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Swiss Combustion Day 2019
24.6.2019Yuri M. Wright 1
Renewable synthetic fuels: challenges and opportunities for IC engine combustion
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Combustion in IC engines some general considerations Challenges
Examples Hydrogen-methane admixtures (premixed) for CHP Synthetic fuels for Diesel combustion
Conclusions and outlook
24.6.2019Yuri M. Wright 2
Outline
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Gas turbines open system, pressure boundaries Continuous operation
IC engines Closed during combustion variable volume, pressure and temperature Phasing important Flexible w.r.t. fuels
24.6.2019Yuri M. Wright 3
Some general consideration
Ensure some compatibility between flow, turbulence and what the fuel «wants to do»
N. Noiray, 2019 (a few minutes ago)
Farrace et al., SAE Int. J. Engines 6(3), 2013
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Unstrained laminar flame speeds Serious lack of experimental data at engine conditions! From deflagration to propagating ignition fronts
Ignition processes Process often two-stage Low-T kinetics for large molecules
very complex, especially if oxygenated Strong impact of pressure/EGR on NTC
24.6.2019Yuri M. Wright 4
Challenges – chemical kinetics
Lu & Law, PECS 35, 2009
Habisreuther et al., CNF 160, 2016
A. Vandersickel. Diss ETH No.19965
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Diesel type auto-ignitionbetween hot air/cold fuel
Pre-chamber system: auto-ignition by means of a hot jet
24.6.2019Yuri M. Wright 5
Challenges – coupling with turbulence
De Paola et al., CST 180, 2008ξMR
Dec, 1997
G. Xu, Diss ETH no. 25427
Benekos, Hamm et al., in preparation
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Challenges – premixed
Turbulent flame speed / flame surface density Closures needed! Ideally valid for wide ranges of length
and time scale ratios
Near-wall phenomena Impact on emissions and heat transfer! Hydrogen modifies both
Thermodiffusive effects of hydrogen/air flames
24.6.2019Yuri M. Wright 6
Jafargholi et al., CNF 2018
Xu et al., IJER 2019
Altantzis et al., 2010
|| 17.12.2018PhD defence Jann Koch 7
Hydrogen-Methane admixtures in a single-cylinder 250cc engine for CHP
16 bar
Measurements Ch. Schürch
3000 rpm, Methane λ=1
|| 17.12.2018PhD defence Jann Koch 8
Hydrogen-Methane admixtures in a single-cylinder 250cc engine for CHP
16 bar
Measurements Ch. Schürch
3000 rpm, Methane λ=1
|| 24.6.2019Yuri M. Wright 9
CCV for methane/hydrogen air admixturesOP1: 0 vol% H2, λ=1 OP3: 50 vol% H2, λ=1 OP6: 50 vol% H2, λ=1.4
Koch, Schürch et al., in preparation for Int. J. Engine Research
|| 24.6.2019Yuri M. Wright 10
Cycle to Cycle Variations – drivers
◄- slow fast -►
40 50 60 7040
50
60
70
80
Pmaxn-1 [bar]
Pm
axn [b
ar]
MeasurementLES
Pmaxn vs Pmaxn-1
80
Adapted from PhD defence Jann Koch, LAV
|| 10/07/2019Jann Koch 11
SA250 Methane-Hydrogen AdmixturesH2 Influence MBT Timing: DCA02-Pmax
λ=1.0 λ=1.4
Strong correlation between peak pressure and DCA02
Measurement Ch. Schürch
H2↗H2↗
|| 17.12.2018Yuri M. Wright 12
CCV for Hydrogen Addition: Origins
Koch, Schürch et al., in preparation for Int. J. Engine Research
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High potential for reduced CCV operation Fuel flexible and rapid load uptake capability Decentralized at various scales, no grid upgrades needed Could play a significant role for domestic application, i.e.
replacement of natural gas boilers
Potentials of pre-chamber ignition systems with (lean-burn) hydrogen-methane admixtures to be explored
24.6.2019Yuri M. Wright 13
Conclusions methane/hydrogen in ICE for CHP
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FAME and HVO highly questionable Ethers as promising candidates for spray combustion High ignition propensity (CN), similar to Diesel Absence of C-C bonds, virtually no soot
DME most researched, but difficulties present w.r.t. Storage/handling issues due to low critical temperature Cavitation Atomization strongly affected
OMEs highly promising candidates, cf. posters Barro et al.
H3CO(CH2O)nCH3
24.6.2019Yuri M. Wright 14
Synthetic fuels for Diesel combustion
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Impact inner nozzle flow/cavitation, atomization, evaporation
24.6.2019Yuri M. Wright 15
Challenges – thermo-physical properties
Park & Lee, PECS 39, 2013
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Significant potential remaining for ICE combustion with improved fuel flexibility, especially using synthetic fuels for
substantial CO2 reduction higher efficiency lower emissions
All ‘classical’ research topics relevant and some new ones Orchestrated, internationally collaborative efforts required (Engine
Combustion Network, IEA, etc.)
CHP and heavy-duty sectors (marine, off-road, long-haulfreight) with high potentials/corresponding research needs
24.6.2019Yuri M. Wright 16
Conclusions
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All LAV members for many helpful discussions, valuableinput and organization
Financial support: Swiss Federal Office of Energy Swiss Competence Center Energy and Mobility SCCER KTI FVV LMB
24.6.2019Yuri M. Wright 17
Acknowledgements