technical challenges and opportunities · evolution of specific torque power density (kw/l) 50...
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Technical Challenges and OpportunitiesLight-Duty Diesel Engines in North America
August 24, 2005Chicago
Technical Challenges and OpportunitiesLight-Duty Diesel Engines in North America
August 24, 2005Chicago
John PinsonGroup Manager Diesel R&DGeneral Motors Corporation
2
Spe
cific
Pow
er (k
W/l)
Future HSDIDiesel Engines
Spe
cific
Pow
er (h
p/l)
Turbo ChargedSI Engines
4V-SI Engines
80
60
20
0
40
20
100
60
0
40
80
2V-SIEngines
1930 1940 1950 1960 1970 1980 1990 2000 2010
Diesel EnginesNaturally AspiratedTurbocharged (TC)TC-Intercooled
Model YearSource: FEV Data
Benchmark Power Density Trends Benchmark Power Density Trends
3
Evolution of Specific TorqueEvolution of Specific Torque
Power Density (kW/l)50
2005+2005+GasolineGasoline
Turbo SIDITurbo SIDI
2005+2005+DieselDiesel
22--stage Turbostage Turbo
20052005performanceperformance
gasoline turbogasoline turbo
20052005Diesel turboDiesel turboAdv. Comb.Adv. Comb.
20052005
19901990Gasoline turboGasoline turbo
19901990Diesel Diesel TurboTurbo
19901990Gasoline
Naturally Aspirated
Torq
ue D
ensi
ty (
Nm
/l)
100
100
200 ??Next Gen.
Diesel?
4
Emission EvolutionEmission EvolutionEuro 3 (2000)
Euro 4 (2005)
Euro 5Prop
Tier 2, Bin 10 (2007-2010)
T2 Bin 5 10-14k HD Chassis
0
0.01
0.02
0.03
0.04
0.05
0.06
0.07
0.08
0.09
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1NOx (g/mi)
Part
icul
ate
Mat
ter (
g/m
i)
T2 Bin 8 / 8.5-10k HD Chassis
Low Temperature Combustion (near-HCCI)Air/EGR System InnovationCombustion Feedback Control
Innovations in Lean NOx ATActive Dispersion Management
Injection System, Cooled EGR, Reduced Compression Ratio
5
NOx – Load RequirementsNOx – Load Requirements
2 4 6 8 10 120
1
2
3
4
5
6Euro 5
Tier 2Bin 8
Tier 2Bin 5
Tier 2Bin 2
Emis
sion
Inde
x N
Ox
(g/k
g fu
el)
Engine BMEP (Bar)
Engine-Out Asymptote?
6
Clean Combustion with DieselClean Combustion with Diesel
NOx
Soot
Equ
ival
ence
Rat
io
10987654321
Temperature (K)1000 1400 1800 2200 2600 3000
Com
bust
ion
Effic
ienc
y H
C/C
O Is
sues
Conventional CombustionFuel rich combustion leads to NOx and PM formation.
Conventional
Near-HCCI CombustionTight control on charge temperature and mixture formation is required
7
Near-HCCI Potential for DieselNear-HCCI Potential for Diesel
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
0 1 2 3 4 5 6 7Engine Out NOx (g/kg)
Bos
ch S
mok
e N
umbe
r
ConventionalCombustion(Euro 4/5 Cal)
8
Near-HCCICombustion
Simulated Vehicle Cruise Condition
8
Towards Wide Range Charge ControlTowards Wide Range Charge Control
System Complexity
Cha
rge
Tem
pera
ture
Conventional EGR Cooler
+ Optimized EGR cooler+ Bypass for light-load and cold operation
+ Separate water circuit
+ Clean EGR (low pressure)
Temperature and composition
+ VVA
VGT
2-Stage
EmergingConcepts
VGC
Boost System EvolutionAirAir--System FoulingSystem Fouling
Fouled EGR Cooler Tube
9
The Next RevolutionThe Next RevolutionThe Next Revolution
Near-HCCI combustion Ultra-low NOx operationTransients + mode switching
Adaptive dispersion controlComponent wearEnvironmental factors
Enhanced OBD diagnostics
Lots of development to do!
Near-HCCI combustion Ultra-low NOx operationTransients + mode switching
Adaptive dispersion controlComponent wearEnvironmental factors
Enhanced OBD diagnostics
Lots of development to do!
ECU
Combustion Sensor
Regaining control with direct combustion-feedback
10
0.6
0.8
1.0
1.2
1.4
65 70 75 80 85 90 95Time (s)
Control OffControl On
Combustion FeedbackCombustion Feedback
TargetFueling
Over
Under
Production Variability
An example of injector dispersion control
11
Ligh
t Dut
y D
iese
l US0
6 C
atal
yst T
emps
Ligh
t Dut
y D
iese
l FTP
C
atal
yst T
empe
ratu
res
Balancing catalyst activity between the FTP & US06Lean-NOx Aftertreatment OptionsLean-NOx Aftertreatment Options
0
20
40
60
80
100
0 100 200 300 400 500 600
SCR-Urea 1
NO
xC
o nve
rsio
n E
ffici
e ncy
(%)
Catalyst Operating Temperature (degrees C)
LNT 2
SCR-HC 3
1 Aged 120 k mi, transition metal Zeolite 2 Aged 120 k mi, vehicle measurement3 Aged 120 k mi, transition metal Zeolite4 Bench Test – Combinatorial & High Throughput Materials Science – DOE Award DE-FC26-05NT42415
SCR-HC Improved 4
12
SummarySummaryTechnical case for US LD diesels is improvingMajor innovation is underway
What will it take for wide-spread US LD Diesels?Continued technical progressMarket demand
Continued energy supply pressurePublic experience with new clean diesels
Technical case for US LD diesels is improvingMajor innovation is underway
What will it take for wide-spread US LD Diesels?Continued technical progressMarket demand
Continued energy supply pressurePublic experience with new clean diesels
Thank you for your attention
GM R&D Center