| Controlling of harmful emissions from diesel engine has always being research hot spot of domestic and overseas scholars. Non-thermal Plasma technology (NTP) is a new type of industrial decontamination method. Many middle state high-energy particles from NTP can make chemical reactions which are hard to be achieved in general condition to start. It has wide usage conversion efficiency, low consumption, control convenient and other advantages. It may become the main technical means to decomposition the passageway carbon, super fine PM and NOx and other harmful emissions from diesel exhaust. An approach of diesel exhaust gas treatment applying DNTP/INTP system was proposed in this paper. Gas flow inner DNTP/INTP system, particulate matters deposition and mechanism of NTP reaction on mixtures composing various components were investigated. The rule of diesel exhaust gas decomposition of DNTP system were studied and the feasibility of DPF regeneration using INTP system were verified, which are of great significance for effective treatment of diesel exhaust gas. The following research work had been done in the dissertation.(1) Different DNTP system internal flow field mathematical model is established with inlet and outlet relative deflection angle 0°,30°and 45°and the inside gas flow characteristics was simulated. The results show that while the inlet and outlet relative deflection angle is 30°, the air flow along the inside electrode surface and move forward spirally. The flow distance in the discharge area prolong and increase the contract area. The air flow from the reaction zone outlet into the total exhaust pipe crosses to form'#'style. Four strands of crossed flow air do not collide with each other; the turbulent kinetic energy in total exhaust pipes is distributed in a spiral star style to be more uniform for gas flow. Meanwhile, the temperature distribution is more uniform in the DNTP and the gas flow character is improved.(2) Internal two phase flow models of DNTP system with different structure are established. And how the internal electrode structure, inlet gas flow velocity, particle dimension etc. react on particle tracks distribution and particle deposition is studied. The research results show that the particle flow speed in the reaction area is stable and is difficult to deposit. The residence time prolong, the flow speed is low and is easy to deposit in the inside electrode lumen, the semi-closed space on the left intake of reaction area and the semi-closed space on the right outlet of reaction area to impact the working stability of the reactor. When the inlet and outlet relative deflection angle is 30°, the particles inside the reactor deposition rates is low. Particle size has greater influence on the deposition rate, the particle deposition rates increase with particle size rising.(3) Internal active substances track line of INTP system with different inject angles is analysed to determine the optimum inject angle. The impact of jet speed on active substances with exhaust mixed flow field distribution characteristics is analyzed and uses INTP system for DPF regeneration. The results show that when the inject angle is 45°, active substances collide and rendezvous with exhaust in the exhaust pipe to form the turbulence to realize the active substances and exhaust fast mixing, help to improve the catalytic conversion efficiency of active substances on NOX and PM, the improvement of injection velocity could enhance the intensity of eddy near injecting valve and then increase the internal turbulent energy of the system, which is helpful for fast mix of active material and exhaust gas. If the operating parameter of INTP system is right, DPF could be regenerated completely. (4) Use different gas ratio constituents system to form different mixtures to carry out the simulated experiment. The comparative study of function law of different internal electrode structures of DNTP system on gas mixture is carried out. The discharge emission spectrum of N2 and NO in different mixtures are tested by the emission spectrum diagnosis technology. Comparison and analysis on the electrode structure, electrical parameters and gas composition on the NTP active material processing NO reaction mechanism and the influence law are carried out. The activity in the energy level structure of particles, motion between particles and the interaction law and other information in DNTP system are studied. Real-time monitor excited states particles with short discharge space life cycle and explore the outside the nuclear particle excited states electronic warp ray of light energy parameters, explores the NTP responses in mechanism. The following results were obtained:①For different structure generator, the discharge power will increase as peak voltage increases. The discharge power will reduce with the increasing of gas flow rate in the same peak voltage.②For the N2/NO mixture gas, when the inlet and outlet relative deflection angle is 30°, the discharge power is larger than the 0°one. When the peak voltage is 17 kV, discharge is more uniform in the 30°electrode reactor discharge area and the conversion rate of NO can reach 97%, the power need is 21watt, the corresponding NO-y emission spectrum peak is 3815 a.u, the peak strength of N2 second emission spectrum is 8525 a.u. When the inlet and outlet relative deflection angle is 0°and the peak voltage is 17 kV, the conversion rate of NO is 65%, the power need is 21watt, the corresponding NO-y emission spectrum peak is 22770 a.u, the peak strength of N2 second emission spectrum is 5904 a.u.③For the N2/NO/C3H6 mixture gas, when electrode structure is different, the discharge power increase as the peak voltage increase. When the inlet and outlet relative deflection angle is 30°, discharge is more uniform in the internal electrode reactor discharge area, the discharge power increase rapidly. The NOx has the highest conversion rate while the flow rate of C3H6 is 6001m/min. While when the inlet and outlet relative deflection angle is 0°, the NOx has the highest conversion rate while the flow rate of C3H6 is 7001m/min. For the above two kinds reactors, polymerization of mixture gases in the reaction area will happen, generate dark brown polymers, the main elements are N, C, H and O with strong adsorption effect and they can absorb emission spectrum produced by the gas discharge.④For the N2/NO/C3H6/O2 mixture gas, when the inlet and outlet relative deflection angle is 30°, C3H6 can participate in reaction makes NO convert into NO2 gas. When the concentration of C3H6 is 1220x10-6 and the dischrage power 16 watt,75% of NO can be converted but the oncentration of NOX is still high. When the concentration of C3H6 is 200×10-6 and the dischrage power 28 watt, the NOX in mixture can reach the lowest concentration. O2 in the N2/NO/C3H6/O2 mixture gas has the quenches role on NO(A2 a+) andN2 (C3Pu).(5) The bench test research of the DNTP system for real-time processing of diesel exhaust was carried out. Concentration variations of CO, NO, NO2 and soot of diesel exhaust with and without the treatment of DNTP system were analyzed. The INTP system was used for the offline regeneration of DPF. The variation of the exhaust components in the DPF regeneration process and the probable reaction were also studied. A complete regeneration of DPF was achieved in the experiment. The results indicated:with the increasing of diesel engine load, the O2 content in the exhaust decreased with and without the treatment of DNTP system. When the engine load was less than 75%, the CO concentration decreased with the increasing of the engine load and the CO concentration in the gas with the treatment of DNTP system was higher than that without the treatment. When the engine load was higher than 75%, the CO concentration increased with the increasing of the engine load. The CO concentration in the exhaust with the treatment of DNTP system was low when the engine load was increased to 100%. The NO concentration increased with the increasing of the engine load, and the NO concentration in the exhaust treated by DNTP system was lower than that of untreated. The NO2 concentration in the exhaust treated by DNTP system was higher than that of untreated when the load was low. As diesel load increased, the NO2 generated in the DNTP system quickly reduced by oxidizing PM, CO, HC in the exhaust. A complete regeneration of DPF could be achieved with the treatment of INTP system by controlling the appropriate electrical parameters and environment conditions.
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