Research On Simulation Of High-pressure Common Rail Electronic-controlled Diesel Injection System

With the future emission legislation challenging goals will be defined for Diesel engine manufactures. Lowest emissions with highest engine performance, low noise level, low fuel consumption and attractive costs are defining the targets of their development activities for future engine. A fuel injection system assists this development and becomes the decisive factor to reach targets. The electronic-controlled high-pressure common rail diesel injection system is more effective in emission reduction and engine performance improvement among all of the fuel injection system currently. This new system has the features of adjustable injection pressure, injection quantity and injection rate.This paper introduces the advantages of the high-pressure common rail fuel injection system, the domestic and foreign researches; and the components of system and how they work in detail. With the simulating calculation and experiment, the detail analysis has been done on injection characteristic and dynamic pressure characteristic inside rail. First, the numerical models of high-pressure pump, rail and injector is founded, using the calculating method of model unit, the simulating model is developed. By experimented on the optimum common rail system on the fuel pump test bench, the results of test are compared with simulation results; their whole changing trends are similar. It is considered that the model can reach simulating goal and request.Then the influence of different parameters (start of injection, pulse duration of injection, construction parameter of injector etc.) on injection characteristic and dynamic pressure characteristic is gotten with a parameter changed independently and simulated. Through the simulation, it provides the necessary basis for future design and improvement.