Implementation of a non-surfactant water-in-diesel emulsion fuel in a common rail direct injection diesel vehicle.

Abstract

Water-in-diesel emulsion fuel has become a popular alternative fuel for diesel engines. The main limitation is related to its stability, whereby it relies heavily on surfactants to remain homogeneous, therefore causing production costs to rise. This paper highlights the application of real-time non-surfactant emulsion fuel supply system (RTES), a water/diesel emulsifying device without surfactants, to produce water-in-diesel emulsion fuel in a common rail direct injection diesel engine powered vehicle. In this study, RTES was installed near to the diesel fuel pump to ensure water-in-diesel emulsions were continuously fed to the engine. The test vehicle was set up on a roller dynamometer and operated following a modified West Virginia University (WVU) 5-Peak cycle. Fuel consumption and exhaust emissions were measured to determine the optimum water percentage of emulsion fuel and suitable timing for emulsion fuel to be introduced into the fuelling system based on the vehicle speed. The results revealed that the optimum water percentage of the emulsion fuel for the test vehicle is 10 wt%, as it was capable to reduce fuel consumption as well as nitrogen oxides and smoke emissions of a common rail direct injection diesel engine powered vehicle.