混联双级NTP系统协同DPF和SCR同步降低柴油机PM和NOx排放的化学反应机理研究

In order to simultaneously reducing diesel PM and NOx emissions, the techonology of combining multiple-series twin-stage NTP system with DPF and SCR will be applied, the mechanism of activity particles produced by the NTP system physically ablationing suspending carbon particles and chemically erosioning depositional carbon, as well as the chemical reaction mechanism of NTP-SCR system will be researched. Firstly, Electron energy distribution, species and life spans of active particles in NTP system and the dynamic function relationship of pollutants treatment efficiency with power input will be studied; Secondly, to study PM physical characteristics, such as microscopic morphology, particles size distribution, the number of concentration variation ,a model of activity particles produced by the NTP system physically ablationing suspending carbon particles will be built; to explore chemical variation of the PM element valence state, weightlessness characteristics, SOF component , a model of activity particles produced by the NTP system chemically erosioning depositional carbon will be established, too. Finally, a modified NTP-SCR model will be set up to research the flexible expanding capacity of NTP tandem system to SCR activity temperature window.The work will lay a theoretical foundation and scientific basis for simultaneously decomposing PM and NOx of diesel using the techonology of multiple-series twin-stage NTP system combining with DPF and SCR.

利用混联双级NTP系统协同DPF和SCR同步降低柴油机PM和NOx排放，对NTP系统活性粒子物理消融悬浮碳粒和化学剥蚀积碳，以及NTP-SCR系统的化学反应机理进行研究。探索NTP系统电子能量分布及跃迁、活性物质种类及其生命周期规律，系统能量注入与排放污染物处理效率的动态函数关系；建立一级NTP喷射系统活性粒子物理消融悬浮碳粒模型，研究PM微观形态、粒径分布、数量浓度等物理特性的变化规律；建立活性粒子化学剥蚀积碳的化学模型，探索PM元素价态、失重特性、SOF组分等化学特性变化机制；建立改进型NTP-SCR模型，研究二级NTP串联系统对SCR活性温度窗口的柔性拓展能力，为利用NTP结合DPF和SCR技术同步降低柴油机PM和NOx排放奠定理论基础和科学依据。

通过对DBD型NTP放电特性的研究，对放电空间活性粒子的物化形态及生命周期规律进行了研究；结合内燃机排放污染物的生成及转化机理，设计了适于柴油机后处理系统的双介质NTP反应器，首先利用该反应器开展了空气放电试验研究，并对该反应器工作参数进行了优化；其次利用该NTP反应器对柴油机排放污染物中的NOx进行了预氧化研究，探寻了NTP预氧化NO的化学反应机理；然后开展了SCR后处理系统降低柴油机NOx排放的研究工作，通过台架试验，细致分析了SCR系统转化效率的影响因素和SCR系统的NH3存储特性，结合CAE分析方法，对SCR系统内部流场、温度场、物质分布场进行了探讨，最后探讨了NTP系统对SCR催化活性温度窗口的柔性扩展能力，研究结果为利用NTP技术降低柴油机排放污染物提供了理论依据。