System Simulation Analysis Of Gasoline Exhaust Gas Recirculation (EGR) Control

In the past one or two years, both northern and southern areas have suffered the effectsof the haze weather, which make people take more attention to air pollution. The hazeweather not only cause serious damage to the human body, but also increasingly affects ourdaily life. The exhaust gas of Motor vehicle occupy a certain proportion of pollution in theatmosphere, the country and the world organization of the motor vehicle emissions bringmore regulations and strict standards. Not up to standard cars are not allowed to put intoproduction or on the road. This paper mainly research on gasoline engine emissions. Thekey to control the vehicle exhaust pollution is to minimize the NOx in the automobileexhaust emissions.The main purpose of the thesis is in keeping with the car economy and powerperformance, improves the emission performance of the car, reduce the emission of NOx.As we all know, Oxygen-rich environment and high temperatures inside the cylinder aretwo necessary conditions for the main pollutants generated NOx. Exhaust gas recirculationsystem (EGR) is to take the exhaust gas reintroduced to the intake manifold, into the enginecylinder, destroying oxygen cylinder and high temperature environment, thereby reducingthe emission of NOx.Through the analysis of the experiment, finally got the best engine EGR rate, which isthe core of this paper is a key part can achieve the desired tests. For the best EGR rate, isdetermined by the test of experimental engine in a number of specific conditions. When weobtained the best EGR engine at different operating conditions, we can then obtain the bestEGR rate control MAP graph, which is to determinate size of the opening angle valvecontrol EGR basis. The engine under different working conditions, there is an optimal EGRwith the corresponding rate (or value), determine its MAP diagram, according to thenumber of rotation steps of the stepping motor, which controls the EGR valve openingangle size. Using this method, we can make the engine NOx emission can be effectivelycontrolled.