8/6/2019 Challenges in Making Natural Gas Vehicles
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Materials Science &Technology
Challenges and Potential ofadvanced methane gas vehicles
Christian Bach
Internal Combustion Engine Laboratory
8/6/2019 Challenges in Making Natural Gas Vehicles
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SATW Congress, 29.08.2008
Materials Science &Technology
Content
Methane gasIn future used for low temperature or high temperature application?Very suitable fuel for otto cycled combustion engines
The Clean Engine Vehicle project (CEV)
A natural gas Euro-4/SULEV with 30% reduced CO2 emissions
Impact of fuel quality on knock behavior
a) Propane (Methane number of about 33)b) Hydrogen (Methane number of 0)
OutlookDevelopment of a natural gas hybrid powertrain concept
Conclusions
8/6/2019 Challenges in Making Natural Gas Vehicles
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Materials Science &Technology
Gaseous fuels as one option for CO2reduction and motor fuel diversification
Natural gas / preprocessed biogas driven engines
- 20-25% red. CO2 emissions per MJ fuel used (methane vs. gasoline)- Add. engine efficiency potential of 10% (optimized gas engines)- Very low exhaust emissions are possible (incl. non-limited pollutants)- Possible to integrate preprocessed biogas (produced from waste)- Transition technology to hydrogen (incl. socio economic aspects)
Additional potential of reformulated methane gas fuels- Conversion of natural gas / biogas methane(increased know-resistance, extended range)
- Enrichment of methane with hydrogen (improved efficiency)
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Materials Science &Technology
Natural gas: a fuel for vehicles or furnaces?
High temperature heat vs. low temperature heat
Existing know-how in distributing naturalgas world wide
40% (in CH) is used for low temperatureheat (substitution potential for heatpumps)
Situation
If used as fuel for motor vehicles:
Direct CO2 reduction (lower C-content)
with significant lowering of air pollutants
Additional CO2 reduction due to:- less overpowered vehicles- more efficient vehicles (range!)- increased demand on fueling stations
but reduced demand on grid dispersion
Short term view
Important biogas potential available(75 PJ/a biomass, resp. 40 PJ/a methane)
Technical and socio economic bridge fromtodays fossil fuels to hydrogen
Mid and long term view
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Materials Science &Technology
Methane as fuel for otto cycled engines
Efficient and clean
Thermal efficiency:1
11
=
thn
where: = compression ratio
= adiabatic exponentv
p
cc
Fuel spec. Gasoline Methane
Octane number 95 98 130
Compression ratio 10 - 11 13 - 13.5
Reduced thermal NOx emissions(engine out)
Reduced CO2 emissions
Disadvantage!?
Calorific value 43 MJ/kg 50 MJ/kg
Flame temperature 2500 K 2150 K
H:C ratio 2 : 1 4 : 1
Spec. CO2 emissions 74 g/MJ 55 g/MJ
Energy density 30 MJ/dm3 7 MJ/dm3
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Materials Science &Technology
NGV roadmap
From conversion to optimized gas engines
ConversionDriving with natural gas
- Each vehicle modelavailable as NGV
- Low technical level- Unreliable
- Potential not used- Increased skepticism
Opt. gas enginesreal gas engines
- Efficient, clean, reliable- Near Zero Emissions- potential- Range limitation- forces high efficiency
- Overcome technical- backlog
OEM bifuelGas driven gasoline engines
- Clean, reliable
- Limited vehicle models- Range (300 km)
- Costs (2 fuels)
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Materials Science &Technology
Content
Methane gasIn future used for low temperature or high temperature application?Very suitable fuel for otto cycled combustion engines
The Clean Engine Vehicle project (CEV)
A natural gas Euro-4/SULEV with 30% reduced CO2 emissions
Impact of fuel quality on knock behavior
a) Propane (Methane number of about 33)b) Hydrogen (Methane number of 0)
OutlookDevelopment of a natural gas hybrid powertrain concept
Conclusions
8/6/2019 Challenges in Making Natural Gas Vehicles
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SATW Congress, 29.08.2008
Materials Science &Technology
Clean Engine Vehicle Project (CEV)
Project overview
Aim of project -30% CO2
Euro-4 and SULEV
Exhaust aftertreatment Catalytic converter concept Oxygen management
Engine Increased compression Controlled turbo charging Optimized engine control
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Materials Science &Technology
Clean Engine Vehicle Projekt (CEV)
CO2 reduction path
148.6159.0
116.5113.4
109.5
37.0
31.0
44.0 44.0
33.0
0
20
40
60
80100
120
140
160
180
BenzinBasismotor
ErdgasOhne nderung
ErdgasOptimierte
Verdichtung
ErdgasMit Downsizing
Benzin1.4 l
CO2-Emissioning/km
0
10
20
30
4050
60
70
80
90
Motorleistun
ginkW
CO2-Emission Leistung
CO2: -31%
Leistung: +20%
-21.6%
-16.2%
-2.7%
+6.5%
-3.4%
+33.3%
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Materials Science &Technology
Clean Engine Vehicle Project (CEV)
Zero NOx emissions
0.001
0.010
0.100
1.000
10.000
100.000
1000.000
0 200 400 600 800 1000 1200 1400
Zeit in s
NOxKonzentrat
ioninppmV
0
20
40
60
80
100
120
Geschwindigk
eitinkm/h
NOx Ansaugluft NOx TMessung 154 NOx Messung 151 NOx Messung 153 sch_speed
NOx-Konzentration in der Ansaugluft
NOx-Konzentration im Abgas
ca. 700 m
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Materials Science &Technology
Content
Methane gasIn future used for low temperature or high temperature application?Very suitable fuel for otto cycled combustion engines
The Clean Engine Vehicle project (CEV)
A natural gas Euro-4/SULEV with 30% reduced CO2 emissions
Impact of fuel quality on knock behavior
a) Propane (Methane number of about 33)b) Hydrogen (Methane number of 0)
OutlookDevelopment of a natural gas hybrid powertrain concept
Conclusions
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Materials Science &Technology
Impact of gas quality
Investigated gas qualities
0 15%- - -- - -- - -Vol-%Hydrogen H2
- - -3.0- - -- - -Vol-%>C3 HCs
- - -1.0- - -- - -Vol-%Carbon Dioxide CO2
- - -2.014.0- - -Vol-%Nitrogen N2
- - -1.0- - -- - -Vol-%Propane C3H8
- - -4.0- - -- - -Vol-%Ethane C2H6
100 - 85%89.086.0100.0Vol-%Methane
Hydrogen enrichedmethane
Natural gas(Swiss grid)
G25G20
68104100- - -Methane number
15.97613.35917.173Kg/kgStoic A/F ratio
46.2738.6249.65MJ/kgCalorific value
0.8330.7900.716kg/m3Density (0C)
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90
95
100
105
110
115
120
5 10 15 20 25
Ignition point [KWvOT]
Torque[Nm]
Md G20
Md G25
Md NG
Eff G20
Eff G25
Eff NG
late
Impact of methane gas fuel quality
Ignition point (Engine rev. 2000 rpm, bmep = 2 bar)
30 35
30
31
32
33
34
35
36
37
38
39
40
Efficiency[%]
early
Natu
ralGasNG
MethaneG20
Methane/N2G2
5
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Materials Science &Technology
30 31 32 33 34 35 36 37 38 39 401.8
1.9
2
2.1
2.2
2.3
2.4
2.5
2.6
2.7
2.8
mU/m
tot(1-x
B) bei Klopfbeginn [%]
dQ/dLocMin
Max
[%/CA]
Relation between burn rate and knocking
Methane (G20) a
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Materials Science &Technology
Admixture of hydrogen (HCNG)
Comparison of laminar combustion velocity
4.07
9.50
29.58
concstoic[cm/s]
3346.04.2747.2Propane C3H8
10042.010.1743.0Methane CH4
0237.042.5346.0Hydrogen H2
MZSLstoic[cm/s]
concmax[cm/s]
SLmax[cm/s]
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Materials Science &Technology
330
332
334
336
338
0 5 10 15
Hydrogen in Fuel [vol%]
Opt.SparkTim.[Crank.
Deg.]
10
20
30
40
50
60
70
DistancetoST[Crank.
Deg.]
ST 2bar bmep M FB5, 2 bar bmep
M FB50, 2bar bmep M FB90, 2 bar bmep
Admixture of hydrogen (HCNG)
Impact on combustion
19
19.5
20
20.5
21
5 10 15 20
EGR rate [mass-%]
EngineFuelConv.
Efficiency[%]
no H2 DoE no H2 Meas.
5vol% H2 DoE 10vol% H2 DoE
15vol% H2 DoE 15vol% H2 Meas.
5% H2
10% H2
15% H2
0% H2
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Materials Science &Technology
CLEVER project
Downsized natural gas hybrid powertrain
Development of a newcombustion cycle (with
gas direct injection) Optimization of thermo
dynamic cycle (de-throttling)
Development of enhanceddownsizing concept(controlled turbo charging)
Hybridization (design ofconcept, recuperation,
starting torque, turbo lagcompensation)
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Materials Science &Technology
NG-hybrid vs. with EU-mix electric vehicle
Concawe, EUCAR, JRD Well-to-wheel Study 2006
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SATW Congress, 29.08.2008
Materials Science &Technology
Content
Methane gasIn future used for low temperature or high temperature application?Very suitable fuel for otto cycled combustion engines
The Clean Engine Vehicle project (CEV)
A natural gas Euro-4/SULEV with 30% reduced CO2 emissions
Impact of fuel quality on knock behaviora) Propane (Methane number of about 33)b) Hydrogen (Methane number of 0)
OutlookDevelopment of a natural gas hybrid powertrain concept
Conclusions
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Materials Science &Technology
Conclusions
Methane is a suited fuel for turbo charged engines Methane is a high temperature capable fuel and well suited for turbo
charged motor applications due to the high knock resistance.
Dedicated methane gas engines have the potential for increasedefficiency and reduced emissions. The compliance with futureemission regulations is much easier than for liquid fuels.
Preprocessed biogas can be added in all possible ratios without
modifications on the vehicle. Propane should be limited in the natural gas grid or reduced/
eliminated at the fueling station due to the knock increasing impact(low methane number)
The admixture of hydrogen (e.g. at the fueling station) could giveanother potential for increased efficiency, if the hydrogen is notproduced from fossil sources.
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Materials Science &Technology
Thank you for your attention!