燃烧系统结构对中载汽油机爆震边界内燃烧的影响  

Effects of Combustion System Structures on Medium-Duty Gasoline Engine Knock-Limited Combustion

作　　者：张立鹏[1] 周颖[1] 赵旭敏 王浒[2] 郑尊清[2] 尧命发[2] Zhang Lipeng;Zhou Ying;Zhao Xumin;Wang Hu;Zheng Zunqing;Yao Mingfa(Tianjin Internal Combustion Engine Research Institute,Tianjin 300072,China;State Key Laboratory of Engines,Tianjin University,Tianjin 300072,China)

机构地区：[1]天津内燃机研究所,天津300072 [2]天津大学内燃机燃烧学国家重点实验室,天津300072

出　　处：《燃烧科学与技术》2021年第5期514-520,共7页Journal of Combustion Science and Technology

基　　金：国家重点研发计划资助项目(2017YFE0102800);国家自然科学基金资助项目(51876140).

摘　　要：针对中载汽油机,设计开发了4种进气道和燃烧室的匹配方案,通过数值模拟的方法研究了不同燃烧系统结构对缸内宏观流场、湍流场及爆震边界内燃烧的影响.结果表明:进气道和燃烧室结构对缸内宏观流场及湍流场演化有显著影响.初期火焰传播速度主要由火花塞周围气流的平均速度决定,而主燃烧阶段的燃烧速度与该区域的湍动能大小成正比.双切向进气道匹配中置倒楔形燃烧室能够同时提高湍流强度及气流速度,从而有效缩短滞燃期及燃烧持续期,但其爆震倾向严重.采用复合进气道匹配中置倒楔形燃烧室的方案可显著抑制爆震,提前点火时刻,燃烧速度较快,可明显降低燃烧损失,提升中载汽油机的性能.The effects of four combustion system structures of a medium-duty(MD)gasoline engine on the incylinder macroscopic flow field,turbulent field and knock-limited combustion were studied numerically.The re-sults show that the geometries of intake ports and combustion chambers have a great impact on the evolution of incylinder macroscopic scale flow structures and turbulence field.The initial flame propagation speed is mainly af-fected by the average flow speed around the spark plug at spark timing,whereas the combustion rate of main combustion period is proportional to the turbulent kinetic energy of this region.Double tangential intake ports coupled with middle symmetrical inverted wedge combustion chamber could increase the turbulent kinetic energy and the average flow speed,resulting in the shortened ignition delay time and combustion duration.However,the knock tendency is more severe for this scheme.In contrast,compound intake ports coupled with middle symmetrical inverted wedge combustion chamber could improve the anti-knock performance as well as the combustion heat release rate,which is favorable for the reduction of combustion loss and improvement of thermal efficiency of the MD gasoline engine.

关 键 词：中载汽油机 进气道 燃烧室 湍流 爆震 

分 类 号：TK411[动力工程及工程热物理—动力机械及工程]