Effort at Using 20% Biodiesel in IC Engines: A Study with Enhanced Intake Pressure and Different Injector Nozzle Configurations

The paper examines if higher efficiency could be gained while using 20% biodiesel in IC engines, by enhancing the intake pressure and using different injector nozzle configuration. The performance, combustion and emission characteristics of a four stroke compression ignition engine running on Pongamia methyl ester blend with diesel as fuel have been examined with normal induction and enhanced intake pressure conditions with three different fuel injectors having different nozzle hole numbers and sizes. The performance and combustion parameters such as brake thermal efficiency, exhaust gas temperature, air fuel ratio, ignition delay, peak cylinder pressure and emission parameters such as NOx and smoke opacity have been discussed in this work. Based on the data generated it is observed that the performance and smoke emission have improved with enhanced intake pressure in comparison to normal intake conditions for all injector nozzle configurations. The data reveal that the enhanced intake pressure is more effective for biodiesel blend compared to diesel. From the study it is found that best brake thermal efficiency of 34.6% is obtained with 3 hole fuel injector at full load for B20 blend under enhanced intake pressure, which is 6% higher than that for normal intake conditions at the same load. Changing the fuel injector configurations did not result in improvement in performance of the engine compared to normal injector at the enhanced intake pressure considered for this study, but indicated the need to increase the boost pressure further, when injectors with increased nozzle hole number/size are used.