Numerical Simulation Of Catalytic Converter And Emissions Of Motorcycle For National Stage Ⅲ Standards

This paper makes a motorcycle as the research object. The control of engine emissions was simulated on the basis of tests. First, the catalyst sample was simulated and analyzed and then it created an engine numerical model. Using the numerical model, the emission characteristics and conversion efficiency of catalytic converter were simulated under the steady-state operating condition. Finally, the UDC condition of the motorcycle was carried out. It formed a simulation method of engine emission control. Specific tasks are as the follows:â‘ The catalyst sample's characteristics of air-fuel ratio and light-off temperature when the oxygen balance factor was 0.97,1 and 1.03 were experimented by using the CES08A catalytic converter activity test equipment. The results of air-fuel ratio characteristics show that the conversion rate of CO is high, and the conversion rate maintains at above 90%. It is because that the formulation of catalyst is rich in the noble metals of Pt and Pd, which have a strong ability to cleansing CO. The results of light-off temperature characteristics show that the balance factor has little effect on CO. Model of catalytic chemical reaction was set up by using BOOST software. The results from numerical calculations have good agreement with experimental data, which prove the correctness of the model. It laid the foundation for the simulation of vehicle emissions. Based on the engine numerical model, the characteristics of engine's emission under different operating conditions were simulated.â‘¡Through the engine test platform, the engine full load characteristics and cylinder combustion pressure and intake and exhaust transient pressure were measured and analyzed. Based on the test, the engine numerical model was established by using the cyclic simulation software. At the same time, this paper made a detailed discussion of the parameters in the model. The simulation results contrasted with the experimental results verified the reliability of the model, and it had the foundation for the simulation of driving cycles.â‘¢The trial of steady-state conditions at different vehicle speed were tested on the chassis dynamometer and it got the emissions value before and after the first catalyst with or without the secondary air injection. Using the numerical model, this condition was simulated. The trend of simulation results and experimental results was consistent. The emissions of motorcycle were test with the methods of direct sampling and constant volume sampling when it operated at the UDC condition. The constant volume sampling results showed that the national stageâ…¢emission standards was met. The single urban driving cycle was simulated with the numerical model and the cumulative emission of CO from simulation was close to the actual result. So the simulation provided some assistance for the test.