Research On Injection Characteristics Of The WP12 High Pressure Common Rail Fuel System

To meet the increasingly stringent emission and noise regulations, high pressure common rail fuel injection technology, has gradually attracted widespread attention as the most advanced electronically controlled fuel injection technology. The advantages of the high pressure common rail fuel injection technology consist of the low fuel consumption, low emission, low noise, high power and high injection pressure. It can achieve independent control of fuel injection timing and fuel injection quantity. In addition, it can realize a pre-spray or a post-spray under different circumstances to better organize of combustion. As a result, it can increase the engine power and fuel economy. What’s more, it is an effective technology of emissions control. Based on a large number of researches, this paper proposed an improved high-pressure pump optimization after in-depth study of the high-pressure common rail fuel injection characteristics of the system. The main work includes the following aspects:The working principle of high pressure common rail fuel system has been analyzed, and the mathematical model has been established. In order to get reasonable and accurate simulation results, the high-pressure common rail fuel system has been simplified. Then, the simulation models of high pressure pump and common rail injector was built based on hydsim software.On the basis of the experimental research, used the experimental results proved the correctness and rationality of the simulation models. Afterwards, the influence of different structural parameters on the fuel injection characteristics has been analyzed.The design of high-pressure pumps has been optimized using three factors and three levels orthogonal analysis method. Furthermore, the primary and secondary order of the three factors on the high-pressure fuel supply efficiency and peak torque has been identified. Then, the optimal solution has been discovered considering the overall performance of the high-pressure pump. Finally, the optimization program has been compared with the original, and its oil properties have been analyzed at different speeds and different rail pressures.On the basis of the experimental research, the error sources of the experimental and simulation data have been analyzed. When analyzing the camshaft peak torque of the experimental and simulation data, it has been discovered that the measured torque is indicated torque while the torque obtained by simulation is effective torque. Indicated torque not only includes the effective torque but also includes a torque generated by friction between the test benches and the camshaft. Before comparing peak torque of experimental and simulation data, the effective torque should be calculated from the experimental data in advance.