Medium speed engine application of a piezo electric actuated fuel injection valve

Abstract

Significant efforts are spent in the medium speed diesel engines industry to over-come the limitations encountered with solenoid actuated injection valves, which are not capable of modulating their operation but can only be forced to be fully open or fully closed. In parallel, research on piezo electric actuators begins to offer attractive products even for large engines applications. While some promising experimental result is achieved on standalone injectors, there is no system in place to test these performances on a real engine. The present work aims at filling this gap, by providing a study on how the experimental setup needs to be expanded in order to achieve its full integration in the existing Engine Automation and Control System. The work is conducted in two parts, the first of them dealing with a study of the host system and of the experimental piezo driver to be integrated in it. In this part both systems are analysed and the features that are relevant in an integration per-spective are explored in greater detail, providing all the necessary information in order to elaborate on the subsequent steps, with special focus on the identification and prioritisation of the requirements. The second part consists of the engineering of an upgraded system, where the host environment is equipped with all the func-tionalities needed to support the piezo electric actuated injectors. This part elabo-rates from the considerations on the general technical aspects that have to be ad-dressed, in order to define and explain the strategic choices deriving from them, also based on the target working environment. Among the results are the designs of the power supply architecture and of the control logic handling the most impor-tant functions of the piezo driver.