EXPERIMENTAL INVESTIGATION OF USING EMULSION FUELS AS ALTERNATIVE FUELS IN A DIRECT INJECTION DIESEL ENGINE

The effects of water-diesel fuel (WD), methanol-diesel fuel (MD), and methanol- water-diesel fuel (MWD) emulsions on the performance and exhaust emissions characteristics of a DI diesel engine were experimentally investigated in this study. In this work four cylinders, naturally aspirated, four cycle, DI diesel engine was used. The test results indicated that water-diesel fuel emulsion leads to a considerable reduction of nitrogen oxides (NOx), and smoke emissions, As well as lower values of oxygen (O2), unburned hydrocarbon (HC), brake specific fuel consumption (BSFC), and exhaust gas temperature, while the brake thermal efficiency (BTE) increased, with a growth of water content in the emulsified fuel, over the wide range of engine operation in comparison with that of neat diesel fuel operation. A model has been developed and was effectively used to estimate smoke density and BSFC at various water percentages in the fuel emulsion and engine load at rated engine speed. The smoke density and BSFC prediction values agreed with the experimental results. The results also showed that the high methanol percentages in fuel-emulsion caused a reduction in both smoke and CO emissions with lower BSFC level while NOx and BTE increase under all engine operating conditions. Furthermore, adding up to a 4 percent of water to a methanol-diesel fuel emulsion showed improved engine performance compared to methanol-diesel fuel blend at a methanol blended ratio of 10 percent.