Research On Emission Control Technology Of Gasoline Engline Based On EGR And LB

At present,the concentration and impact of domestic automobile exhaust pollutants range from 0.3 meters to 2 meters(the range that enters the main organs and respiratory passages of the human body),which is very harmful to human health and the environment.Engine exhaust gas recirculation combustion technology can effectively improve the mass fraction and fuel economy of the combustion mixture.Lean combustion(LB)technology makes the mass percentage of gasoline and oxygen in the engine not less than 1:25,effectively improving the combustion performance.Combining exhaust gas recirculation combustion technology and lean combustion technology can give full play to the advantages of both,effectively reduce the probability of deflagration in gasoline engines,reduce incomplete combustion compounds such as nitrogen oxides(NOx),carbon monoxide(CO)and hydrocarbons(HC),and improve gasoline engines.Combustion quality and efficiency.The research goal of this subject is to combine lean combustion technology with engine exhaust gas recirculation through precise control,and lay a technical foundation for improving the emission performance of gasoline engines.The specific research contents are as follows:(1)Analyze the research status and development prospects of gasoline engine emission control,compare the applicable occasions,advantages and disadvantages of several commonly used gasoline engine exhaust emission control technologies,and then formulate an organic combination of lean combustion technology and engine exhaust gas recirculation as a gasoline engine exhaust emission control Scheme and control method of exhaust gas recirculation under different working conditions.The EGR engine electronic control system module with DSP(ECU)sensor as the control core has been established.According to the working condition parameters collected by the electronic sensor,the opening degree of the relevant EGR valve is accurately discriminated and automatically adjusted to realize the precise adjustment of the amount of recirculated exhaust gas.(2)Establish a mathematical model of the intake system of the gasoline engine and carry out optimization analysis of the air-fuel ratio.Based on the engine intake cycle state and the average value of emissions,a mathematical model of the engine intake system is established,the pressure and temperature changes in the intake manifold are studied,and the thermodynamic characteristics of the intake state are analyzed.Using GT-Power software to simulate and verify the structure and parameters of the established gasoline engine intake and exhaust system model,the air-fuel ratio optimization results show that the overall model accuracy is better,which can fully reflect the gasoline engine emission control performance.(3)Optimize and improve the conventional PID controller based on the particle swarm control algorithm.The values of throttle opening,engine speed and air-fuel ratio are selected as the input of engine combustion control,and the data input that affects the engine operating state and performance parameters are reasonably restricted and restricted.Based on the MATLAB software platform,a simulation experiment was conducted on the combustion performance of the engine.The exhaust emission and fuel consumption of the gasoline engine decreased significantly,which verified the accuracy,effectiveness and feasibility of the engine exhaust purification scheme.(4)Bench test was carried out on the experimental sample car using the simple transient operating method.The selected gasoline engine has a displacement of 1.8L,and the test results of the test vehicle emissions show that the engine combustion based on EGR and LB technology is accurately controlled,and the measured exhaust components CO(ppm),HC(ppm),NOx(ppm),CO2(%)are significantly lower than before,reaching the national six emission standards.