Technical Paper
Experimental Investigation of the Effect of Needle Opening (NOP) Pressure on Combustion and Emissions Formation in a Heavy Duty DI Diesel Engine
2004-10-25
2004-01-2921
This paper presents an investigation of the effects of varying needle opening pressure (NOP) (375 to 1750 bar), engine speed (1000 rpm to 1800 rpm), and exhaust gas recirculation (EGR) (0% to 20 %) on the combustion process, exhaust emissions, and fuel consumption at low (25 %) and medium (50 %) loads in a single cylinder heavy duty DI diesel research engine with a displacement of 2.02 l. The engine was equipped with an advanced two-actuator E3 Electronic Unit Injector (EUI) from Delphi Diesel, with a maximum injection pressure of 2000 bar. In previous versions of the EUI system, the peak injection pressure was a function of the injection duration, cam lift, and cam rate. The advanced EUI system allows electronic control of the needle opening and closing. This facilitates the generation of high injection pressures, independently of load and speed.
