汽油机外部EGR瞬态延迟与点火正时匹配的研究  

Correlation of Transient Delay of External EGR and Ignition Timing for Gasoline Engines

作　　者：程传辉 龚韵秋 彭超 CHENG Chuanhui;GONG Yunqiu;PENG Chao

机构地区：[1]上汽集团创新研究开发总院,上海201804

出　　处：《上海汽车》2025年第1期3-8,25,共7页Shanghai Auto

摘　　要：在一台1.5 L的自然吸气缸内直喷汽油机上,应用分缸独立引入EGR系统,通过缸内燃烧压力变化和直接测试缸内CO_(2)浓度两种EGR瞬态延迟时间测量方法进行了研究和对比分析。通过全工况范围内EGR阀由关到开过程中的瞬态延迟测量,结果表明,该1.5 L自然吸气汽油机的EGR瞬态延迟为3-4个燃烧循环,部分工况达到5-6个燃烧循环。EGR瞬态延迟时长与发动机转速、EGR气体流量均成反比。根据EGR阀口流量模型、EGR瞬态延迟测量结果及特征,制定了相应的EGR点火角匹配策略,以满足在EGR瞬态工况下合理匹配点火正时。In a 1.5 L naturally aspirated direct-injection gasoline engine,a cylinder-independent EGR(Exhaust Gas Recirculation)system is applied.After the introduction of EGR,two methods of EGR transient delay measurement are studied and compared:in-cylinder combustion pres-sure variation and direct measurement of in-cylinder CO_(2) concentration.The transient delay measure-ments during the process of opening the EGR valve from closed to open across the entire operating range indicate that the EGR transient delay of the 1.5 L naturally aspirated gasoline engine is between 3 to 4 combustion cycles,with some operating conditions reaching 5 to 6 combustion cycles.The du-ration of EGR transient delay is inversely proportional to both engine speed and EGR gas flow rate.Based on the EGR valve orifice flow model,the EGR transient delay measurement results,and char-acteristics,corresponding EGR ignition timing calibration strategies are developed to ensure reason-able ignition timing calibration under EGR transient operating conditions.

关 键 词：EGR瞬态延迟 缸压 缸内CO_(2)浓度 点火角修正 燃烧相位 

分 类 号：TK4[动力工程及工程热物理—动力机械及工程]