DEVELOPMENT OF A CHASSIS BASED INSPECTION AND MAINTENANCE PROGRAM FOR HEAVY-DUTY DIESEL
POWERED VEHICLES
California Environmental Protection Agency
Air Resources Board
13th CRC On-Road Vehicle Emissions Workshop San Diego, California
April 2003Presented by: Donald J. Chernich
SIP Commitment/M17 Project Goals
0
12
3
45
67
8
910
2005 2006 2008 2010
ROG
NOX
Emission Reductions - TPD in SCAB (Southern CA)
As a result of environmental law suit, the timeline for M17 was accelerated by 1 year.
Elements of SIP Measure M17
Emission reductions from in-use HDDEs10 TPD NOx, 1 TPD ROG in SCAB 2010Strategies to be considered
HDDE NOx field screening program HDDE in-use compliance test program Heavy-duty on-board diagnostic program
Development of a Field NOx Screening Test
How Would the Program Work?Portable dynamometers set up at
roadside locationsEnroute heavy-duty trucks would be
detached from trailersEmissions testing for excess NOx
conductedRepairs required for failing trucks
Stockton Laboratory
Truck ready for testing. ARB staff performing power curve test.
Laboratory grade emissions analyzers. Clean lab ready for next truck.
Powercurve Test Cycle
0
50
100
150
200
250
300
350
1 8 15 22 29 36 43 50 57 64 71 78 85 92 99 106
113
120
127
134
141
148
155
162
169
Time in Seconds
Co
rrec
ted
Veh
icle
Hp
-
2
4
6
8
10
12
14
16
18
20
NO
x (g
/wh
p-h
r)
CV Hp
Measured NOx
Ramp Lugdown
100 hp line
Analysis Region
Test Sequence Comparison
Emission results• Calculated g/whp-hr, g/mi, g/gal
Modal comparison between 3 test sequence
• QA for Modal CO, CO2, THC, and NOx• Integrated Modal emission rate• QA for integrated MPG, CO, CO2
I/M Test Cycle Evaluation Criteria
NOx calculated in (grams/wheel hp-hour) for pre- and post-repair tests (mechanical repairs only) g/whp-hr is a uniform matrix treats low and high hp
engines equally and demonstrates repeatability within and between tests
Vehicles were sent for repairs if the pre-repair NOx g/whp-hr >8 (more repair data needed)
The test must be repeatable for a broad range of vehicles.
Cycle duration need only be as long as necessary to get a representative emission rate
Vehicle Testing Summary
91 vehicles tested Selection designed to characterize
HDD Vehicle Fleet1550 total tests conducted 42 vehicles sent for repair
Critical Questions to Determine Value of Program
1. Are there excess NOx emissions in the vehicle population that are caused by tampering & malmaintenance?
2. Is there a practical field test that can identify those vehicles with high NOx emissions?
3. Can these excess NOx emissions be reduced through repairs and maintenance?
4. Can the reduction be made cost-effectively?
What Percentage of HDD Population can be Characterized as High NOx Emitters?
15 percent may have excess NOx
2
4
6
8
10
12
14
Mea
n N
Ox
(gw
hp
_hr)
0 20 40 60 80 100Percentile
Percentiles Plot
Highest emitter group constitutes 5% of the population, >12 g/whp-hr.
No clear line between high and normal emitters
Effect of Repairs on NOx Emissions (g/whp-hr)
2
4
6
8
10
12
14
16
NO
x (g
/wh
p-h
r) P
re a
nd
Po
st
0284
0529
0757
1388
1429
3622
3664
3990
3994
4635
5594
5756
6184
6401
7182
7419
8165
8592
8866
9051
9707
VEH_SER_NO
(2) Post-repair(1) Pre-repair
Mechanical Repairs Only N = 21
Reflashes not included
Effects of Repairs(10g/whp-hr cutpoint)
3 trucks showed emissions decrease2 trucks showed emissions increase1 truck unchanged
Average reduction / per truck repaired: 2.1% Approx. 3TPD reduction in South Coast
Average Repair cost: $1018
NOx Screening Program Conclusions
Current data indicates difficulty in developing a NOx screening test Per vehicle emission reductions from
repair are minimal No clear cut point to screen out high
emitters
ARB will continue to investigate magnitude and causes of high NOx emissions from HDD vehicles
Changing NOx with Time During Three Steady State Modes
(NOx vs. Vehicle Power) Test 967 - 1987 Mechnical Controlled Engine
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5.00
6.00
7.00
8.00
9.00
10.00
11.00
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13.00
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17.00
18.00
19.00
20.00
0 50 100 150 200 250
Series1
Test 936 - 1994 Electronic Controlled Engine
0.001.002.003.004.005.006.007.008.009.00
10.0011.0012.0013.0014.0015.0016.0017.0018.0019.0020.00
0 50 100 150 200 250 300 350 400
Series1
Test 892 - 1993 Mechanical Controlled Engine
0.001.002.003.004.005.006.007.008.009.00
10.0011.0012.0013.0014.0015.0016.0017.0018.0019.0020.00
0 20 40 60 80 100 120 140 160 180 200
Series1
Test 737 - 1995 Electronic Controlled Engine
0.00
1.00
2.003.00
4.00
5.00
6.00
7.008.00
9.00
10.00
11.00
12.0013.00
14.00
15.00
16.00
17.0018.00
19.00
20.00
0 50 100 150 200 250 300
Series1
Baseline NOx Test Resultsby Model Year
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2
4
6
8
10
12
14
NO
x g
/wh
p-h
r
1984 1986 1988 1990 1992 1994 1996 1998 2000 2002Model Year
Mfr 5
Mfr 4
Mfr 3
Mfr 2
Mfr 1
NOx Standard (g/bhp-hr)
6 g Std. 5 g Std. 4 g Std.
UDDS Test Data NOx vs. Model Year
NY CIFER WVU and E55 UDDS Combined: NOx Data
0
5
10
15
20
25
30
35
40
45
1965 1970 1975 1980 1985 1990 1995 2000 2005
Model Year
Em
iss
ion
Ra
te (
g/m
ile
)
NY WVU Data CRC Data
UDDS Test DataPM vs. Model Year
NY CIFER WVU and E55 UDDS Combined: PM Data
0
2
4
6
8
10
12
14
1965 1970 1975 1980 1985 1990 1995 2000 2005
Model Year
Em
iss
ion
Ra
te (
g/m
ile
)
NY WVU Data CRC Data
Proof of Concept Large Scale HD I/M Program with Portable Analyzer
Concept:Use existing repair grade dynamometers and
portable emissions analyzers.
An extensive network of waterbrake dynamometers exists in the state.
Simultaneous measurements with a Sensor’s SEMTECH-D emissions analyzer were collected.
CARB and SEMTECH Mass emissions computed using intake airflow meter and dyno power.
SEMTECH-D Correlation Results
2.8%@ 1.3 g/whp-hr
0.7%@ 15 g/whp-hr
4.6%@ 5 g/whp-hr
2.1% @ 610 g/whp-hr
Coefficient of Variance, % of standard
0.0360.120.2312.895% CI Measurement Uncertainty, g/whp-hr
1.315.54 – 6NAEmissions Standard g/Bhp-hr
0.04 – 0.30.1 – 0.54.4 – 11.3520 – 700Mass Emissions Range g/whp-hr
17 – 103 ppmC
25 – 93 ppm
481 – 1385 ppm
6.1 – 7.8%Concentration Range (mean flow weighted)
THCCONOxCO2
SEMTECH-D Correlation Results(Continued)
SEMTECH-D Correlation results consistent with published data.
Coefficient of Variance was less than 5% for all pollutants at applicable standards.
Exceeds EMA Task Force standards of 10%.
SEMTECH-D accuracy is suitable for a large scale I/M program.
NOx Screening Program Conclusions
Large scale I/M program with existing dynamometers and portable emissions analyzers is feasible from a technical standpoint.
Current data indicates difficulty in developing an effective NOx screening test. Per vehicle emission reductions from repair are minimal. There may be other unidentified engine problems that
repairs did not address. No clear cut point to screen out high emitters.
ARB will continue to investigate magnitude and causes of high NOx emissions from HDD vehicles.
Acknowledgements
It is with sincere gratitude that I would like to thank all the people who helped with the development of the Stockton Laboratory and with the M17 testing effort:Mark Burnitzki, Robert Ianni, Tullie Flower, Mike Bernard, Roelof Riemersma, Brian Weitz, John Urkov, Allen Lyons, MSOD QA Section, Dipak Bishnu,Tom Cackette, Kathleen Walsh, Jim Ryden, Paul Jacobs, Chuck Owens, William Vance, Hector Maldonaldo Yvette Friend, Anise Foust, Arlene Bingaman, Lynn Pile, and Paul Loscutoff.
Special Thanks to:Bell Turbo of Stockton (Barbara, Pius, Bill and Joe)DynoMaster (Rob and Lynette Youngblood)UC Riverside CE-CERT (Dr. Wayne Miller, Matt Smith, and Ted Younglove) Sensors, Inc. (Carl Ensfield, Atule Shaw, and Rob Wilson)California Analytical Inc. (Loren Mathews and Matt Swanson) Sincerely, Don Chernich
The Statements and Conclusions presented are not necessarily those of the California Air Resources Board . The mention of commercial products reported herein is not to be construed as an actual or implied endorsement of such products.
