高压共轨多次喷射油量波动现象分析

Analysis on Multiple-Injection Fuel Quantity Fluctuation for High Pressure Common Rail System

采用实验测量与数值模拟研究相结合的方法,研究了共轨燃油喷射系统动力学的基本原理,重点关注多次喷射过程中,水击现象造成的随间歇时间变化的喷射油量波动现象.利用AMES im软件建立的高压共轨燃油系统模型进行仿真,分析了多次喷射过程中,水击压力波动影响下的喷油器控制腔、蓄压腔液力过程和控制球阀、针阀运动规律.结果表明,高压共轨多次喷射油量波动是由于水击压力波动对针阀运动特性和喷射压力产生的周期性综合影响造成的.

By an integrated numerical-experimental approach, fundamental aspects of CR system dynamics were investigated, paying specific attention to the multi-injection fuel quality fluctuation induced by water hammer with dwell time （DT）. The model of high pressure common rail injection system model was built based on AMESim package and the simulation was implemented using the data of experimental injection rate. The hydraulic process of control chamber and delivery chamber, as well as the lift process of pilot and needle valve were simulated and analyzed under the impact of water hammer wave. It is summarized that the multi injection fuel quantity fluctuation is caused by synthetic cyclical factors of needle opening and closure delays, and injection pressure due to the impulse of water hammer.