Hydrogen Addition For Improved Lean Burn Capability of Slow and Fast Burning Natural Gas Combustion Chambers

Research output: Chapter in Book/Report/Conference proceedingPaper in conference proceeding


One way to extend the lean-burn limit of a natural gas engine is by addition of hydrogen to the primary fuel. This paper presents measurements made on a one-cylinder, 1.6- liter natural gas engine. Two combustion chambers, one slow and one fast burning, were tested with various amounts of hydrogen (0, 5, 10 and 15%-vol) added to natural gas. Three operating points were investigated for each combustion chamber and each hydrogen content level; idle, part load (5 bar IMEP) and 13 bar IMEP (simulated turbocharging). Air/fuel ratio was varied between stoichiometric and the lean limit. For each operating point, a range of ignition timings were tested to find maximum brake torque (MBT) and/or knock. Heat-release rate calculations were made in order to assess the influence of hydrogen addition on burn rate. Addition of hydrogen showed an increase in burn rate for both combustion chambers, resulting in more stable combustion close to the lean limit. This effect was most pronounced for lean operation with the slow combustion chamber.


  • Per Tunestål
  • Magnus Christensen
  • Patrik Einewall
  • Tobias Andersson
  • Bengt Johansson
  • Owe Jönsson
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Energy Engineering


  • Natural Gas, CNG, Hydrogen, Hythane, Spark Ignition, Combustion, Engine
Original languageEnglish
Title of host publicationSAE Special Publications
PublisherSociety of Automotive Engineers
Number of pages13
Publication statusPublished - 2002
Publication categoryResearch
EventSAE Powertrain & Fluid Systems Conference & Exhibition, 2003 - Pittsburgh, PA, United States
Duration: 2003 Oct 272003 Oct 30

Publication series

ISSN (Print)0099-5908


ConferenceSAE Powertrain & Fluid Systems Conference & Exhibition, 2003
CountryUnited States
CityPittsburgh, PA

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