摘要
[目的]为改善大功率船用发动机燃烧、性能及排放,采用柴油微喷引燃甲醇喷射方式,研究发动机缸内燃烧和排放特性。[方法]基于一台大缸径船用ACD320中速柴油机,建立柴油微喷引燃甲醇发动机三维仿真模型,研究喷油器参数(喷孔数与甲醇喷雾夹角γ)对大缸径船用甲醇发动机燃烧性能与排放特性的影响。[结果]研究结果表明:随着喷孔数的增加,缸内甲醇雾化效果较好,使缸内工质混合较充分,CA50提前,燃烧持续期缩短,获得了较高的指示热效率和较好的燃油消耗率,并有助于降低碳烟排放,但会导致NO_(x)排放量升高。但随着甲醇喷雾夹角的增大,指示热效率增大,能够获得较好的燃油经济性和较低碳烟排放量。当甲醇喷雾夹角位于柴油喷雾夹角时(γ>60°),缸内火焰传播速度较快,指示热效率较大,燃料燃烧较充分,获得碳烟最低排放量和最优燃油消耗率。[结论]分析结果可为发动机喷油器布置提供了理论依据。
[Objective]To improve the combustion,performance and emissions of high-power marine engines,diesel fuel micro-injection with methanol ignition is adopted to study the in-cylinder combustion and emission characteristics.[Methods]A three-dimensional simulation model of a diesel micro-injection pilotignition methanol engine is established on the basis of an ACD320 high-power marine medium-speed diesel engine in order to study the effects of injector parameters(nozzle number and methanol spray angleγ)on the combustion performance and emission characteristics of a marine large-bore methanol engine.[Results]With the increase in the number of nozzle,the in-cylinder methanol atomization improves and the in-cylinder work mass mixing becomes more adequate,leading to the advancement of CA50 and the shortening of the combustion duration.While this yields higher indicated thermal efficiency(ITE)and a better equivalent indicated specific fuel consumption(EISFC),as well as contributing to the reduction of soot emissions,it also causes the elevation of NOx emissions.Moreover,as the methanol spray angle increases,the ITE increases,obtaining better fuel economy and lower soot emissions.With the optimal methanol spray angle(γ=60°),the methanol spray is located in front of the diesel spray injection point,the flame propagation speed in the cylinder is faster,the indicated thermal efficiency is at its maximum and the fuel combustion is fuller,thereby obtaining the lowest soot emissions and most optimal EISFC.[Conclusion]The results of this analysis can provide a theoretical basis for engine injector parameters.
作者
吴德杨
温华兵
徐昌春
李敬瑞
沈建华
靖海国
WU Deyang;WEN Huabing;XU Changchun;LI Jingrui;SHEN Jianhua;JING Haiguo(School of Energy and Power,Jiangsu University of Science and Technology,Zhenjiang 212114,China;CSSC Marine Power Co.,Ltd.,Zhenjiang 212002,China)
出处
《中国舰船研究》
CSCD
北大核心
2024年第4期131-138,共8页
Chinese Journal of Ship Research
基金
江苏省工业和信息化厅关键核心技术攻关项目资助(2145072206)。
关键词
甲醇
微喷引燃
缸内直喷
甲醇喷雾夹角
排放
methanol
micro-jet ignition
direct injection
methanol spray angle
emission
作者简介
吴德杨,女,1997年生,硕士生。研究方向:燃料发动机。E-mail:1921663042@qq.com;通信作者:温华兵,男,1977年生,教授。研究方向:轮机工程。E-mail:whb@just.edu。
