Modelling the High-speed Injector for Diesel ICE

Abstract

Abstract. The article describes the results of research on the option of improving the operation speed of the electro-hydraulically driven injectors (Common Rail) for diesel ICE. The injector investigated in this article is a modified serial injector Common Rail-type with solenoid. The model and the injector parameters are represented in the package LMS Imagine.Lab AMESim with the detailed description of the substantiation and background for the research. Following the research results, the advantages of the proposed approach to analysing the operation speed were detected with outlining the direction of future studies. IntroductionIn the fuel injection systems of diesel internal combustion engines (ICE), there is a problem of overcoming the contradiction between the fuel injection laws and ensuring the fuel atomization quality. The characteristics of injection and spraying of fuel depends on the design of the nozzle. The characteristics such as: the geometric characteristics of flow of sprayed fuel, the structure of the fuel flare, the fineness of fuel spraying, a number of other parameters of the fuel supply process. To ensure high-efficiency combustion of fuel and, consequently, to obtain high technical and economic indicators of the diesel, it is necessary to organize a rational mixture formation. The quality of fuel spraying is characterized by its fineness and uniformity. It is necessary to organize the process of jet disintegration so as to obtain a high quality of spraying at all stages of injection, including the initial and final, when there is a low level of fuel pressure in front of the nozzle. A quality atomization requires continuous flow at a high pressure upstream the holes in the atomizer. Compliance with the fuel injection law, i.e. distribution of the crankshaft angle cycle charge in different ICE modes requires a wide flow variation range. The assumed priority of the requirements of the fuel injection law in systems employs variable pressure, including in the Common Rail systems [1,2]. Electrohydraulic injectors (EHI) in these systems are intended for implementing a multicycle injection with the number of cycles and duty ratio being limited by the speed of the injector. Partial limitation of the operation speed is due to the injector flexibility in terms of its operating pressures. The consequence of insufficient operating speed is deviation of the real injection conditions from the requirement [3][4][5].