【作者】 宋涛；

【导师】 林学东；

【作者基本信息】 吉林大学 ， 动力机械及工程， 2006， 硕士

【摘要】 本文试验用柴油机采用Bosch第二代高压共轨喷射系统,系统的控制软件使用INCA在线标定软件。本文的主要内容有如下几个方面:首先,分析高压共轨喷射系统的轨压、喷油定时、预喷时间和预喷量等参数的控制方法,并深入理解各参数之间的关系及其控制MAP的影响因素,确定发动机标定流程及各MAP的标定方法;在其他参数不变的条件下,分别改变轨压、喷油定时、预喷量及预喷时间,分析其对发动机燃烧过程、经济性和排放的影响;调整发动机转速和负荷,在各个工况通过比较不同喷射系统参数下发动机的综合性能,选取最佳喷射系统参数,分析最佳喷射系统参数随发动机转速、负荷的变化关系;对比喷射系统参数优化前后发动机各方面的性能,实验证明,喷射系统的参数优化使发动机外特性在烟度允许范围内低速扭矩得以增加,中高速时在发动机动力性保持不变的前提下,经济性及HC、CO都有所改善,NOx排放在发动机外特性全程中都有较大程度的改善,下降了约10%左右。更多还原

【Abstract】 Using diesel fuel has been a trend of modern automobile engine. But under the function of energy crisis and environmental pollution, the diesel engine is also facing various aspects questions. Using the high pressure common rail fuel injection system is a reasonable way to improve its efficiency, emission and so on.The high pressure common rail fuel injection system has two aspect merits: first, it can come true the high pressure injection which improves the mixture formation and the combustion process. The generation of high pressure is independent of the injection process. So there is no influence of engine speed, the load and the fuel injection quantity on it in a certain range. Second, strengthens to the flexible controlling of the injection system parameters, specially the injection quantity, injection timing, injection rate, injection pressure and so on, in order to get the ideal regularity of fuel injection.Enhancing the injection pressure will make the fuel increase the beginning speed from nozzle, and then obtain higher relative speed with air, thus it is advantageous to reduce the mean diameter of fuel particle, so the speed of evaporation is improved; While enhancing the injection pression, the spraying momentum will increases, which accelerate the fuel spray diffusing with the air in combustion chamber. The more fast the air and fuel mix, the more uniform the formation of gas mixture will be. Better mixture formation represents better combustion procession, which improve the combustion process and reduce the soot emission.The high pressure injection can control the particulate and soot effectively , but the increased mixture which formation during the delayed burning period promote the pilot mixture combustion and then the maximal heat release increase, that will increase the NOx emission and the noise. The high pressure common rail fuel system chntrols the injection characteristics through adding pilot injection and postponing the injection advance angle, which made it possible to reduce NOx as well as the更多还原