Abstract:

Singlefactor adjustment tests for the fuel injection parameter optimization were performed on a CA6DL235E3 heavyduty common rail diesel engine with the basic Euro3 injection maps by means of the INCA calibration tool, and the influences of the fuel injection parameters  on the airfuel mixing and combustion were analyzed comprehensively with the help of the microscopic field histories found by the software STARCD. The results show that boosting the injection pressure(single injection) enhances the airfuel mixing rate, and improves all performance indexes except NOx emission. Introducing the post injection(triple injections), decreasing the time interval between the main and the post injections under the prerequisite of sufficient oxygen in the spray vicinity, and selecting the proper quantity of post injection to reinforce the disturbance of the airfuel mixture at the late phase of fuel injection, can realize the control over the airfuel mixing during the whole combustion process to achieve the engine performance optimization.

Key words: power machinery and engineering, diesel engine, airfuel mixing, combustion process, multiple injection, numerical simulation, exhaust emission