共轨燃油系统分析与优化毕业论文
2021-10-24 15:27:17
摘 要
柴油机有着热效率高、经济性好、工作可靠等优点,在经过100多年的技术改进后,被广泛运用于各种动力系统,特别是在船舶领域,为社会经济发展提供源源不断的动力。然而现在随着随着石油资源的日益减少和大气资源的污染愈发严重,对柴油机的油耗和排放控制要求也更加严格,所以柴油机经历机械式喷油系统、增压与中冷、电控燃油喷射系统三次重大技术革新后,应用高压共轨燃油喷射系统成为提升柴油机各方面性能的有效手段,因为电控喷油系统能控制调节喷油压力、喷油正时、喷油量等关键参数,实现燃烧过程的尽量理想化。
本文以船用中速柴油机MAN 6L16/24高压共轨燃油喷射系统为对象,分析比较了不同信号处理方法的特点,对高压共轨系统的结构组成和工作原理进行了详细说明,对系统三大组成部件的数学模型进行分析阐述。
然后使用AMESIM软件先后建立高压油泵、共轨管、喷油器的模型,组成系统的一维仿真模型,在时频域范围进行轨压信号分析,在不同工况下,分析研究共轨系统轨压信号的波动及频率分布,并根据结果对系统进行一定优化。
关键词:共轨系统;信号分析;AMESIM软件;一维仿真
Abstract
Diesel engines have the advantages of high thermal efficiency, good economy, and reliable operation. After more than 100 years of technical improvement, they are widely used in various power systems, especially in the field of ships, to provide continuous power for social and economic development. However, with the diminishing oil resources and the increasing pollution of atmospheric resources, the fuel consumption and emission control requirements for diesel engines are also stricter, so diesel engines undergo mechanical injection systems, supercharging and intercooling, and electronically controlled fuel. After three major technological innovations in the injection system, the application of the high-pressure common rail fuel injection system has become an effective means to improve the performance of all aspects of diesel engines, because the electronically controlled fuel injection system can control and adjust key parameters such as injection pressure, injection timing, and fuel injection amount. Realize the idealization of the combustion process as much as possible.
This article takes the MAN 6L16/24 high-pressure common rail fuel injection system of the marine medium-speed diesel engine as the object, analyzes and compares the characteristics of different signal processing methods, explains the structural composition and working principle of the high-pressure common rail system in detail, and describes the three major components of the system The mathematical model of the components is analyzed and explained.
Then use AMESIM software to build models of high-pressure fuel pumps, common rail pipes, and injectors to form a one-dimensional simulation model of the system, analyze rail pressure signals in the time-frequency domain, and analyze and study the common rail system rails under different working conditions. Pressure signal fluctuation and frequency distribution, and optimize the system according to the results.
Key Words: Common rail system; signal analysis; AMESIM software; one-dimensional simulation
目 录
第1章 绪论----------------------------------------------------------------1
1.1研究背景------------------------------------------------------------1
1.2国内外高压共轨燃油系统的特性研究现状--------------------------------1
1.2.1国外高压共轨燃油系统特性研究现状-------------------------------1
1.2.2国内高压共轨燃油系统特性研究现状-------------------------------2
1.3研究的目的与意义----------------------------------------------------3
1.4论文主要内容--------------------------------------------------------4
第2章 轨压信号分析处理----------------------------------------------------5
2.1不同信号处理方法比较------------------------------------------------5
2.2轨压信号波动来源----------------------------------------------------6
2.3轨压信号的分析处理--------------------------------------------------7
2.4小结----------------------------------------------------------------8
第3章 高压共轨系统模型建立------------------------------------------------9
3.1高压共轨系统主要部件及工作原理--------------------------------------10
3.1.1高压油泵-------------------------------------------------------10
3.1.2共轨管---------------------------------------------------------11
3.1.3电控喷油器-----------------------------------------------------11
3.2高压共轨系统主要部件的数学模型--------------------------------------11
3.2.1高压油泵的数学模型---------------------------------------------11
3.2.2高压管路的数学模型---------------------------------------------12
3.2.3电控喷油器的数学模型-------------------------------------------12
3.3高压共轨系统仿真模型建立--------------------------------------------13
3.3.1高压共轨模型相关假设-------------------------------------------13
3.3.2仿真模型建立流程-----------------------------------------------14
3.3.3系统相关参数和求解设置-----------------------------------------15
3.3.4仿真模型校验---------------------------------------------------16
第4章 共轨系统压力波动分析及结构优化--------------------------------------19
4.1共轨系统不同工况轨压波动特性分析------------------------------------19
4.2共轨管结构参数优化--------------------------------------------------24
4.3小结----------------------------------------------------------------24
发展与展望-----------------------------------------------------------------26
参考文献-------------------------------------------------------------------27
致谢-----------------------------------------------------------------------29
- 绪论
1.1研究背景
随着可持续发展战略的逐步落实,节约能源和环境保护已成为社会经济发展中的两大重要主题。我国经济高速发展,越来越多的家庭有了自己的汽车,随着而来的是能源的急剧消耗和环境污染,为此越来越严格的排放法规出台。合理的喷油过程是优化燃油燃烧过程,从而改善发动机燃油经济性和排放的主要手段,传统机械燃油喷射系统无法根据发动机工况精准地调节喷油过程的各种参数,而电控喷油系统就能很好地解决这一问题,所以现在电控喷油技术成为研究热点。而其中高压共轨燃油系统由于将共轨管内油压产生和喷油过程独立开来,所以一直是人们进行技术研发的重点对象。
高压共轨燃油系统是包含电磁、液压、机械的复杂系统,如何实现对系统各组件的精确控制是实现系统功能、保证发动机正常工作的关键。在柴油机工作的多个循环中,本要保证轨压的稳定,但每个循环的前一个循环都会使共轨系统轨压和燃油流速发生变化,从而导致压力振荡,这种压力波动会影响下一循环的喷油参数,从而导致我们无法对喷油过程实现精确控制。因此,良好的轨压控制和系统的结构优化是降低柴油机工作过程中共轨管压力波动的两大主要途径,本文主要从共轨系统结构参数优化这个方面入手,研究其对压力波动特性的影响。