【作者】 袁文华；

【导师】 李德桃； 龚金科；

【作者基本信息】 湖南大学 ， 车辆工程， 2010， 博士

【摘要】 具有电控高压共轨燃油喷射系统的清洁节能环保型柴油机在21世纪仍将作为交通运输领域主要动力,其关键核心技术-高压共轨燃油喷射系统是未来燃油喷射系统发展的必然趋势。柴油机高压共轨燃油喷射系统整体最优设计、高压共轨燃油喷射系统多次喷射协调机理、共轨压力的智能控制策略对增强共轨系统运行稳定性、提高油量控制精确度、优化发动机整体性能、实现节能减排目标具有重要的现实意义。本文以国家“863”项目子项(2008AA11A116)“新一代环保高效柴油机研发”和湖南大学“985”二期——汽车先进设计制造技术科技创新平台(动力排放与电控子项目)(教重函[2004]1号)为依托,以实现提高高压共轨燃油喷射系统的工作稳定性和改善柴油机动力性、经济性和排放性为目的,采取理论分析与实验研究相结合的方法,主要工作及创新点如下:(1)针对高压共轨喷油系统多学科设计优化复杂性问题,建立了高压共轨喷油系统基本物理-数学模型和高压共轨喷油系统多学科设计分布式并行优化基本构架,为高压共轨喷油系统多学科设计优化提供了有力的理论支持。(2)将量子计算,混沌理论以及遗传算法理论相结合,采用折叠次数无限的混沌模型产生混沌变量,提出了一种新型的优化算法——自适应变尺度混沌量子遗传算法,为高压共轨喷油系统多学科设计优化和智能控制提供坚实的技术保障。(3)首次以高压共轨喷油系统泵油性能、压力波动性能、雾化性能和质量为目标函数,以高压共轨喷油系统的多工况等几何、结构以及状态等为约束条件,系统研究了高压共轨喷油系统的整体优化,结果表明,高压共轨喷油系统泵油性能可提高16.7%,压力损失可下降18.9%,系统质量可减少14.7%,雾化性能可提高6.2%,整体性能可提高9.5%。(4)综合考虑环境及电控系统因素,基于分层次设计方法,分环境层、限制层和设定层等关键控制部件进行了算法设计,并采用LS-SVM建立了单工况多次喷射动态组合模型和多工况多次喷射动态组合模型,并验证了多次喷射动态协调控制策略的正确性。(5)基于柴油机高压共轨压力设定值确定、高压共轨压力传感器非线性智能校正和柴油机喷油量测量模型智能优化校正等措施,提出了高压共轨压力神经元-模糊推理融合的组合控制策略,仿真与实验结果表明,共轨压力控制曲线波动比较平稳,波动幅度不超过4MPa。利用研制的喷雾可视化试验装置进行了高压共轨喷油系统改进前后的喷雾过程对比分析,结果表明:改进后的高压共轨喷油系统燃油雾化较好,其喷雾性能得到较大的改善。更多还原

【Abstract】 The clean, energy-saving and Environment-protection diesel engine, with electronically controlled high pressure common-rail fuel injection system,will be the main driving force in the field of transportation in the 21st century, and has become the inevitable trend of development in the field of automotive power. The overall optimal design of diesel engine high-pressure common rail fuel injection system, the coordination mechanism of multiple injection and the intelligent control strategy of common rail system have very important practical significance to enhance the stability of common rail system, improve the accuracy of injecting fuel, optimize the overall performance of the engine and reduce the pollution and save the energy.Based on National“863”Program(2008AA11A116)“Manufacture of High Efficiency & Low Emission Diesel”and the "985" second stage of Hunan University——the innovation platform of science and technology of automotive design and manufacture (thesub-project of power emission and electric control) (Education accented term [2004] No. 1) , with the method of combining theoretical analysis with experimental study, the goal of the paper is to improve the stability of high-pressure common rail fuel injection system and make the diesel engine’s power and economy better and also to reduce the emissions. This paper’s main work and innovative points are as follows:(1) For the complex issues of MDO for the high pressure common rail fuel injection system, the paper establishes the basic physics - mathematical models of the high pressure common-rail fuel injection system and the basic framework of MDO for distributed parallel of high-pressure common rail fuel injection system, it provides a strong theoretical support for MDO for the high pressure common rail injection system.(2)Combining quantum computing, chaos theory with the theory of genetic algorithms, the paper uses the chaos model of infinite fold frequency to produce chaotic variables and proposes a novel optimization algorithm——adaptive mutative scale chaos quantum genetic algorithm to provide a solid technical support for MDO and IC for the high pressure common rail injection system.(3)This paper takes the oil-pumping performance , the pressure fluctuation performance, spray performance and mass of the high-pressure common rail fuel injection system as the target function and takes the multiple conditions such as geometry, structure, and the state of the high pressure common rail fuel injection system as the constraints in order to study the overall optimization of the high pressure common rail fuel injection system systematically , the results show that the pumping performanceηof the high pressure common rail fuel injection system is increased by 16.7%, pressure lossΔp is decreased by 18.9%,mass M is decreased by 14.7%, atomization performance Vi is enhanced 6.2%, and the overall performance U is increased by 9.5%.(4)Considering of environmental and electrical control system factors comprehensively, based on a hierarchical design methodology, the paper designs the control algorithm for the key components of environment layer, constraint layer and set layer etc, and establishes a single-condition multiple injection dynamic combination model and multi-condition repeated injection dynamic combination model with LS-SVM, and it has verified the correction of the multiple injection dynamic coordinated control strategy.(5)Based on the determination of the set value of the high pressure common rail pressure, nonlinear intelligent correction of high pressure common rail pressure sensor and intelligent optimization correction of diesel fuel consumption measurement model and other measures, the paper proposes a combination control strategy of neurons of high pressure common rail pressure and integration of fuzzy reasoning. Simulation and experimental results show that the fluctuation of common rail pressure control curve is relatively stable and fluctuation is less than 4MPa.With the visualization spray combustion test equipments, the paper carries on the process experiment of spray combustion before and after improving for the high pressure common rail fuel injection system and comparative analysis of spray development map, the results show that: the improved high-pressure common-rail fuel injection system has better atomization performance, the main combustion period is shorter and its spray combustion performance is improved significantly.更多还原