Combustion and Performance Analysis of a CI Engine Fuelled with Soybean Oil Biodiesel Blends

In the present experimental investigation, comparative analysis of combustion and performance characteristics of a DI diesel engine fuelled with diesel and soybean biodiesel blends was done. Biodiesel was produced through catalytic transesterification method and its blends with diesel were prepared in various concentrations (B10, B20 and B30) by volume. In BX blend, X indicates percentage concentration of the biodiesel in the diesel fuel. Analysis of various combustion and performance parameters such as in-cylinder pressure, rate of pressure rise, net heat release, ignition delay period, brake thermal efficiency and brake specific fuel consumption were performed at different engine loads (20, 40, 60, 80 and 100%) keeping constant the engine speed. Combustion parameters obtained are the averages of five engine cycles. It is observed that with increasing loads, higher values of various combustion parameters are found for all fuels. Results indicated better combustion and performance parameters at full engine load for all fuels. Increase in biodiesel concentrations result in higher in-cylinder pressure, net heat release, rate of pressure rise and lower ignition delay periods at full load. It is found that at full load condition, S30 and S20 blend have shown improved combustion over S10 blend. There has been a marginal improvement in performance parameters for S10 blend at full load.