Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Cooxidation in the auto-ignition of primary reference fuels and n-heptane/toluene blends
KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Chemical Reaction Engineering.
KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Chemical Reaction Engineering.
KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Chemical Reaction Engineering.
KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Internal Combustion Engines.ORCID iD: 0000-0002-4243-7134
Show others and affiliations
2005 (English)In: Combustion and Flame, ISSN 0010-2180, E-ISSN 1556-2921, Vol. 140, no 4, 267-286 p.Article in journal (Refereed) Published
Abstract [en]

Auto-ignition of fuel mixtures was investigated both theoretically and experimentally to gain further understanding of the fuel chemistry. A homogeneous charge compression ignition (HCCI) engine was run under different operating conditions with fuels of different RON and MON and different chemistries. Fuels considered were primary reference fuels and toluene/n-heptane blends. The experiments were modeled with a single-zone adiabatic model together with detailed chemical kinetic models. In the model validation, co-oxidation reactions between the individual fuel components were found to be important in order to predict HCCI experiments, shock-tube ignition delay time data, and ignition delay times in rapid compression machines. The kinetic models with added co-oxidation reactions further predicted that an n-heptane/toluene fuel with the same RON as the corresponding primary reference fuel had higher resistance to auto-ignition in HCCI combustion for lower intake temperatures and higher intake pressures. However, for higher intake temperatures and lower intake pressures the n-heptane/toluene fuel and the PRF fuel had similar combustion phasing.

Place, publisher, year, edition, pages
2005. Vol. 140, no 4, 267-286 p.
Keyword [en]
HCCI, homogeneous charge compression ignition, auto-ignition, fuel chemistry, primary reference fuels, n-heptane, toluene, co-oxidation, CHEMKIN
National Category
Chemical Engineering
Identifiers
URN: urn:nbn:se:kth:diva-7570DOI: 10.1016/j.combustflame.2004.11.009ISI: 000227865300003Scopus ID: 2-s2.0-14744268733OAI: oai:DiVA.org:kth-7570DiVA: diva2:12637
Note
QC 20101109Available from: 2007-11-06 Created: 2007-11-06 Last updated: 2017-12-14Bibliographically approved
In thesis
1. Kinetic modelling of autoignition phenomena
Open this publication in new window or tab >>Kinetic modelling of autoignition phenomena
2007 (English)Licentiate thesis, comprehensive summary (Other scientific)
Abstract [en]

To fully understand the elementary reactions behind the ignition of automotive fuels the interaction between the fuel components must be known. The ignition initiation is most often caused by loss of an H radical from a reactive fuel molecule, for example n-heptane. The formed alkyl radical is prone to react with oxygen under lean conditions. However, it can also abstract hydrogen from other fuel molecules, hence activating more unreactive species. This type of reactions is called cooxidation reactions and including it in combustion mechanisms improve ignition delay predictions in a wide range of experiments, for Primary Reference Fuel mixtures and toluene/heptane mixtures. Example of such reactions are

C7H15• + C8H18 = C7H16+ C8H17•

C7H15OO• + C8H18 = C7H15OOH+ C8H17•

Adding cooxidation reactions also significantly improves prediction of the general trend of auto-ignition phasing as function of operating conditions in Homogeneous Charge Compression Ignition, HCCI, engine combustion.

The effect of NO addition on engine combustion has also been studied in this work. A novel strategy to control ignition onset in HCCI engines is to retain exhaust gases in the cylinder to control the cylinder temperature. While this not only controls the engine temperature it also introduces NOx in the cylinder. The NO will advance ignition onset by several crank angle degrees at concentrations below 10 ppm. This is because NO activates HO2 in the reaction: HO2• + NO = OH• + NO2. At higher concentrations the ignition onset is not as advanced and in the PRF case even retarded. This is because NO has cool flame-inhibiting effects.

Kinetic modelling can also be used to predict combustion efficiency in catalytic combustors for power generation. It was shown that at high pressures the number of free sites decreases which limits the combustion efficiency. Thus a hybrid concept could be used where only a fraction of the air and fuel is burned catalytically.

Place, publisher, year, edition, pages
Stockholm: KTH, 2007. 53 p.
Series
Trita-CHE-Report, ISSN 1654-1081 ; 2007:65
National Category
Chemical Engineering
Identifiers
urn:nbn:se:kth:diva-4516 (URN)978-91-7178-778-1 (ISBN)
Presentation
2007-11-15, 591, KTH, Teknikringen 42, Stockholm, 10:00
Opponent
Supervisors
Note
QC 20101109Available from: 2007-11-06 Created: 2007-11-06 Last updated: 2010-11-09Bibliographically approved
2. A method of defining the auto-ignition quality of gasoline-like fuels in HCCI engines
Open this publication in new window or tab >>A method of defining the auto-ignition quality of gasoline-like fuels in HCCI engines
2005 (English)Licentiate thesis, comprehensive summary (Other scientific)
Place, publisher, year, edition, pages
Stockholm: KTH, 2005. 74 p.
Series
Trita-MMK, ISSN 1400-1179 ; 2005:10
Keyword
Engineering design, auto-ignition quality, HCCI, CAI and fuels, Konstruktionsteknik
National Category
Reliability and Maintenance
Identifiers
urn:nbn:se:kth:diva-343 (URN)
Presentation
2005-04-29, M3, Brinellv 64, Stockholm, 10:00
Supervisors
Note
QC 20101220Available from: 2005-08-01 Created: 2005-08-01 Last updated: 2010-12-20Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full textScopushttp://dx.doi.org/10.1016/j.combustflame.2004.11.009

Authority records BETA

Risberg, Per

Search in DiVA

By author/editor
Andrae, JohanJohansson, DavidBjörnbom, PehrRisberg, PerKalghatgi, Gautam
By organisation
Chemical Reaction EngineeringInternal Combustion Engines
In the same journal
Combustion and Flame
Chemical Engineering

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 199 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf