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LABORATORY OF APPLIED THERMODYNAMICS ARISTOTLE UNIVERSITY THESSALONIKI SCHOOL OF ENGINEERING DEPT. OF MECHANICAL ENGINEERING 1 LAT Technical Support for the Development of WLTP Phase 2 and RDE Part A: Revision of the Durability procedure DTF Teleconference 16 May 2018

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Page 1: LABORATORY OF APPLIED THERMODYNAMICS Technical … fileType V test: Durability of Pollution Control Devices Options 1. Whole vehicle durability o 160,000km on test track, road, chassis

LABORATORY OF APPLIED THERMODYNAMICS

ARISTOTLE UNIVERSITY THESSALONIKI

SCHOOL OF ENGINEERING

DEPT. OF MECHANICAL ENGINEERING

1

LAT

Technical Support for

the Development of

WLTP Phase 2 and RDE

Part A: Revision of the Durability

procedure

DTF Teleconference16 May 2018

Page 2: LABORATORY OF APPLIED THERMODYNAMICS Technical … fileType V test: Durability of Pollution Control Devices Options 1. Whole vehicle durability o 160,000km on test track, road, chassis

Overview

➢ Part A: Revision of the Durability procedure

Revision of the durability verification procedure of pollution control devices (Type 5 or Type V test)

• Literature review of ageing mechanisms of After-Treatment Systems (ATS)

• Experimental campaign: temperature distribution along the exhaust line of the vehicle, as well

as inside the ATS devices

• Modelling of temperature distribution

• Proposals for the revision

o Current procedure

o Proposals for revised procedure

• 1st step: Focus on the revision of technical issues

• 2nd step: Revision of procedural issues

2

Page 3: LABORATORY OF APPLIED THERMODYNAMICS Technical … fileType V test: Durability of Pollution Control Devices Options 1. Whole vehicle durability o 160,000km on test track, road, chassis

Current Procedure

➢ Type V test: Durability of Pollution Control Devices

Options

1. Whole vehicle durability

o 160,000km on test track, road, chassis dynamometer

2. Bench ageing durability

o Test of ATS durability on a bench

o Standard Bench Cycle (SBC) for SI engines

o Standard Diesel Bench Cycle (SDBC) for CI engines

3. Application of Assigned Deterioration Factors (ADF)

3

Source: Regulation No. 83, Revision 4, 26 April 2011

Page 4: LABORATORY OF APPLIED THERMODYNAMICS Technical … fileType V test: Durability of Pollution Control Devices Options 1. Whole vehicle durability o 160,000km on test track, road, chassis

Current Procedure – Option 1

➢ Type V test: Durability of Pollution Control Devices

Option 1 : Whole vehicle durability

✓ 160,000km on test track, road, chassis dynamometer

I. 1st alternative: Repetitive operating cycle

o 11 cycles

o 6km/cycle

o Different maximum speed of each cycle

o Dyno load setting at 80km/h

4

Page 5: LABORATORY OF APPLIED THERMODYNAMICS Technical … fileType V test: Durability of Pollution Control Devices Options 1. Whole vehicle durability o 160,000km on test track, road, chassis

Current Procedure – Option 1

➢ Type V test: Durability of Pollution Control Devices

Option 1 : Whole vehicle durability

✓ 160,000km on test track, road, chassis dynamometer

II. 2nd alternative: Standard Road Cycle – SRC

o 7 laps

o ~6km/lap

o Dyno load setting at 80km/h

o Gear shifting strategy not defined

o Necessary to include gear strategy

5

0

20

40

60

80

100

120

140

0 200 400 600 800 1000 1200 1400 1600 1800 2000 2200

Vel

oci

ty [

km/h

]

Time [s]

Gear Shift Strategy Equiv. AT [h]

5 gears 1247.7

6 gears, 6th above 100km/h 1529.6 (=100%)

JRC with corrections 1769.4 (=116%)

Free gear shifting 2051.4 (=134%)

JRC w/o corrections 1970.9 (=129%)

Page 6: LABORATORY OF APPLIED THERMODYNAMICS Technical … fileType V test: Durability of Pollution Control Devices Options 1. Whole vehicle durability o 160,000km on test track, road, chassis

Current Procedure – Option 2

➢ Type V test: Durability of Pollution Control Devices

Option 2: Bench ageing durability✓ Test of ATS durability on a bench

➢ SI Engines: Standard Bench Cycle (SBC)

o Ageing bench with an engine as the source of exhaust gas

o Run SBC for the BAT

• R – catalyst thermal reactivity

• Tr – effective reference temperature

• A – to consider other ageing than thermal

o Tr is determined following a specific

procedure

o R and A values under revision

6

r bin

R RT Ti i

e bint t e

=

1

nie

i

BAT A t=

=

Page 7: LABORATORY OF APPLIED THERMODYNAMICS Technical … fileType V test: Durability of Pollution Control Devices Options 1. Whole vehicle durability o 160,000km on test track, road, chassis

Current Procedure – Option 2

➢ Type V test: Durability of Pollution Control Devices

Option 2: Bench ageing durability✓ Test of ATS durability on a bench

➢ SI Engines: Standard Bench Cycle (SBC)

o Analysis of the BAT equation

• R – catalyst thermal reactivity

• Tr – effective reference temperature

• A – to consider other ageing than thermal

7

r bin

R RT Ti i

e bint t e

=

1

nie

i

BAT A t=

=

➢ Reaction speed (Arrhenius)

• C – concentration• Ea – activation energy of the reaction• Ru – 8.314 kJ/kmol/K• AArrh – pre-exponential factor

➢ Conversion ratio

➢ Considering a starting point at t=0 the time Δt needed to achieve a

conversion ratio CR at a given temperature 𝑇𝑏𝑖𝑛𝑖 will be 𝑡𝑏𝑖𝑛

𝑖 .

• R=Ea/Ru – catalyst thermal reactivity

➢ Considering a starting point at t=0 the time Δt needed to achieve a

conversion ratio CR at a reference temperature Tr will be 𝑡e𝑖 .

o R depends on the activation energy of each reaction

Arrh

d[C]A [C]

dt

a

u

E

R Te−

=

d[C] [C]

[C] [C]CR

= =

ArrhAi

bin

R

T

ibin

CRe

t

=

ArrhA r

R

T

ie

CRe

t

=

Arrh

Arrh

A

A

ibin i

r bin

r

RR RTiT Ti ibin

e binR

Tie

CR

t et t e

CRet

− −

→ =

=

Page 8: LABORATORY OF APPLIED THERMODYNAMICS Technical … fileType V test: Durability of Pollution Control Devices Options 1. Whole vehicle durability o 160,000km on test track, road, chassis

Current Procedure – Option 2

➢ Type V test: Durability of Pollution Control Devices

Option 2: Bench ageing durability✓ Test of ATS durability on a bench

➢ SI Engines: Standard Bench Cycle (SBC)

o Revision of R (catalyst thermal reactivity values) values

• R=Ea/Ru – catalyst thermal reactivity

o ATS to be applied: TWC

o Value given in regulation: 17,500 → Corresponds to Eact=145 kJ/mol

o A=1.1

o Additional reactions to be considered (?)

• Oxidation of NH3 – possible only on O2 presence, competitive reactions with CO, HC oxidation, selectivity of O2

reactions in case of higher CO, HC concentrations

• NH3 is produced in the TWC in rich conditions, lower concentration of CO, HC → importance of this set of reactions ?

• Oxidation of NH3 – activation energy up to 178 kJ/mol → thermal reactivity: 21,410 K

8

TWC

Reaction Activation Energy Range [kJ/mol] Catalyst thermal reactivity [K]

CO oxidation 70 – 110 8,420 – 13,230

HC oxidation 85 – 130 10,223 – 15,636

NOx reduction 25 – 130 3,007 – 15,636

Page 9: LABORATORY OF APPLIED THERMODYNAMICS Technical … fileType V test: Durability of Pollution Control Devices Options 1. Whole vehicle durability o 160,000km on test track, road, chassis

Current Procedure – Option 2

➢ Sensitivity of Ageing Time (AT) on Catalyst Thermal Reactivity (R)

• Tr=400⁰C

• ΔR=R/R0

• ΔAT=AT/AT0

• R0=18,050

9

0

200

400

600

800

1000

1200

1400

1600

1800

2000

0

20

40

60

80

100

120

140

160

180

0 50 100 150 200 250 300 350 400 450 500 550 600 650 700

Fre

qu

en

cy

Temperature - inlet ATS

ATS inlet Frequency

Cumulative [s]

y = 0.9701x3 - 0.9475x2 + 0.4161x + 0.5506R² = 0.9997

0.0

0.5

1.0

1.5

2.0

2.5

3.0

0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8

AT/A

T 0

R/R0

Sensitivity of AT on R

0 0

,0

r bin

R RT Ti i

e bint t e

=

r bin

R RT Ti i

e bint t e

= ( )( )

Δ

Δ 1

,0

R

R

ie

ibin

ie

tt

t−

=

ΔR ΔAT

0.4 0.640.6 0.650.8 0.77

0.9 0.871.0 1.00

1.1 1.161.2 1.361.4 1.92

1.6 2.77

Page 10: LABORATORY OF APPLIED THERMODYNAMICS Technical … fileType V test: Durability of Pollution Control Devices Options 1. Whole vehicle durability o 160,000km on test track, road, chassis

Current Procedure – Option 2

➢ Selection of the R value for each ATS

o High R value, i.e. high activation energy → insensitive reaction, low reaction rate (from Arrhenius eq.)

o Low R value, i.e. low activation energy → sensitive reaction, high reaction rate (from Arrhenius eq.)

➢ Selection criteria

o Most sensitive (to temperature) reaction, i.e. the one with the lowest activation energy

o Most insensitive (to temperature) reaction, i.e. the one with the highest activation energy

o Other?

✓ According to the regulation, the lowest R value (worst case) is used for the BAT equation

Reg. 83, Annex 9, App. 1, 4.1.7: Compare the R-factor determined separately for each exhaust constituent.

Use the lowest R-factor (worst case) for the BAT equation.

10

Page 11: LABORATORY OF APPLIED THERMODYNAMICS Technical … fileType V test: Durability of Pollution Control Devices Options 1. Whole vehicle durability o 160,000km on test track, road, chassis

Current Procedure – Option 2

➢ Type V test: Durability of Pollution Control Devices

Option 2: Bench ageing durability✓ Test of ATS durability on a bench

➢ CI Engines: Standard Diesel Bench Cycle (SDBC)

o Revision of R (catalyst thermal reactivity values) values

• R=Ea/Ru – catalyst thermal reactivity

o ATS to be applied: DOC

o Oxidation of SOF adsorbed on soot (C) – oxidation of solid C particles requires higher temperature

o Value proposed in (Heavy Duty Vehicle) HDV regulation: 18,050 → Corresponds to Eact=150 kJ/mol

o Proposal for the A factor

• DOC: 1.1 – similar operation to TWC

• cDPF: 1.1 – sharing the same with DOC, since the catalytic coating is similar

11

DOC

Reaction Activation Energy Range [kJ/mol] Catalyst thermal reactivity [K]

CO oxidation 100 -110 12,028 – 13,230

HC oxidation 80 – 130 9,622 – 15,636

NO oxidation 35 – 40 4,210 – 4,811

Page 12: LABORATORY OF APPLIED THERMODYNAMICS Technical … fileType V test: Durability of Pollution Control Devices Options 1. Whole vehicle durability o 160,000km on test track, road, chassis

Current Procedure – Option 2

➢ Type V test: Durability of Pollution Control Devices

Option 2: Bench ageing durability✓ Test of ATS durability on a bench

➢ CI Engines: Standard Diesel Bench Cycle (SDBC)

o Revision of R (catalyst thermal reactivity values) values

• R=Ea/Ru – catalyst thermal reactivity

o ATS to be applied: SCR

o Values proposed in HDV regulation

• Cu-Z: 11,550 → Eact=96 kJ/mol

• Fe-Z: 5,175 → Eact=43 kJ/mol

• V: 5,175 → Eact=43 kJ/mol

o Proposal for the A factor

• Cu-Z:

• Fe-Z:

• V:

12

Cu-SCR

Reaction Activation Energy Range [kJ/mol] Catalyst thermal reactivity [K]

Standard SCR 45 – 65 5,413 – 7,818

Fast SCR 30 – 50 3,608 – 6,014

NO2 SCR 40 – 65 4,811 – 7,818

Fe-SCR

Reaction Activation Energy Range [kJ/mol] Catalyst thermal reactivity [K]

Standard SCR 65 7.818

Fast SCR 50 6,014

NO2 SCR 30 3,608

TiV-SCR

Reaction Activation Energy Range [kJ/mol] Catalyst thermal reactivity [K]

Standard SCR 70 8,420

Fast SCR 95 11,427

NO2 SCR 95 11,427

Page 13: LABORATORY OF APPLIED THERMODYNAMICS Technical … fileType V test: Durability of Pollution Control Devices Options 1. Whole vehicle durability o 160,000km on test track, road, chassis

Current Procedure – Option 2

➢ Type V test: Durability of Pollution Control Devices

Option 2: Bench ageing durability✓ Test of ATS durability on a bench

➢ CI Engines: Standard Diesel Bench Cycle (SDBC)

o Revision of R (catalyst thermal reactivity values) values

• R=Ea/Ru – catalyst thermal reactivity

o ATS to be applied: LNT

o Value proposed in HDV regulation: 18,050 → Corresponds to Eact=150 kJ/mol

o Oxidation action of LNT to be considered (?)

o Proposal for the A factor

• LNT: Currently analyzing additional literature to separate thermal ageing and chemical poisoning effects on

quantitative manner

13

LNT

Reaction Activation Energy Range [kJ/mol] Catalyst thermal reactivity [K]

NOx reduction 25 – 90 3,007 – 10,825

Page 14: LABORATORY OF APPLIED THERMODYNAMICS Technical … fileType V test: Durability of Pollution Control Devices Options 1. Whole vehicle durability o 160,000km on test track, road, chassis

Current Procedure – Option 2

➢ Type V test: Durability of Pollution Control Devices

Option 2: Bench ageing durability✓ Test of ATS durability on a bench

➢ CI Engines: Standard Diesel Bench Cycle (SDBC)

o Revision of R (catalyst thermal reactivity values) values

• R=Ea/Ru – catalyst thermal reactivity

o ATS to be applied: ASC

o Not considered in any regulation

o Very important for diesel engines

o ASC already installed in a number of vehicles, either as a separate device or at the last part of SCR

o ASC stores NH3, apart from oxidizing it

o Proposal for the A factor

• ASC: Available literature/data/information ?

14

ASC

Reaction Activation Energy Range [kJ/mol] Catalyst thermal reactivity [K]

NH3 oxidation

on PGM80 – 110 9,622 – 13,230

Page 15: LABORATORY OF APPLIED THERMODYNAMICS Technical … fileType V test: Durability of Pollution Control Devices Options 1. Whole vehicle durability o 160,000km on test track, road, chassis

Current Procedure – Option 2

➢ Type V test: Durability of Pollution Control Devices

Option 2: Bench ageing durability✓ Test of ATS durability on a bench

➢ Considerations on the approach of combined systems

o Gasoline engines (indicative ATS layouts)

• TWC

• TWC + GPF

• TWC + LNT

• TWC + pSCR (p=passive)

• TWC + aSCR (a=active) + ASC

➢ Proposed options

o Option 1: Apply a global R, calculate global ageing time (AT)

o Option 2: Apply individual R and calculate individual AT for each after-treatment device

✓ The combination, the position and the order of the ATS vary significantly

✓ Since temperature (as well as concentrations of the various constituents in the exhaust gas) varies along the exhaust, e.g. great temperature difference between a close-coupled device and an underfloor one, Option 2 is more suitable for ATS consisted of various after-treatment devices.

15

o Diesel engines (indicative ATS layouts)

• DOC + DPF + SCR

• DOC + DPF + SCR + ASC

• DOC + DPF + LNT

• DOC + DPF + SCR + LNT

• LNT + LNT + DPF

Page 16: LABORATORY OF APPLIED THERMODYNAMICS Technical … fileType V test: Durability of Pollution Control Devices Options 1. Whole vehicle durability o 160,000km on test track, road, chassis

Current Procedure

➢ Type V test: Durability of Pollution Control Devices

Option 3: Assigned Detarioration Factors

3. Application of Assigned Deterioration Factors (ADF)

• The most preferred option by car manufacturers

• Important in order to comply with durability requirements at the Type Approval (TA) step and for all vehicles

16

Sources:1. Regulation 692/2008, 18

July 20082. Durability demonstration

procedures of emission control devices for Euro 6 vehicles, JRC, 2014

Source: Regulation No. 83, Revision 4, 26 April 2011

Page 17: LABORATORY OF APPLIED THERMODYNAMICS Technical … fileType V test: Durability of Pollution Control Devices Options 1. Whole vehicle durability o 160,000km on test track, road, chassis

Current Procedure

➢ Type V test: Durability of Pollution Control Devices

Option 3: Assigned Detarioration Factors

3. Application of Assigned Deterioration Factors (ADF)

• However, application of DF may not ensure full compliance with the durability requirements, as it does

not incorporate the actual degradation rate

• Case A: High initial conversion efficiency with different cases of degradation rate – possibility of

noncompliance with durability requirements

• Case B: Low initial conversion efficiency, but final compliance with durability requirements

• Should the procedure to determine ADF be discussed?

17

Source: Durability demonstration procedures of emission control devices for Euro 6 vehicles, JRC, 2014

Page 18: LABORATORY OF APPLIED THERMODYNAMICS Technical … fileType V test: Durability of Pollution Control Devices Options 1. Whole vehicle durability o 160,000km on test track, road, chassis

Sources

➢ Part A: Revision of the Durability procedure

Sources used

1. Regulation 83, Revision 4, 26 April 2011

2. Regulation 692/2008, 18 July 2008

3. Relevant procedure for the Heavy Duty vehicles – Regulation 2016/1718, 20 September 2016

4. A relevant report from JRC – Durability demonstration procedures of emission control devices for Euro 6 vehicles, JRC, 2014

5. Open literature

6. Any information/data from the experimental campaign that can provide input

18

Page 19: LABORATORY OF APPLIED THERMODYNAMICS Technical … fileType V test: Durability of Pollution Control Devices Options 1. Whole vehicle durability o 160,000km on test track, road, chassis

Contact

19

Thank you for your attention

Athanasios (Thanasis) Dimaratos

+30 2310 996521

[email protected]

http://lat.eng.auth.gr