摘要
基于计算流体力学平台CONVERGE以及MATLAB后处理程序,通过数值仿真的方法,研究了船用柴油-天然气双燃料发动机预燃室内外的着火燃烧过程和火焰发展机制.此外,研究了双燃料发动机有害污染物氮氧化物(NO_(x))和碳氢(HC)生成及迁移过程.结果表明:整个燃烧过程分为三个阶段,首先,在预燃室内的流动和进气作用下,近通孔处的油束率先着火;随后预燃室内燃烧并产生射流火焰,射流火焰包含部分未燃燃料和燃烧中间产物,在进入主燃烧室初期火焰内部存在剧烈的预混燃烧;随着射流火焰进一步发展,反应区集中在火焰表面,开始出现火焰传播特征.燃烧过程中NO_(x)的高浓区都在预燃室内部,表明NO_(x)主要在预燃室内生成,受射流作用向主燃烧室迁移,而HC残留区域在主燃烧室内靠近射流火焰碰壁处.
Based on the computational fluid dynamics platform of CONVERGE and the after-treat program of MATLAB,the combustion process and the jet flame development mechanism were investigated on a two-stroke low-speed natural gas/diesel dual-fuel marine engine with pre-chamber.The production mechanisms of NO_(x) and HC emissions were also researched.The results show that the combustion process can be divided into three major stages.Firstly,the diesel spray near the orifice in the pre-chamber ignites,the flame develops to the unburn region and then the jet flame is generated and passes through the orifice.Secondly,the premixed methane in the main chamber is subsequently ignited by the jet flame in which the premixed combustion of unburn mixture and mid-production from the pre-chamber was observed.Thirdly,flame propagation occurs in the main chamber.In addition,it is found that NO_(x) emissions mainly produce inside the pre-chamber,while HC emissions mainly produce at the flame-wall interaction region and piston-to-wall region,respectively.
作者
叶映
吴朝晖
刘海峰
董晶瑾
李敬瑞
尧命发
Ye Ying;Wu Chaohui;Liu Haifeng;Dong Jingjin;Li Jingrui;Yao Mingfa(State Key Laboratory of Engines,Tianjin University,Tianjin 300350,China;China Shipbuilding Power Engineering Institute,Shanghai 200131,China)
出处
《内燃机学报》
EI
CAS
CSCD
北大核心
2022年第1期1-9,共9页
Transactions of Csice
关键词
低速船机
双燃料
射流火焰
燃烧过程
污染物生成机理
low-speed marine engine
dual-fuel
jet flame
combustion process
emission production mechanism
作者简介
叶映,博士研究生,E-mail:ye_y@tju.edu.cn;通信作者:刘海峰,教授,博士生导师,E-mail:haifengliu@tju.edu.cn.
