郑州科技学院
毕业设计（论文）
设计（论文）题目：涡轮增压发动机在公交
车上的应用
所在系：机械工程系
专业名称：公交车检测与维修
学生姓名：
学号：
指导教师：
完成时间：2010年3月10日
涡轮增压发动机在公交车上的应用
摘要
城市公交车用六缸涡轮增压发动机上进行可变喷嘴涡轮增压器(VNT)的匹配与优化，旨在提高城市公交车用涡轮增压发动机的低速扭矩，降低排气烟度，提高公交车用涡轮增压发动机的加速响应性能，解决加速时冒黑烟严重的现象，同时使涡轮增压发动机的经济性得到提高。通过对城市公交车用涡轮增压发动机典型工况的分析，总结了城市公交车用涡轮增压发动机的运行特点，并且提出了采用VNT对其进行改善的方案。继而对VNT的优化和匹配，通过大量的试验验证，总结和分析了VNT电控系统对公交车用涡轮增压发动机性能和排放的影响规律，确定综合电控方案中各系统的最佳优化规律和电控脉谱。可变喷嘴涡轮增压器(VNT)的作用像一个尺寸按无级变化的涡轮壳，通过改变喷嘴环叶片的转角位置来改变涡轮的流通面积，进而控制增压器的转速和增压压力，在发动机宽阔的转速范围内获得最佳的增压匹配，使发动机不仅能够保持高速时的涡轮效率，而且可以提高低速时的涡轮效率，能大幅度减低低速烟度，扩大低油耗的运行区，提高发动机的加速性。同时，VNT增压器可减低涡轮滞后，提高发动机的瞬态响应性。另外，VNT还具有结构紧凑，匹配方式灵活，增压系统改动少，控制方式简单等优点。
关键词涡轮增压器发动机公交车
Turbo-charged engine in the application of buses
ABSTRACT
City buses with six-cylinder diesel engine on a variable nozzle turbocharger (VNT) of the matching and optimization, aimed at improving the urban public transport low-speed diesel engine torque to reduce exhaust smoke, improve bus speed diesel engine response performance to address the serious phenomenon of black smoke when accelerating, while making the economics of diesel engine has been upgraded. Through a typical urban bus diesel engine condition analysis, summarized in urban bus diesel engine operating characteristics, and proposed use of VNT for improvement of their programs. Then the optimization of the VNT and matching, through a large number of test validation,Summarizing and analyzing the VNT bus electronic control system for diesel engine performance and emissions impact of the law to determine the integrated power control scheme in the best optimization of the law of the systems and electric control pulse spectrum. Variable Nozzle Turbocharger (VNT) role as a change in size under the no-class turbine shell, the nozzle ring by changing the blade angle to change the location of the flow of turbine size, and thus control the speed and the turbocharger boost pressure, a wide range of engine speed within the optimum pressurization match, so that the engine not only to maintain the high speed of the turbine efficiency, but also can improve the low speed of the turbine efficiency, can greatly reduce the low-smoke, low fuel consumption to expand The operation area, to improve the engine acceleration. At the same time, VNT turbocharger to reduce turbo lag, improve transient response of the engine. In addition, VNT also has a compact structure, matching flexible and change less pressurization system, the control is simple and so on.
KEYWORD turbocharger engine buses
目录
中文摘要 (Ⅰ)
英文摘要 (Ⅱ)
1 前言 (1)
2 涡轮增压的原理 (1)
3 涡轮增压的种类 (7)
3.1 机械增压系统 (8)
3.2 气波增压系统 (8)
3.3 废气涡轮增压系统 (8)
3.4 复合增压系统 (8)
4 涡轮增压发动机的缺点 (8)
5 涡轮增压发动机在公交车的使用 (9)
结论 (12)
致谢 (13)
参考文献 (14)
