Effect of fuel injection strategies on the performance of the common rail diesel injection (CRDI) engine powered by biofuel

The effects of fuel injection strategies on the characteristics of common rail diesel injection engine using mahua methyl ester (MME20) blend have been investigated. Fuel injection strategies such as fuel pressure and split injection have been implemented on a test engine. When MME20 was used as the fuel on mechanical injection at an injection pressure of 22 MPa, specific fuel consumption and NOx emission were found to be increased and brake thermal efficiency (BTE) decreased. In the first phase, in order to optimise the utilisation of the mahua methyl ester blend, fuel injection pressure was increased from 20 to 50 MPa with an increment of 10 MPa. The experimental observation reveals that high fuel injection pressure (50 MPa) exhibits higher BTE and better combustion characteristics when compared with decremented injection pressures. HC, CO and smoke level decreased with an increase in injection pressure due to better-atomised spray and mixture formation. In the second phase, implementation of spilt injection 5% MME20 as pilot injection at 5 degrees, 10 degrees and 15 degrees CA before main injection was identified with the decrease of HC, CO, NOx and smoke emission with marginal sacrifice of BTE compared with diesel fuel.