Improving Efficiency, Extending the Maximum Load Limit and Characterizing the Control-related Problems Associated with Higher Loads in a 6-Cylinder Heavy-duty Natural gas Engine

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


High EGR rates combined with turbocharging has been identified as a promising way to increase the maximum load and efficiency of heavy duty spark ignition Natural Gas engines. With stoichiometric conditions a three way catalyst can be used which means that regulated emissions can be kept at very low levels. Most of the heavy duty NG engines are diesel engines which are converted for SI operation. These engine's components are in common with the diesel-engine which put limits on higher exhaust gas temperature. The engines have lower maximum load level than the corresponding diesel engines. This is mainly due to the lower density of NG, lower compression ratio and limits on knocking and also high exhaust gas temperature. They also have lower efficiency due to mainly the lower compression ratio and the throttling losses. However performing some modifications on the engines such as redesigning the engine's piston in a way to achieve higher compression ratio and more turbulence, modifying EGR system and optimizing the turbocharging system will result in improving the overall efficiency and the maximum load limit of the engine. This paper presents the detailed information about the engine modifications which result in improving the overall efficiency and extending the maximum load of the engine. Control-related problems associated with the higher loads are also identified and appropriate solutions are suggested.


Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Energy Engineering


  • Internal Combustion Engine, Efficiency, Load Limit, Control
Original languageEnglish
Title of host publicationProceedings of the ASME 2010 Internal Combustion Engine Division Fall Technical Conference
PublisherAmerican Society Of Mechanical Engineers (ASME)
Number of pages8
ISBN (Electronic)978-0-7918-3882-2
ISBN (Print)978-0-7918-4944-6
Publication statusPublished - 2010
Publication categoryResearch
EventFall Technical Conference of the ASME Internal Combustion Engine Division, 2010 - San Antonio, TX, San Antonio, TX, United States
Duration: 2010 Sep 122010 Sep 15


ConferenceFall Technical Conference of the ASME Internal Combustion Engine Division, 2010
CountryUnited States
CitySan Antonio, TX

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