Investigation of the Feasibility of Achieving Euro VI Heavy-Duty

Investigation of the Feasibility of Achieving Euro VI Heavy-Duty Diesel Emissions Limits

by Advanced Emissions Controls

D Bosteels, J MayAECC – Association for Emissions Control by Catalyst, Belgium

A J Nicol, C H Such, J D Andersson, R D SellersRicardo UK Ltd

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Contents

• Objectives and project details- Test engine and system- Optimisation potential- Protocols

• ETC & WHTC Results- Regulated emissions- Particle number- Conversion efficiencies- Effect of cold start and soak period- Elemental Carbon and PAH emissions

• Key results from all cycles• Summary

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Objectives of AECC heavy-duty Euro VI test programme

• Demonstrate the performance of an integrated emissions control system on a modern, low NOx engine.

• Provide data on regulated and non-regulated emissions.• Compare current gravimetric and heavy-duty PMP method

for particulate mass (PM).• Assess heavy-duty PMP particle number methodology.• Provide data on European and World-harmonised transient

and steady-state test procedures.

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AECC heavy-duty Euro VI test engine

• Engine designed for US2007, provided by an engine manufacturer- 6 cylinder 7.5 litre engine- Common rail- Turbocharged (fixed vane)- Max. injection pressure 180Mpa- Cooled lambda-feedback EGR - Original particulate filter replaced by AECC system.

• No modification to base engine calibration- no changes made to optimise engine-out emissions

on the European cycles- engine-out emissions are ‘as received’.

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Emissions control system for AECC heavy-duty Euro VI test programme

• Oxidation catalyst (DOC), catalyst-based wall-flow particulate filter and urea-SCR with ammonia slip catalyst (ASC).

• System oven aged for 200hours at 600oC. • Bosch advanced airless urea dosing system.• NOx sensors at engine-out and downstream of the SCR

system (upstream as input for dosing control, second as monitor; not for closed loop control).

• No optimisation was undertaken.

7,5 l 14 l 14 l

Urea

3,5 l

Engine SCRC-DPF ASC

3,8 l

DOC

Mixer1m mixing length between injector and SCR face.

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Testing and Preconditioning procedures • Triplicate tests were carried out for tailpipe emissions on

each of the test cycles. Average results are presented.• Single additional tests were used to measure engine-out

PM, particle number and some speciation analyses.• For repeatability, each day started with a cold start test.• Standard end-of day preconditioning was:

- mode 4 warm-up: 15 min. 2130 rev/min. 560 Nm- followed by: 60 min. 2575 rev/min. 700 Nm- then: 60 min. 1300 rev/min. 150 Nm

• Following each test cycle the engine was run at a Mode 4 standardisation condition for 15 minutes.

• Pre-test conditioning for hot cycles was:- ETC, ESC: 7.5 min. mode 4 (2130 rev/min, 560 Nm)- WHSC: 10 min. mode 9 (1816 rev/min, 373 Nm)

followed by 5 min. soak.

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ETC results for engine-out and tailpipeg/

kWh

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

2.0

NOx THC CO/10 PM

Engine OutTailpipe

Euro V PM limit 0.03g/kWh

Euro V limit(NMHC)

Euro V NOx limit

Euro V CO limit

0

1

2

3

4

5

6

7

8

9

10

PM

mg/

kWh

Euro VPM limit

30mg/kWh

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ETC and WHTC testsCO & HC emissions, engine-out and tailpipe

ETC, tailpipeETC, engine-0ut WHTC, tailpipeWHTC, engine-0ut

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

ETC WHTC (5 min hot soak,10% cold weighting)

CO

[g/k

Wh]

Euro V limit

90% conversion

79% conversion

0.0

0.2

0.4

0.6

0.8

1.0


Tota

l HC

[g/k

Wh]

Euro V NMHC limit

63% conversion

69% conversion

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ETC and WHTC testsNOx emissions for engine-out and tailpipe


0.0

0.5

1.0

1.5

2.0

2.5

ETC WHTC (5 min hot soak, 10% cold weighting)

NO

x [g

/kW

h]

Euro V limit

86% conversion

76% conversion

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ETC and WHTC testsPM emissions for engine-out and tailpipe


Measurements using partial flow (mini-dilution tunnel) system

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.80


Par

ticul

ate

Mas

s [g

/kW

h]

99.8% conversion

99.7% conversion

0.0

2.0

4.0

6.0

8.0

10.0

ETC WHTC (5 min soak,10% cold weighting)

Par

ticul

ate

Mas

s [m

g/kW

h]

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.80


Par

ticul

ate

Mas

s [g

/kW

h]

99.8% conversion

99.7% conversion

0.0

2.0

4.0

6.0

8.0

10.0


Par

ticul

ate

Mas

s [m

g/kW

h]

0.0

2.0

4.0

6.0

8.0

10.0


Par

ticul

ate

Mas

s [m

g/kW

h]

0.0

2.0

4.0

6.0

8.0

10.0


Par

ticul

ate

Mas

s [m

g/kW

h]

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PMP particle number results for ETC & WHTC• Particle measurements WERE MADE according to the latest draft of the

heavy-duty PMP inter-laboratory correlation exercise guide

1.00E+10

1.00E+11

1.00E+12

1.00E+13

1.00E+14

1.00E+15

ETC

part

icle

s/kW

h

Engine-outTailpipe

• ETC tailpipe emissions ~ 4 x 1011/kWh • DPF Efficiency > 99.9%

1.00E+10

1.00E+11

1.00E+12

1.00E+13

1.00E+14

1.00E+15

weighted WHTC

parti

cles

/kW

h

Engine-outTailpipe

• WHTC tailpipe emissions < 5 x 1011/kWh • DPF Efficiency > 99.8%

1.00E+10

1.00E+11

1.00E+12

1.00E+13

1.00E+14

1.00E+15

ETC

part

icle

s/kW

h

Engine-outTailpipe

• ETC tailpipe emissions ~ 4 x 1011/kWh • DPF Efficiency > 99.9%

1.00E+10

1.00E+11

1.00E+12

1.00E+13

1.00E+14

1.00E+15

weighted WHTC

parti

cles

/kW

h

Engine-outTailpipe

• WHTC tailpipe emissions < 5 x 1011/kWh • DPF Efficiency > 99.8%

WHTC (5 min. hot soak, 10% cold weighting)

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Conversion efficiencies for ETC and WHTC

Non-optimised system – no thermal managementWHTC (5 min soak,10% cold weighting)

76%

86%

69%63%

79%

90%

99.7%99.8%

0%

20%

40%

60%

80%

100%

ETC WHTC

Con

vers

ion

Effi

cien

cy

NOx THC CO PM

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Further optimisation potential

• Thermal Management - a heating strategy is expected to be used in future

to further improve cold NOx emissions and particulate filter regeneration.

• System design- Component volumes and integration would be optimised

for a production application.

• System optimisation- including urea dosing and distribution.

• Engine calibration.

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SCR temperatures for ETC and cold WHTC

0

100

200

300

400

500

600

0 300 600 900 1200 1500 1800

Time [s]

Tem

pera

rture

[°C

]

WHTC ColdStart TestETC Test

Temperature at SCR inlet

EGR valve starts operating after ~570s

on cold start tests

Urea injection for SCR started

operating after ~800s on cold start tests

ETC is ahot start test

The results indicate that there is potential for further improvement of emissions on cold-start cycles through thermal management

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Effect of cold weighting and soak periodon composite WHTC results

0.0

0.1

0.2

0.3

0.4

0.5

0.6

NOx THC CO/10 PM*100

Em

issi

ons

[g/k

Wh]

5 min hot soak, 10% cold weighting10 min hot soak, 10% cold weighting20 min hot soak, 10% cold weighting20 min hot soak, 14% cold weighting

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95.0095.5096.0096.5097.0097.5098.0098.5099.0099.50

100.00

WHTC_C WHTC_H ETC ESC WHSC

Filtr

atio

n E

ffici

ency

For

Car

bon

Filtration efficiency for elemental carbon

• Particulate filter efficiency for removal of elemental carbon is > 99%.• Efficiencies for particles and elemental carbon are very similar.

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PAH emissions essentially eliminatedMDLT MDLT

ETC results Split Ratio Split Ratio

1910 1003

Engine-out Post-cats System ng/µl ng/µl Efficiency

FLUORENE 0.01880 0.00000 100.00PHENANTHRENE 0.28530 0.00170 99.69ANTHRACENE 0.00320 0.00009 98.61FLUORANTHENE 0.19390 0.00040 99.89PYRENE >0.53 0.00050 >99.95BENZ(A)ANTHRACENE 0.00450 0.00030 96.50CHRYSENE 0.01130 0.00020 99.07BENZO(B)FLUORANTHENE 0.01130 0.00010 99.54BENZO(K)FLUORANTHENE 0.00310 0.00006 98.98BENZO(A)PYRENE 0.00300 0.00000 100.00BENZO(GHI)PERYLENE 0.04450 0.00000 100.00INDENO(1,2,3CD)PYRENE 0.01330 0.00010 99.61

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NOx, PM and particle number comparisons

PM result on ESC appears due to desorption of low volatility materials in Mode 10.

0.0

0.5

1.0

1.5

2.0

ETC WHTC Bus Cycle ESC WHSC

NO

x g/

kWh

0.000

0.005

0.010

0.015

0.020


PM

g/k

Wh

1.E+10

1.E+11

1.E+12

1.E+13

1.E+14

1.E+15

1.E+16

ETC WHTC Bus cycle ESC WHSC

parti

cles

/kW

h

Engine-out levels

0%

20%

40%

60%

80%

100%


NO

x co

nver

sion

%

- EEV limit value - - EEV limit value -

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Summary of findings of the AECC heavy-dutyEuro VI test programme

• A state-of-the-art engine system comprising a low emissions “world engine” and an emissions control system produced substantial reductions in all regulated pollutants.

• NOx conversion efficiencies were 86% and 76% over the ETC and EU-composite WHTC respectively, resulting in tailpipe levels of 150 and 300mg/kWh.

• PM conversion efficiencies were >99.5% over the ETC and EU-composite WHTC, resulting in PM tailpipe levels of 1 to 2mg/kWh when measured with the partial flow method.

• There is potential for further improvement of emissions through thermal management and optimised system design and engine and urea dosing calibration.

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Summary of findings of the AECC heavy-dutyEuro VI test programme

• The PMP particle number method proved very reliable even at near-ambient particle emissions levels.

• Engine-out particle emissions of 2.5 to 5 x 1014/kWh were reduced to levels below 1012/kWh at tailpipe and were essentially cycle-independent.

• The emissions control system reduced elemental carbon emissions by more than 99% and virtually eliminated PAH emissions.

• The combined engine and emissions control system metthe most stringent scenarios from the Commission’s Euro VI validation exercise.

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0.000

0.020

0.040

0.060

0.080

0.100

0.120

0.140

0.160

0.180

0.00 1.00 2.00 3.00 4.00 5.00 6.00

NOx g/kWh

PM

g/k

Wh

2002 2006 2007 (Euro V & EEV data)

Euro III limits

Euro III limits (<0.75dm3 & >3000min-1 rated power speed)

Euro IV limitsEuro V limits

0.000

0.020

0.040

0.060

0.080

0.100

0.120

0.140

0.160

0.180

0.00 1.00 2.00 3.00 4.00 5.00 6.00

NOx g/kWh

PM

g/k

Wh

2002 2006 2007 (Euro V & EEV data)

Euro III limits



Euro III limits



Euro III limits



PM vs NOx (ESC test)

Source: KBA data, June 2002, January 2006, March 2007AECC Euro VI tailpipe result

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Acknowledgements

the OE engine manufacturerBosch, urea dosing system supplier

Yara International, urea supplierRicardo UK and the AECC Members

Thank you for your attention

Investigation of the Feasibility of Achieving Euro VI Heavy-Duty

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