Combustion Performance and Emission Characteristics of a Diesel Engine Using a Water-Emulsified Heavy Fuel Oil and Light Diesel Blend

Using low price heavy fuel oil (HFO) in high-speed diesel engines is a practical way to reduce running costs. However, most high-speed diesel engines’ fuel systems and combustion systems cannot adapt to HFO. This causes the problem of deterioration of combustion performance. In order to solve this problem, the authors have modified the fuel injection system and combustion system of a high-speed diesel engine to use HFO. In addition, reducing the viscosity of HFO is necessary before it is fed into the engine. Because heating apparatus are not feasible for high-speed engine users, light diesel was blended with HFO to reduce the fuel viscosity. The blend is called HFO-L. Meanwhile, for the purpose of further reducing NOx emissions and soot emissions, water-emulsified HFO-L, named HLW, was used on the research engine. When fueled with 10% water content HLW, the engine presented the same power performance and thermal efficiency as the baseline engine fueled with light diesel. Due to the low price of HFO, the fuel economy of the engine was greatly improved. In addition, fueling HLW led to a considerable reduction of the engine’s NOx emissions compared with the baseline engine.