ID 278

Spray Characteristics of Methanol-in-Diesel Emulsions

 

Abstract:

The objective of this study is to investigate spray characteristics of methanol-in-diesel emulsions using a common rail diesel injection system under evaporating conditions. Studies in the literature have reported that alcohol–diesel fuel blends reduce the engine emissions without any serious impact on engine performance. However, it is important to understand the effect of alcohol–diesel fuel blends on the atomization and evaporation processes in sprays, which play an important role in air-fuel mixing. As methanol(CH3OH) is immiscible with diesel, two emulsifiers, Span-80 (sorbitan mono-oleate) and Tween-80 (Polyoxyethylene sorbitan mono-oleate) were used to make a stable emulsion of methanol and diesel The effect of emulsion on spray characteristics is studied for various mixing ratios of methanol and diesel. A constant volume chamber with optical access was used to create engine-like conditions of 50 bar and 900 K. Nitrogen gas was used to pressurize the constant volume chamber and to avoid combustion. Experiments were conducted at fuel injection pressures of 500 bar, 1000 bar, and 1500 bar. The shadowgraphy technique has been used to measure liquid penetration, vapor penetration of methanol-in-diesel emulsion sprays. The data on liquid & vapor penetration of the emulsions are compared with those of diesel to understand the effect of blend ratio of methanol on the fuel spray characteristics.