Detroit Diesel Corporation - · PDF fileDetroit Diesel Corporation SCR Potential and Issues for Heavy Duty Applications in the USA Rakesh Aneja, Kuno Flathmann, Craig Savonen, Tim

Detroit Diesel Corporation

SCR Potential and Issues for Heavy Duty Applications in the USA

Rakesh Aneja, Kuno Flathmann, Craig Savonen, Tim Tindall

02 September 2004 10th Annual DEER Conference

©2004 Detroit Diesel Corporation. All Rights Reserved.2

Truck Product Creation

Presentation Outline

Global Emissions Potential & Strategy

Lifecycle Cost Estimations & Trade-Offs

Truck Application Issues

Urea Infrastructure



SCR and DPF Filter Configuration

12

34

56

CDiesel Oxidation

CatalystCatalyzed

Particulate Filter

Temperature Sensors

HC Dosing Unit

Air to Air Cooler

SCR Catalyst Pump and InjectorAqueous Urea

Solution Tank

Additional Oxidation Catalyst May Be Used to Control Ammonia Slip



SCR PotentialMeeting Regulated Emissions While Providing Economic Advantage

Improved Fuel ConsumptionNet Benefit on Energy ConsumptionReduced Engine Heat Rejection Resulting in Simplified Vehicle Cooling RequirementsNo Impact on Vehicle AerodynamicsIncreased Oil Drain IntervalsProven Technology Available for Fleet Testing



Global Emission Test Procedures

Europe USA Japan

Steady-state test ESC ESC D13

Transient test ETC FTP MOE

Not-to-exceed t.b.d.(EURO5)

NTE(additional ambient

conditions)

Each mode of D13

Deterioration DF(EURO4)

DF(435,000 miles ≈

700,000 km)

DF(650,000 km)

Smoke test Full load, ELR1,free acceleration

STP2 Single full loadpoints, freeacceleration

OBD Yes Yes Yes1European Load Response 2Smoke Test Procedure



Comparison of Global Transient Emission Cycles

0

20

40

60

80

100

0 20 40 60 80 100Engine Speed [RPM-%]

Engi

ne L

oad

120

USEuropeJapan



SCR NOx Reduction PotentialTransient Test Cycles for Europe, US, Japan

93

84

60

0

25

50

75

100

NO

x Co

nver

sion

* [%

]

Europe US Japan* Closed Loop: NH3 Slip Control Via NH3 Sensor



SCR NOx Reduction PotentialEuropean Transient Test (ETC) Cycle

65

82

93

0

25

50

75

100

NO

x Co

nver

sion

[%]

open loop closed loop* closed loop* &pre-oxi-cat

* Closed Loop: NH3 Slip Control Via NH3 Sensor



Effect of NO2 Ratio on NOx Conversion Efficiency



SCR NOx Control PotentialUS Transient Test (FTP) Cycle

30 29

47 45

80 76

0

25

50

75

100

NO

x Co

nver

sion

[%]

Strategy A Strategy B Strategy C

FTP (Hot)FTP (Cold)

Additional NOx Reduction Possible

via Precise Exhaust

Temperature Management



Global Emission Control ScenariosMedium and Heavy Duty Trucks

2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014Heavy DutyMedium Duty

Heavy Duty

Medium Duty

Heavy DutyMedium Duty

Japan

EGR

EGR, DPF

EGR, DPF

EGR, DPF

EGR

EGR

DPF, SCR

EGR, DPF, SCR

EGR, DPF, SCR

EGR, DPF, SCR

EGR, DPF, NSC or EGR, DPF, SCR

EGR, DPF

DPF, SCR

USA

EuropeSCR

SCR

SCR

SCR

EGR

Engineering Vehicles& Development

Final Validation & Customer Testing

Urea Infrastructure

US SCR Implementation



Typical Lifecycle Cost DistributionLine Haul Trucks

Monthly Tractor Payments

11%

Insurance7%

Fuel26%

Component Repair5%

Driver Wages30%

Driver Meals6%

Taxes / Licenses / Permits

11%

Steer Tires (100,000 miles)1%

Drive Tires (250,000 miles)1%

Preventive Maintenance2%

Source: White Paper on Life Cycle CostKenworth Truck Companywww.kenworth.com

Fuel Expense Typically Constitutes 25% - 30% of the Lifecycle Cost

Vehicle & trailer

Insurance

Taxes

Fuel

Service

Tires

Salary

Administrative

Road pricing

Europe U.S.

Fuel

Fuel



Combustion / Aftertreatment System IntegrationEstablishing An Optimum Combination for 2010

0.0 1.0 2.0 3.0 4.0 5.0 6.0NOx (g/hp-hr)

Effe

ctiv

e Fu

el (I

nclu

ding

Ure

a) C

onsu

mpt

ion

NOx Reduction Efficiency85% 96%93% 95% 97%

Tailp

ipe

Out

NO

x Ta

rget

= 0

.15

g/hp

-hr

Varying Combustion System Strategies

Optimum Effective Fuel ConsumptionEngine Out NOx ~ 3 g/hp-hr

NOx Reduction Efficiency ~95%

European Stationary CycleUrea Cost = Diesel Fuel Cost



SCR Conversion Efficiency Engine-Out Versus Tailpipe-Out NOx

US’10

0

0.1

0.2

0.3

0.4

0.5

0 1 2 3 4 5NOx Emission Engine-Out [g/kWh]

NO

x Em

issi

on T

ailp

ipe-

Out

[g/k

Wh]

65%80%90%95%

US’

10

NOx Conversion Rate

US’

10

US’

10

Best BSFC

Intermediate

85% η-DeNox



DPF Conversion EfficiencyEngine-Out versus Tailpipe-Out PM

US’10

0

0.005

0.01

0.015

0.02

0 0.1 0.2 0.3PM Emission Engine-Out [g/kWh]

PM E

mis

sion

Tai

lpip

e-O

ut [g

/kW

h]

70%

80%

90%

95%

XY

US’

10

Filtration Efficiency

US’

10

Best BSFC

Intermediate

High Efficiency

US’

10



Urea Cost Sensitivity vs Fuel Savings

Urea Cost Sensitivity as a Function of Fuel Savings Assuming 6% Urea Consumption

-$1,500

-$1,000

-$500

$0

$500

$1,000

$1,500

$2,000

$0.25 $0.50 $0.75 $1.00 $1.25 $1.50 $1.75 $2.00 $2.25

Urea Cost per Gallon

$ Sa

ving

s pe

r 100

,000

Mile

s 8% Fuel Savings6% Fuel Savings4% Fuel Savings



Urea Consumption Versus NOx Reduction

0

5

10

15

20

25

30

0 2 4 6 8 10 12

ESC NOx Reduction [g/kWh]

Ove

r th

e Ro

ad U

rea

Con

sum

ptio

n [g

/kW

h]

NOx = 10.0 → 3.5 g/kWh (η=65%)

13

NOx 2.0 → 0.2 g/kWh (η = 90%)



Typical US SCR Truck Application

Diesel Fuel Tank 200 Gallons

Urea Tank 30 Gallons

Vehicle Range Based on Diesel Fuel Capacity = 1360 Miles (6.8 mpg)

Vehicle Range Based on Urea Capacity = 5100 Miles

Assuming 4% Urea to Fuel Consumption Ratio

Ratio May Be Lower in 2010SCR Catalyst Urea Tank Urea Doser



Vehicle Mounted Elements of SCR System

Urea pump;Filter;pressureaccumulatorDosing valve;

Urea temperaturesensor (Turea);Urea pressuretransducer (purea);Air pressuretransducer (pair)

Valve;Pressurereduction

Dosing unit

Urea

leve

l sen

sor

Urea

tem

pera

ture

sen

sor

Urea pipe(to be heated)

Catalysthousing

t° t°

Electronic control unit

Wiring harness

Urea tank(to be heated)

Urea supply unit

exhaust gastemperature sensors

Air pressure unit



Quality Control, OBD, and Anti-Tampering

Control of Vehicle Urea Consumption is the Responsibility of the Engine Manufacturer.

Control of Urea Quality is A Shared Responsibility Between Engine Manufacturer, Urea Dealer, Urea Supplier, and Truck Operator.

Market Availability of Urea is A Shared Responsibility Between Urea Suppliers, Urea Distributors, and Authorities.

As With Other Engine Systems, Prevention Measures Against Tampering Are Necessary.

Tampering Is Not Completely Avoidable:It Should Be Rare (and Costly).

Impact When Tampering Is Detected: The Operator Should Prefer Not to Tamper

Tampering Diagnostics Should Be Efficient,Independent of the Technology.

OBD Cannot Necessarily Differentiate Between Tampering and Malfunction.

Reliable / Durable Exhaust Emission Sensors Should Be Implemented.



Failure Mode Detection

“Insufficient Ammonia Feed Rate”

Symptom: Urea Supply Rate Is Lower Than Anticipated Possible Causes:

Diluted or Altered Urea SolutionNo UreaPlugged LinesLeakagesActuator Failure

“Inadequate Catalyst Efficiency”

Symptom: Urea or NOx Conversion Rate Is Lower Than AnticipatedPossible Causes:

Catalyst AgingCatalyst FailureRemoval of CatalystLoss of Air Pressure



Urea Sensing and Action ScenarioScenario: Insufficient Ammonia Feed Rate

Vehicle Urea TankIntermediate Level

Warn Operator That 3 Hours of Operation Remain

Low Level

Warn Operator That 5 Minutes of Operation Remain.

Driver Deterrents and Shutdown Initiated Soon Thereafter

Low Urea Level

Light Flashes

Quality

Operator Must Address Urea Quality Issue Within 3 Hours

of Operation



Plausibility Checks Using NOx or NH3 SensorsScenario: Inadequate Catalyst Efficiency

0

2 0

4 0

6 0

8 0

1 00

1 2 0

1 2 3 4

NO

x Em

issi

on /

Ure

a In

j. Q

uant

ity

NOx emission NOx + NH3*

Urea inj. tables Urea injection

0

2 0

4 0

6 0

8 0

1 2 3 4

NH

3 Em

issi

on /

Ure

a In

j. Q

uant

ity

NH3 table NH3 emission

Urea inj. table Urea injection

NOx sensor“negative feed back control”

NH3 sensor“positive feed back control”

Plausibility Threshold

NOx

Urea

Urea

NH3

Plausibility Threshold

Malfunctiondetected

Malfunctiondetected

NOx + NH3



Urea Infrastructure Plan

Affiliated Truck Stop Locations

Other Large Chains

Independent

Establish Agreements to Provide Urea

Target More Than 1000 Locations

Provide Safety Net (Emergency Supply)

Industry Stakeholders

Urea Producers

Commercial Distributors

Truck Stop Operators

Fleet Operators

Component Manufacturers

Engine Manufacturers

Vehicle Manufacturers



Progressive Urea Infrastructure Implementation ≈ 6000 Truck Stops in the US

Proximity of Truck Stops to HD Diesel Vehicle Miles Traveled

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0 100 200 300 400 500 600 700 800

Cumulative Number of Truck Stops

Perc

ent o

f Nat

iona

l HD

Die

sel V

ehic

le

Mile

s Tr

avel

ed

Within 100 MilesWithin 50 MilesWithin 25 Miles

140 Truck Stop Locations (Less Than 3% of All Truck Stops) Can Ensure Urea Availability Within a 100 mile Radius for Greater Than 95% of the Heavy Duty Vehicle Miles Traveled



Urea InfrastructureEuropean Approach



Urea (AdBlue) Filling Equipment Urea (AdBlue) Filling Equipment

Indoor Version

A Variety of Urea Filling Equipment Solutions Are Being Established, Depending on Type of Station and Need.

Outdoor Version



How to Prevent Vanadium Slip?

1) More Precise Exhaust Temperature Management 2) Non-Vanadium SCR Catalyst Materials

Experimental Data From DOE Funded Light Truck / SUV Engine Test Platform with Non-Vanadium SCR Systems



Summary

Model Based Control Systems with Feedback Sensors Will Enhance NOxConversion Efficiencies, Determine Plausibility, and Help Detect NH3 Slip, Failure Modes, and Tampering.

Strategic Arrangement of Aftertreatment System Components And More Precise Management of Exhaust Temperature and NOx/PM Ratios Will Enhance NOx Conversion Efficiency.

Investigations for Urea Freezing and Heating Were Conducted During Winter Testing in Finland With Very Good Results.

Customer Vehicles in Europe With Prototype Samples Revealed No Cracks or Contamination After Several Years of Operation. Product Release Is Planned for Euro IV and/or Euro V by Most European HD Truck Manufacturers.

Engineering Vehicles Now Operating in the US With SCR & CDPF Technology.

The SCR & CDPF System Is An Advantageous Technical and Economic Choice for Many Worldwide Applications, Including Euro IV, Euro V, JP05, and US2010, If Not Earlier.



Thank You

Advanced Transient Advanced Transient Combustion & EmissionsCombustion & Emissions

Integration ofIntegration ofAftertreatment Aftertreatment TechnologiesTechnologies

Next GenerationNext GenerationControl StrategiesControl Strategies

Fuel Systems andFuel Systems andIntegrated StrategiesIntegrated Strategies

Next GenerationNext GenerationEGR SystemEGR System

Documents

Detroit Diesel Corporation - · PDF fileDetroit Diesel Corporation SCR Potential and Issues for Heavy Duty Applications in the USA Rakesh Aneja, Kuno Flathmann, Craig Savonen, Tim