柴油引燃掺氢-甲烷混合燃料发动机的燃烧特性  

Combustion Characteristics of a Methane-Hydrogen Dual-Fuel Engine Ignited by Diesel Pilot Injection

作　　者：尹丛勃[1] 周健朱 张振东[1] 申小雨 Yin Congbo;Zhou Jianzhu;Zhang Zhendong;Shen Xiaoyu(School of Mechanical Engineering,University of Shanghai for Science and Technology,Shanghai 200093,China)

机构地区：[1]上海理工大学机械工程学院,上海200093

出　　处：《内燃机学报》2024年第6期508-516,共9页Transactions of CSICE

基　　金：上海市科技计划资助项目(21010503000).

摘　　要：对引燃柴油能量比例为5%的甲烷-氢气双燃料燃烧中不同初始进气温度、氢能量比例以及喷射时刻对燃烧过程的影响进行研究.在接近上止点(TDC)时喷射甲烷-氢气-空气的混合气,并由先导柴油引燃.在初始进气温度为25℃和50℃下,研究了氢能量比例和喷气时刻对双燃料发动机着火延迟期、燃烧持续期和各阶段燃烧放热率的影响.通过高速摄像机记录燃烧过程的自然光度图像,计算每个自然光度图像对应的曲轴转角,并结合放热率(HRR)和放热率二阶导数(SDHRR)曲线识别出燃烧的阶段.结果表明:进气温度为25℃时着火延迟期随氢能量比例的升高先减小,在氢能量比例达到60%后有所增加,燃烧持续期随氢能量比例的增加,下降幅度为41%.进气温度为50℃时着火延迟期进一步下降,燃烧持续期显著降低.随着温度升高,燃烧放热阶段第一阶段、第二阶段占比逐渐增加,第三阶段占比逐渐减少,使得燃烧放热过程提前.Combustion process characteristics were studied on a methane-hydrogen dual-fuel engine ignited by diesel pilot injection at different initial intake temperature,hydrogen energy ratio and injection time.The methane-hydrogen-air mixture is injected near top dead center(TDC)and ignited by pilot injection of 5%(energy ratio)diesel fuel.The effects of hydrogen energy ratio on ignition delay time,combustion duration and heat release rate in each stage of the dual-fuel engine were investigated under the intake temperature of 25℃and 50℃,respectively.The natural photometric images of the combustion process were recorded by a high-speed camera,and the crankshaft rotation angle corresponding to each natural photometric images was calculated.The combustion stages were identified by analyzing heat release rate(HRR)curves and second derivative of heat release rate(SDHRR)curves.The results show that the ignition delay period first decreases with the increase of hydrogen energy ratio when the intake temperature is 25℃,and then increases after the hydrogen energy ratio reaches 60%.The combustion dura-tion decreases by 41%with the increase of hydrogen energy ratio.When the intake temperature is 50℃,the ignition delay period further decreases and the combustion duration significantly decreases.As the temperature increases,the proportion of the first and second stages of combustion heat release gradually increases,while the proportion of the third stage gradually decreases,leading to an earlier combustion heat release process.

关 键 词：双燃料燃烧 放热率二阶导数 自然光度图像 

分 类 号：TK464[动力工程及工程热物理—动力机械及工程]