Performance and durability analysis of a single-cylinder direct injection diesel engine operated with water emulsified biodiesel-diesel fuel blend

In this work, reliability of using water emulsified biodiesel-diesel fuel blend in diesel engine for prolonged period was investigated. For this, experiments were conducted to evaluate the combustion, performance and emission of a 10 kW, single-cylinder, 4-stroke, water-cooled direct injection (DI) diesel engine using water emulsified biodiesel-diesel fuel blend PB20S10W (89% v/v B20 + 10% v/v water + 1% v/v surfactants), B20 (20% v/v palm biodiesel + 80% v/v diesel) and high speed diesel (HSD). Engine wear and lubricant contamination characteristics were also investigated for the same engine by running it for 100 h. The test results showed that PB20S10W had longer ignition delay (1.78-6.30%) and higher heat release rate than those obtained with B20 and HSD for all engine loadings tested. PB20S10W showed higher BSFC than B20 and HSD at all engine loads. At higher loads, PB20S10W and B20 showed 4.83-5.14% and 1.41-4.527%, higher BTE respectively, than that with HSD. Reduced CO (up to 16.59%) and HC (up to 24.56%) along with a little increase in CO2 (up to 20%) were observed for both B20 and PB20S10W as compared to HSD. PB20S10W showed the lowest NOx emissions (up to 13.80%) among all the tested fuels. As compared to HSD fuelled engine, 16.94 and 14.45% lesser soot deposits on cylinder head and piston crown respectively, and 0.48-28.57% lower concentrations of Cu, Zn, Fe, Mg and Mn in the lubricating oil of the engine were found with PB20S10W fuelled engine due to its better combustion and additional lubricity.