部分预混耦合EGR对天然气直喷发动机的影响  

Effect of natural gas partially premixed coupled EGR on direct injection natural gas engine

作　　者：黄文庆 魏立江 余胜 张雨 HUANG Wen-qing;WEI Li-jiang;YU Sheng;ZHANG Yu(Merchant Marine College,Shanghai Maritime University,Shanghai 201306,China)

机构地区：[1]上海海事大学商船学院,上海201306

出　　处：《舰船科学技术》2024年第5期95-102,共8页Ship Science and Technology

基　　金：国家自然科学基金资助项目(51909154);上海高水平地方高校创新团队(海事安全与保障)项目;上海船舶智能运维与能效监控工程技术研究中心项目(20DZ2252300)。

摘　　要：以一台四冲程高压直喷天然气发动机为研究对象,模拟研究了5种天然气预喷量耦合5种废气再循环(EGR)率对部分预喷天然气发动机的燃烧和排放特性的影响。结果表明,相比于高压直喷模式,部分预喷模式有着更高的缸内峰值压力、峰值热释放率和最大压力升高率。预喷比例的增加会提前发动机燃烧相位、缩短燃烧持续期,进而降低发动机的指示燃料消耗率,但是EGR的加入会削弱这种效果。较高的预喷量耦合中等比例EGR能够削弱NOx-soot的“trade-off”关系;30%EGR率耦合40%预喷量能够使发动机具有较低的指示燃油消耗率,产生较低的甲烷、未燃HC和CO排放,以及优于非预喷方案的NOx和soot排放特性。Based on a four stroke high pressure direct injection natural gas engine,the coupling effects of five natural gas pre-injection volumes and five EGR rates were simulated and studied to compare and discuss the combustion and emis-sion characteristics of a partially premixed natural gas engine.The results show that compared with the high pressure direct injection mode,partial pre-injection mode has higher peak in-cylinder pressure,peak heat release rate and maximum pres-sure rise rate.Increasing of pre-injection ratio will advance the engine combustion phase and shorten the combustion dura-tion,thereby reducing the engine's indicated fuel consumption rate,but the addition of EGR will weaken this effect.The higher pre-injection rates coupled with moderate EGR can weaken the NOx-soot"trade-off"relationship.The 30%EGR rates coupled with 40%pre-injection can result in engine with lower indicated fuel consumption rates,lower methane,un-burned HC and CO emissions,and better NOx and soot emission characteristics than direct injection solutions.

关 键 词：天然气高压直喷 部分预喷 预喷比例 甲烷逃逸 碳烟 

分 类 号：U664.121[交通运输工程—船舶及航道工程] TK402[交通运输工程—船舶与海洋工程]