Spray Parameters of Fuel Blends of Recycled Lubricating Oil and Diesel

The use of alternative fuels consisting of mineral and synthetic waste substances such as recycled lubricating oil blended with diesel is a measure to mitigate the environmental impact of the fossil fuels. However, to inject these fuel blends into contemporary engines without changes to their components, it must maintain or improve the fuel injection characteristics compared to neat diesel, in order to maintain or improve the engine performance. In the present research, the spray parameters of injected fuel, such as length, angle and atomization particle diameter in terms of the Sauter mean diameter (SMD), are modeled depending on the characterization of different concentration of the recycled lubricating oil blended with diesel. It was found that the same nozzle geometry of the injectors can provide an equivalent fuel spray performance for different concentrations of these alternative fuel blends, and that the increase of the recycled lubricating oil in the fuel blend reduced the wear of the needle and nozzle of the injector. The densities and viscosities between each fuel type are very similar and any correction of injection duration or pressure is not required. Due to simple distillation and blending process, alternative and environmentally friendly fuel blends can be obtained to reduce the combustion of fossil diesel and reuse waste pollutant substances as a sustainable and immediately applicable solution for modern engines and fuel injection systems.