Strategies for improving the idle performance of a spark-ignited gasoline engine

Abstract Because of the increased residual gas fraction and low combustion temperature, the traditional spark-ignited (SI) gasoline engines tend to encounter the dropped thermal efficiency and increased emissions at idle. This paper experimentally investigated the effects of hydrogen addition, cylinder cutoff, lean combustion and idle speed reduction on improving the combustion and emissions performance of gasoline engine at idle. The tests were conducted on a modified 1.6 L SI engine equipped with a hydrogen port-injection system and a self-developed hybrid electronic control unit (HECU). In the experiments, cylinder cutoff was realized by stopping the hydrogen and gasoline injections to the specified cylinders. The HECU was adopted to control the opening of idle bypass valve and spark timing at the reduced idle speed of 600 rpm. The test results showed that hydrogen addition, lean burn, cylinder cutoff and idle speed reduction were all effective on decreasing the engine fuel consumption at idle. Under the given test conditions, the combination of cylinder cutoff and hydrogen addition was the most effective, which reduced the fuel consumption by 33.25% at a hydrogen volume fraction in the intake of 2.87% and two-cylinder cutoff mode, compared with that of the original engine. Moreover, engine cyclic variation, HC and CO emissions were also decreased after hydrogen addition and cylinder cutoff. Because of the dropped combustion temperature, NOx emissions were decreased at the lean combustion and decreased idle speed. However, due to the increased residual gas fraction and weakened charge flow, HC emissions from the engine operating at an idle speed of 600 rpm and a hydrogen addition fraction of 3.20% were slightly higher than those from the original gasoline engine at idle.

[1]  R. L. Rowley,et al.  Estimation of the lower flammability limit of organic compounds as a function of temperature. , 2011, Journal of hazardous materials.

[2]  Richard Stone,et al.  Analysis of the particulate emissions and combustion performance of a direct injection spark ignition engine using hydrogen and gasoline mixtures , 2010 .

[3]  John Hoard,et al.  Relating Subjective Idle Quality to Engine Combustion , 1997 .

[4]  K. Boulouchos,et al.  Hydrogen–natural gas blends fuelling passenger car engines: Combustion, emissions and well-to-wheels assessment , 2008 .

[5]  Nafiz Kahraman,et al.  Experimental study on a spark ignition engine fuelled by methane–hydrogen mixtures , 2007 .

[6]  Fanhua Ma,et al.  Performance and emission characteristics of a turbocharged CNG engine fueled by hydrogen-enriched compressed natural gas with high hydrogen ratio , 2010 .

[7]  Bing Liu,et al.  Experimental Study on Emissions of a Spark-Ignition Engine Fueled with Natural Gas-Hydrogen Blends , 2008 .

[8]  Bing Liu,et al.  Cycle-by-cycle variations in a spark ignition engine fueled with natural gas–hydrogen blends combined with EGR , 2009 .

[9]  P. M. Diéguez,et al.  Conversion of a commercial spark ignition engine to run on hydrogen: Performance comparison using hydrogen and gasoline , 2010 .

[10]  Maher A.R. Sadiq Al-Baghdadi,et al.  A prediction study of the effect of hydrogen blending on the performance and pollutants emission of a four stroke spark ignition engine , 1999 .

[11]  Thomas Wallner,et al.  Operating strategy for a hydrogen engine for improved drive-cycle efficiency and emissions behavior , 2009 .

[12]  Gopichandra Surnilla,et al.  Fuel Assisted Idle Speed Control for Lean Burn Gasoline Engines , 2006 .

[13]  John B. Heywood,et al.  Internal combustion engine fundamentals , 1988 .

[14]  Shuofeng Wang,et al.  Experimental study on combustion and emissions performance of a hybrid hydrogen–gasoline engine at lean burn limits , 2010 .

[15]  Jinhua Wang,et al.  Effect of hydrogen addition on early flame growth of lean burn natural gas–air mixtures , 2010 .

[16]  Bo Zhang,et al.  Combustion and emissions characteristics of a hybrid hydrogen–gasoline engine under various loads and lean conditions , 2010 .

[17]  H. May,et al.  Possibilities of improving exhaust emissions and energy consumption in mixed hydrogen-gasoline operation , 1983 .

[18]  David S.-K. Ting,et al.  The addition of hydrogen to a gasoline-fuelled SI engine , 2004 .

[19]  Zuo-hua Huang,et al.  Experimental study on combustion characteristics of a spark-ignition engine fueled with natural gas–hydrogen blends combining with EGR , 2009 .

[20]  Ronald K. Jurgen.  Automotive Electronics Handbook , 1999 .

[21]  L. M. Das,et al.  Near-term introduction of hydrogen engines for automotive and agricultural application , 2002 .

[22]  Yong Li,et al.  Effects of hydrogen addition on cycle-by-cycle variations in a lean burn natural gas spark-ignition engine , 2008 .

[23]  Jing Sun,et al.  MODELS AND CONTROL METHODOLOGIES FOR IC ENGINE IDLE SPEED CONTROL DESIGN , 1996 .

[24]  Hiroshi Enomoto,et al.  Decreasing of the Engine Idle Speed of a Small Gasoline Engine with Feedback Control , 2009 .

[25]  Yong Li,et al.  Experimental study on thermal efficiency and emission characteristics of a lean burn hydrogen enriched natural gas engine , 2007 .

[26]  Syed Yousufuddin,et al.  Effect of ignition timing and compression ratio on the performance of a hydrogen–ethanol fuelled engine , 2009 .

[27]  Derek Dunn-Rankin,et al.  Lean Combustion Technology and Control , 2011 .

[28]  Eiichi Watanabe,et al.  Cylinder Cutoff of 4-Stroke Cycle Engines at Part-Load and Idle , 1982 .

[29]  Ali Mohammadi,et al.  Performance and combustion characteristics of a direct injection SI hydrogen engine , 2007 .

[30]  Wing-tat Hung,et al.  Development of a driving cycle for Hong Kong , 1999 .

[31]  V. Balasubramanian,et al.  Hydrogen fueled spark ignition engine with electronically controlled manifold injection: An experimental study , 2008 .

[32]  David Mumford,et al.  Challenges in Developing Hydrogen Direct Injection Technology for Internal Combustion Engines , 2008 .

[33]  F. Salimi,et al.  Role of mixture richness, spark and valve timing in hydrogen-fuelled engine performance and emission , 2009 .

[34]  Yong Li,et al.  Influence of Different Volume Percent Hydrogen/Natural Gas Mixtures on Idle Performance of a CNG Engine , 2008 .

[35]  Shuofeng Wang,et al.  Effect of hydrogen addition on the idle performance of a spark ignited gasoline engine at stoichiometric condition , 2009 .