设计简介
摘 要
北方冬季，环境温度较低，汽车尾气中的水蒸汽就会在排气管壁冷凝成水滴，并且随排气流至路面，尤其针对使用乙醇汽油的车辆。乙醇汽油作为一种车用清洁燃料，其富含氧元素，但乙醇汽油燃烧的排放物中生成的水分也较多，受周围的环境温度以及排气降噪能量转换的影响，汽车的排气管会向外滴水，这是一个很普遍的现象。
基于乙醇汽油燃烧特点，车辆使用乙醇汽油导致路面结冰，在公交站台、上坡路段、十字路口等处，尤其在在一些拥挤路段，冬季更容易形成冰层，大多路段都是难清理的薄冰。这不仅减缓了车速，造成冬季拥挤市区行车的不便，延长了车在路面的时间，更增加燃油消耗，而且增加了有害物质的排放，减少制动距离，使刮碰等事故不断，不但没有达到节能减排的目的，还增加了大量人力、时间和物质成本。
因此，针对东北寒冷的冬季，在尽量少的影响原有排气系统下，如何改进排气系统以减少或消除汽车燃烧乙醇汽油所排除的水分导致的路面结冰问题，对乙醇汽油在寒冷地区的应用，及道路的交通拥挤问题的缓解有着重大而深远的意义。
本设计主要是针对捷达汽车排气装置进行展开，首先介绍了捷达汽车排气装置的内部结构、工作原理及运行情况。在此基础上，提出了一种以试验为目的的排气装置实验台设计方案。针对它的性能测试目的，该实验台的特点是结构相对较为简单，实验台设有数显温度传感器，便于在试验过程中，让操作者直观了解并通过更换不同排气装置进行性能测试来增强其动手能力，以达到良好的试验效果。
关键词：；排气装置；消声器；实验台；试验；温度；
ABSTRACT
The north winter, environmental temperature is lower, the automobile exhaust steam will exhaust pipe wall into the droplets in condensation, and exhaust flow to the pavement with, especially to use ethanol and gasoline vehicles. Ethanol and gasoline, as a kind of car, and the rich in oxygen clean fuel element, but the burning ethanol and gasoline emissions generated by the surrounding water more, also the environment temperature and exhaust noise reduction of energy conversion, the influence of the car exhaust the drop of water, this to is a common phenomenon.
Based on ethanol and gasoline, combustion characteristics vehicle use ethanol in gasoline, bus station in the icy road intersection, uphill, the place such as in crowded, especially in some sections, more easy to form ice in winter, most of the roads are clear, it is the thin ice. This not only slow its speed, and cause the winter driving the inconvenience, crowded downtown extended the car in the pavement of the time, the more increase fuel consumption, and increased the discharge of harmful materials, reduce braking distance, scraping the touch, etc, not only have no accidents have reached the purpose of energy conservation and emission reduction, and also adds a great human, time and material cost.
Therefore, in view of the northeast cold winter, in the influence of less as far as possible the original exhaust system, how to improve the exhaust system to reduce or eliminate the burning ethanol and gasoline car out of the icy road to the water problem, ethanol and gasoline in cold area, and the application of road traffic congestion relief has a great and profound significance.
This design is mainly aimed at faw car exhaust device, opened first introduced the exhaust device inside the jetta structure, working principle and operation. Based on this, puts forward a kind of to test for the purpose of exhaust device test bench design scheme. According to its performance testing purpose, this test bench is characteristic of the structure are relatively simple, test bench with digital display temperature sensor, facilitate in the study, let the operator can learn about and by changing different exhaust device performance testing to enhance its beginning ability, to achieve good testing result.
Key words：Exhaust device；Muffler；Experimental stage；Trial；Temperature；
目 录
摘 要 I
Abstract II
第1章 绪 论 1
1.1 课题的来源和意义 1
1.2 汽车试验装置的发展概况 1
1.3 汽车排气装置性能试验台国内外发展概况 2
1.4 本课题研究内容及主要工作 3
第2章 汽车排气装置的组成和工作原理 5
2.1汽车排气装置的作用和组成 5
2.2汽车排气装置的工作原理 5
2.3汽车排气装置相关资料 8
2.4 本章小结 9
第3章 燃乙醇汽油车排气管内部温度与滴水量测定试验方案设计 10
3.1试验方案 10
3.2试验装置 10
3.3排气管内部温度变化的测定 12
3.3.1怠速试验 12
3.3.1.1平地怠速试验 12
3.3.1.2坡道怠速试验 14
3.3.2低速工况试验 15
3.3.3中速工况试验 16
3.3.4高速工况试验 17
3.4排气尾管末端滴水量的试验测定 18
3.4.1怠速试验 18
3.4.1.1平地怠速试验 18
3.4.1.2坡道怠速试验 18
3.4.2低速工况试验 19
3.4.3中速工况试验 19
3.4.4高速工况试验 20
3.5排气管末端滴水量的分析 21
3.6本章小结 21
第4章 捷达汽车消声器结构改进设计 22
4.1 乙醇汽油燃烧理化特性分析 22
4.1.1车用乙醇汽油的定义 22
4.1.2车用乙醇汽油的优点 22
4.2材料涂层保温特性分析以及热传递效率分析 23
4.3汽车消声器制作加工工艺 24
4.3.1汽车消声器介绍 24
4.3.2消声器的技术指标 25
4.3.3消声器的设计步骤 27
4.4消声器改进及设计 27
4.5 本章小结 28
第5章 汽车排气装置性能实验台整体结构设计及校核 29
5.1 实验台总体设计方案 29
5.2定位件的校核 31
5.3 实验台的整体校核 31
5.4 本章小结 31
结 论 34
参考文献 35
致 谢 36
附录A 37
附录B 38
