The Electro-Hydraulic Valve Actuation (EHVA) for Medium-Speed Diesel Engines - Development Steps With Simulations and Measurements

摘要

Electro-Hydraulic Valve Actuation (EHVA) is one of the most promising ways to improve the performance and reduce the emissions of the diesel engines. The EHVA gives fully variable lift and event duration of the gas exchange valves and thus the combustion process can be better controlled in different operation points such as idle and partial load situation. Also totally new kinds of gas exchange processes are possible to achieve. This paper consists of alternative solutions of EHVA systems, the comparison of them by means of simulation and measurements, the empirical tests of EHVA system in a laboratory and finally conclusion and future research activities. The developed EHVA system fulfills the requirements very well. The lift of the gas exchange valve is fast enough, and the seating velocity is under control. The system is able to run with open and closed loop control.