生物柴油喷射系统嘴端压力分析

发布时间：2019-05-11 02:10

【摘要】：随着内燃机技术的广泛使用,导致可利用资源的日益短缺和环境污染,为了有效的解决发动机排放污染导致的环境问题,各个国家相继颁布了很多法规来限制内燃机排放,为了达到相关法规的要求,内燃机技术必须进行完善和改进,来减小尾气排放。生物柴油的燃烧性能非常好,它是一种含氧燃料,能够减少发动机的有害排放物,起到改善大气质量的作用,也可以解决能源危机问题。本文主要研究内容为:首先,对国内外生物柴油的研究发展状况做相关调研分析后,通过实验对生物柴油理化特性进行研究,先在0#柴油中掺入5%的生物柴油,我们将这种混合燃油标记为生物柴油B5,依上述方法分别得到其余两种不同比例的混合燃油记为:B15、B25,然后进行实验分析,得到这三种生物柴油的理化特性。其次,借助仿真软件GT-Suite中的子模块GT-Fuel,搭建电控单体泵燃油喷射系统仿真模型。借助某厂家对博世电控单体泵进行试验得出的实验数据来调整仿真模型,不断改进模型设置,最终得到相对精确的仿真模型。最后,本文利用验证过的仿真模型对比分析了该系统采用柴油、生物柴油B5、B15、B25时喷油器嘴端压力的变化;探究了系统采用生物柴油B5、B15、B25时,系统结构参数高压油管长度和直径不同组合、喷孔数目和直径、针阀弹簧预紧力、柱塞腔容积,以及供油参数供油压力、凸轮轴启喷角度、凸轮轴转速对喷油器嘴端压力的影响。研究表明:生物柴油可以作为柴油的替代燃料;高压油管管长越短,直径越小,喷油器喷孔直径越小,喷孔数目越少,则嘴端压力越大;针阀弹簧预紧力增大时,嘴端压力略微增大;柱塞腔容积增大时,嘴端压力略微下降。供油压力的变化对嘴端压力影响不大;凸轮轴启喷角度越大,嘴端压力越高,但喷油持续期会增长,会降低内燃机的燃油经济性;凸轮轴转速越快,嘴端压力越高,但凸轮轴转速要在最大泵许用压力之间。
[Abstract]:With the wide use of internal combustion engine technology, there is an increasing shortage of available resources and environmental pollution. In order to effectively solve the environmental problems caused by engine emission pollution, various countries have promulgated a lot of laws and regulations to limit internal combustion engine emissions. In order to meet the requirements of relevant laws and regulations, internal combustion engine technology must be improved and improved to reduce exhaust emissions. The combustion performance of biodiesel is very good. It is an oxygen-containing fuel, which can reduce the harmful emissions of engine, improve the atmospheric quality and solve the problem of energy crisis. The main contents of this paper are as follows: first of all, after investigating and analyzing the research and development of biodiesel at home and abroad, the physical and chemical properties of biodiesel were studied through experiments, and 5% biodiesel was added to 0# diesel. The mixed fuel was marked as biodiesel B5, and the other two different proportion of mixed fuel were recorded as B15 and B25 according to the above method, and then the physical and chemical properties of the three biodiesel were obtained by experimental analysis. Secondly, with the help of the sub-module GT-Fuel, of the simulation software GT-Suite, the simulation model of the fuel injection system of the electronic control single pump is built. The simulation model is adjusted by the experimental data obtained from the experiment of Bosch electronic control monomer pump by a certain manufacturer, and the model setting is improved continuously. Finally, a relatively accurate simulation model is obtained. Finally, the pressure changes at the nozzle end of the injector with diesel, biodiesel B5, B15 and B25 are compared and analyzed by using the verified simulation model. When biodiesel B5, B15 and B25 are used in the system, the length and diameter of high pressure tubing, the number and diameter of injection holes, the pretightening force of needle valve spring, the volume of plunger cavity and the oil supply pressure of fuel supply parameters are investigated. The influence of camshaft start-up angle and camshaft speed on nozzle pressure of injector. The results show that biodiesel can be used as an alternative fuel for diesel oil, and the shorter the length and diameter of high pressure tubing, the smaller the diameter of injector nozzle and the smaller the number of nozzle holes, the greater the nozzle pressure. When the pretightening force of needle valve spring increases, the pressure at the end of the nozzle increases slightly, and when the volume of the plunger cavity increases, the pressure at the end of the nozzle decreases slightly. The change of fuel supply pressure has little effect on the nozzle pressure, the larger the starting injection angle of camshaft is, the higher the nozzle pressure is, but the fuel injection duration will increase, which will reduce the fuel economy of internal combustion engine. The faster the camshaft speed, the higher the mouth pressure, but the camshaft speed should be between the maximum allowable pressure of the pump.
【学位授予单位】：广西科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TK403

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