Investigation of intake pressure and fuel injection timing effect on performance characteristics of diesel engine

Abstract

The low fuel consumption and efficient power usage in diesel engine has made diesel engine as the more appealing option in comparison with other type of engines. To raise the performance of DI (direct injection) diesel engine further, injection timing and intake pressure variation were studied under 2000 RPM (rotation per minute) engine rotation. This experiment used DI diesel engine with single cylinder. The length of stroke was set to 96.9 mm, the diameter of bore was set to 85 mm and the compression ratio of the engine was 16.3. The variations of main injection timing were set for 1° after TDC (top dead centre) as advanced injection timing, and 3° after TDC as retarded injection timing. Boost pressures for intake pressure were varied with 20 in increments and started from 0 KPa to 60 KPa. In-cylinder pressure characteristics and heat release rate were used to evaluate the engine performance. The experiment indicated, as the boost pressure raises, the heat release rate and in-cylinder pressure are increased. The main injection timing advancement from 3° after TDC to 1° after TDC causes increase to the peak of in-cylinder pressure after TDC in DI diesel engine. This phenomenon is due to the slower combustion in retarded injection timing. For heat release rate, the advancement of injection timing causes the differences between various intake pressures to be more apparent.