Characteristics of Preheated Bio-Oils Sprays

Abstract

Global atmosphere pollution has become a serious problem for today. The emissions from the combustion of fossil fuels contribute a notable part to this pollution. Environmental care together with the limited stock and growing prices of fossil fuels has given alternative fuels the potential to supplant a significant portion of fuel for combustion applications such as gas turbine engines and IC engines. Given a widespread of different biofuels available for combustion applications, the present study concentrates on atomization spray characteristics of vegetable oils. Vegetable oils have energy density, cetane number, heat of vaporization, and stoichiometric air/fuel ratio comparable to diesel fuel. Different techniques have been employed so far to improve on the physical properties of biooils and thus opening the doors to clean combustion. The high kinematic viscosity has an adverse effect on the combustion of vegetable oils, posing problems in the associated fuel supply line and injector system. Some well-known techniques to deal with high kinematic viscosity levels of neat vegetable oils include dilution, pyrolysis, micro-emulsion, and trans-esterification. These techniques, however, require additional energy input to improve the physical properties of the fuel. Preheating of the fuel is also one of the ways that reduces the kinematic viscosity to improve the atomization. Preheating is employed in the present study to investigate the spray characteristics in a non-evaporating spray as well as flame spray.