氢气直喷与EGR协同作用对汽油机燃烧和排放的影响研究  

A Study on the Collaboration Effects of Hydrogen Direct-injection and EGR on the Combustion and Emissions of Gasoline Engine

作　　者：于秀敏[1] 吴海明[1] 杜耀东[1] 刘林[1] 牛仁旭 董伟[1] 

机构地区：[1]吉林大学,汽车仿真与控制国家重点实验室,长春130022

出　　处：《汽车工程》2016年第9期1044-1051,共8页Automotive Engineering

基　　金：国家自然科学基金(51276079);高等学校博士学科点专项科研基金(20110061110032);吉林大学研究生创新基金项目(2016022)资助

摘　　要：为揭示氢气对传统燃料燃烧的改善作用,在一台加装EGR的氢气缸内直喷、汽油进气道喷射的复合喷射火花点火双燃料发动机上,开展了不同掺氢比和EGR率下发动机性能和排放的试验研究。结果表明:EGR的引入会降低发动机转矩,而掺氢可有效提高发动机转矩。有效燃油消耗率随着EGR率的增大呈现先减小后增加的趋势,掺氢可降低有效燃油消耗率,改善发动机经济性。缸压峰值随EGR率的增加呈现先增大后减小的趋势,其对应的时刻推迟;随着掺氢比的增加缸压峰值增大,且出现的时刻提前。平均指示压力循环变动系数随EGR率的增加而增大,掺氢可有效降低燃烧循环变动。汽油掺氢后NOx排放增加,EGR的引入能有效降低NOx排放,这种降低效果在大掺氢比下更显著;HC和CO排放随EGR率增大而增加,随掺氢比的增加而降低。在氢气缸内直喷与EGR协同作用下,发动机可获得较好的综合性能。For revealing the improvement effects of hydrogen on the combustion of traditional fuel,an experimental study on the performance and emission of a compound fuel injection spark-ignition dual-fuel engine （ hydrogen in-cylinder direct injection and gasoline port injection） with exhaust gas recirculation （EGR） device under different hydrogen fractions and EGR rates. The results indicate that the introduction of EGR reduces engine torque and hydrogen addition can effectively increase engine torque. Effective specific fuel consumption shows a trend of deducing first then increasing with the rise of EGR rate,but can be lowered by hydrogen addition with the fuel economy of engine improved. With the increase of EGR rate,cylinder pressure peak rises first then falls,with corresponding timing retards. The cyclic variation coefficient of mean indicted pressure rises with the increase of EGR rate,but can be effectively lowered by hydrogen addition. With hydrogen added into gasoline,the emission of NOx increases,but which can be effectively lowered by the introduction of EGR,being more apparent in large hydrogen fraction. The emissions of HC and CO increase with the rise of EGR but decrease with hydrogen fraction. To sum up,under the collaboration of EGR and hydrogen in-cylinder direct injection,the engine can achieve better overall performance.

关 键 词：汽油机 氢气直喷 废气再循环 燃烧 排放 

分 类 号：U464.171[机械工程—车辆工程]