【作者】 张多军；

【导师】 林学东；

【作者基本信息】 吉林大学 ， 动力机械及工程， 2005， 硕士

【摘要】 废气再循环(Exhaust Gas Re-circulation,EGR)是降低发动机氮氧化物(NOx)排放的一种非常有效的方法。随着电子控制技术的发展,电控EGR技术获得了广泛的研究和应用。本文是在GW2.8TDI 型增压柴油机上进行的一种柴油机电控EGR 系统的开发研究。进行了系统软硬件设计,并开发了系统与个人电脑(PC 机)之间的串行通信程序和通信界面。在硬件设计方面,加工了一块印刷电路板(PCB),基于Intel 公司的16 位单片微型计算机N80C196KC,扩展了程序存储器27128和可编程I/O 扩展接口8255,系统输入由霍尔传感器采集的转速和由滑片电阻器采集的油门位置信号,输出电磁阀开/关控制信号,并且用一块显示板实时显示了发动机的工况参数。系统控制软件用MCS-96 汇编语言编写,控制系统采取读取MAP 的方法对EGR 进行控制,EGR-MAP 通过试验标定法制取。在系统与PC 机的串行通信方面,将单片机采集到的发动机转速、油门位置等信号发送给PC 机上的显示界面,实现了发动机工况等参数的实时显示。以仪表或者以实时曲线形式显示了发动机转速等数据。完成后的系统完全脱离了PC 机和仿真器组成的开发平台而运行,即将系统软件烧写入单片机程序存储器(EPROM),系统直接从单片机外围扩展的EPROM 中读取程序而没有用仿真器执行程序。对系统装机进行了发动机台架试验。试验表明:系统可以可靠、有效的工作。它对NOx 排放具有很好的控制效果,在各个转速下的中小负荷对发动机的其它性能指标(烟度排放除外)也有很大的改善,在大负荷情况下发动机的烟度排放比较高,还需要对系统进行进一步的改进并且可能还需要对EGR-MAP 作进一步的调整。更多还原

【Abstract】 Nowadays, Automobiles are getting more and more dieselized. In America, Europe and Japan, 100 percent of heavy-duty vehicles and 90 percent of commercial vehicles are powered by diesel engines, and the percent of cars also increases yearly. But in our country, the percent of diesel vehicles, especially diesel cars are very little in the market, which is decided by the laggard diesel engine technology. In our country, the diesel engine technology is laggard behind the technology in foreign countries, and many technologies now widely used in foreign countries are during research or even blank in our country. We have no time to delay to speed up the research on the technology of diesel engine. In this thesis, we carried out some study on the electronically controlled EGR system. The platform for the development is WAVE E2000 simulator system and the tools used are oscillograph, signal generator, speed adjustable motor, program writer and program eraser etc. The engine tested is provided by BaoDing Great Wall Engine Made Company Ltd. The principle of the system is collecting speed and fuel adjusting position(FAP), and then judging the operating condition of the engine, and at last reading the MAP to control the EGR valves, which can lead to a lower NO_x emission, and in the mean time let the other emissions not very high. Our EGR-MAP is a steady operating condition MAP, which means that it was made in the conditions that the engine was working in steady status, and it lists the distributing of the number of the opened EGR valves on various engine operating conditions. When making the EGR-MAP, deciding speed and FAP as the two parameters. Speed can be measured conveniently by Hall sensor. Because the load cannot be measured with a sensor, we use dynamic FAP to evaluate it, the dynamic FAP and the FAP can be transfered into each other. Defined the 0% FAP, the 100% FAP and the zero-power-export FAP. Through engine bench test, converting the 0%～100% dynamic FAP to FAP, then during the making of the MAP, using the dynamic FAP to replace the load. The optimal EGR-MAP is made through engine bench test. The method of making the MAP is as follows: firstly, carrying out the engine bench test(load test) with the EGR valve neither opened, single opened and both opened, the speeds chosen for bench test are calculated according to the light-duty vehicle emission test circle; secondly, deciding the number of the opened EGR valve on some chosen engine operating condition points. At last extend the above choose to the areas including the points then the MAP was made. Designed a printed circuit board, on which there are single chip更多还原