Application of real-time non-surfactant emulsion fuel supply system for common rail diesel engine

Abstract

Water-in-diesel emulsified fuel (W/D) has become an alternative fuel for diesel engines, as it minimizes harmful emissions. However, its main limitation is the stability issue, which relies on the surfactant to remain stable. Too much reliance on surfactant is more costly than conventional diesel fuel. This research highlights the application of non-surfactant emulsion fuel in a common rail direct injection diesel powered vehicle. To eliminate the dependency on surfactants, a device known as Real-Time Non-Surfactant Emulsion Fuel Supply System (RTES) was used to produce and instantaneously supply W/D into the engine. This study carried out two types of experimental methods: roller dynamometer testing and on-road testing. Exhaust emissions and fuel consumption were measured while the optimal water percentage was also analyzed. The roller dynamometer testing was conducted based on the High Speed Modified WVU 5-Peak Cycle. The base test fuel used during this experiment was Euro 2 diesel (D2), while other test fuels were W/D with different water percentages; 6.4 %, 10 %, 15 %, and 20.6 %. The results from the roller dynamometer testing reveal that the optimum water percentage for W/D in this type of engine is 10 %. The application of RTES has been demonstrated to function well in a common rail diesel engine without stability issue and at the same time has been able to maintain the benefits of emulsion fuel for the road testing and roller dynamometer testing on fuel consumption. Overall, the application of non-surfactant emulsion fuel in common rail fuel injection diesel-powered vehicles shows potential benefits to balance between environmental and economic development.