EVALUATION OF THE EUROPEAN PMP METHODOLOGIES USING CHASSIS
DYNAMOMETER AND ON-ROAD TESTING OF HEAVY-DUTY VEHICLES
Thomas D. Durbin, Kent C. Johnson, Heejung
Jung, Ajay Chaudhary, and David R. Cocker IIICollege of Engineering-Center for Environmental Research and Technology
(CE-CERT), University of California, Riverside
Jorn
D. Herner, William H. Robertson,Tao
Huai
and Alberto AyalaCalifornia Air Resources Board
(CARB)
David KittelsonDepartment of Mechanical Engineering, University of Minnesota
Diesel Engine Efficiency & Emissions Research ConferenceAugust 4-7, 2008
Overview•
Background
•
Objectives•
Experimental setup
•
Results–
Integrated data
–
Real time data•
Conclusion
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Background•
Current gravimetric method have increasing difficulty quantifying post-DPF PM mass emissions accurately.–
Background contribution
–
Insensitive to DPF fill state
•
Euro 5/6 standard includes measurement of solid particles (>23nm) as an additional new metric of particles emitted from light-duty diesel vehicle.
Objectives
•
Critical evaluation of the proposed European PMP method for determining particle emissions from heavy-
duty diesels and its potential in California for PM measurement and in-use screening.
•
Evaluate PMP under both laboratory and on-road conditions.
•
Particle mass
vs
particle number.
Courtesy of W. Robertson at CARB
Gravimetric vs
PMP measurements
CVSBlower
2.5 um size cut
Secondary dilution
Pump
Filter sampling system
2.5 um size cut
Primary dilutionat PMP (150 ̊C)
Secondary dilutionat PMP
Evaporation tube(300 ̊C)
Condensation particle counter(cut-off at 23nm)
Vehicleexhaust
Courtesy of W. Robertson for MD-19 diagram
Golden systemClone PMP system
TSI 3790
Experimental conditionsLab test On-road test
Base Chassis dynamometer Mobile Emission Lab
PMP system Clone system Clone & Alternative (ISO 8178) systems
Vehicle 1999 International 4900 Freightliner class 8
Engine International DT 466E (7.6L) Caterpillar C-15 (14.6L)
Fuel ULSD ULSD
Lube oil SAE 15W-40 SAE 15W-40
DPF Engelhard DPX JM CRT
Vehicle weight 27,000 lb 65,000 lb
Cycles 2x UDDS (35 min)50 mph Cruise (45 min)Idle (40 min)
UDDS (18 min)ETC Cruise (10 min)CARB Creep (4 min)Flow-of-traffic
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Lab testing (at CARB MTA lab)
UCR/CE-CERT’s
Mobile Emission Lab (MEL) for On-Road Testing
Diluted Exhaust: Temperature, Absolute Pressure, Throat ΔP, Flow.
Gas Sample Probe.
Secondary Dilution System* PM (size, Mass).
Drivers Aid.
CVS Turbine: 1000-4000 SCFM, Variable Dilution.
Gas Measurements: CO2 %, O2 %, CO ppm, NOx ppm, THC ppm, CH4 ppm. Other Sensor: Dew Point, Ambient Temperature, Control room temperature, Ambient Baro, Trailer Speed (rpm), CVS Inlet Temperature.
Engine Broadcast: Intake Temperature, Coolant Temperature, Boost Pressure, Baro Pressure, Vehicle Speed (mph), Engine Speed (rpm), Throttle Position, Load (% of rated).
Dilution Air: Temperature, Absolute Pressure, Throat ΔP,Baro (Ambient), Flow, Dew Point (Ambient).
Secondary Probe.
GPS: Pat, Long, Elevation, # Satellite Precision.
Exhaust: Temperature, ΔP (Exhaust-Ambient), Flow.
Cocker et al. Environ. Sci. Technol. 2004, 38, 6809-6816
Flow diagram of PM measurement system
CVS Filter sampling train (gravimetric)
PMP diluter TSI 3790 CPC (23 nm)TSI 3025 CPC (3 nm)
TSI 3022 CPC (7 nm)TSI 3025A CPC (3 nm)
Primarydilution
Secondarydilution
Sampling & Measurement
MEL CVS MEL secondary diluter Filter sampling train (gravimetric)
PMP diluter(Clone system)
TSI 3790 CPC (23 nm)TSI 3760 CPC (11 nm)TSI 3025 CPC (3 nm)
PMP diluter(Alternative system)
TSI 3760 CPC (11 nm) TSI 3025 CPC (3 nm)
TSI 3022 CPC (7 nm)
Primarydilution
Secondarydilution
Sampling & MeasurementOn-road test
Lab test
F-SMPS and EEPS at MEL CVS and PMP diluter
(Clone system)PMP CPC
PMP CPC
Integrated Results (using Clone PMP system)
PM mass (from gravimetric method)
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-5
0
5
10
15
20
25
30
Cruise Double UDDS
Idle ETC Urban
ETC Cruise
ARB Creep
UDDS Route 1
PM (m
g/m
i), (m
g/hr
) for
Idle
Lab test On-road test
-5
0
5
10
15
20
25
30
ETC Urban ETC Cruise ARB Creep UDDS Route 1
PM (m
g/hp
-hr)
2007 Emission Standard 10 mg/hp-hrfor an FTP Engine Dynamometer Test
2007 In-Use Emission NTE 30mg/hp-hr
Cruise Double UDDS Idle ETC Urban ETC Cruise ARB Creep UDDS Route 1
PM M
ass
on F
ilter
(µg)
0
50
100
150200
250
On-road testLab test
3 × reference filter weight for on-road testing (3 × 2.5 = 7.5 µg)σ
PM number
* Means at VS and ** means at MEL PMP system
Cruise 2 UDDS ETC Urban ETC Cruise ARB Creep UDDS Route1 Route2
Parti
cle
coun
t (#/
mi)
1e+10
1e+11
1e+12
1e+13
1e+14
1e+15
1e+16
3790 (23nm)3025A (3nm)3022* (7nm)
Lab test On-road test
/mi)#10(8StandardDutyLight 5/6Euro
11⋅
ETC UrbanETC CruiseARB Creep UDDS Route 1 Route 2
Par
ticle
cou
nt (#
/hp-
h)
1e+10
1e+11
1e+12
1e+13
1e+14
1e+15
3790 (23nm) 3025A (3nm)
ETC UrbanETC CruiseARB Creep UDDS Route 1 Route 2
Par
ticle
con
cent
ratio
n (#
/cc)
1e+0
1e+1
1e+2
1e+3
1e+4
1e+5
1e+6
1e+7
3790 (23nm)3025A (3nm) 3022* (7nm)
PMP CPC
PMP CPC
PMP CPC
Coefficient of Variation (COV)
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Cruise 2 UDDS ETC UrbanETC CruiseARB Creep UDDS
CO
V(%
)
0
50
100
150
200
250
300
3790 3025 3022* PM Mass
Lab test On-road test
**
(23nm)(3nm)(7nm)
Results (Real time data)
Concentrations normalized to those at CVS for comparison.
ETC (European Transient Cycle)
European Transient Cycle (ETC) CruiseA spike showed up in the beginning of ETC cruise cycles all the time due to gear shift before the cycle.
Time (hh:mm:ss)
11:57:00 12:02:00 12:07:00
dN/d
logD
p (#/cm
3 )
789
20
30
40
50
60708090
200
10
100
1e+2 1e+3 1e+4 1e+5 1e+6 1e+7
CPCs
Under PMP F-SMPS at CVS
0
50
100
150
200
250
300
350
400
450
1.00E+02
1.00E+03
1.00E+04
1.00E+05
1.00E+06
1.00E+07
1.00E+08
600 700 800 900 1000 1100 1200
Exha
ust t
empe
ratu
re (C
)
Part
icle
con
cent
ratio
n (#
/cc)
Cycle time (s)
3025 (3nm)
3022* (7nm)
3760 (11nm)
3790 (23nm)
EEPS (6nm)
Exh_temp_C
Dp(
nm)
3 hypotheses: • Solid particle penetration-
-> Size distribution from previous studies using EEPS and DMS-> Need to confirm with f-SMPS or nano-SMPS-> Continuous ash particle emissions at DPF?-> Unlikely
• Partial evaporation of large particle• Re-nucleation of sulfate
Driving cycle (UDDS)
UDDS (Schedule D)
0
5
10
15
20
25
30
35
40
45
50
55
60
0 100 200 300 400 500 600 700 800 900 1000 1100Time - seconds
Vehi
cle
Spee
d - m
ph
US EPA Urban Dynamometer Driving Schedule (UDDS)
Time (s)
0 200 400 600 800 1000
Parti
cle
Size
, Dp
(nm
)
789
20
30
40
50
60708090
200
10
100
1e+2 1e+3 1e+4 1e+5 1e+6 1e+7
CPCs
under PMP F-SMPS at CVS
1.0E+02
1.0E+03
1.0E+04
1.0E+05
1.0E+06
1.0E+07
0 100 200 300 400 500 600 700 800 900 1000
part
icle
con
cent
ratio
n(#/
cc)
Cycle time (s)
3025 (3nm)
3022*(7nm)
3760 (11nm)
3790 (23nm)
Real time data (flow-of-traffic)
Comparison of MEL vs MD19 Dilution System For CPC's 3760 11nm and 3790 20nmNormalized to MD19 Dilution (MEL DR ~100 MD19 DR~300)
10
100
1000
10000
100000
0 50 100 150 200 250 300 350 400 450 500
Time (sec)
Part
icle
Cou
nt (#
/cc)
0
100
200
300
400
500
600
700
800
Engi
ne P
ower
(bhp
) Veh
icle
Spe
ed (m
ph)
CPC3760 MD19CPC3760 MELCPC3790 MD19Vehicle SpeedEng PowerExh Temp
Time (sec)
0 100 200 300 400 500
Part
icle
Siz
e, D
p (n
m)
789
20
30
40
5060708090
200
300
400
500
10
100
1e+4 1e+5 1e+6 1e+7 1e+8
CPCs
under PMP EEPS at CVS
Hydrated sulfate concentration contributes to 45% of mass
Conclusion•
The overall combined laboratory and on-road results indicate that particle number can provide a superior measurement for current wall-flow DPFs
with particle emission levels well below the 2007 US PM mass standard, but not necessarily at higher PM levels near the standards.
•
The DPF-equipped medium and heavy-heavy-duty-vehicle 3790 PMP number emissions are lower than the European light duty standard of 8.0 x 1011
#/mi. The emissions range from 6.7 x 1011
to 0.5 x 1011
#/mi depending on the cycle, vehicle/technology, and other test conditions used.
•
Under more aggressive, on-road driving conditions, significant nucleation was observed, indicated by very high count levels below the PMP system. These particles had a large sulfate contribution
indicating that the nucleation mode particles could be due to the conversion of SO2
to SO3
.
Conclusion•
The particle number measurements for the low cut point CPCs
below the PMP system were approximately an order of magnitude higher than those for the PMP-compliant CPC and the other high cut point CPCs
below the PMP system. This indicates the presence of a significant fraction of solid sub-23nm particles that are not being counted by the PMP approach. –
Advantage is nucleation particles that can contribute to variability are removed.
–
Disadvantage removes the ability to characterize very small particles that survive the heating in the VPR.
•
For the on-road tests, the coefficients of variation (COVs) for the particle number counts below the PMP were all lower than those for the PM mass measurements for nearly all testing scenarios.
•
For the laboratory tests, however, outliers were found on both the 50 mph cruise and the UDDS. The development of statistical techniques for the removal of outlier tests for particle number should be considered. Also, while the PM mass measurements have a lot of scatter at current wall-flow DPF tailpipe levels, the particle number measurements have outliers that can be removed using statistics.
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Acknowledgements•
The funding for this research is from the California Air Resources Board (CARB)
under contract No. 05-320.
–
Dr. Marcus Kasper
of Matter Engineering Inc.–
Mr. Jon Andersson
of Ricardo–
Dr. Andreas Mayer of Technik
Thermischer
Maschinen
(TTM).–
for their assistance in developing the test plan procedures, in carrying out the experiments, and in analysis of the data.
–
Mr. Donald Pacocha, for his contribution in setting up and executing this field project, the data collection and quality control.
–
Joint Research Center (JRC)
of the European Commission–
The statements and opinions expressed in this presentation are solely the authors’
and do not represent the official position of the California Air Resources Board.
The mention of trade names, products, and organizations does not constitute endorsement or recommendation for use." We usually toss the disclaimer in at the bottom of the author list/acknowledgments.
•
Disclaimer -
The statements and opinions expressed in this presentation are solely the authors’
and do not represent the official position of the California Air Resources Board.
The mention of trade names, products, and organizations does not constitute endorsement or recommendation for use.
Thanks
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