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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
©2004 Detroit Diesel Corporation. All Rights Reserved.3
Truck Product Creation
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
©2004 Detroit Diesel Corporation. All Rights Reserved.4
Truck Product Creation
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
©2004 Detroit Diesel Corporation. All Rights Reserved.5
Truck Product Creation
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
©2004 Detroit Diesel Corporation. All Rights Reserved.6
Truck Product Creation
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
©2004 Detroit Diesel Corporation. All Rights Reserved.7
Truck Product Creation
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
©2004 Detroit Diesel Corporation. All Rights Reserved.8
Truck Product Creation
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
©2004 Detroit Diesel Corporation. All Rights Reserved.9
Truck Product Creation
Effect of NO2 Ratio on NOx Conversion Efficiency
©2004 Detroit Diesel Corporation. All Rights Reserved.10
Truck Product Creation
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
©2004 Detroit Diesel Corporation. All Rights Reserved.11
Truck Product Creation
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
©2004 Detroit Diesel Corporation. All Rights Reserved.12
Truck Product Creation
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
©2004 Detroit Diesel Corporation. All Rights Reserved.13
Truck Product Creation
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
©2004 Detroit Diesel Corporation. All Rights Reserved.14
Truck Product Creation
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
©2004 Detroit Diesel Corporation. All Rights Reserved.15
Truck Product Creation
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
©2004 Detroit Diesel Corporation. All Rights Reserved.16
Truck Product Creation
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
©2004 Detroit Diesel Corporation. All Rights Reserved.17
Truck Product Creation
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%)
©2004 Detroit Diesel Corporation. All Rights Reserved.18
Truck Product Creation
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
©2004 Detroit Diesel Corporation. All Rights Reserved.19
Truck Product Creation
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
©2004 Detroit Diesel Corporation. All Rights Reserved.20
Truck Product Creation
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.
©2004 Detroit Diesel Corporation. All Rights Reserved.21
Truck Product Creation
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
©2004 Detroit Diesel Corporation. All Rights Reserved.22
Truck Product Creation
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
©2004 Detroit Diesel Corporation. All Rights Reserved.23
Truck Product Creation
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
©2004 Detroit Diesel Corporation. All Rights Reserved.24
Truck Product Creation
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
©2004 Detroit Diesel Corporation. All Rights Reserved.25
Truck Product Creation
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
©2004 Detroit Diesel Corporation. All Rights Reserved.26
Truck Product Creation
Urea InfrastructureEuropean Approach
©2004 Detroit Diesel Corporation. All Rights Reserved.27
Truck Product Creation
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
©2004 Detroit Diesel Corporation. All Rights Reserved.28
Truck Product Creation
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
©2004 Detroit Diesel Corporation. All Rights Reserved.29
Truck Product Creation
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.
©2004 Detroit Diesel Corporation. All Rights Reserved.30
Truck Product Creation
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