Post on 05-Jun-2018
TOYOTA
Development on simultaneous reduction system of
NOx and PM from a diesel engine
TetsuTetsu WatanabeWatanabeTOYOTA MOTOR CORPORATIONTOYOTA MOTOR CORPORATION
1
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Contents
1. Concepts of Simultaneous PM and NOx Reduction System
2. Emission Data of DPNR field trial in Europe
4. Application of DPNR for Light-Duty Truck
3. Emission Potential in USA FTP 75 testing Mode
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1. Concepts of Simultaneous PM and NOx Reduction System
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Enlarged view of exhaust gas flowing substrate wall
Exhaust gas
NOx, storage reduction catalyst
NOx storage reduction catalyst
Fine porous ceramic structure
Exhaust gas flow
Fine porous ceramic structure
Exhaust gas
DPNR Catalyst
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NOxNOx
LeanLean RichRich
PMPM
Reduction of NOxReduction of NOx
HCHCCOCO
HH22OONN22
NONO++O*O*PtPtCOCO22
Filter SubstrateFilter Substrate
O*O* O*O*
COCO22
PtPt
PMPM
Filter SubstrateFilter Substrate
Storage of NOxStorage of NOx
NONOOO22 NONO22++O*O*
SubstrateSubstratePtPt
NO+ONO+O22 COCO22
PtPtO*O*
PMPM
NONO22
SubstrateSubstrate
NOx NOx Storage Storage MaterialMaterial
Continuous OxidationContinuous OxidationContinuous OxidationContinuous Oxidation
NOx NOx Storage Storage MaterialMaterial
NOx and PM Reaction Mechanism NOx and PM Reaction Mechanism of DPNR Catalystof DPNR Catalyst
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Stored NOx
NOx Reduction
Exhaust Port InjectionN
Ox
(mg/
s)A
ir Fu
el R
atio
101520253035
0
5
10
15
100secTime
Cat. In
Cat. Out
2L TDI2900 rpmPme=0.50MPaInjection Interval = 10sec
Characteristics of NOx Storage Reduction
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Effect of air-fuel ratio modulation on ESR spectra in DPNR catalyst
7S.Hirota etc. JSAE Paper 20034054(Japanese)
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Effect of the amount of active oxygen on PM oxidation rate
8S.Hirota etc. JSAE Paper 20034054(Japanese)
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Vehicle Speed 60km/h Const.
100sec.
Bed
Tem
p.(d
eg.C
)
Time300400500600700
Cat. FrontCat. Rear
Air
Fuel
Rat
io
10152025
3530
Low temp.combustion & EPI
SO
x, H
2S(p
pm)
200400600
0H2S
SO2800
Rich and lean
Characteristic of SOx DischargingPassenger VehicleEngine : 2L TDI, DPNR : 2L
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Characteristic of Forced PM Oxidation
Tem
p.(d
eg.C
)
200300400500600700
Bed Temp.
Cat. Inlet Temp.
Sto
red
PM
Qua
ntity
(g)
Time100sec.0246
Veh
icle
Spe
ed(k
m/h
)4080
0Forced PM Oxidation
Air
Fuel
Rat
io
1520
3025
with Exhaust Pipe Injection
Passenger Vehicle, Engine : 2L TDI, DPNR : 2L
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10 6
10 7
10 8
10 9
1010
1011
1012
1 10 100 1000PM Diameter(nm)
before DPNR
60km/h constant speed
PM (N
umbe
r/km
)Distribution of PM diameter
after DPNR
Measured by SMPS
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on forced oxidationafter DPNR
2L TDI
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2. Emission Data from DPNR field trialin Europe
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Conditions Country Driving pattern Nr. Of cars Fuel S content
HighwayCity
Normal Germany
Standard
27 39ppm
CityNormal UK
Standard19 35 ppm
High altitude Austria Standard 7 277 ppm
Cold area Norway City - Standard 3 30 ppmHighwayNormal Italy
City2 271 ppm
Cold area Finland Standard 1 32 ppmNormal Belgium Standard 1 50 ppm
Field trial overview
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c Engine Specification
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82.2mm*94mm
Field Monitoring Car
Power 81(kW) at 4000 rpm
Max.Torque250(Nm) at2000-2400rpm
Combustion Noise at 750 rpm Idle 68.0 (dB)
Compression ratio 18.2:1
Injection system2nd Generation CR
(Max.180MPa)
Current Model
(Max.135MPa)
18.6:1
←
73.0 (dB)
250(Nm) at2000-2400rpm
1st Generation CR
Swept Volume 1995cc ←
Bore*Stroke ←
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Oxidation Catalytic Converter
DPNR Catalytic Converter
Base Vehicle :AvensisIW 1470kg
Base Engine:1CD-FTVz
c Installation of DPNR
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cc Emission History
STEP 4
S 50ppm
0
0.05
0.10
0.15
0.20
0.25
0.30
0 20000 40000 60000 80000 100000
Running distance (Km)
NO
x (g
/Km
)
In House Data
Standard, High Speed Pattern
S 300ppm
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cc Emission History
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0
0.005
0.010
0.015
0.020
0.025
0.030
PM (
g/K
m)
In House Data
STEP 4
0 20000 40000 60000 80000 100000
S 300ppm
Standard, High Speed Pattern
Running distance (Km)
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0
0.5
1.0
1.5
2.0
0 50000 100000 150000 200000Rel
ativ
e Pr
essu
re D
iffer
ence
Target
All Driving Pattern
cc Pressure Drop History
Running distance (Km)18
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3. Emission Potential for US Regulation
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Emission on US FTP75 modeEmission on US FTP75 mode
Test Cycle
PM(g/mile)
NOx(g/mile)
NMHC(g/mile)
CO(g/mile)
CO2(g/mile)
FE(mile/gal)
FTP75
US06
SC03
HWFET
NYCC
From SAE2002-01-2877 J.McDonald,B.Bunker
Fresh Cat.& Fuel:C.N.50.4 Aromatics26.0% Sulfur 6ppm
0.0057
0.005
0.007
0.002
0.007
0.05
0.14
0
0
0
0.07
0.19
0.14
0.12
0.04
0
0
0
0
0
273
289
367
192
474
37.2
35.2
27.7
52.9
21.5
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0
5
1015
20
25
35 38 40 43 46 48 51 53 56 59Cetane Number
Freq
uenc
y (
%)
0
5
1015
20
25
5 10 15 20 25 31 36 41 46 52Total Aromatics (vol. %)
Freq
uenc
y (
%)
557 samples of US fuel( '00 Winter - '02 Summer, surveyed by AAM)
Cetane NumberAve. 44.8Max. 60.1Min. 37.8
Total Aromatics (%)Ave. 35.8Max. 54.2Min. 9.8
Extreme low cetane and high Aromatics diesel fuelshave existed in the US market.
West EuropeJapan
West EuropeJapan
U.S.A.
U.S.A.
Cetane Number and Aromatics in US Market
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4. Application of DPNR for Light-Duty Truck
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DPNR catalystDPNR catalystand oxidation catalystand oxidation catalyst
Installation of DPNRInstallation of DPNRfor Lightfor Light--Duty Truck Duty Truck
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EGR Valve EGR Valve
EGR Cooler EGR Cooler
Throttle Valve Throttle Valve
Common Rail Injection System Common Rail Injection System
VG Turbo Charger VG Turbo Charger
Air flow Sensor Air flow Sensor
Temp.Sensor Temp.Sensor
Inter-Cooler Inter-Cooler
Intake AirIntake Air
DPNR Catalyst DPNR Catalyst
Air-Fuel Ratio Sensor Air-Fuel Ratio Sensor
Engine Control Unit Engine Control Unit
Oxidation Catalyst Oxidation Catalyst
Exhaust GasExhaust Gas
System Diagram of DPNR
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Decrease of NOx Storage Capacity according to continuous engine operation
Rel
ativ
e no
rm.N
Ox
Rel
ativ
e no
rm.N
Ox
stor
age
capa
city
stor
age
capa
city
0000 500500 10001000 15001500 20002000
2.02.01.51.51.01.00.50.5
3.03.02.52.5
Time (hour)Time (hour)
Sulfur 7ppmSulfur 7ppm
Sulfur 40ppm
= 200,000= 200,000kmkm
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PM Reduction Ratio TransitionPM Reduction Ratio Transitionthroughout the Durability Testthroughout the Durability Test
PM re
duct
ion
PM re
duct
ion
ratio
(%
)ra
tio (
%)
707000 500500 10001000 15001500 20002000
9090858580807575
1001009595
Time (hour)Time (hour)
Japan D 13 modeSulfur 40ppm
= 200,000= 200,000kmkm
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PM (
g/kW
h)PM
(g/
kWh)
NOx (g/kWh)NOx (g/kWh)
0.10.1
0.20.2
0.30.3
1.01.0 2.02.0 3.03.0 4.04.0 5.05.00000
Japan newJapan newshort term short term
Japan D13 modeJapan D13 mode
Before cat.Before cat.Fresh cat.Sulfur:7ppm(estimated).
Japan new long termJapan new long term
Aged cat.Aged cat.(2000hrs.)(2000hrs.)sulfur:40ppmsulfur:40ppm
Emission Potential of Aged Cat.
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Summary
■ The effects of aged DPNR has been verified byvehicle field testing in Europe and long hoursdurability testing on engine bench for Japanese market.
■ On USA FTP75 testing, DPNR with fresh catalystshown remarkable emission reduction efficiencyalthough durability of catalyst is severe subject.
■ Fuel specificatins, such as S contents, cetane number and aromatics, are very important for the realization of very low emission diesel engine.
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The end of presentationThank you for your attention
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Emission Regulation Trend Emission Regulation Trend HDT CategoryHDT Category
0.40.40.30.30.20.20.10.1
00
PM (
g/kW
h)PM
(g/
kWh)
8866442200
NOx
NOx(( g
/kW
h)g/
kWh)
Euro 5Euro 5
'00'00 '02'02 '04'04 '06'06 '08'08 '10'10
Euro 4Euro 4
YearYear
New long termlong termNew short term
Euro 3Euro 3
Japan long term
a
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System Control Strategies- Forced PM Oxidation-
Engine speedEngine speed(% of rated speed)(% of rated speed)
Torq
ue (%
)To
rque
(%)
100100
8080
6060
4040
001001008080606040402020
2020
Normal combustion Normal combustion + post injection
Normal combustion + 2 times post injections
Main inj.
BDCTDC
Post inj.
Main inj.1st. Post inj.
BDCTDC
2nd. Post inj.
b
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System Control Strategies- Sulfur Discharging-
Engine speedEngine speed(% of rated speed)(% of rated speed)
Torq
ue (%
)To
rque
(%)
100100
8080
6060
4040
001001008080606040402020
2020
Normal combustion + post injection
Low temp. combustion + exhaust pipe injection
Main inj.
BDCTDC
Post inj.
Main inj.
TDC
Fuel injection from exhaust pipe injector
+
operating zone ofsulfur discharging
c
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■■ Reduction of Cost
■■ Improvement of Durability・・Heavy Duty Truck : Guarantee over 650,000 km
(in Japanese Case)
・・Further simple control system
■■ Improvement of Fuel Economy・・Rich pulse for NOx and PM reduction・・Regeneration of sulfur poisoning
Technical Issues of DPNRTechnical Issues of DPNR
d
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11
44
00100100
22
200200 300300 400400 500500Bed TemperatureBed Temperature
in DPNR Catalyst (in DPNR Catalyst (ººC)C)
PM O
xida
tion
and
Engi
ne
PM O
xida
tion
and
Engi
ne
out
PM R
ate(
Rel
ativ
e)ou
t PM
Rat
e(R
elat
ive)
Engine out PMEngine out PMEngine : TDI, 2LEngine : TDI, 2LDPNR DPNR :: 3L3L
Relationship between PM Oxidation Rate Relationship between PM Oxidation Rate and Bed Temperature in DPNR Catalystand Bed Temperature in DPNR Catalyst
e