Simulating Calculation And Investigation On Electronic-Controlled Common-Rail Injection System Of Diesel

This paper introduces a new kind of hydraulic intensified common-rail (CR) system, which is developed through the analyses of various common-rail systems in detail on the basis of the experiment analysis and simulating calculation of the accumulated common-rail system. This new system has the features of adjustable injection pressure, injection quantity and injection rate. The detail analysis on this system has been done with the simulating calculation and experiment.In this new kind of hydraulic intensified common-rail (CR) system, a kind of working medium was used for intensification and injection. The additional mechanism is not needed. Through the usage of the present variable solenoids the precise control of injection process were realized successfully. The independent controlling of the injection pressure could be realized. In this system, the adjustment of the injection quantity could be realized through the controlling of the pressure in the common-rail system and the dwell time of solenoid, to meet the need of the diesel.The 3-D simulation method of unsteady flow is used in the simulation and analysis of the fuel injecting system of diesel. Using 3-D simulation the fields of the fuel pressure and the fuel flow speed in the common-rail are calculated. It is raised to simplify calculation model by using the mean value in the common-rail. It has laid down a theoretical foundation for the fuel flow calculation in a large volume of the common-rail system by using simplified 1-D calculation. The effects of the constructive parameter of the common-rail on the fuel pressure fluctuation are calculated and analyzed.Using the calculating method of model units, the simulating model of the injector of the accumulated common-rail system is developed. Using this model, the injecting process of this system is simulated and analyzed. The effects of some factors on the injecting process are calculated and analyzed.The simulating model of the injector of the hydraulic intensified common-rail system is developed. Using this model, the injecting process of this system is simulated. The effects of the constructive parameters of injector on the injecting process are calculated and analyzed. With calculating and analyzing, the problem ofabnormal hydraulic fluctuation is solved, which appears in experiment.These models developed in this thesis are proved to be precise by the results of test. By using these models to calculate and analyze the injecting process with different parameters, it will provide the valuable basis for improving and perfecting the injector of hydraulic intensified common-rail system.