John Stetter, Nate Forster Jaal Ghandhi, David Foster
University of Wisconsin-Madison
The Impact of Oil Consumption Mechanisms on Diesel Exhaust
Particle Size Distributions and Detailed Exhaust Chemical Composition
DEER Conference, August 24, 2003, Newport RI
Acknowledgements
• Army Research Office (ARO)• Nippon-Mitsubishi Oil Co.• BP-Amoco Co.• Yanmar Co.• Cummins Engine Co.• Lubrizol Co.
Strategies for Reducing PMAftertreatment Systems
Catalytic Diesel Particulate TrapsParticulate oxidation rate depends on its composition
and historyFuel Composition
Ultra Low Sulfur Diesel FuelSynthetic Diesel Fuel (i.e. Fischer-Tropsch Fuel)Impact on EC, OC, trace metals, sulfates
Lubrication Oil Composition and VariablesViscosity, Volatility, and Sulfur Content
Engine DesignElectronic Engine ControlFuel Injection System Intake Air System (Turbo-charging, etc.)Combustion Chamber ModificationLubrication Oil Consumption Reduction
Introduction
Studies on the impact ofengine operating conditionson particulate characteristicsare underway
This study
Oil Consumption Mechanisms
1. Blowby Return – PCV (Effect not studied)
2. Migration of oil past valve stem seals
3. Migration of oil past piston rings
4. Turbocharger leakage (Effect not studied)
Adapted from SAE1999-01-3460.
Introduction
Test Engine
FUEL TANK
PUMP
FILTER
MICROMOTION
TANK PUMP
HEAT EXCHANGERH2O
ENGINE AND DYNAMOMETER
BUILDINGAIR
FILTER
REGULATOR
HEATER
CRITICAL FLOWORIFICES
TOFTIR
HEATEDFILTER
INTAKESURGETANK
EXHAUSTSURGETANK
CHARGEAMPLIFIER
STRAIN GAGEAMPLIFIER
ELECTRONICINJECTION CONTROL SYSTEM (SHAFT8)
ECM
FRO
MEN
CO
DER
FRO
MO
PTIC
AL IN
TER
RU
PTER
EXHAUST
BUILDINGAIR
ARROW PNEUMATICSLARGE CAPACITY FILTEROILESCER FILTER
REGULATOR
FLOW ORIFICE
FULL
DIL
UTI
ON
TUN
NEL
EXH
AU
ST
NI DAQ
152°Spray Angle
4.1Length/Diameter of holes (l/d)
8 ×Φ0.2 mmNozzle Dimension
Unit Injector, Direct Injection (DI)Injection System
NonePiston Pin Offset
304.8 mmConnection Rod Length
97.8 mmCombustion Chamber Diameter
152.4 mmStroke
139.7 mmBore
2336 ccDisplacement
1.4Swirl Ratio
13.1:1Compression Ratio
2Number of Exhaust Valves
2Number of Intake Valves
Shallow DishPiston Chamber
QuiescentCombustion Chamber
4-strokeCycle
Cummins N14 Single Cylinder DieselEngine Type
152°Spray Angle
4.1Length/Diameter of holes (l/d)
8 ×Φ0.2 mmNozzle Dimension
Unit Injector, Direct Injection (DI)Injection System
NonePiston Pin Offset
304.8 mmConnection Rod Length
97.8 mmCombustion Chamber Diameter
152.4 mmStroke
139.7 mmBore
2336 ccDisplacement
1.4Swirl Ratio
13.1:1Compression Ratio
2Number of Exhaust Valves
2Number of Intake Valves
Shallow DishPiston Chamber
QuiescentCombustion Chamber
4-strokeCycle
Cummins N14 Single Cylinder DieselEngine Type
Engine Bench Setup Engine Specification
Experimental Setup
600 800 1000 1200 1400 1600 1800 20000
20
40
60
80
100
120
140
160
180
200
220
240
260
(50% load)
(75% load)
(100% load)
(25% load)
(50% load)
(75% load)
(100% load)
Rated Speed
Peak Torque
Mode 3
Mode 2
Mode 1
Mode 5
Mode 6
Mode 4
Mode 7
Mode 8(Idling)
Eng
ine
Torq
ue/C
ylin
der [
Nm
]Engine Speed [rpm]
Experimental Operating Conditions
CARB 8-Mode Test PointsSteady-State Operation
Mode 1 Mode 2 Mode 3 Mode 4 Mode 5 Mode 6 Mode 7 Mode 8 Speed [rpm] 1800 1800 1800 1200 1200 1200 1200 700
Load [%] 100 75 50 25 100 75 50 10 (idle)
Remark Rated speed Peak
torque
Intake T [°C] 46.48 46.48 46.48 46.11 45.93 45.74 46.30 45.74 Intake P [kPa] 148.05 148.97 143.00 160.46 152.87 157.01 162.07 164.37
Exhaust P [kPa] 181.91 195.54 160.23 162.41 152.94 202.67 182.18 151.52 SOI, CA aTDC
[degrees] -5.0 -5.0 -5.0 -2.0 -11.0 -2.0 -2.0 -2.0
Experimental Design
Fuel was a 2006 EPA lowsulfur fuel, 14 PPM
LOC Rate Measurement Method
• Calcium: a viable LOC tracer (SAE 980523 and SAE 2003-01-0076)
• Calcium compounds are common additives
• Other metals in oil (Fe, Al, Cu, etc.) can also be attributed to engine wear.
• Ca and Zn show good agreement.
Experimental Results
0.0 0.5 1.0 1.5 2.0
0.0
0.5
1.0
1.5
2.0
LOC
Rat
e C
alcu
late
d by
Zin
c [g
/hr]
LOC Rate Calculated by Calcium [g/hr]
Lube Oil ConsumptionExperimental Results
Exhaust Lube Oil Consumption Variation from Base Condition
-80%
-60%
-40%
-20%
0%
20%
40%
60%
80%
100%
120%
No IntakeVSS
No E or IVSS
No E or IVSS
NoExhaust
VSS
Base 50% OCR 50% OCR
Mode 5 - Peak Torque 1200 rpmMode 1 - Peak Power 1800 rpm
Lube Oil Consumption
• Measured LOC rates: 0.3 – 1.5 g/hr(Mode 4 LOC < 0.1 g/hr)
• Typical LOC (High Speed Diesels): 0.1-0.5% of full load fuel which would correspond to 7 – 40 g/hr
• Test points are steady state conditions
Experimental Results
Transient Lube Oil Consumption
Experimental Results11
:47:
00
11:4
7:30
11:4
8:00
11:4
8:30
11:4
9:00
11:4
9:30
11:5
0:00
11:5
0:30
11:5
1:00
11:5
1:30
11:5
2:00
11:5
2:30
11:5
3:00
11:5
3:30
11:5
4:00
11:5
4:30
11:5
5:00
11:5
5:30
11:5
6:00
11:5
6:30
Mn+P-
Fe+Ca+
ECOC
0
5
10
15
20
25
30
35
40
# of
par
ticle
s(C
a+, F
e+, M
n+, P
-, E
C)
Time
Timeline 31502m415TR
Mn+P-Fe+Ca+ECOC
BP-ARCO fuel
17:0
1:00
17:0
1:30
17:0
2:00
17:0
2:30
17:0
3:00
17:0
3:30
17:0
4:00
17:0
4:30
17:0
5:00
17:0
5:30
17:0
6:00
17:0
6:30
17:0
7:00
17:0
7:30
17:0
8:00
17:0
8:30
17:0
9:00
17:0
9:30
17:1
0:00
17:1
0:30
Mn+P-
Fe+Ca+
ECOC
0
5
10
15
20
25
30
35
40
45
50
# of
par
ticle
s(C
a+, F
e+, M
n+, P
-, EC
)
Time
Timeline 31502m325TR
Mn+P-Fe+Ca+ECOC
BP-ARCO fuel
• “Transient” calcium spikes on order of 10x steady state operation from raw ATOFMS data
Ca Ca
Lube Oil Consumption
• Measured LOC rates: 0.3 – 1.5 g/hr• Typical LOC (High Speed Diesels):
0.1 – 0.5% of full load fuel which would correspond to 7 – 40 g/hr
• Test points are steady state conditions• Transient operation critical to
understanding overall LOC, but…• What can be learned from less complex,
fundamental steady state operation?
Experimental Results
Engine Out PMExperimental Results
Engine Out Particulate Matter Variation from Base Condition
-20%
-15%
-10%
-5%
0%
5%
No IntakeVSS
No E or IVSS
No E or IVSS
NoExhaust
VSS
Base 50% OCR 50% OCR
Mode 5 - Peak Torque 1200 rpmMode 1 - Peak Power 1800 rpm
Reconstructed Mass vs.PM2.5 Mass
0 1 2 3 4 5 6 7 8
0
1
2
3
4
5
6
7
8
1:1 Slope
Reconstructed Mass = EC+1.2*OC+sulfates
Rec
onst
ruct
ed M
ass
[mg/
m3]
Filter PM2.5 Mass [mg/m3]
Experimental Results
• Very Good Agreement
• Recon > Measured for low loading
• This may be due to sorption of semi-volatile gas-phase organic compounds to the filter.
Particulate Matter Composition• Varying composition with
engine mode
• Fairly consistent (±5%) composition among variations in LOC for each engine mode
Experimental Results
Mode 4 25% Load 1200 rpm
OM83%
EC16%
Ash0.01%
SO40.33%
Mode 5 100% Load 1200 rpm
OM38%
EC61%
Ash0.13%
SO40.13%
Mode 1 100% Load 1800 rpm
SO40.7%
Ash0.2%
EC85%
OM14%
0.000.020.040.060.080.100.120.140.160.180.20
0.40.60.81.0
SulfateDetectionLimit
EC OC LOC SO4
Em
issi
on R
ate
[g/h
r] EC OC LOC SO4
No Intake VSS
No E or I VSS
No E or I VSS
No Exhaust VSS
Base
50% OCR
50% OCR
0.00
m4
No Intake VSS
No E or I VSS
No E or I VSS
No Exhaust VSS
Base
50% OCR
50% OCR
0.00
0.25
0.50
0.75
1.00
1.25
456789
1011
EC OC LOC SO4
Em
issi
on R
ate
[g/h
r]EC, OC, and Sulfates with LOC
Experimental Results
No Intake VSS
No E or I VSS
No E or I VSS
No Exhaust VSS
Base
50% OCR
50% OCR
0.00
0.25
0.50
0.75
1.00
1.25
1.50
1.75
7
8
9
EC OC LOC SO4
Em
issi
on R
ate
[g/h
r]
m5 m1
• Modes 5 and 1 show significant differences in OC emissions
• Differences do not correspond with variations in lube oil consumption
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.80.8
0.9
1.0
1.1
1.2
1.3
1.4
1.5
1.6
Org
anic
Car
bon,
OC
[g/h
r]Lube Oil Consumption, LOC [g/hr]
No EVSS
No IVSS
No E or I
No E or IBase
50% OCR 50% OCR
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.23.5
4.0
4.5
5.0
5.5
6.0
6.5
7.0
7.5
8.0
Org
anic
Car
bon,
OC
[g/h
r]
Lube Oil Consumption, LOC [g/hr]
No E or I
No EVSS
No E or I
Base
No IVSS
50% OCR50% OCR
OC vs. LOC for Mode 5 and Mode 1
• No obvious relationship between Organic Carbon and Lube Oil Consumption for Modes 5 and 1
Experimental Results
Mode 5 Mode 1
Lube Oil Contribution to OCExperimental Results
Potential Lube Oil Contribution to Organic Carbon(assuming no lube oil combustion)
0%20%40%60%80%
100%120%140%160%180%200%
No
Inta
ke V
SS
- m
4
No
E o
r I V
SS
- m
4
No
E o
r I V
SS
- m
4
No
Exh
aust
VS
S -
m4
Bas
e - m
4
50%
OC
R -
m4
50%
OC
R -
m4
No
Inta
ke V
SS
- m
5
No
E o
r I V
SS
- m
5
No
Exh
aust
VS
S -
m5
No
Exh
aust
VS
S -
m5
Bas
e - m
5
50%
OC
R -
m5
50%
OC
R -
m5
No
Inta
ke V
SS
- m
1
No
E o
r I V
SS
- m
1
No
E o
r I V
SS
- m
1
No
Inta
ke V
SS
- m
1
Bas
e - m
1
50%
OC
R -
m1
50%
OC
R -
m1
LOC
[g/h
r]/O
C [g
/hr]
Mode 4Up to 42%
Mode 5Up to 32%
Mode 1Up to 100+%
-1
-0.75
-0.5
-0.25
0
0.25
0.5
0.75
17.
377.
918.
519.
149.
8210
.611
.312
.213
.114
.115
.116
.317
.518
.820
.221
.723
.3 2526
.928
.931
.133
.435
.938
.541
.444
.547
.851
.455
.259
.463
.868
.573
.779
.185
.191
.498
.210
611
312
213
114
115
116
317
518
820
221
723
325
026
928
9
-1
-0.75
-0.5
-0.25
0
0.25
0.5
0.75
1
PM [mg/m3]OC [mg/m3]EC [mg/m3]SO4 [mg/m3]Lube Oil [mg/m3]
Filter and SMPS CorrelationsExperimental Results
-1
-0.75
-0.5
-0.25
0
0.25
0.5
0.75
1
7.37
7.91
8.51
9.14
9.82
10.6
11.3
12.2
13.1
14.1
15.1
16.3
17.5
18.8
20.2
21.7
23.3 25
26.9
28.9
31.1
33.4
35.9
38.5
41.4
44.5
47.8
51.4
55.2
59.4
63.8
68.5
73.7
79.1
85.1
91.4
98.2
106
113
122
131
141
151
163
175
188
202
217
233
250
269
289
-1
-0.75
-0.5
-0.25
0
0.25
0.5
0.75
1
PM [mg/m3]OC [mg/m3]EC [mg/m3]SO4 [mg/m3]Lube Oil [mg/m3]
No Clear Correlation
No Clear Correlation
-1
-0.75
-0.5
-0.25
0
0.25
0.5
0.75
17.
377.
918.
519.
149.
8210
.611
.312
.213
.114
.115
.116
.317
.518
.820
.221
.723
.3 2526
.928
.931
.133
.435
.938
.541
.444
.547
.851
.455
.259
.463
.868
.573
.779
.185
.191
.498
.210
611
312
213
114
115
116
317
518
820
221
723
325
026
928
9
-1
-0.75
-0.5
-0.25
0
0.25
0.5
0.75
1
PM [mg/m3]OC [mg/m3]EC [mg/m3]SO4 [mg/m3]Lube Oil [mg/m3]
Filter and SMPS CorrelationsExperimental Results
No Clear Correlation
y = 1.18E+06x + 1.60E+06R2 = 0.954
9.0E+06
9.2E+06
9.4E+06
9.6E+06
9.8E+06
1.0E+07
1.0E+07
1.0E+07
1.1E+07
6.2 6.4 6.6 6.8 7 7.2 7.4 7.6
Dilution Tunnel PM Concentration [mg/m3]
Part
icle
Con
c @
146
nm
dN/
dlog
(Dp)
[#/c
m3]
y = 1.07E+06x + 7.13E+06R2 = 0.955
9.0E+06
9.2E+06
9.4E+06
9.6E+06
9.8E+06
1.0E+07
1.0E+07
1.0E+07
1.1E+07
1.80 2.00 2.20 2.40 2.60 2.80 3.00 3.20
Dilution Tunnel OC Concentration [mg/m3]
Parti
cle
Con
c @
146
nm
dN/
dlog
(Dp)
[#/c
m3]
Filter and SMPS CorrelationsExperimental Results
-1
-0.75
-0.5
-0.25
0
0.25
0.5
0.75
17.
377.
918.
519.
149.
8210
.611
.312
.213
.114
.115
.116
.317
.518
.820
.221
.723
.3 2526
.928
.931
.133
.435
.938
.541
.444
.547
.851
.455
.259
.463
.868
.573
.779
.185
.191
.498
.210
611
312
213
114
115
116
317
518
820
221
723
325
026
928
9
-1
-0.75
-0.5
-0.25
0
0.25
0.5
0.75
1
PM [mg/m3]OC [mg/m3]EC [mg/m3]SO4 [mg/m3]Lube Oil [mg/m3]
No Clear Correlation
y = 8.17E+05x + 1.04E+06R2 = 0.947
3.7E+06
3.8E+06
3.8E+06
3.9E+06
3.9E+06
4.0E+06
4.0E+06
4.1E+06
4.1E+06
3.30 3.35 3.40 3.45 3.50 3.55 3.60 3.65 3.70 3.75
Dilution Tunnel EC Concentration [mg/m3]
Par
ticle
Con
c @
209
nm
dN/
dlog
(Dp)
[#/c
m3]
y = 8.32E+05x + 2.02E+06R2 = 0.762
5.3E+06
5.4E+06
5.4E+06
5.5E+06
5.5E+06
5.6E+06
5.6E+06
5.7E+06
5.7E+06
5.8E+06
5.8E+06
4 4.05 4.1 4.15 4.2 4.25 4.3 4.35 4.4 4.45 4.5 4.55
Dilution Tunnel PM Concentration [mg/m3]
Parti
cle
Con
c @
181
nm
dN/
dlog
(Dp)
[#/c
m3]
Filter and SMPS CorrelationsExperimental Results
-1
-0.75
-0.5
-0.25
0
0.25
0.5
0.75
17.
377.
918.
519.
149.
8210
.611
.312
.213
.114
.115
.116
.317
.518
.820
.221
.723
.3 2526
.928
.931
.133
.435
.938
.541
.444
.547
.851
.455
.259
.463
.868
.573
.779
.185
.191
.498
.210
611
312
213
114
115
116
317
518
820
221
723
325
026
928
9
-1
-0.75
-0.5
-0.25
0
0.25
0.5
0.75
1
PM [mg/m3]OC [mg/m3]EC [mg/m3]SO4 [mg/m3]Lube Oil [mg/m3]
No Clear Correlation
y = -2.67E+05x + 1.57E+06R2 = 0.792
1.4E+06
1.4E+06
1.4E+06
1.4E+06
1.4E+06
1.5E+06
1.5E+06
1.5E+06
1.5E+06
1.5E+06
1.6E+06
1.6E+06
0.03 0.13 0.23 0.33 0.43 0.53 0.63 0.73 0.83
Dilution Tunnel Lube Oil Concentration [mg/m3]
Par
ticle
Con
c @
289
nm
dN
/dlo
g(D
p) [#
/cm
3]
y = -2.18E+07x + 2.12E+06R2 = 0.797
1.4E+06
1.4E+06
1.4E+06
1.4E+06
1.5E+06
1.5E+06
1.5E+06
1.5E+06
1.5E+06
1.6E+06
1.6E+06
0.025 0.026 0.027 0.028 0.029 0.03 0.031 0.032 0.033 0.034
Dilution Tunnel SO4 Concentration [mg/m3]
Par
ticle
Con
c @
289
nm
dN/
dlog
(Dp)
[#/c
m3]
0.0
0.5
1.0
1.5
2.0
2.5
50 100 150 200 250 300Mobility Diameter, Dp [nm]
Effe
ctiv
e D
ensi
ty [g
/cm
3]
Mode 5 100% LoadMode 1 100% LoadDMA-ELPI 1998 1DMA-ELPI 1998 2DMA-ELPI 2000DMA-ELPI 2002DMA-APM 2002DMA-APM 2003 10% LoadDMA-APM 2003 50% LoadDMA-APM 2003 75% Load
Particulate Matter Effective Density
• Some effective density data available from various instruments
• Assume empirical density function of the similar functional form
• Spherical particles
• PM = Conc * Vol * ρeff
Experimental Results
0.0
0.5
1.0
1.5
2.0
2.5
50 100 150 200 250 300Mobility Diameter, Dp [nm]
Effe
ctiv
e D
ensi
ty [g
/cm
3]
Mode 5 100% LoadMode 1 100% LoadDMA-ELPI 1998 1DMA-ELPI 1998 2DMA-ELPI 2000DMA-ELPI 2002DMA-APM 2002DMA-APM 2003 10% LoadDMA-APM 2003 50% LoadDMA-APM 2003 75% Load
Particulate Matter Effective Density
Experimental Results
200 nm 200 nm
20030529m125 - 50% Oil Control Ring
0
2000000
4000000
6000000
8000000
10000000
12000000
0 50 100 150 200 250 300 350
Midpoint Diameter, Dp [nm]
dN/d
logD
p [#
/cm
3]
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
Mas
s C
once
ntra
tion
[mg/
m3]
Average Conc [#/cm3]Mass Conc p=var [mg/m3]Mass Conc p=1.2 [mg/m3]
20030529m530 - 50% Oil Control Ring
0
2000000
4000000
6000000
8000000
10000000
12000000
0 50 100 150 200 250 300 350
Midpoint Diameter, Dp [nm]
dN/d
logD
p [#
/cm
3]
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
Mas
s C
once
ntra
tion
[mg/
m3]
Average Conc [#/cm3]Mass Conc p=var [mg/m3]Mass Conc p=1.2 [mg/m3]
Experimental Results – SMPS Size Distributions
• Highest LOC but no significant nanoparticleformation (nuclei mode)
• Constant density (SMPS) overestimates filter mass
m5
m1• 12 samples shown for each hour test with average and 1 standard deviation shown
• Data for comparison to gravimetric filters
Conclusions (Stead State Operation)
• Lube oil consumption for steady state operation has insignificant effect on diesel particulate matter
• Engine operating conditions have significant effects on the detailed particulate matter composition
• Lube oil has a small contribution to overall organic carbon for some operating conditions
• Effective density calculations provide additional insight in understanding the details of diesel PM.
• No apparent changes in particle size distributions with changes in oil consumption
Questions?