9. Symposium Steuerungssysteme für automobile AntriebeBerlin, September 21st, 2012

SCR System of the Future;From Complex Hardware to SCR Functions

Jean-François Zebo; Emitec SAS

Agenda

• Introduction

• Challenges to Achieve High Efficient SCR

• Components of SCR System; Hardware

- Dosing System

- SCR Injector

- SCR Controller and Sensors

- SCR Catalyst System

• Limitations and Optimization of Dosing Control on SCR Efficiency

• OBD side of SCR

• Close Coupled SCR System; Practical Test Results

• Conclusion

Heavy Duty /NRMM – Emission Standards (ETC) & -Technology Shift of Priorities

PM

[m

g/k

Wh

]

NOx [g/kWh]1

60

30

42 6

EU V EU IV

03

Engine TechnologyEU VI; NRMM >130 kW Stage 3 B

NRMM EUStage IV

SCR 80 % NRMMStage IIIB(2012)

NRMM EU IIIB

SCR 80 % EU VI

Heavy Duty /NRMM – Emission Standards (ETC) & -Technology Shift of Priorities

PM

[m

g/k

Wh

]

NOx [g/kWh]1

60

30

42 6

EU V EU IV

03

Engine TechnologyEU VI; NRMM >130 kW Stage 3 B

NRMM EUStage IV

SCR 80 % NRMMStage IIIB(2012)

NRMM EU IIIB

EU VI

Heavy Duty /NRMM – Emission Standards (ETC) & -Technology Shift of Priorities

PM

[m

g/k

Wh

]

NOx [g/kWh]1

60

30

42 6

EU V EU IV

EU VI

03

Engine TechnologyEU VI; NRMM >130 kW Stage 3 B

NRMM EUStage IV

NRMM EU IIIB

SCR >92 -95 %

Agenda

• Introduction

• Challenges to Achieve High Efficient SCR

• Components of SCR System; Hardware

- Dosing System

- SCR Injector

- SCR Controller and Sensors

- SCR Catalyst System

• Limitations and Optimization of Dosing Control on SCR Efficiency

• OBD side of SCR

• Close Coupled SCR System; Practical Test Results

• Conclusion

High Efficient SCRTechnolgyη.NH3 > 94 %

Advanced DOC Technology

OptimizedNH3 Slip Catalyst

Perfect Mixing of NH3 with Exhaust Gas

UI.NH3 > 0,98

SCR Catalyst Technoloy

Robust AdBlue-Injection

Excellent Decompostion of Reduction Agent

Minimum HNCO concentration

10110100 10110100

10110100 01010101

01001010 01001010

01010100 01001010

Advanced Dosing Strategy,OBD

η.HC > 90 %NO2/NOx < 0,5

High Efficient SCRTechnolgyη.NH3 > 94 %

Advanced DOC Technology

OptimizedNH3 Slip Catalyst

Perfect Mixing of NH3 with Exhaust Gas

SCR Catalyst Technoloy

Robust AdBlue-Injection

Excellent Decompostion of Reduction Agent

Minimum HNCO concentration

10110100 10110100

10110100 01010101

01001010 01001010

01010100 01001010

Advanced Dosing Strategy,OBD

η.HC > 90 %NO2/NOx < 0,5

Calculated NOx-Reduction and NH3 Slip as Function of NH3-Uniformity and AdBlue-Dosing Rate

NOx-Reduction

NH3-Uniformity

Alpha = 1.00

Alpha = 0.95

Alpha = 0.90

Alpha = 0.80

NH3- Slip

NH3-Uniformity

Calculated NOx-Reduction and NH3 Slip as Function of NH3-Uniformity and AdBlue-Dosing Rate

NOx-Reduction

NH3-Uniformity

Alpha = 1.00

Alpha = 0.95

Alpha = 0.90

Alpha = 0.80

In AdditionExact Adblue dosing control is needed

Influence of Dosing Frequency on the NOx Conversion Rate

NOx tailpipe +- 14%Delta_peak = 80 ppm

NOx tailpipe +- < 1%Delta_peak = 5 ppm

n = 1800 min-1

TQ = 700 NmNOxUP = 450 ppmAlpha NOx = 0,9

time [s]

0 5 10 15 20

NO

x d

ow

n S

CR

[ppm

]

260

280

300

320

340

360

380

400

High dosing frequency Low dosing frequency

Actu

al_

Dosin

g_R

ate

[m

l/h

0

400

800

Time

NO

x T

ail

pip

e

Do

sin

g R

ate

High efficiency SCR system has to have a continuous flow of Adblue At high conversion rate targets is a high dosing frequency mandatory

Agenda

• Introduction

• Challenges to Achieve High Efficient SCR

• Components of SCR System; Hardware

- Dosing System

- SCR Injector

- SCR Controller and Sensors

- SCR Catalyst System

• Limitations and Optimization of Dosing Control on SCR Efficiency

• OBD side of SCR

• Close Coupled SCR System; Practical Test Results

• Conclusion

Emitec SCR-Dosing System Gen III

In Tank SCR-Dosing system Gen III

Customized Tank for the application

Complex Emitec Gen III Dosing SystemAll in One Integration

Suction lanceTemperature sensorUrea filterLevel sensorTank heater

Heated suction line

External DCU

Installation cost:Electrical harnessFixing devicesLines connectionsQuality sensor

- Robust design based on mass production

- gasoline injector- Spray charactristic optimized

SCR Injector

Water Cooling for robustOff Road demands

GenIII – Integrated Electronics DCU

• Highly integrated electronics• Dosing injector control• Analog inputs for PT200 temperature

sensors• High current output for line heater• 32 bit microcontroller• Integrated pump and tank heater• Ultrasonic level sensor• SAE J1939 CAN bus

SCR Catalyst System and Sensors

Temp

Temp

NOx

Dosing (SW & HW)

AdBlue

LevelTemp

ECU

m_exhNOx

CAN

• Introduction

• Challenges to Achieve High Efficient SCR

• Components of SCR System; Hardware

- Dosing System

- SCR Injector

- SCR Controller and Sensors

- SCR Catalyst System

• Limitations and Optimization of Dosing Control on SCR Efficiency

• OBD side of SCR

• Close Coupled SCR System; Practical Test Results

• Conclusion

Agenda

AdBlue Decomposition with UDP + Hydrolysis Catalyst Technology

Gas T

em

pera

ture

[°C

]

150

200

250

300

350

Mass flow [kg/h]

50 250 450 650

100

150

200 300

400

600

1000

Hydrolysis catalyst supportsAdBlue Decomposition at low

temperature condition

Potential AdBlue Dosing for robust In-Pipe Dosing

Exhaust Gas Temperature during European Driving Cycle

Exhaust Gas Temperature

Start of Dosing

Theoretical AdBlue Dosing Demand based on NOx-Engine Out Emission

0

100

200

300

400

500

600

t [sec]

0 200 400 600 800 1000 1200

Adblue demand based on engine out NOx

Ad

Blu

eg

/h

0

100

200

300

400

500

600

t [sec]

0 200 400 600 800 1000 1200

Limited AdBlue Dosing based on thermal Conditionsand AdBlue Decomposition

AdBlue Dosing Limit based on Temperature���� No dosing possible

Demand can be addressedWith minor limitations

Ad

Blu

eg

/h

Increased Thermal Conditions based on EmiCat Technology

Increase Temperature using EmiCat - Technology

Start of Dosing

AdBlue Dosing Limitation and Intervall for robust Dosing!

Ad

Blu

e lim

it

0

100

200

300

400

500

600

t [sec]

0 200 400 600 800 1000 1200

AdBlue Dosing Limit basedon Temperature

Supply can behigher than Demand(Potential CO2 reduction)

Ad

Blu

eg

/h

Overall Emission Reduction based on advanced Dosing Strategy

0

100

200

300

400

500

600

t [sec]

0 200 400 600 800 1000 1200

Ad

Blu

e lim

it

0

100

200

300

400

500

600

t [sec]

0 200 400 600 800 1000 1200

NOx-Removed after Dosing Release

Ad

Blu

em

g/h

• Introduction

• Challenges to Achieve High Efficient SCR

• Components of SCR System; Hardware

- Dosing System

- SCR Injector

- SCR Controller and Sensors

- SCR Catalyst System

• Limitations and Optimization of Dosing Control on SCR Efficiency

• OBD

• Close Coupled SCR System; Practical Test Results

• Conclusion

Agenda

Overview of OBD structure

Failure handling

System OBD

Pump OBD

• MIL

• Torque limiter

• Inhibition matrix

• Failure memory

• Interface to diagnostic tester

• Specific Emission

• CAN Communication

• NOx Sensor

• Temp Sensor

• Tank level

• Electrical diagnose

• Temp / Pressure Sensor

• Motor

• Injector / Air valve

• Air in system detection

• Blocked system detection

• Interface to ECU with mask function

ECM SmartDoser

SCR System

Aftertreatment CAN BUS J1939Dosing Command

Diagnostic

Pump

Pump OBD

System OBDRegulated

Urea TankLevel

Temperature

TemperatureSensor

MAF

SensorsDrivers

Aftertreatment CAN BUS J1939Dosing Command

Diagnostic

Dosing Algorithm

Engine ParametersCatalyst Parameters

From Smart Doser to ECU

SCR Software Modules; OBD Function Smart Doser

Dosing Valve,Heater

ValvesDosing, Heater

ECM ECU Doser

SCR System

Urea TankLevel

Temperature

TemperatureSensor

MAF(Test Bench)

SensorsDrivers

Aftertreatment CAN BUS J1939Engine Working Point

Diagnostic, Full OBDEmitec Dosing

Algorithm

Catalyst Parameters Pump

Pump OBD

ValvesDosing, Heater

NOx SensorsVia CAN

System OBDRegulated System OBD

Regulated

SCR Software Modules; OBD Function ECU Doser

Emitec Technical solutions to comply with OBD Requirements

OBD Requirement Technical Solution System/ Pump

Lack of required reagent for a deNOXsystem

Level Sensor Measurement

System/ Pump(GenIII)

The quality of the required reagent being within the specifications declared by the manufacturer

Quality Sensor Measurement

Reagent consumption and dosing activityComparison of Level sensor information and average of dosing command

Emitec Technical solutions to comply with OBD Requirements

OBD Requirement Technical Solution System/ Pump

Lack of required reagent for a deNOXsystem

Level Sensor Measurement

System/ Pump(GenIII)

The quality of the required reagent being within the specifications declared by the manufacturer

Quality Sensor Measurement

Reagent consumption and dosing activityComparison of Level sensor information and average of dosing command

Failure of any SCR electrical component, any electrical failure of a component(e.g. sensors and actuators, dosing control unit) including reagent heating system

Out of range, Shorted high and Shorted low diagnostics on sensors and actuators including heater driver

Pump

Failure of the reagent dosing system (e.g. missing air supply, clogged nozzle, dosing pump failure)

Dosing system internal diagnostics

Major breakdown of the system Dosing system internal diagnostics

• Introduction

• Challenges to Achieve High Efficient SCR

• Components of SCR System; Hardware

- Dosing System

- SCR Injector

- SCR Controller and Sensors

- SCR Catalyst System

• Limitations and Optimization of Dosing Control on SCR Efficiency

• OBD

• Close Coupled SCR System; Practical Test Results

• Conclusion

Agenda

Compact SCR System for Heavy Duty and Non Road Mobile Machineries

DOCLS/PE-Metalit®

Compact SCR System for Heavy Duty and Non Road Mobile Machineries

AdBlue-Injector

DOCLS/PE-Metalit®

Compact SCR System for Heavy Duty and Non Road Mobile Machineries

AdBlue-Injector

Mixing Element /Hydrolysis CatalystDOC

LS/PE-Metalit®

Comparison of a Mixer / Hydrolysis Catalyst regarding Deposits at Low Temperature AdBlue Injection

Variant 1 withMixing Element

Variant 2 with Hydrolysis Catalyst

N= 1200 1/min; Md = 215 NmExhaust Mass: 326 kg/h; T = 230°CAdBlue-Dosage = 560 g/h, α = 0.8

Compact SCR System for Heavy Duty and Non Road Mobile Machineries

AdBlue-Injector

Mixing Element /Hydrolysis CatalystDOC

LS/PE-Metalit®

SCR- CatalystLS-Metalit®

Compact SCR System for Heavy Duty and Non Road Mobile Machineries, Demonstrator

close coupledDOC + 1. stage SCR

2.Stage SCR

High Efficient SCR Catalyst System for NRMM Applications

Engine

DOC(2,2 ltr) static mixer

SCR 1(6,5 ltr)

SCR 2(4,0 ltr)

close coupled

NOx T NOxT

NOx

1. Stage 2. Stage

0 Total velocity [m/s] 10

Flow / NH3 Distribution @ Close Coupled SCR Catalyst

UI = 0,96

Accumulated NOx Emissions at Alpha = 1 during NRTC

0 200 400 600 800 1000 1200 1400

0

100

200

300

0

5

0.0

30.0

60.0

90.0

time [s]

Acu

mu

late

d N

Ox [

g]

Acu

mu

late

d N

Ox [

g]

Acu

mu

late

d A

dB

lue [

g]

AdBlue-Mass

NOx Tailpipe

NOx after 1. Stage

NOx engine out

Accumulated NOx Emissionen after 1st and 2nd SCR Stage during NRTC Test

1. SCR Stage

2.SCR Stage

post SCR 2

94,6 %

91,1 %

0 200 400 600 800 1000 1200 1400

0

30

60

90

0

3

time [s]

Acu

mu

late

d N

Ox [

g]

Acu

mu

late

d N

Ox [

g]

Total NOx Reduction and NH3 Slip during NRTC Test

TailpipeNH3 concentration(no NH3 slip catalyst)

SCRa

94,6 %

time [s]

0 200 400 600 800 1000 1200 1400

0

30

60

90

0

100

NH

3[p

pm

]A

cu

mu

late

d N

ox [

g]

• Introduction

• Challenges to Achieve High Efficient SCR

• Components of SCR System; Hardware

- Dosing System

- SCR Injector

- SCR Controller and Sensors

- SCR Catalyst System

• Limitations and Optimization of Dosing Control on SCR Efficiency

• OBD

• Close Coupled SCR System; Practical Test Results

• Conclusion

Agenda

• Future engines have a tendancy of higher NOx raw emissions

• To achieve EU VI and Stage 4 final legislations, NOx conversions higher

than 95% are mandatory

• This means high efficient SCR systems working together with accurate

Adblue dosing control

• Low temperature AdBlue decomposition can be achieved with hydrolysis

catalyst technology

• Emitec flexible HW and SW architectures in dosing systems enable OBDs

system integration

Conclusion