d
LogD
p
1.0E+02.0E+44.0E+46.0E+48.0E+41.0E+51.2E+51.4E+51.6E+51.8E+52.0E+5
Quelle: Horiba Ltd. Quelle: Cambustion Ltd.
99
Overview
1. Motivation
2. Particle Formation and Measurement
4. Applying Calibration Measures to a GDI Concept
5. Summary
3. Process Description
1010
Process DescriptionIAV's approach to gasoline engines
NEDC range usedfor stationary model
Hull information
Vehicle emission calibration
Map optimization→ Particle min , ...
Steady-state model
Steady-stateDoE measurements
of test plan underwarm conditions
Stationary Data
Dynamic(sinusoidal)measurements under warm-up conditions
Dynamic Data
Compare steady-state/dynamic→ Particle min , ...
Dynamic model
1111
Process DescriptionSteady-state model
Output:
• Torque
• Fuel consumption
• AL50
• COV
• Exhaust temperature
• NOx, HC, CO
• Particle concentration
engine load20 30 40 50 60 70 80
0
5x106
Pnac
c [#
/cm
3 ]
[%]
exhaust timing60 70 80 90 100 110 120
0
5x106
Pnac
c [#
/cm
3 ][°CA]
rail pressure4 5 6 7 8 9 12
0
5x106
Pnac
c [#
/cm
3 ]
10 11[mpa]
lambda0.90 0.92 0.94 0.96 0.980
5x106
Pnac
c [#
/cm
3 ]
[-]
engine speed1000 1500 2000 2500 3000
0
5x106
Pnac
c [#
/cm
3 ]
rpm [1/min]
intake timing50 70 80 90 100 110 120
0
5x106
Pnac
c [#
/cm
3 ]
[°CA]60
ignition angle-10 0 10 20 30 40
0
5x106
Pnac
c [#
/cm
3 ]
50[°CA]
start of injection200 220 240 260 320
0
5x106
Pnac
c [#
/cm
3 ]
[°CA]280 300
Pnacc: [#/cm³] Particle concentration
12
Process DescriptionDynamic (sinusoidal) measurements under warm-up conditions
Engine speed
Engine load
Intake timing
Exhaust timing
Ignition angle
Lambda
Rail pressure
Start of injection
Watertemperature
1313
Process DescriptionDynamic model - validation
Output:
• Torque
• Fuel consumption
• AL50
• COV
• Exhaust temperature
• NOx, HC, CO
• Particle concentration
ModelMeasurement
ModelMeasurement
1414
Overview
1. Motivation
2. Particle Formation and Measurement
4. Applying Calibration Measures to a GDI Concept
5. Summary
3. Process Description
15
Vehic
le sp
eed
in km
/h
0
20
40
60
80
100
120
140
Time in sec0 200 400 600 800 1000 1200
Cum
ulate
d pa
rticle
num
ber i
n %
0
20
40
60
80
100
Base measurement
15
Applying Calibration Measures to a GDI ConceptBasis of investigations
GDI Concept4-cylinder homogeneousTurbocharged engine with
• Solenoid injector• Sideways position• Max. double injection
Boundary conditionsNo influence on
• Exhaust emissions• Drivability• Consumption
Vehic
le sp
eed
in km
/h
0
20
40
60
80
100
120
140
Time in sec0 200 400 600 800 1000 1200
Parti
cle co
ncen
tratio
n in
#/cm
3
0
4·1010
8·1010
12·1010
16·1010
20·1010
24·1010
Base measurement
1616
Applying Calibration Measures to a GDI ConceptCalibration in “cold range”
Veh
icle
spe
ed in
km
/h
0
20
40
60
80
100
120
140
Time in sec0 200 400 600 800 1000 1200
Cum
ulat
ed p
artic
le n
umbe
r in
%
0
20
40
60
80
100
Basic measurement Cold optimized Vehicle speed
Coldrange
+ Start of injection Start of 1st injection was adjusted (~35 °CA later)
+ Injection split Was matched with regard to particle number and rough running
+ End of injection The end of 2nd injection was adjusted to the split
+ Fuel pressure Was set near the maximum fuel pressure after engine startand to maximum at the start of 2nd hill
+ Air fuel ratio Better air/fuel ratio pilot control up to start of engine, reaching ideal Lambda as fast as possible
+ Ignition angle Subsequent adjustment at 7°CA on 1st hill and at 12°CA on 2nd hill
- Valve timing Changed valve timing results in efficiency reduction and increased fuel consumption
171717
Applying Calibration Measures to a GDI ConceptCalibration in “warm range”
Veh
icle
spe
ed in
km
/h
0
20
40
60
80
100
120
140
Time in sec0 200 400 600 800 1000 1200
Cum
ulat
ed p
artic
le n
umbe
r in
%
0
20
40
60
80
100Warmrange
Basic measurement Warm optimized Vehicle speed
+ Fuel pressure Was set to maximum fuel pressure in complete range except idleand at low loads (near to minimum injection quantities)
+ Start of injection Start of 1st injection was adjusted (~20 °CA later)+ Injection split Was matched with regard to particle number
- Ignition angle Later ignition angle results in particle reduction - but comes with rising fuel consumption
- Valve timing Changed valve timing results in efficiency reduction and increased fuel consumption
- Air/fuel ratio Operating at lambda = 1 ensures particle optimum regarding the other emission components
181818
Applying Calibration Measures to a GDI ConceptResult of particle optimization
Vehic
le sp
eed i
n km/
h
0
20
40
60
80
100
120
140
Time in sec0 200 400 600 800 1000 1200
Partic
le co
ncen
tratio
n in #
/cm3
0
4·1010
8·1010
12·1010
16·1010
20·1010
24·1010
Base measurement Optimized measurement
Vehic
le sp
eed
in km
/h
0
20
40
60
80
100
120
140
Time in sec0 200 400 600 800 1000 1200
Cum
ulate
d pa
rticle
num
ber i
n %
0
20
40
60
80
100
Reduction of 65 %
1919
Overview
1. Motivation
2. Particle Formation and Measurement
4. Applying Calibration Measures to a GDI Concept
5. Summary
3. Process Description
2020
Summary
• Future particle limits require optimized calibration and optional hardware adjustment
• IAV has developed a steady-state and a dynamic model to optimize particulate emissions
• Significant decrease of particle number in a GDI concept
2121
Acknowledgements
IAV GmbH
- Matthias Kratzch
- Olaf Kannapin
- Dr. Stephan Liebsch
- Michael Preisner
- Thomas Guske