Vaporization modeling of petroleum–biofuel drops using a hybrid multi-component approach

Abstract Numerical modeling of the vaporization characteristics of multi-component fuel mixtures is performed in this study. The fuel mixtures studied include those of binary components, biodiesel, diesel–biodiesel, and gasoline–ethanol. The use of biofuels has become increasingly important for reasons of environmental sustainability. Biofuels are often blended with petroleum fuels, and the detailed understanding of the vaporization process is essential to designing a clean and efficient combustion system. In this study, a hybrid vaporization model is developed that uses continuous thermodynamics to describe petroleum fuels and discrete components to represent biofuels. The model is validated using the experimental data of n-heptane, n-heptane–n-decane mixture, and biodiesel. Since biodiesel properties are not universal due to the variation in feedstock, methods for predicting biodiesel properties based on the five dominant fatty acid components are introduced. Good levels of agreement in the predicted and measured drop size histories are obtained. Furthermore, in modeling the diesel–biodiesel drop, results show that the drop lifetime increases with the biodiesel concentration in the blend. During vaporization, only the lighter components of diesel fuel vaporize at the beginning. Biodiesel components do not vaporize until some time during the vaporization process. On the other hand, results of gasoline–ethanol drops indicate that both fuels start to vaporize once the process begins. At the beginning, the lighter components of gasoline have a slightly higher vaporization rate than ethanol. After a certain time, ethanol vaporizes faster than the remaining gasoline components. At the end, the drop reduces to a regular gasoline drop with heavier components. Overall, the drop lifetime increases as the concentration of ethanol increases in the drop due to the higher latent heat.

[1]  X. Chesneau,et al.  Comparison of multicomponent fuel droplet vaporization experiments in forced convection with the Sirignano model , 1998 .

[2]  Jorge M. M. Barata,et al.  Modelling of biofuel droplets dispersion and evaporation , 2008 .

[3]  W. Sirignano,et al.  Fluid Dynamics and Transport of Droplets and Sprays , 1999 .

[4]  P. Dagaut,et al.  VAPORIZATION AND OXIDATION OF LIQUID FUEL DROPLETS AT HIGH TEMPERATURE AND HIGH PRESSURE: APPLICATION TO N-ALKANES AND VEGETABLE OIL METHYL ESTERS , 2004 .

[5]  Avinash Kumar Agarwal,et al.  Biodiesel Development and Characterization for Use as a Fuel in Compression Ignition Engines , 2001 .

[6]  Octavio Armas,et al.  Effect of biodiesel fuels on diesel engine emissions , 2008 .

[7]  Van P. Carey,et al.  The properties of gases & liquids: 4th Edition. Robert C. Reid, John M. Prausnitz, and Bruce E. Poling, McGraw-Hill Book Company, New York, NY, 1987, 741 pages, $49.50. , 1988 .

[8]  A. A. Amsden,et al.  Efficient multicomponent fuel algorithm , 2003 .

[9]  Yangbing Zeng,et al.  Multicomponent-Fuel Film-Vaporization Model for Multidimensional Computations , 2000 .

[10]  Céline Morin,et al.  Droplet vaporisation characteristics of vegetable oil derived biofuels , 2000 .

[11]  S. Kong,et al.  Modeling of multi-component fuel vaporization and combustion for gasoline and diesel spray , 2009 .

[12]  W. Hallett,et al.  A continuous thermodynamics model for multicomponent droplet vaporization , 1995 .

[13]  Chung King Law,et al.  A d2-Law for Multicomponent Droplet Vaporization and Combustion , 1981 .

[14]  Wenmiao Chen,et al.  A study on emission performance of a diesel engine fueled with five typical methyl ester biodiesels , 2009 .

[15]  S. Sazhin Advanced models of fuel droplet heating and evaporation , 2006 .

[16]  Josette Bellan,et al.  Direct numerical simulation of a transitional temporal mixing layer laden with multicomponent-fuel evaporating drops using continuous thermodynamics , 2004 .

[17]  H. Mongia,et al.  Multicomponent and High-Pressure Effects on Droplet Vaporization , 2002 .

[18]  Avinash Kumar Agarwal,et al.  Biofuels (alcohols and biodiesel) applications as fuels for internal combustion engines , 2007 .

[19]  S. Jayaraj,et al.  Performance and emission evaluation of a diesel engine fueled with methyl esters of rubber seed oil , 2005 .

[20]  Rolf D. Reitz,et al.  A vaporization model for discrete multi-component fuel sprays , 2009 .

[21]  A. Hansen,et al.  Vapor pressure and normal boiling point predictions for pure methyl esters and biodiesel fuels , 2005 .

[22]  S. Wittig,et al.  Experimental and theoretical study of one- and two-component droplet vaporization in a high pressure environment , 1999 .

[23]  M. Ramos,et al.  Influence of fatty acid composition of raw materials on biodiesel properties. , 2009, Bioresource technology.

[24]  J. Bellan,et al.  Modeling evaporation of Jet A, JP-7, and RP-1 drops at 1 to 15 bars , 2004 .

[25]  W. Hallett A simple model for the vaporization of droplets with large numbers of components , 2000 .

[26]  G. Brenn Concentration fields in evaporating droplets , 2003 .

[27]  Younis Jamal,et al.  A review of biodiesel as vehicular fuel , 2008 .

[28]  W. Sirignano,et al.  Droplet vaporization model for spray combustion calculations , 1989 .

[29]  Alan Christopher Hansen,et al.  PREDICTING THE PHYSICAL PROPERTIES OF BIODIESEL FOR COMBUSTION MODELING , 2003 .

[30]  W. Sirignano,et al.  Multicomponent-liquid–fuel vaporization with complex configuration , 2008 .