Bio-ethanol is used in many areas of the world as ethanol blended gasoline at low concentrations such as “E10 gasoline”. In this study, a method was examined to effectively use this small amount of ethanol within ethanol blended gasoline to improve thermal efficiency and high-load performance in a high-compression-ratio engine. Ethanol blended gasoline was separated into high-concentration ethanol fuel and gasoline using a fuel separation system employing a membrane. High-ethanol-concentration fuel was selectively used at high-load conditions to suppress knocking. In this system, a method to decrease ethanol consumption is necessary to cover the wide range of engine operation. Lower ethanol consumption could be achieved by Miller-cycle operation because decrease of the effective compression ratio suppresses knocking. However, high-load operation was limited due to the decrease in intake air volume with Miller-cycle operation. To solve this problem, conventional Otto-cycle operation is used in high-load conditions, utilizing large quantities of ethanol injection to avoid knocking. The two different cycles were smoothly switched with innovative application of a variable valve timing system. In summary, optimum control of the variable valve timing (i.e. effective compression ratio) and ethanol injection fraction allows efficient use of the limited amount of ethanol available. As a result, higher-load and higher thermal efficiency operation was achieved due to the increased compression ratio. Additionally, it is possible to complete the US-06 driving cycle using the above-mentioned system, assuming a realistic engine displacement has been selected according to the vehicle weight.


    Access

    Check access

    Check availability in my library

    Order at Subito €


    Export, share and cite



    Title :

    Study of High-Compression-Ratio Engine Combined with an Ethanol-Gasoline Fuel Separation System


    Additional title:

    Sae Int. J. Engines


    Contributors:

    Conference:

    SAE 2014 International Powertrain, Fuels & Lubricants Meeting ; 2014


    Published in:

    Publication date :

    2014-10-13


    Size :

    8 pages




    Type of media :

    Conference paper


    Type of material :

    Print


    Language :

    English




    Gasoline Engine Combustion - Compression Ratio and Knock

    Overington,M.T. / Thring,R.H. / Ricardo,GB | Automotive engineering | 1981


    Investigation of knock limited compression ratio ethanol gasoline blends

    Szybist,J. / Foster,M. / Moore,W.R. et al. | Automotive engineering | 2010


    A high compression ratio engine running on low octane gasoline

    Youjun,L. / Gangyi,J. / Tianjin Univ.,Thermodynamics Engng.Dep.,CN | Automotive engineering | 1986


    Investigation of Knock Limited Compression Ratio of Ethanol Gasoline Blends

    Youngquist, Adam / Szybist, James / Confer, Keith et al. | SAE Technical Papers | 2010


    High compression ratio gasoline engines and their impact on fuel economy

    Overington,M.T. / Ricardo Consult.Eng.,GB | Automotive engineering | 1982