Research And Development Of The EGR System For The Light Trucks Based On The Emission State Standards Ⅲ

With the development of global automobile industry, the pollution caused by automobile exhaust has become more and more severe, especially NOx pollution. During these years, the government recognize the problem and legislate to limit the exhaust emission. As the main power source of vehicle, the question how to purify NOx emission for diesel has become one of the hotspots. Now, technology of EGR is known as the effective methods to purify NOx emission which is available for diesel.The purpose of this paper is to design a set of economic and practical EGR systems for the light trucks that use of a 4JB1ZQ diesel engine, in order to enable it to meet Emission State Standards III. It is including a designed and developed new type of cooler, a optimizing EGR control valve, and a use of single-chip developed EGR control system. In the finally, the light trucks through the real vehicle chassis dynamometer tests conducted tests to verify. The following are the main contents:The first part is to analysis the working principle and realization method of the EGR, and The overall design of the EGR is established according to the performance and structural characteristics of the diesel engine and vehicle.The second part is to design the EGR cooler. To select the structure of the cooler through compare the performance of the different structure cooler's damping rates and plug. At the same time, to determine initial the cooler's material and structural parameters according to the general principles and working conditions of the cooler design. And through some performance test to verify the performance of the cooler.The third part is to design a simple structure, convenient operation of the EGR control valve in accordance with the development characteristics and the economy of the EGR control valve. And to determine the performance parameters of the control valve selected.The fourth part is to carry out real vehicle chassis dynamometer test for the light trucks that installed in the EGR system designed, in accordance with the national standards on light trucks emission limits and measurement method.Finally is to analyzed the experimental data. The results show that the performance of the EGR system designed is good, and the light trucks meet Emission State Standards 3.