Renewable synthetic fuels: challenges and opportunities for ......Gas turbines open system, pressure...

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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

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Synthetic fuels for Diesel combustion

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Impact inner nozzle flow/cavitation, atomization, evaporation

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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

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Acknowledgements