柴油机电控单体泵燃油系统的稳定性研究

Analysis on Stability of Electron-Controlled Unit Pump System for Diesel Engine

利用AMESim软件建立电控单体泵系统仿真模型,与试验数据对比证实仿真模型能够准确预测系统各工况的喷射特性参数。选取典型工况下的不同时刻点对系统进行线性化处理,得出电控单体泵单缸高压喷射系统和多缸高低压耦合系统的特征值分布规律。结果表明:不同工况下同一系统矩阵特征值的分布具有相似的规律,只是随着时间的推移,系统矩阵发生很大的变化。在整个燃油喷射系统的工作过程中,单缸高压喷射系统是一个在喷油过程中处于准稳定状态、其他过程非稳定的系统;而多缸高低压耦合系统则是一个时变、不稳定的高度复杂系统。

An electron-controlled unit pump （EUP） fuel injection system simulation model was established using the software AMESim. Compared simulated and experimental results, it was concluded that the AMESim simulation model can precisely estimate the injection system parameters under all operating conditions. By use of linearization approach, the eigenvalue distributing rules of the high-pressure injection system and the high-low pressure coupling system were achieved based on the model. Results show that the eigenvalue distribution of the same system under different conditions has the similar change rule and the system matrix changes strikingly with the passing time. In whole injection process, the single-cylinder high- pressure injection system is in quasi-stable state during injection, and in extremely unsteady for the rest, but the multi-cylinder high-low pressure coupling system is a highly complex system of time-variation and unstability.