Operation of Piezoelectric Common Rail Injector with Diesel and FT-Kerosene

The paper is devoted to the theoretical and experimental analysis of the piezoelectric injector of a modern common rail system. A detailed one-dimensional dynamic model of the injector is created using AVL software Hydsim. It consists of multiple hydraulic and mechanical components for the modeling of the compressible fuel flow and dynamic motion of the solid parts including elastic deformation. Furthermore, the injector model contains the electro-mechanical description of the piezoelectric stack actuator with the hysteresis behavior. Specific aspects of the piezo-actuator modeling are discussed. Different operating conditions of the injection system are modeled and tested. These conditions are defined for a specific diesel engine and include full and part load cases with multiple pilot and main injections. Two fuel types are chosen for the investigation: conventional diesel and FT-kerosene based on Fischer-Tropsch synthesis. The performance of the injection system is discussed.