Experiment And Simulation Study Of The Effect Of Hydrogen Blending On The Performance And Pollutants Emission Of A Four Stroke Spark Ignition Engine

With petroleum deposits becoming less and less and emission control regulationsbecoming stricter and stricter, many countries and research institutes are paying moreattention to finding clear alternative fuel which can reduce the pressure of energyshortage and environment pollution. Hydrogen is a renewable clear energyˋand it canbe applied in lots of eases especially in automotive. So hydrogen shows considerablepromise as an ideal alternative fuel.In this article, the applications of hydrogen using in automotive and state ofdevelopment of hydrogen energy were overviewed in detail. Many researchers studiedthe effect of using hydrogen as a fuel (pure or mixed with gasoline) on engineperformance and pollutants emissions, however the research of lean burn of hydrogenin SI engine reported rarely. In the present work a SI engine whose intake system andcontrol system was reconstructed was developed to study the effect of hydrogen onpower, fuel consumption and pollutant concentrations. The combustion performanceinfluenced by hydrogen was researched from the aspects of mixture formation,ignition energy, inflammability limit, flame propagation speed, flame extinction,combustion pressure and temperature, pollutant formation, lean-burn limit and etc.Simulation of combustion duration, ignition timing and combustion speed was carriedout by AVL Boost software. This work also studied the lean burn ofgasoline-hydrogen mixture in SI engine. The result showed that it's very convenientto use hydrogen in a SI engine without reconstructing too much. Besides, it isessential to consider the influence of hydrogen volume fraction, hydrogen injectiontiming and duration, ignition timing, NOx emission and abnormal combustion forusing hydrogen in SI engine.The present research showed that hydrogen blended into gasoline can expand theinflammability limit, accelerate flame propagation, improve combustion quality, andenhance combustion pressure. Hydrogen diffusibility helps mixture to form heavyintensity of turbulence, this improve the flame speed and decline the amount of heattransfer loss. Consequently, hydrogen combustion resulted in a raise of cylindertemperature and NOx emission. The emissions of HC and NOx were reduced at idlecondition through hydrogen addition. With load and speed increasing, NOx emissionand combustion noise will increase. In conclusion, hydrogen is an ideal fuel to use invehicle in the future.