Combustion analysis of the diesel-biogas dual fuel direct injection diesel engine- the gas diesel engine

In this investigation, biogas (BG) was used as an alternative fuel in a single-cylinder, four-stroke, air-cooled, direct injection (DI) diesel engine that was operated on a dual fuel mode. Biogas was produced from a nonedible seed de-oiled cake-pongamia pinnata (Karanja), which was collected from the biodiesel industries. The BG was inducted along with the air in suction of the engine at four different flow rates varying from 0.3 kg/h to 1.2 kg/h in steps of 0.3 kg/h. The investigation results revealed that BG inducted at a flow rate of 0.9 kg/h gives better combustion characteristics of engine behaviour than those of other flows throughout the engine operation. The ignition delay (ID) and combustion duration of the engine run by dual fuel operation at a BG flow rate of 0.9 kg/h were found to be longer by about 2 degrees CA and 2.9 degrees CA, respectively, in comparison with diesel at full load. The cylinder peak pressure was found to be overall higher by about 11 bar than that of diesel at full load.