富氧燃烧与EGR对船用柴油机NO-碳烟排放和燃烧特性的影响  

Influences of Oxygen-Enriched Combustion and EGR on NO-Soot Emissions and Combustion Characteristics of Marine Diesel Engine

作　　者：王科 赵昌普[1] 蔡玉洁 Wang Ke;Zhao Changpu;Cai Yujie(State Key Laboratory of Engines,Tianjin University,Tianjin 300072,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

出　　处：《燃烧科学与技术》2020年第3期248-256,共9页Journal of Combustion Science and Technology

基　　金：国家高技术研究发展计划(863计划)资助项目(2012AA111705);国家自然科学基金资助项目(50676067).

摘　　要：针对一台满足TierⅡ排放标准的船用柴油机,采用富氧燃烧与EGR相结合实现NO-碳烟排放同时降低并保证发动机功率没有损失,并探讨了实现TierⅢ排放标准的技术路线.AVLFire软件被用于建立仿真模型.研究表明,当单独使用富氧燃烧时,观察到较短的燃烧持续期、较高的缸内温度和指示功率,碳烟排放减少而NO排放恶化,而单独使用EGR时出现相反的趋势.研究发现,当发动机运行在1 350 r/min,75%负荷工况下,进气氧浓度为21%~24%,EGR率为0~25%时,上述范围内的4种组合可以实现低NO-碳烟排放且指示功率与原机基本持平.正如预期,通过富氧燃烧与EGR优化组合,可得到同时降低NO-碳烟排放低于原机的最佳优化区域.同时也发现,当超过15%的EGR率与较低的氧浓度结合时,可将NO排放降低至TierⅢ标准.NO-soot emissions can be simultaneously reduced without heavy penalty in the power of the original engine by an optimized combination of oxygen-enriched combustion and exhaust gas recirculation(EGR)for a marine diesel engine that meets TierⅡemission standards.In addition,the technical route to achieving TierⅢemission standards is also analyzed in this paper.A simulation model is established by using software AVL Fire.Results show that when only oxygen-enriched combustion is applied,shorter ignition delay,higher cylinder temperature and higher indicated power are observed,and soot emissions are reduced while NO emissions increase.In contrast,opposite trends are found when only using EGR.The NOx-soot emissions can be reduced without penalty in power under conditions of 1350 r/min of engine speed,75%load,0-25%EGR rate and 21%-24%of intake oxygen concentration.As expected,the optimal operation zone for NO-soot emissions lower than those of the original engine can be obtained by an optimized combination of oxygen-enriched combustion and EGR.It is also revealed that NO emissions can meet the requirement of TierⅢlevel when the EGR rate is above 15%together with a low oxygen concentration.

关 键 词：船用柴油机 富氧燃烧 EGR NO-碳烟排放 指示功率 数值模拟 

分 类 号：TK421.5[动力工程及工程热物理—动力机械及工程]