Research On Purification Of Diesel Engine Exhaust By The Non-thermal Plasma Technology And Catalyst

At present, the researches on diesel engine emission reduction-technology mostly focus on inside treatment, and have become more mature. But the after-treatment technology will provide broader clew and more far-reaching foreground, as a result, this technology become a hotspot in automobile industry. In spite of this, current researches mainly aim at processing certain or two kinds of exhaust emissions. So some initial researches on the diesel engine control technology using Non-thermal Plasmas has been done this thesis, so as to decrease four toxicants at one time.Firstly, the reactor of Dielectric Barrier Discharge has been designed. The elemental physic-chemical reactions between different exhaust species were analyzed in the atmosphere of Non-thermal Plasmas at the beginning of this design. It aimed at seeing about the catalyzing mechanism of emission reduction applying Non-thermal Plasma and catalyst, then established a feasible route of reducing exhaust, and designed this reactor.Secondly, some factors such as the exhaust component, choice of catalysts, voltage and frequency of discharge, main configuration parameters of the reactor which affected on the reduction efficiency have been discussed from calculating simulation on chemical kinetics and experiments respectively based on a simulation tester, and some instructive conclusions were gained from this research: the existing of O₂ is a disadvantage to the removing of NO_x separately, but it promoted the contemporary removing of all noxious exhaust. The integrated performance of catalyst La_0.8K_0.2MnO₃ (LKM) was the best and fit for the designed reactor.Thirdly, the researches of energy consumption and integrative elimination efficiency on the reactor have been done based on an actual experimental engine test bed. The conception of energy density was introduced into this research and the relationship between the elimination efficiency of harmful gas and energy density was also opened out through abundant experimental data. It provided some instructions for seeking the best working point. In addition, it has been found that there was high elimination efficiency of this reactor on HC and CO, furthermore, HC could promote the elimination efficiency.Lastly, the outlook of Non-thermal Plasma technology for application on diesel emission after-treatment was also discussed in this paper.