米勒循环汽油机燃用氢气燃烧及排放特性分析  

Analyzing Combustion and Emission Characteristics of Miller-cycle Gasoline Engine Fueled with Hydrogen

作　　者：吴广权 杜家坤 陈泓 占文锋 高文志[1] 吴威龙 WU Guangquan;DU Jiakun;CHEN Hong;ZHAN Wenfeng;GAO Wenzhi;WU Weilong(State Key Laboratory of Engines,Tianjin University,Tianjin 300072,China;GAC Automotive Research&Development Center,Guangzhou 511434,China)

机构地区：[1]天津大学内燃机燃烧学国家重点实验室,天津300072 [2]广州汽车集团股份有限公司汽车工程研究院,广州511434

出　　处：《机械科学与技术》2024年第5期750-755,共6页Mechanical Science and Technology for Aerospace Engineering

基　　金：国家重点研发计划(2017YFB0103300)。

摘　　要：基于一台高压直喷米勒循环汽油机加装氢气喷射系统,试验研究了发动机燃用汽油与氢气时燃烧与排放的差异。结合电子增压器,通过增大过量空气系数,探索氢气发动机超稀薄燃烧模式热效率潜力,分析了汽油机三效催化转化器对氮氧化物转化效率和NH3的影响规律。结果表明:大负荷工况下氢气发动机对爆震较为敏感,采用稀薄燃烧方式可进一步提升氢气发动机有效热效率水平。2500 r/min转速条件下,缸内平均有效压力(Brake mean effective pressure,BMEP,记为PBME)=0.8 MPa时,过量空气系数由1.0增大至3.0时,热效率值增幅可达30%,NO_(x) 排放降幅可达约98%,且当负荷进一步提升至PBME=1.1 MPa时,热效率突破43.0%。传统汽油机TWC对氢发动机NO_(x) 转化效率在偏浓工况下相对较高,且在偏浓工况下,TWC后会产生大量氨气,当混合气进一步稀释后NH3生成量显著降低。The high-pressure Miller-cycle direct gasoline injection engine was installed with a hydrogen injection engine.The combustion and emission differences between the engine's use of gasoline and hydrogen were experimentally studied.We used an electronic compressor to explore the thermal efficiency of the ultra-rarefied combustion of the hydrogen injection engine in its lean burn mode.The effects of a three-way catalytic(TWC)converter on the conversion efficiency of nitrogen oxide and NH3 were analyzed.The results show that the hydrogen engine is sensitive to engine knock under large load condition.Lean combustion can further improve the thermal efficiency.At the speed of 2500 r/min,when PBME=0.8 MPa and the excess air coefficient increases from 1.0 to 3.0,the thermal efficiency increases by 30%and the NO_(x) emission decreases by about 98%.When the load further increases to PBME=1.1 MPa,the thermal efficiency exceeds 43.0%.The NO_(x) conversion efficiency of the traditional gasoline engine TWC for hydrogen engine is relatively high under rich content condition.A large amount of ammonia may be generated after TWC conversion.When the mixture is further diluted,the amount of NH3 generation decreases significantly.

关 键 词：缸内直喷汽油机 氢气 稀薄燃烧 排放 

分 类 号：TK411[动力工程及工程热物理—动力机械及工程]