【作者】 冉勇；

【导师】 宋金瓯；

【作者基本信息】 天津大学 ， 动力机械及工程， 2007， 硕士

【摘要】 能源短缺和环境污染是世界汽车工业面对的两大挑战,内燃机必需通过技术创新来寻求发展。在燃油中加入添加剂以提高油品的质量是提高内燃机燃油经济性和降低有害排放的有效途径之一,但是传统的添加剂对人体或发动机部件有危害。本文主要研究一种生物基汽油添加剂对目前先进的汽油发动机性能的影响。已有的研究表明这种生物添加剂能够促进燃烧,缩短燃烧持续期,使燃烧进行得更快更完全,因此能有效地提高发动机燃油经济性,同时降低尾气排放。这些研究为开发新一代绿色添加剂奠定了基础。近年,VVT等技术广泛应用,内燃机综合性能大幅提升,国家发布关于燃油的新法规。因此,有必要研究在性能优良的先进汽油机上生物添加剂所起的作用。研究中通过台架试验考查了生物添加剂对高性能汽油发动机燃油经济性、排放性以及动力性的影响。发动机台架试验表明:在具有较高燃油经济性汽的油机上,生物添加剂仍然有发挥作用的空间,93#汽油中加入添加剂后在2000r/min和3500r/min下最大能减少燃油消耗8.24%和10.2%;排放方面, NOx有所降低,HC则略有升高,对CO影响不明显;通过对两个转速下油门全开时功率的比较发现,加入生物添加剂后发动机动力性有轻微的提升。乙醇汽油在我国的使用范围不断扩大,因此试验中也将乙醇汽油作为基础燃油之一进行加剂对比试验。结果表明:生物添加剂同样能提高乙醇汽油品质,一定程度上弥补了乙醇汽油在经济性方面的劣势;生物添加剂对乙醇汽油排放性的影响,除NOx变化不大以外,其它规律与93#检测用油时基本一致。分析发现在影响生物添加剂作用效果的因素较多。不同的油品具有不同的最佳加剂比例,同一加剂比例时不同的发动机运行工况效果也有差异。但是生物添加剂对发动机燃油经济性的提高作用具有普遍性。更多还原

【Abstract】 With the challenges of energy sources shortage and environment pollution in global vehicle industry, the development of internal combustion engine depends on the innovation of technologies. Using additive is one of the most effective methods to change the character of fuel in order to improve fuel economy and emission performance of engine. However, traditional additives are harmful to human beings or engine components. In this paper the influence of a bio-additive on an advanced gasoline engine nowadays is studied.Preexistent researches indicate that the bio-additive can improve fuel combustion, shorten combustion duration period, make the combustion faster and more complete. So this bio-additive can improve the fuel economy and emission performance. These researches lay a foundation for the development of new green bio-additive.Because the performance of engine have been improved largely by new technologies and new regulation of fuel have been issued , it needs to be confirmed that whether bio-additive can take effect on advanced gasoline engine whose comprehensive performance is excellent already . The influence of bio-additive on engine was tested by bench tests, including fuel economy, emission performance and power performance.The bench tests showed that the bio-additive can improve the fuel economy obviously, though the engine has excellent fuel economy already. When bio-additive was added to 93# gasoline, the fuel consumption can be reduced 8.24% and 10.2% at most respectively when engine speed is 2000r/min and 3500r/min. According to the tests of exhaust emissions, NOx emissions decreased, CO emission keeps the same level, but HC emission has small increase. By comparing the maximal powers of the two speeds it was found that the bio-additive had a minor effect to the power performance of engine.Because the use of gasohol becomes wider in our country we added bio-additive into gasohol to take comparative experiment. The results show that bio-additive can improve the character of gasohol too. So it can compensate for the loss of fuel economy to a certain extent. The main emissions have a same trend as 93# gasoline except NOx emission. The NOx emission is affected by bio-additive slightly.According to the results of bench tests, it is found that the effects of bio-additive have relation to the percent of bio-additive, power, speed, the type of engine and the component of fuel. So it needs to take account of these factors when the optimalt percent of bio-additive is chosen.更多还原