Future emission standards for heavy duty diesel engines will require extensive development using an integrated approach. This paper describes the latest results from HINO heavy duty diesel engine combustion research program.
Improvement of the NOx/particulate/fuel economy trade off requires fuel injection equipment of Pump Line Nozzle (PLN) System and unit injector with high pressure capability, injection rate control and timing control, and a combustion system matched with high pressure injection.
Combustion characteristics (ignition delay, combustion period, heat release curve), fuel consumption, particulate, and exhaust gas emission of each injection system are compared and discussed.
The unit injector system has an advantage of lower particulate level, especially dry soot, than the Pump Line Nozzle system.
The potential for further improvement through engine modification and aftertreatment is also discussed.