天然气发动机高压共轨系统的建模与仿真研究

根据天然气的气体特性,建立了基于AMeSim的"两级调压"共轨系统模型。为研究天然气发动机高压共轨系统的动态特性,以压力波动幅值为控制目标,综合分析了转速、共轨腔容积、长径比和共轨腔压力等对压力波动幅值的影响,提出了相应的控制策略,并利用MATLAB/Simulink建立了控制系统模型。仿真结果表明,该联合仿真系统能够反映天然气发动机高压共轨系统的实际工作过程,所采用的控制策略能够减小共轨腔中气体压力的波动,为天然气高压直喷发动机的研究奠定了基础。

Study on Modeling and Simulation of High-pressure Common Rail for Natural Gas Engine

The 'two-staged pressure regulation' model of common rail system was built with AMeSim software according to the gas characteristic of natural gas.For researching the dynamic characteristics of high-pressure common rail system for natural gas engine,the influences of speed,common rail volume,aspect ratio and rail pressure on pressure fluctuation amplitude were synthetically analyzed at the controlling aim of pressure fluctuation amplitude,the corresponding control strategy was put forward and finally the model of control system was built with MATLAB/Simulink software.The simulation results show that the simulation system can simulate the actual working process of the high-pressure common rail system for natural gas engine and that the used control strategy can reduce the pressure fluctuation of common rail cavity.Accordingly,the system lays the foundation for researching high-pressure direct injection natural gas engine.