Effect of Fuel Injection Conditions during Cold-Starting of Diesel Engine on Startability and Exhaust Emissions

Abstract

The effect of fuel injection conditions during cold-starting at －25 ℃ of DI diesel engine on startability and exhaust emissions was evaluated experimentally. Injection strategy during cranking period was two-stage injection consisting of a pilot and a main. Dynamic strains of glow plugs were measured for evaluation of the ignition quality. Furthermore, temporal variations of hydrocarbon and aldehyde concentrations during engine warm-up were obtained. Cold startability and ignition quality were good when the pilot injection timing was later and the fraction of pilot quantity was 15 or 20 %. Exhaust emission was relatively high when the pilot injection timing was earlier.