G0700507 Effect of Fuel Injection Conditions during Cold-Starting on Ignition Quality and Startability of Diesel Engine

Abstract

The effect of fuel injection conditions during cranking period on cold startability of DI diesel engine under low-temperature condition was evaluated experimentally. Injection strategy during cranking period was two-stage injection consisting of a pilot injection and a main injection. The main injection timing was fixed at 9 deg. BTDC, and the pilot injection timing was changed from 15 to 35 deg. BTDC. Allocation of injection quantity to the pilot injection and the main injection was changed between 5:95 and 25:75. Dynamic strain of glow plug was measured for evaluation of ignition quality. Cold startability resulting from the ignition quality was good when the pilot injection timing was late and the pilot injection rate was 15-20 %. Furthermore, temporal variation of aldehyde emissions during engine warm-up was obtained. Aldehyde emission was relatively high when the pilot injection timing was 35 deg. BTDC.