Transcript Document 7399903

ARB – Exhaust Emissions – Tier 3
Small Off-Road Engine Workshop – Expanded file
EMA / OPEI
Engine Manufacturers Association / Outdoor Power Equipment Institute
Clean Air Act Committee
Expanded file -- July 2, 2003
1
ARB – Exhaust Emissions – Tier 3

Production Catalyst Systems
– Small Off-Road Engine experience

ARB Test Program
– Southwest Research Institute

High Efficiency Catalysts
– Thermal energy management
Expanded file -- July 2, 2003
2
Small Off-Road Engine -Production Catalyst Systems

International Catalyst System – B&S
– Quantum & Mod. 9/10 Side valve
• 1.3 in3 ceramic -or- wire mesh substrate
• 10-15% Engine Displacement
– 20-30% HC+NOx Efficiency (0 hrs)
• 2-3 g/hp-hr (minimum)
– 10-15% CO Efficiency (0 hrs)
• Tier I Carburetor calibration (moderate CO levels)
• 50 g/hp-hr CO conversion (maximum)
• Limited secondary air / controlled heat release
– International Market Product Feature
Expanded file -- July 2, 2003
3
Average Emissions -
Quantum International Catalyst System -0 hr data ( 1.3 in Catalyst )
18.0
350
325
16.0
300
289
275
12 %
14.0
254
250
12.0
200
9.80
10.0
8.17
175
26 %
8.0
150
7.24
6.14
SWCO (g/hp-hr)
HC - NOx - HC+NOx
225
125
6.0
100
4.0
75
50
1.63
2.0
1.10
25
0.0
0
HC (g/hp-hr)
NOx (g/hp-hr)
Engine Out
HC+NOx (g/hp-hr)
CO (g/hp-hr)
Catalyst Out
Expanded file -- July 2, 2003
4
Average Emissions -
Quantum International Catalyst System -125 hr data ( 1.3 in Catalyst )
18.0
350
325
15.59
16.0
302
294
300
14.53
14.0
13.84
275
12.78
3%
250
7%
12.0
200
10.0
175
8.0
150
SWCO (g/hp-hr)
HC - NOx - HC+NOx
225
125
6.0
100
4.0
75
1.75
2.0
50
1.74
25
0.0
0
HC (g/hp-hr)
NOx (g/hp-hr)
Engine Out
HC+NOx (g/hp-hr)
CO (g/hp-hr)
Catalyst Out
Expanded file -- July 2, 2003
5
Small Off-Road Engine -Production Catalyst Systems

Tecumseh TVM220
•
•
•
•
21.8 in3 Vertical L-Head
Certified EPA Phase II
4.2 in3 Reducing Catalyst / 19% Engine Displacement
15% HC+NOx Efficiency at 0 Hours
Tecumseh H35
•
•
•
•
9.5 in3 Horizontal L-Head
Certfied EPA Phase I, CARB Tier II
4.2 in3 Reducing Catalyst / 44% Engine Displacement
29% HC+NOx Efficiency at 0 Hours
Expanded file -- July 2, 2003
6
Small Off-Road Engine -Production Catalyst Systems

Emission Sentry System - Kohler
– Automotive type system
• 12.2 in3 substrate / 50% of Engine displacement
• LPG application
• 3-way catalyst loading
– Full Engine control unit
• Closed-loop feedback fuel control
• O2 sensor
– Low CO levels / High NOx reductions
– Low volume production
– High-end commercial market
Expanded file -- July 2, 2003
7
ARB / SwRI Test Program

Emission Strategies
– Enleanment (2 of 5 engines)
• Modified to improve catalyst efficiency - SwRI
• Increased NOx / Reduced HC
• Engine performance/durability concerns
– Secondary Air
•
•
•
•
(all 5 engines)
Needed to achieve target HC reductions - SwRI
Increased CO% efficiency / energy release
40 to 60% CO conversion (4 of 5 engines)
B&S Intek #2 - 29% CO converted @ 0 hrs.
Expanded file -- July 2, 2003
8
ARB / SwRI Test Program

Emission Strategies
– Large Metallic Catalyst substrates
(4 of 5 engines)
• ensured substrate mechanical/emission durability
• 75% to more than 185% of engine displacement
• Removed all sound reduction and cooling chamber
capacity => “Catalyst container” per SwRI
– Honda GCV160 retained cooling
• B&S Intek #2 - 32% of engine displacement catalyst
Expanded file -- July 2, 2003
9
ARB / SwRI Test Program

Emission Strategies
– Remote mounted containers
(3 of 5 engines)
• Provided “package space” for Secondary Air
• Reduced engine/ catalyst temperature interaction
– Reduced catalyst system temperatures
• pre-catalyst, substrate mid-bed, container
surface & exhaust temperatures
• Reduced vibration interaction – system durability
• Both B&S Inteks close mounted
Expanded file -- July 2, 2003
10
Catalyst Secondary Air – % CO reductions
Automotive closed loop fuel
systems use feed-back from
various sensors to trim or adjust
the mixture to the chemicallycorrect strength for maximum
catalyst efficiency
Small Off-road air cooled engine
will use simple fixed carburetors,
set at the best compromise for
performance and life.
Expanded file -- July 2, 2003
11
Catalyst Secondary Air – % CO reductions
E x ha us t T e m p e r a tur e R is e fr o m C O
O x id a tio n
T e m p e ra tu re R is e (D e g F )
700
600
500
A ir to Fuel
Ratio
400
11:1
12:1
13:1
300
200
100
0
0
10
20
30
40
50
60
70
80
90
100
C a ta ly s t E ffic ie n c y (% )
Expanded file -- July 2, 2003
12
Catalyst Secondary Air – % CO reductions
Engine
Description
HC +
NOx
%
CO
1 – Honda
.
Stock
8.79
Cat J w/o
secondary air
5.92
33%
241
Cat J with
secondary air
2.51
71%
108
2 B&S Intek 2
.
Stock
9.45
Cat L w/o
secondary air
6.70
29%
269
Cat L with
secondary air
4.08
57%
218
%
Exhaust
Temp
Surface
Temp
850-424
570-350
27%
Temps Not
Recorded
504-304
63%
763-418
685-465
815-385
618-352
12%
799-548
580-441
29%
846-596
568-407
293
307
Expanded file -- July 2, 2003
Remote
Mounting
Thermocouple ?
13
Catalyst Secondary Air – % CO reductions
Engine
Description
HC +
NOx
%
CO
3 –Tecumseh
.
Stock
7.58
Cat C w/o
secondary air
3.93
48%
197
Cat C with
secondary air
2.79
63%
169
3 –Tecumseh
.
Stock
9.93
Cat C with
secondary air
3.76
%
Exhaust
Temp
Surface
Temp
Temps not
Recorded
Temps not
Recorded
45%
842-450
765-591
53%
964-550
810-668
916-490
871-607
Stock Temps
@ 250 hrs.
956-625
884-750
Remote
Mounting
361
397
62%
240
40%
Expanded file -- July 2, 2003
Remote
Mounting
14
Catalyst Secondary Air – % CO reductions
Engine
Description
HC + NOx
4 –Kawasaki
.
Stock
7.45
%
CO
%
380
Exhaust
Temp
Surface
Temp
847-408
Temps not
Recorded
5.51+1.94
Cat E w/o
secondary air
4.82
35%
264
30%
1040-560
649-427
Tier 3 Jet
secondary air
7.43
0%
226
41%
524-330
Temps not
Recorded
Thermocouple ?
61%
106
53%
vs 226
1110-623
468-397
Thermocouple ?
749-380
480-307
Stock Temps
@ 125 hrs.
Enleanment
= Temp rise
3.55+3.89
Cat E with
secondary air
2.89
4 - Kawasaki
.
Stock
6.70
Tier 3 Jet
secondary air
Cat E with
secondary air
422
5.59+0.81
7.93
-18%
199
53%
808-364
553-362
82%
123
38%
1080-683
725-538
3.77+4.16
1.45
Expanded file -- July 2, 2003
Temps vs.
0 hrs. 15
SwRI – Briggs & Stratton Intek #1

Emission Strategies
– Enleanment - A/F Ratio modified
• Performance and Durability concerns
– Passive Secondary Air Injection
• Increased HC and CO efficiency
• Increased Thermal energy release
– 9.0 in3 Substrate = 75% of displacement
• Replaced Stock Muffler with SLT Optional
Muffler
• Removed sound/cooling chambers
• Catalyst “container” only
Expanded file -- July 2, 2003
16
Catalyst Gas Temperatures - SwRI B&S #1 ( 0 hrs )
1600
1500
Ave Weighted Temp (muffler-in) = 1224°F
Ave Weighted Temp (pre-cat) =
962°F
Ave Weighted Temp Decrease =
-262°F ( -21% )
Cat C = 59% CO Efficiency =
133 g/hp-hr
Ave Weighted Temp (mid-bed) = 1304°F
Ave Weighted Temp Increase => +342°F ( +36% )
1400
1309
Temperature (°F)
1309
1300
1302
1321
1303
1300
1264
1221
1204
1181
1200
1100
1100
1038
1000
967
897
884
900
800
100% Load - 9%
75% Load - 21%
B&S #1 -Jet #2 (muffler-in)
50% Load - 31%
25% Load - 32%
B&S #1 (pre-catalyst)
10% Load - 7%
B&S #1 (mid-bed)
Expanded file -- July 2, 2003
17
Exhaust Gas Temperatures - SwRI B&S # 1 ( 0 hrs )
1000
Cat C = 59% CO Efficiency = 133 g/hp-hr
Ave Weighted Temp Increase =>
900
Temperature (°F)
800
+135°F ( 26% ) from 529°F to 664°F
856
760
767
700
666
655
581
600
542
506
500
409
400
337
300
200
100% Load - 9%
75% Load - 21%
B&S #1-STK
50% Load - 31%
25% Load - 32%
10% Load - 7%
B&S #1 Cat C
Expanded file -- July 2, 2003
18
Muffler Skin Temperatures - SwRI B&S #1 ( 0 hrs )
1000
Cat C = 59% CO Efficiency = 133 g/hp-hr
Ave Weighted Temp Increase =>
900
+133°F ( 25% ) from 540°F to 673°F
770
800
Temperature (°F)
721
700
671
675
629
622
614
600
539
500
471
438
400
300
200
100% Load - 9%
75% Load - 21%
B&S #1-STK
50% Load - 31%
25% Load - 32%
10% Load - 7%
B&S #1 Cat C
Expanded file -- July 2, 2003
19
SwRI – B&S Intek Catalyst System
Expanded file -- July 2, 2003
20
SwRI – B&S Intek Catalyst System
Expanded file -- July 2, 2003
21
SwRI – Tecumseh OVRM120

Emission Strategies
– No Enleanment
• Engine close to recommended Temperature limits
– Passive Secondary Air Injection
• Increased HC and CO efficiency
• Increased Thermal energy release
– 9.0 in3 Substrate = 75% of engine displacement
• Replaced Stock Muffler with Briggs & Stratton SLT
Optional Intek Muffler
• Removed sound/cooling chambers
• Catalyst “container” only
• Location modified away from engine to allow room
for passive air system
Expanded file -- July 2, 2003
22
Catalyst Gas Temperatures - SwRI Tecumseh OVRM120 #2 ( 250 hrs )
1600
Cat C = 40% CO Efficiency = 157 g/hp-hr
Average Weighted Temperature Increase =>
1550
1500
+172°F ( 16% ) from 1082°F to 1325°F
1425
1450
Pre-catalyst Temps not measured by SwRI
1400
1337
Temperature (°F)
1350
1318
1302
1290
1300
1250
1208
1200
1150
1111
1100
1073
1045
1050
1035
1000
950
900
850
800
100% Load - 9%
75% Load - 21%
50% Load - 31%
TEC2-STK (muffler-in)
25% Load - 32%
10% Load - 7%
TEC2 Cat C (mid-bed)
Expanded file -- July 2, 2003
23
Exhaust Gas Temperatures - SwRI Tecumseh OVRM120 #2 ( 250 hrs )
1200
Cat C = 40% CO Efficiency = 157 g/hp-hr
Average Weighted Temperature Increase =>
+103°F ( 16% ) from 657°F to 760°F
956
1000
916
Note: Catalyst Remote Mounted
830
Temperature (°F)
800
751
759
698
655
600
625
556
490
400
200
0
100% Load - 9%
75% Load - 21%
TEC2-STK
50% Load - 31%
25% Load - 32%
10% Load - 7%
TEC2 Cat C (remote)
Expanded file -- July 2, 2003
24
Muffler Skin Temperatures - SwRI Tecumseh OVRM120 #2 ( 250 hrs )
1200
1100
Note: Catalyst Remote Mounted
Cat C = 40% CO Efficiency = 157 g/hp-hr
Average Weighted Temperature Increase =>
+68°F ( 9% ) from 727°F to 795°F
1000
900
871
884
793
Temperature (°F)
800
812
786
776
750
738
700
657
607
600
500
400
300
200
100
0
100% Load - 9%
75% Load - 21%
TEC2-STK
50% Load - 31%
25% Load - 32%
10% Load - 7%
TEC2 Cat C (remote)
Expanded file -- July 2, 2003
25
SwRI – Honda GCV160

Emission Strategies
– No Enleanment
• Manufacturer concerns with startability
– Passive Secondary Air Injection
• Increased HC and CO efficiency
• Increased Thermal energy release
– 9.0 in3 Substrate = 92% of engine displacement
•
•
•
•
Increased muffler/container size 2 times
Removed sound reduction capability
Catalyst “container” with mixing/cooling chambers
Location modified away from engine to allow room
for passive air system
Expanded file -- July 2, 2003
26
SwRI – Honda GCV160
Expanded file -- July 2, 2003
27
Catalyst Gas Temperatures - SwRI Honda GVC160 ( 0 hrs )
1500
1437
1450
Cat J = 63% CO Efficiency = 185 g/hp-hr
Average Weighted Temperature Increase =>
1400
+138°F ( 12% ) from 1130°F to 1268°F
1359
1350
Pre-catalyst Temps not measured by SwRI
Temperature (°F)
1300
1274
1250
1250
1203
1194
1200
1147
1150
1117
1087
1100
1050
1003
1000
950
900
850
800
100% Load - 9%
75% Load - 21%
50% Load - 31%
Honda-STK (muffler-in)
25% Load - 32%
10% Load - 7%
Honda Cat J (mid-bed)
Expanded file -- July 2, 2003
28
Exhaust Gas Temperatures - SwRI SwRI Honda GVC160 ( 0 hrs )
1200
Note: Catalyst Remote Mounted
1000
Cat J = 63% CO Efficiency = 185 g/hp-hr
Average Weighted Temperature Increase / Decrease =>
-33°F ( -6% ) from 593°F to 560°F
845
Temperature (°F)
800
766
700
655
590
600
552
494
479
418
413
400
200
0
100% Load - 9%
75% Load - 21%
Honda-STK
50% Load - 31%
25% Load - 32%
10% Load - 7%
Honda Cat J (remote)
Expanded file -- July 2, 2003
29
Muffler Skin Temperatures - SwRI SwRI Honda GVC160 ( 0 hrs )
1200
1100
1000
Note: Catalyst Remote Mounted
Cat J = 63% CO Efficiency = 185 g/hp-hr
Average Weighted Temperature Increase =>
+116°F ( 26% ) from 445°F to 561°F
900
Temperature (°F)
800
698
700
600
631
571
556
505
508
500
449
441
393
400
350
300
200
100
0
100% Load - 9%
75% Load - 21%
Honda-STK
50% Load - 31%
25% Load - 32%
10% Load - 7%
Honda Cat J (remote)
Expanded file -- July 2, 2003
30
SwRI – Honda GCV160
Expanded file -- July 2, 2003
31
SwRI –Honda GCV160
Heat is
Dissipated from
extension pipe
and Muffler.
Catalyst has been
moved away from
engine.
Expanded file -- July 2, 2003
32
SwRI – Kawasaki FH601V (V-Twin)

Emission Strategies
– Enleanment – A/F Ratio modified
• Engine sensitive to intake air temp/humidity
– Passive Secondary Air Injection
• Increased HC and CO efficiency
• Increased Thermal energy release
– 77 in3 Substrate =190% of engine displacement
• Removed sound reduction capability
• Catalyst “container” with mixing/cooling
chambers
• Location modified away from engine to allow
room for passive air system
Expanded file -- July 2, 2003
33
SwRI –Kawasaki Catalyst
Expanded file -- July 2, 2003
34
Catalyst Gas Temperatures - SwRI Kawasaki FH601V #2 ( 0 hrs )
1600
Cat E = 51% CO Efficiency = 115 g/hp-hr
Average Weighted Temperature Increase =>
1550
+241°F ( 22% ) from 1083°F to 1324°F
1500
1423
1450
Pre-catalyst Temps not measured by SwRI
1400
1335
Temperature (°F)
1350
1317
1303
1293
1300
1250
1208
1200
1150
1111
1100
1074
1048
1050
1041
1000
950
900
850
800
100% Load - 9%
75% Load - 21%
KAW2-STK
50% Load - 31%
25% Load - 32%
10% Load - 7%
KAW2 Cat E
Expanded file -- July 2, 2003
35
Exhaust Gas Temperatures - SwRI Kawasaki FH601V #2 ( 0 hrs )
1200
1101
1016
Cat E = 51% CO Efficiency = 115 g/hp-hr
Average Weighted Temperature Increase =>
+240°F ( 38% ) from 628°F to 868°F
1000
884
828
Temperature (°F)
800
743
737
641
600
627
534
423
400
200
0
100% Load - 9%
75% Load - 21%
KAW2-STK
50% Load - 31%
25% Load - 32%
10% Load - 7%
KAW2 Cat E
Expanded file -- July 2, 2003
36
Muffler Skin Temperatures - SwRI Kawasaki FH601V #2 ( 125 hrs )
1200
1100
Cat E = 51% CO Efficiency = 115 g/hp-hr
Average Weighted Temperature Increase =>
1000
+222°F ( 57% ) from 391°F to 614°F
900
Temperature (°F)
800
707
694
700
614
600
500
545
510
478
437
397
400
339
305
300
200
100
0
100% Load - 9%
75% Load - 21%
KAW2-STK
50% Load - 31%
25% Load - 32%
10% Load - 7%
KAW2 Cat E
Expanded file -- July 2, 2003
37
SwRI – Briggs & Stratton Intek #2

Emission Strategies
– No Enleanment
– Passive Secondary Air Injection
• Increased HC and CO efficiency
• Increased Thermal energy release
– 3.7 in3 Substrate = 31% of engine displacement
• Replaced Stock Muffler with SLT Optional Muffler
• Removed sound/cooling chambers
• Catalyst “container” only

Baseline vs. Developed
– New Baseline vs. Oct ’02 – Increased HC
– Potential Fuel/Oil contamination
Expanded file -- July 2, 2003
38
Catalyst Gas Temperatures - SwRI B&S #2 ( 0 hrs )
1600
1500
Ave Weighted Temp (muffler-in) = 1147°F
Ave Weighted Temp (pre-cat) =
975°F (est)
Ave Weighted Temp Decrease = -172°F ( -15% ) (est)
Cat L = 29% CO Efficiency =
89 g/hp-hr
Ave Weighted Temp (mid-bed) = 1174°F
Ave Weighted Temp Increase => +199°F ( +20% ) (est)
1400
Pre-catalyst Temps not measured by SwRI
Temperature (°F)
1300
1283
1252
1222
1193
1200
1100
1163
1166
1174
1150
1091
1077
1039
991
1000
987
915
900
839
800
700
100% Load - 9%
75% Load - 21%
B&S #2-STK (muffler-in)
50% Load - 31%
25% Load - 32%
B&S #2 (pre-catalyst)
10% Load - 7%
B&S #2 Cat L (mid-bed)
Expanded file -- July 2, 2003
39
Exhaust Gas Temperatures - SwRI B&S # 2 ( 0 hrs )
1200
Cat L = 29% CO Efficiency = 89 g/hp-hr (1174°F Ave mid-bed Temp)
Average Weighted Temperature Increase =>
1100
+118°F ( 20% ) from 578°F to 696°F
1000
Temperature (°F)
900
B&S #1 Cat C Ave Weighted Exh Temp = 664°F
w/ 133 g/hp-hr converted and 1304°F Ave mid-bed Temps
846
815
800
760
702
690
700
641
596
592
600
500
462
385
400
300
200
100% Load - 9%
75% Load - 21%
B&S #2-STK
50% Load - 31%
25% Load - 32%
10% Load - 7%
B&S #2 Cat L
Expanded file -- July 2, 2003
40
Muffler Skin Temperatures - SwRI B&S #2 ( 0 hrs )
800
Cat L = 29% CO Efficiency = 89 g/hp-hr (1174°F Ave mid-bed Temp)
Average Weighted Temperature Increase =>
-5°F ( -1% ) from 476°F to 471°F
700
B&S #1 Cat C Ave Weighted SkinTemp = 673°F
w/ 133 g/hp-hr converted and 1304°F Ave mid-bed Temps
618
Temperature (°F)
600
568
537
518
484
500
470
415
427
407
400
352
300
200
100% Load - 9%
75% Load - 21%
B&S #2-STK
50% Load - 31%
25% Load - 32%
10% Load - 7%
B&S #2 Cat L
Expanded file -- July 2, 2003
41
Ignition Time vs. Temp – selected Forest Fuels
U.S Dept of Agriculture, Forest Service
Temp
Material
Time
Noted Effect
518°F
Punky Wood
5 min.
Smoke, Glowing,
Combustion
518°F
Cheat Grass
5 min.
Substantial
Browning
572°F
Cheat Grass
3 min.
Smoke
518°F
Sawdust
10 min.
Smoke &
Browning
Expanded file -- July 2, 2003
42
Catalyst Application - SORE
Reference Ignition
Temp, Gasoline
Gasoline Ignition on
Hot Surface, Open Air
850°F
1250°F
Max Exposed Surface
Temp, Combustion
Max Exhaust Gas
Temp, Combustion
550°F
Max Exposed Surface
Temp, Skin Burns
175°F
475°F
Fire Protection Handbook,
14th Edition
API PSD 2216, 1980
U.S.D.A. Forest Service,
SAE J335
U.S.D.A. Forest Service,
SAE J335
DIN Standards, B&S
Expanded file -- July 2, 2003
43
Catalyst Application – Small Off-Road Engines

Safe & Functional Design Criteria
 Increased Temperatures
– Exhaust gas & surface

“Over-Rich” conditions
– Choke, primers, dirty air cleaners

Field Application concerns
– Temperatures, Fuel spillage, Debris

V-twin & High Inertia applications
– Additional Problems
Expanded file -- July 2, 2003
44
Catalyst Application - Performance

System durability w/application
– High % Class 2 sold w/o mufflers
– “Best-in-Class” vs. Mass Market

Catalyst durability/reliability
– Thermal Failures
• Sintering, Melting, Loosening
– Poisoning
• Metallic Oil additives
Expanded file -- July 2, 2003
45
Catalyst Application – Other Major Issues

Application Concerns
– Increased package size, shielding,
weight
– Increased development / qualification to
ensure compliance – Emissions & Safety
– Reduced reliability & Increased
variability ( 2 systems => engine/catalyst )
– OEM “Add-on” – Certification & audit
– Increased costs – component &
equipment
Expanded file -- July 2, 2003
46
Catalyst Application – Cost Impact

High conversion efficiency will require new
engines (new tooling)
– Current average engine-out levels in production
must be met by nearly all production units if
high-efficiency converters are to perform
according to design
– Thermal management for safety and engine
durability

Other impacts
– Equipment manufacturers
– California consumers and businesses
Expanded file -- July 2, 2003
47
ARB – Exhaust Emissions – Tier 3

High HC+NOx conversion efficiency
catalysts are not possible without
high CO conversion efficiency.
 Thermal Management
 Engine & Equipment manufacturers
cannot meet standards based on
high conversion efficiency without
major engine and equipment
modifications
– New tooling for most lawn & garden
engines    not an add-on package.
Expanded file -- July 2, 2003
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