Effects of Fuel Injection Rate on Combustion and Emission in a DI Diesel Engine

Fuel injection rate pattern represents an important factor for emissions reduction. In this study, fuel spray photography, combustion photography and experimental data analysis indicate.

1. 1)
   effect of pilot injection
2. 2)
   effect of a gradual shaped injection profile using nozzle needle lift control
3. 3)
   effect of a boot shaped injection profile using pressure control

Common rail type fuel injection equipment was used in these experiments, and the engine was single cylinder naturally aspirated D.I. diesel engine.

As a result, we found out that it is important to control the pre-mixed combustion for NOx reduction and to activate the diffusion combustion for smoke, and various fuel injection rate patterns we studied have similar effect on combustion and emissions at the most suitable condition respectively.