EGR对柴油发动机燃烧与排放特性仿真与试验研究
Simulation and Experimental Research on the Combustion and Emission Characteristics of Diesel Engines Uusing EGR
王汇龙 1任洪娟2
作者信息
- 1. 浙江工业职业技术学院,浙江绍兴 312099
- 2. 上海工程技术大学,上海 201620
- 折叠
摘要
在废气再循环(EGR)条件下,以一台柴油发动机为试验对象,搭建柴油机整机及EGR系统模型.研究EGR系统对柴油发动机性能、燃烧及排放特性的影响.试验结果表明,随着EGR开度的增大,废气的引入降低氧气(O2)浓度,使着火延长期增大,燃烧速度减慢,导致最高爆发压力下降且降低明显;EGR降低了空燃比,使燃烧过程滞燃期增长向膨胀阶段延长,部分燃油无法在上止点附近充分燃烧,导致功率小幅度下降和油耗小幅度上升.但EGR的使用减少了缸内燃烧时氮氧化物(NOx)的形成,中高负荷时随着EGR阀开度的增大,氮氧化物(NOx)降低幅度极为显著,最大降低幅度为52.4％.结论表明合理应用EGR系统可以在维持发动机燃油经济性以及动力性的条件下,能够明显抑制氮氧化物(NOx)排放.
Abstract
Under the condition of exhaust gas recirculation(EGR),a diesel engine and EGR system model were con-structed using a diesel engine as the experimental object.Study the impact of EGR system on the performance,combus-tion,and emission characteristics of diesel engines.The experimental results show that with the increase of EGR open-ing,the introduction of exhaust gas reduces the concentration of oxygen(O2),prolongs the ignition period,slows down the combustion speed,and leads to a significant decrease in the maximum burst pressure;EGR reduces the air-fuel ratio,prolonging the ignition delay period of the combustion process towards the expansion stage.Some fuels cannot fully burn near the top dead center,resulting in a slight decrease in power and a slight increase in fuel consumption.However,the use of EGR reduces the formation of nitrogen oxides(NOx)during combustion in the cylinder.At medium to high loads,as the opening of the EGR valve increases,the reduction in NOx is extremely significant,with a maximum reduction of 52.4％.The conclusion indicates that the reasonable application of EGR system can significantly suppress nitrogen oxide(NOx)emissions while maintaining engine fuel economy and power performance.
关键词
柴油发动机/废气再循环/排放Key words
Diesel engine/Exhaust gas recirculation/Emissions引用本文复制引用
出版年
2024
NETL
NSTL
维普
万方数据