基于均匀性要求的多点喷射气体机燃气喷射结构设计研究

Structural Design of Gas Injection for Multi-point Injection Gas Engine Based on Uniformity Requirements

目前国内多点喷射气体机已作为动力主机成功应用到船用市场。虽然相对于预混合式气体机,多点喷射技术提高了发动机的动态响应性,减少了甲烷逃逸,但如果燃气喷射结构设计不合理,将会带来发动机工作均匀性和动态响应性不能满足使用工况的问题。针对该问题,在河柴某V12机型上,基于各缸工作均匀性要求设计了一种新型燃气喷射结构,将高压燃气直接引入到进气道内,使燃气能以更高的压力和速度进入缸内进行燃烧。此外,为避免燃气提前进入进气总管与空气混合,利用ANSYS-Fluent仿真软件对燃气喷射进行了仿真分析和验证研究,建立了燃气进气结构有限元模型,得到燃气在不同出口位置下的流线图,最终确定燃气喷射的最优方案。

At present, the domestic multi-point jet gas engine has been successfully applied to the marine market as a power engine.Although compared with the premixed gas engine, the multi-point injection technology improves the dynamic response of the engine and reduces the escape of methane, if the design of the gas injection structure is unreasonable, it will lead to the problem that the working uniformity and dynamic response of the engine cannot meet the operating conditions. To solve this problem, on a V12 model of Henan diesel engine industry, a new fuel gas injection structure is designed based on the requirements of the working uniformity of each cylinder. The high-pressure fuel gas is directly introduced into the inlet port, so that the fuel gas can enter the cylinder for combustion at a higher pressure and speed. In addition, in order to avoid the gas entering the intake manifold to mix with the air in advance, the simulation analysis and verification research of gas injection are carried out by using ANSYS fluent simulation software, the finite element model of gas intake structure is established, the streamline diagram of gas at different outlet positions is obtained, and finally the optimal scheme of gas injection is determined.