npti approaches for denox - nanoparticles · bern university of applied sciences biel-bienne...

Bern University of Applied SciencesBiel-Bienne SwitzerlandAFHB | IC-Engines and Exhaust Gas Control

Focus Event, 22. Nanoparticle Conference, ETHZ 21.06.2018

Dr. J. Czerwinski, AFHBDr. A. Mayer, TTM

Th. Lutz, ETHZ

NPTI APPROACHESFOR DENOX-SYSTEMS


HD vehicles withDPF + SCR TeVeNOx

2012-2013


TEVENOX …

Testing of Vehicles with NOx-Reduction Systems

SAE Paper 2014-01-1569


TEST TYPE 1 HD Chassis Dynamometer

TEST TYPE 2 Real World Operation on the Road

TEST TYPE 3 Simple Function Test

(short operation on the road)

3 Types of vehicle tests


Investigatedvehicles


Investigated vehicles:

Vehicles Exhaustsystem

F

MercedesActros Blutec 6330 kW 12000km

OEMCRT+SCR

G DAF Truck340 kW OEM SCR

HMAN TGS400 kW

OEM SCR 00KM

I OEM SCR84.9 T km

JMercedesActros260 kW

NOxOFFDPF+SCRretrofit

Vehicles Exhaustsystem

A Bus Volvo180 kW

DINEXDPF+SCRretrofit

BBus volvoHybrid158 kW

OEMDPF+SCR

C

MercedesActros300 kW570 km

OEMSCR

D

MercedesActros300 kW500520 km

OEMSCR

EMAN TGS397 kW220 km

OEM SCR+DPF retrofit


Vehicle E on the MAN HD chassis dynamometer with OEM SCR & retrofitted DPF

SCR

DPF


Sampling positions on vehicle F

CPK-NOx-sensor engine out

CPK-Temp.-sensor engine out

NP (MD-19)

Anapol

Horiba (MEXA120NOx)

2CLD withheated filter

CPK-NOx-sensor tailpipe

CPK-Temp.-sensor engineout

Impinger

engine-out

tailpipe


Measuring set-up with vehicle G

CPK-NOx-sensor engine out

CPK-Temp.-sensor engine out

AVL AMA engine out

CPK-NOx-sensor tailpipe AVL AMA tailpipe

CPK-Temp.-sensor tailpipe

FTIR

NP measurement apparatus

engine-out

tailpipe


Some results


Switch-on dosingretrofit system cDPF & SCR; α = 0.75vehicle A; ULSD; Chassis Dyno

UDS

KNO

x [%

]FT

IR N

H3, N

2O [p

pm]

dosi

ng fl

ow [m

l/h]

tem

pera

ture

[°C]

FTIR

NO

x, N

O2

[ppm

]

0

20

40

60

80

100

100

150

200

250

300

0

100

200

300

400

0100200300400500600

400 460 520 580 640 700 760 820 880 940 1000 1060 1120 1180time [s]

v = 44 km/h

switch-on

t9t8 t8: b. SCR

t9: a. SCR

FTIR NO2

FTIR NOx

UDS NOx in

UDS NOx out

FTIR NH3 = 0 ppm

KNOx (sensors)

I- NOx Sensors -Inot active

FTIR N2O

KN

Ox

UD

S

86%

KN

Ox

FTIR

7

7%


KNOx with different analyzers at stationary operationOEM SCR; dosing & dosing not activatedvehicle C, ULSD; Chassis Dyno LARAG

C C out apo

0

300

600

900

2CLD CPK out Anapol

NO

x[p

pm]

SCR disabled

SCR enabled

OP1 / 50 km/ht. b. SCR ≈ 275 °C

0

300

600

900

2CLD CPK out Anapol

NO

x[p

pm]

SCR disabled

SCR enabled

OP2 / 67 km/ht. b. SCR ≈ 360 °C

0102030405060708090

100

2CLD CPK Anapol

NO

x re

duct

ion

rate

[%

]

0102030405060708090

100

2CLD CPK Anapol

NO

x re

duct

ion

rate

[%

]


2CLD whole trip, average trips 4,5,6 CPK only active periods, average trips 4,5,6

trip: 2CLD whole trip → CPK & SCR active timeVehicle F; ULSD; AdBlue; Dosing activated

Comparison of KNOx-values from different periods of the

0

20

40

60

80

100

who

le tr

ip

non-

urba

n1

(col

d)

mot

orw

ay

non-

urba

n2

K NO

x[%

]

①

②

①②


SWOFF - intervention of ECU after long idlingOEM SCR; dosing activated

Vehicle D; ULSD; Chassis Dyno LARAGC

PK te

mpe

ratu

re [°

C]

CPK

tem

pera

ture

[°C

]C

PK te

mpe

ratu

re [°

C]

CPK

NO

x in

& o

ut [p

pm]

2CLD

NO

x [p

pm]

100

200

300

400

t8

t9OP2 → Idle

t8: b. SCRt9: tailpipe

Dosing activatedReference

OP2 = 70 km/h

0

250

500

750

1000

NOx out NOx-sensors not active

0

250

500

750

1000

2100 2400 2700 3000 3300 3600time [s]

NOx reference

Dosing off 1)

NOx downstream2)

1) The system interrupts the injection of AdBlue as soon as the wheels stop to rotating

2) After long idling the engine control takes automatically intervention

NOx in reference

Dosing off 1)


De-NOx Rates PCFEBus A 80-85% 99.9%Bus B 30-70% DPF not testedTruck C 88-95% no DPFTruck D 42-88% no DPFTruck E 84% (OP1) 99.5%Truck F 63-94% 99.9%Truck G 28-70% Diesel no DPF

19-55% D/CNGTruck H 20-84% no DPFTruck I 20-92% no DPF

Experiences in TeVeNOx (1)


The foundations for the quality verificationprocedures of SCR-systems are established,

The SCR-systems are not active at lowertemperatures < 200°C,

SCR-testing on vehicle is a better approach than on engine dyno,

simple & low-cost quality check is possible.

General conclusions TeVeNOx


LD vehicles withDPF + SCR

IUCD…In Use Control Diesel


IUCD: exhaust emissions during const. speed, with cold startVehicle 1; EGR, DOC, DPF, SCR; fuel: Diesel; tailpipe.

NO2 &

NO

x [p

pm]

CO [p

pm]

spee

d [k

m/h

], P R

ad [k

W]

tailp

ipe

tem

p. [°

C]

0

50

100

150

200

0

20

40

60

80tailpipe temp.

speed

PRad

load jumps

idling9.5 kW

5.1 kW0.8 kW

17.5 kW

0

25

50

75

100

125

0 200 400 600 800 1000 1200 1400 1600 1800 2000

a=118 ppmb=10 ppm

a

stop RAIb

207 sRR=91.5%

0

500

1000

1500

2000

2500


IUCD: exhaust emissions during const. speed and idling.Vehicle 2; EGR, DOC, DPF, SCR; fuel: Diesel; tailpipe.

CO [p

pm]

spee

d [k

m/h

], P R

ad [k

W]

tailp

ipe

tem

p. [°

C]

NO2 &

NO

x [p

pm]

0

40

80

120

160

0

30

60

90

120

tailpipe temp.speed

PRadidling

8.1 kW

0

20

40

60

80

0 200 400 600 800 1000 1200

NOx

NO2

a=55 ppm

b=1 ppm

a

b

490 sRR=98.2%

0

2

4

6

8

10


CO [p

pm]

spee

d [k

m/h

], P R

ad [k

W]

tailp

ipe

tem

p. [°

C]

NO2 &

NO

x [p

pm]

0

40

80

120

160

0

30

60

90

120tailpipe temp.

speed

PRadidling

6.7 kW

0

75

150

225

300

0 200 400 600 800 1000 1200

NOx

NO2

a

b

a=227 ppm

b=2 ppm

RR=99.1%

145 s

0

5

10

15

20

IUCD: exhaust emissions during const. speed and idling.Vehicle 3; EGR, DOC, DPF, SCR; fuel: Diesel; tailpipe.


spee

d [k

m/h

], P R

ad [k

W]

tailp

ipe

tem

p. [°

C]

engi

ne s

peed

[rpm

]

tem

p. [°

C]

0

40

80

120

160

0

30

60

90

120tailpipe temp.

speed

PRadidling

6.7 kW

0

100

200

300

400

0

750

1500

2250

3000

0 200 400 600 800 1000 1200time [s]

catalyst temperature, measured with OBD

engine speedstart increase NOx

IUCD: catalyst temperature during const. speed and idling.Vehicle 3; EGR, DOC, DPF, SCR; fuel: Diesel; tailpipe.


Complementary information(to be required)

OBD data, NOx-sensors AdBlue indication AdBlue purchasing and consumption Visual control of AdBlue system


Open questions

Fixing of the minimum limit value of NOx reduction rate (RR)

Solution of the question “wheel-stop → RAI-stop”, fixing of the time to drive after load jump for LD and

for HD More testing for statistical robustness Testing of LNT Testing with failures


VERTdeNOx certification protocol

For HD/LD SCR-retrofit


VERTdeNOx Testing Procedures for HD/LD SCR-retrofitVehicle equipped with a VERT-conform DPF-system

on chassis dynamometer

• light-off• max. gas flow• max. temp.• KNOX

• gaseous emissions incl. NH3

on road circuit

• 3 repetitions• Gas PEMS• PN PEMS

in customer application

• data logging• AdBlue

consumption• control after

10'000 km

on road circuit

• results from VdeNOx3

• short RDE• simple function test

Abbreviations

HD … heavy dutyLD … light dutyKNOx … NOx conversion efficiency

PN ... particle numberRDE ... real driving emissionsPEMS ... portable emission measuring system


Conclusions• With DPF, SCR and GPF, it is possible to:

Eliminate PN and Reduce NOx below the legal limits

• Quality control in-use is possible (for deNOx PTI more efforts are necessary)

• Quality procedures for deNOx systems are elaborated

npti approaches for denox - nanoparticles · bern university of applied sciences biel-bienne...

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