EGR对正戊醇-生物柴油混合燃料的燃烧排放性能影响研究  

Study on Influences of EGR on the Combustion and Emission Performance of n-Pentanol/Biodiesel Blends

作　　者：余金山 李文浩 颜伏伍[1,2] Yu Jinshan;Li Wenhao;Yan Fuwu(Hubei Key Laboratory of Advanced Technology of Automotive Components,Wuhan University of Technology,Wuhan 430070,China;Hubei Collaborative Innovation Center for Automotive Components Technology,Wuhan University of Technology,Wuhan 430070,China)

机构地区：[1]武汉理工大学现代汽车零部件技术湖北省重点实验室,武汉430070 [2]武汉理工大学汽车零部件技术湖北省协同创新中心,武汉430070

出　　处：《燃烧科学与技术》2021年第3期279-288,共10页Journal of Combustion Science and Technology

基　　金：国家重点研发计划资助项目(2017YFC0211201).

摘　　要：通过构建的一个新的包含79种组分和234个反应的正戊醇简化机理耦合已有的生物柴油简化机理,得到了正戊醇-生物柴油简化机理,该组合机理经过了滞燃期以及发动机缸压、放热率和排放验证,可以用作发动机燃用正戊醇生物柴油时的燃烧及排放特性分析.在一台高压共轨柴油机上,基于Converge仿真软件研究了EGR条件对正戊醇-生物柴油混合燃料的燃烧排放性能影响.结果表明:在不同的正戊醇掺混比例下,随着EGR率的增大,正戊醇-生物柴油混合燃料的缸压和放热率峰值都有所降低,滞燃期和燃烧持续期增加.相同EGR率时,随着正戊醇掺混比例的提高,燃料的雾化特性得到改善,燃烧持续期缩短,放热率峰值升高;添加正戊醇和增大EGR率可显著降低混合燃料的NOx排放,在EGR率为30%、正戊醇掺混比例为40%时,NOx最低排放可达0.08 g/(kW·h),与EGR率为0时相比降低了71%;混合燃料具有较大的的碳烟氧化潜力,碳烟排放都处于较低水平,在较小的EGR率下(<20%)碳烟排放增加并不明显,EGR率增加到30%时,燃烧恶化,碳烟的氧化受到了抑制,碳烟排放显著增加.A new reduced mechanism of n-pentanol containing 79 components and 234 reactions was established,which was coupled with the existing reduced mechanism of biodiesel to form the reduced mechanism of n-pentanol/biodiesel.This mechanism was verified by the ignition delay period as well as the cylinder pressure,heat release rate,and emissions of an engine,which can be used to analyze the combustion and emission characteristics of an engine fueled with n-pentanol/biodiesel.In a high-pressure common rail diesel engine,the influences of EGR on the combustion and emission characteristics of n-pentanol/biodiesel blends were studied using the simulation software CONVERGE.Results show that under different blending ratios of n-pentanol,with the in-crease of EGR,the peak values of both the cylinder pressure and heat release rate of n-pentanol/biodiesel blends decrease,while the ignition delay and combustion duration increase.Under the same EGR condition,with the increase in the blending ratio of n-pentanol,the atomization characteristics of blends are improved,the combus-tion duration is shortened,and the peak heat release rate increases.Adding n-pentanol and increasing EGR can significantly reduce the NOx emissions of blends.At EGR of 30%and the blending ratio of 40%,the lowest emis-sion of NOx is 0.08 g/(kW·h),which is 71%lower than that at EGR of 0.The blends have a great potential for soot oxidation,and the soot emissions are all at a low level.At a small EGR rate(<20%),the soot emissions do not increase significantly.When the EGR rate increases to 30%,the combustion deteriorates,the soot oxidation is restrained,and the soot emissions increase significantly.

关 键 词：EGR 正戊醇 生物柴油 燃烧 排放 

分 类 号：TK16[动力工程及工程热物理—热能工程]