船用低速柴油机电控喷油器预喷射对主喷射循环喷油量的影响

摘要

喷油器进行多次喷射时,不同喷射之间会产生相互影响,导致循环喷油量随着喷射间隔(dwell time, DT)的变化产生波动,给柴油机油量的控制增加了难度。本文根据船用低速柴油机电控喷油器的概念设计,利用AMESim 仿真平台搭建了喷油器的数值仿真模型,研究预喷射对主喷射循环喷油量的影响,揭示出预喷射引起的喷油器内部的压力波动是导致主喷油量随 DT 波动的根本原因。分析控制阀杆最大升程、控制腔进油孔直径、控制腔出油孔直径和喷孔直径等4个特性参数对主喷油量波动规律的影响,得出参数变化主要影响主喷油量的波动幅值和相位的结论。%In the process of multiple injection, different injections have influences on each other, and it lead to fluctuation on cycle fuel injection with DT. This enhances difficulty of controlling fuel quantity. Simulation model of injector was established in AMESim environment according to the conceptual design of low-speed marine diesel engine. Influences of pilot injection to main fuel injection quantity were studied, and it showed the pressure wave fluctuation is the fundamental reason what leads to the fluctuation of main injection quantity with DT. Impacts on variation law of main fuel injection quantity with DT of control valve rod maximum lift, control chamber inlet hole diameter, outlet diameter and nozzle diameter were analyzed in details. And the conclusion was obtained that variation of characteristic parameters impacted on fluctuation range and phase of main fuel injection quantity. Affect degree of different parameters was also summarized.