Application Of Simulation To Design Of Electronic-Controlled High-Pressure Common Rail Diesel Injection System

Diesel engine manufactures are faced with increasingly stringent emissions regulations. Lowest emissions with highest engine performance, low noise level, low fuel consumption and attractive costs are the targets of their future engine development. The 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 emissions reduction and engine performance improvement among all of the fuel injection systems 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. Aiming at CA6DF2 engine of Wuxi Diesel Engine Works affiliated to China FAW Group Corporation, a new common rail fuel injection system of intellectual property is studied and developed.Using numerical simulation and experiment, the detailed analysis has been done on injection characteristics and dynamic pressure characteristics inside rail. First, the physical and mathematic models of high-pressure pump, rail and injector are founded. Using module numerical method, the simulating model is developed. Then the influence of different parameters, such as rail pressure, construction parameter of rail, start of injection, pulse duration of injection, construction parameter of high-pressure line and injector, on injection characteristics and dynamic pressure characteristics is gotten. The simulation provides the optimum parameters and the necessary basis for injection system design and improvement.An experiment on the numerically-optimum common rail system is conducted on a fuel pump test bench. The measured results are compared with the simulation results. They are in agreement on general changing trends. So the above models can meet the simulation needs of electronic-controlled high-pressure common rail diesel injection system.