Experimental Investigation of Six Cylinder Turbocharged Di-Diesel Engine Cold Startability

Modern day ECU controlled Compression Ignition Engine, with its lean burn combustion process and with advanced exhaust aftertreatment devices, is the most sought after IC engine today; Due to its low fuel consumption with lowest possible CO₂ emissions. In order to meet these low emission targets, the compression ratio of many of these new generation Diesel engines are kept as low as low as 16:1. Lowering compression ratio has a negative effect on Engine cold start quality and warm-up.

This paper summarizes experimental investigation conducted on an Inline 6 cylinder 5.7 liter Turbocharged Intercooled Direct Injection Diesel Engine with BOSCH Electronic Rotary Fuel Injection Pump (VP37) in a cold chamber to study the effect of injection parameters on combustion instability (and thereby on Cold Cranking), at different (sub-zero) ambient temperatures. Acceptance criterion for cold cranking of Engine was it should start and stabilize within 30sec of the cranking time without visible white smoke emission. Focus of this exercise was to simulate worst case condition and optimize the calibration of FIE (Fuel Injection Equipment) system to facilitate engine cold cranking without cold start aid (Glow Plugs, Intake Air Heaters, Coolant Heaters, and Fuel Heater).