基于国4轻型车用柴油机EGR技术研究

发布时间：2018-01-08 03:24

本文关键词：基于国4轻型车用柴油机EGR技术研究　出处：《湖南大学》2016年硕士论文　论文类型：学位论文

【摘要】：随着柴油机技术的进步,其相比汽油机节能、高效、环保的优势得到进一步加强,柴油机在国民生产各领域都有着广泛应用,但它工作时产生有害排放物,成为大气污染的一个重要源头,这个已经得到社会的广泛关注,与此相运而生的排放法规也在逐渐加严。中国从2014年起开始实施国四排放标准,针对国四排放,目前国际上主流存在两种技术路线,SCR和EGR路线,两种技术路线有着各自的优势和劣势,但就小型机而言,出于成本和布置空间考虑,目前很多厂家倾向于EGR+DOC+POC的路线。因此对EGR技术的研究对于柴油机技术来说具有相当重要的意义。本文以采用了EGR技术的某型号四缸机为对象,通过对比SCR和EGR路线区别的分析,提出通过针对性的缸内燃烧优化以及EGR系统优化达到达标国四排放的目的。主要研究内容有:(1)分析了EGR系统的机械、气电、电控等多种实现方式,阐述了各自的优缺点,阐述了EGR对柴油发动机工作燃烧过程影响,拟定了EGR的选型原则。详述了EGR系统的设计过程。(2)分析了EGR机型的燃烧特点,对相应的涉及燃烧的零部件进行优化选型,初步确定原机NOx排放。(3)对EGR系统进行了一些探索性的研究。不同EGR阀布置形式的对比、EGR系统管路容积对低速性能的影响以及EGR开环、闭环控制。(4)通过发动机燃油系统参数和EGR系统参数的优化标定,匹配合适的后处理装置,发动机排放达标国四排放。
[Abstract]:Along with the diesel engine technology, compared to energy saving, environmental protection advantages of gasoline engine, diesel engine has been further strengthened, in the national production in various fields have been widely used, but it is harmful emissions, become an important source of air pollution, it has been widespread concern in society, and this phase and emission regulations are gradually tightened. Chinese began to implement the national emission standards for four from 2014, according to the country's four emissions, there are two kinds of current international mainstream technology roadmap, the SCR and EGR routes, two kinds of technologies have their own advantages and disadvantages, but because of cost and minicomputers. The arrangement of space considerations, many manufacturers tend to EGR+DOC+POC line. So the research of EGR technology has very important significance for diesel engine technology. This paper uses EGR technology in a type of four cylinder engine as the object, Through the comparative analysis of SCR and EGR route difference, proposed through optimization and optimization of EGR system for the purpose of reaching the China reached four emissions of combustion in the cylinder. The main research contents are as follows: (1) analysis of the EGR system of machinery, gas and electricity, to achieve a variety of electronic control, expounds the advantages and disadvantages of each, this the effect of EGR on diesel engine combustion, proposed the principle of EGR selection. The detailed design process of EGR system. (2) analyzed the characteristics of EGR combustion models, to optimize the corresponding related combustion components, preliminary determine the original engine NOx emissions. (3) of the EGR system are studied the study on the comparison of different EGR valve arrangement. The effect of EGR pipeline volume on the performance of low speed and EGR open loop, closed-loop control. (4) calibration by optimizing the parameters and EGR parameters of engine fuel system, matching the appropriate postprocessing. Set up, engine emissions four emissions.

【学位授予单位】：湖南大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U464.172

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