Comparison of Three Types of Common Rail Systems Suited for Diesel Engines From 1 to 5 Megawatt

The basic physical law governing the injection in Common Rail Systems is the compressibility of the fuel. The effects of pressure wave dynamics, the layout of the system volume and its geometrical distribution strongly affect the injection events at every injector. In this Paper, three different arrangements of system volumes and their effect upon the performance of the individual injectors are compared using the hydraulics simulation tool AMESim. Two systems are known in the passenger car and the heavy duty diesel engine domains. The third system is new and takes advantage of pressure wave dynamics to tailor the injection event. This system is best suited for Diesel Engines with a power from 1 to 5 MW, as used in locomotives, ships, power generation and heavy earthmoving machinery. It produces a more favorable pattern of the injection pressure and injection rate shape during any injection event by hydraulically interconnecting the individual injector’s accumulators during the injection and taking advantage of pressure wave dynamics. Right after the end of each injection, dynamic pressure pulsations are evened out with a dampening device. A multi-cylinder system provides equal conditions for all injections. Its very simple design and increased performance makes the novel system of very attractive use in the above mentioned fields.