Combustion and emissions characteristics of a hybrid hydrogen–gasoline engine under various loads and lean conditions

Abstract The addition of hydrogen is an effective way for improving the gasoline engine performance at lean conditions. In this paper, an experiment aiming at studying the effect of hydrogen addition on combustion and emissions characteristics of a spark-ignited (SI) gasoline engine under various loads and lean conditions was carried out. An electronically controlled hydrogen port-injection system was added to the original engine while keeping the gasoline injection system unchanged. A hybrid electronic control unit was developed and applied to govern the spark timings, injection timings and durations of hydrogen and gasoline. The test was performed at a constant engine speed of 1400 rpm, which could represent the engine speed in the typical city-driving conditions with a heavy traffic. Two hydrogen volume fractions in the total intake of 0% and 3% were achieved through adjusting the hydrogen injection duration according to the air flow rate. At a specified hydrogen addition level, gasoline flow rate was decreased to ensure that the excess air ratios were kept at 1.2 and 1.4, respectively. For a given hydrogen blending fraction and excess air ratio, the engine load, which was represented by the intake manifolds absolute pressure (MAP), was increased by increasing the opening of the throttle valve. The spark timing for maximum brake torque (MBT) was adopted for all tests. The experimental results demonstrated that the engine brake mean effective pressure (Bmep) was increased after hydrogen addition only at low load conditions. However, at high engine loads, the hybrid hydrogen–gasoline engine (HHGE) produced smaller Bmep than the original engine. The engine brake thermal efficiency was distinctly raised with the increase of MAP for both the original engine and the HHGE. The coefficient of variation in indicated mean effective pressure (COVimep) for the HHGE was reduced with the increase of engine load. The addition of hydrogen was effective on improving gasoline engine operating instability at low load and lean conditions. HC and CO emissions were decreased and NOx emissions were increased with the increase of engine load. The influence of engine load on CO2 emission was insignificant. All in all, the effect of hydrogen addition on improving engine combustion and emissions performance was more pronounced at low loads than at high loads.

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

[2]  Maher A.R. Sadiq Al-Baghdadi A study on the hydrogen–ethyl alcohol dual fuel spark ignition engine , 2002 .

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

[4]  Yu Wang,et al.  Effects of Combustion Phasing, Combustion Duration, and Their Cyclic Variations on Spark-Ignition (SI) Engine Efficiency , 2008 .

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

[6]  Rohit Gulati,et al.  A comparative evaluation of the performance characteristics of a spark ignition engine using hydrogen and compressed natural gas as alternative fuels , 2000 .

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

[8]  L. M. Das,et al.  Hydrogen-oxygen reaction mechanism and its implication to hydrogen engine combustion , 1996 .

[9]  Shuofeng Wang,et al.  Experimental Study on Combustion and Emissions Characteristics of a Spark Ignition Engine Fueled with Gasoline−Hydrogen Blends , 2009 .

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

[11]  Zuo-hua Huang,et al.  Combustion Characteristics and Heat Release Analysis of a Spark-Ignited Engine Fueled with Natural Gas−Hydrogen Blends , 2007 .

[12]  F. Barbir,et al.  Hydrogen: the wonder fuel , 1992 .

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

[14]  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 .

[15]  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 .

[16]  M. Sastri,et al.  Hydrogen energy research and development in India—an overview , 1987 .

[17]  T. Shudo,et al.  Analysis of the degree of constant volume and cooling loss in a spark ignition engine fuelled with hydrogen , 2001 .

[18]  Efthimios Zervas,et al.  Correlations between cycle-to-cycle variations and combustion parameters of a spark ignition engine , 2004 .

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

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

[21]  Nafiz Kahraman,et al.  Investigation of combustion characteristics and emissions in a spark-ignition engine fuelled with natural gas–hydrogen blends , 2009 .

[22]  Bing Liu,et al.  Experimental investigation on performance and emissions of a spark-ignition engine fuelled with natural gas–hydrogen blends combined with EGR , 2009 .

[23]  Bing Liu,et al.  Experimental study on engine performance and emissions for an engine fueled with natural gas-hydrogen mixtures , 2006 .

[24]  M. Wietschel,et al.  The future of hydrogen : opportunities and challenges , 2009 .

[25]  M. Masood,et al.  Performance and Combustion Characteristics of a Hydrogen−Ethanol-Fuelled Engine , 2008 .

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

[27]  Shuofeng Wang,et al.  Effect of hydrogen addition on combustion and emissions performance of a spark ignition gasoline engine at lean conditions , 2009 .

[28]  Maher A.R. Sadiq Al-Baghdadi,et al.  Performance study of a four-stroke spark ignition engine working with both of hydrogen and ethyl alcohol as supplementary fuel , 2000 .

[29]  K. Varde COMBUSTION CHARACTERISTICS OF SMALL SPARK IGNITION ENGINES USING HYDROGEN SUPPLEMENTED FUEL MIXTURES. , 1981 .

[30]  Aiyagari Ramesh,et al.  Effect of hydrogen addition on the performance of a biogas fuelled spark ignition engine , 2007 .

[31]  Fanhua Ma,et al.  Study on the extension of lean operation limit through hydrogen enrichment in a natural gas spark-ignition engine , 2008 .

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

[33]  Baris Ozerdem,et al.  An experimental study on performance and emission characteristics of a hydrogen fuelled spark ignition engine , 2007 .

[34]  Shuofeng Wang,et al.  Combustion and emissions performance of a hybrid hydrogen–gasoline engine at idle and lean conditions , 2010 .

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