This content is not included in your SAE MOBILUS subscription, or you are not logged in.
Warm Start Robustness Improvement Using the Heated Cold Start System in Flex Fuel Engines
ISSN: 0148-7191, e-ISSN: 2688-3627
Published September 22, 2015 by SAE International in United States
Annotation ability available
This paper presents a new ethanol content identification concept, with focus on flex fuel vehicles start ability robustness. The solution refers to the usage of cold start system based on heated fuel rail (normally used for low temperatures) in a preventive way like an ethanol sensor, ensuring a successful start attempt in specific conditions, even at high ambient temperatures.
At most of flex fuel projects, the ethanol content calculation (or the percentage of ethanol in fuel) is done through the oxygen sensor (also called lambda sensor). Therefore the engine start strategy considers the fuel mixture determined in the previous vehicle operation.
In situations when the adaptation cycle is not completed during the operation cycle previous to the start attempt, and also in combination with an extreme fuel exchange situation after tanking (previous to the last vehicle operation cycle), it may happens that the first start attempt is not successful. In this case the engine management strategy acts reactively to ensure a proper engine start and drivability until the correct ethanol content is calculated.
The new concept heats the fuel in these specific conditions, using this additional fuel line ethanol content information to adjust the mixture parameters, ensuring the start ability. Thus, the engine management is not anymore reactive and can preventively act before the engine start, improving the flex fuel system robustness without the need of additional components.
Citationde Oliveira, F., Lepsch, F., Silva, L., de Brito Oliveira, L. et al., "Warm Start Robustness Improvement Using the Heated Cold Start System in Flex Fuel Engines," SAE Technical Paper 2015-36-0202, 2015, https://doi.org/10.4271/2015-36-0202.
- CASTRO , A. C. , KOSTER , C. H. and FRANIECK , E. K. Flexible ethanol otto engine, management system SAE WORLD CONGRESS 1994
- NUKIYAMA , S. Film boiling water on thin wires Society of Mechanical Engineering 1934
- NUKIYAMA , S. The Maximum and Minimum Values of Heat Q Transmitted From Metal to Boiling Water Under Atmospheric Pressure, 1934 Journal of Japanese Society of Mechanical Engineering 37 367 374 1934 International Journal of Heat and Mass Transfer
- FAGHRI , A. , ZHANG , Y. and HOWELL , J. R. Advanced Heat and Mass Transfer Global Digital Press Columbia, MO 2010
- KATTO , Y. Critical Heat Flux Int. J. Multiphase Flow (0301-9322(94)E0008-7 20 53 90 1994 Department of Mechanical Engineering, Nihon University Kanda-Surugadai, Cbiyoda-ku, Tokyo 101, Japan
- KUTATELADZE , S. S. Hydromechanical model of the crisis of boiling under conditions of free convection Journal of Technical Physics, USSR 20 11 1389 1392 1950
- BORTOLOZZO , G. , ALARCÓN , O. Q. , NETO A. T. M. Miscibilidade do Álcool Etílico, Gasolina e Água VII Simpósio de Engenharia Automotiva I 136 145 São Paulo 1993
- NIKOLAYEV , V. , BEYSENS , D. , GARRABOS , Y. CHATAIN , and LECOUTRE , C. Bubble spreading during the boiling crisis: modeling and experimenting in microgravity 2005
- NIKOLAYEV , V. , BEYSENS Modeling of the boiling crisis Abril 2015
- INCROPERA , F. P. and DEWITT , D. P. Fundamentals of Heat and Mass Transfer Boiling and Condensation 4the School of Mechanical Engineering, Purdue USA, John Wiley & Sons Books 1996 5 284 332 535 569
- THEOFANOUS , T.G. , TU , J. P. , DINH , A.T. , DINH , T.N. The boiling crisis phenomenon. Part I: nucleation and nucleate boiling heat transfer University of California Santa Barbara, USA 26 775 792 2002
- CRITICAL HEAT FLUX Wikipedia, the free encyclopedia http://en.wikipedia.org/wiki/Critical_heat_flux Abril 2015
- LIN , P.H , FU , B. R. and PAN C. Critical heat flux on flow boiling of methanol-water mixtures in a diverging microchannel with artificial cavities Int. J. Heat Mass Transfer 2011
- OBUKHOV , S. G. Burnout heat transfer in boiling under conditions of stepwise heat generation Journal of Engineering Physics and Thermophysics, UDC 621.039.517 74 3 2001
- NISHIO , S. , GOTOH , T. and NAGAIB , N. Observation of boiling structures in high heat-flux boiling International Journal of Heat and Mass Transfer 41 1998 3191 3201 1998
- FLEX START Robert Bosch Website www.flexstart.com.br May 2015
- FLEX FUEL Robert Bosch Website http://www.bosch.com.br/br/autopecas/produtos/injecao/flex_fuel.asp May 2015
- DE OLIVEIRA JUNIOR , F. , LEPSCH . F. , COLETTO T. Ethanol Sensor using the Critical Heat Flux (CHF) principle SAE Brazil Congress
- LEDER , M.M. Unburned Ethanol Emissions Reduction Using a Fuel Heating System Engine-Expo 2014 Novi Michigan, USA
- POMALESKI , D. R. M. ; CONTI , E. W. Emissão de Compostos Orgânicos por Veículos Flexfuel de Acordo com Diferentes Regulamentações XVII Congresso e Exposição Internacional de Tecnologia da Mobilidade 2008 São Paulo 2008