不同操作参数下介质阻挡放电的固氮性能研究及机理分析

介质阻挡放电(DBD)是一种典型的低温气体放电等离子体手段，能够在温和的条件下产生大面积的放电等离子体从而进行固氮，具有绿色环保、高效节能等特点。然而目前DBD的固氮能耗偏高，有着相当大的优化空间。探究了调控电压与气流量对DBD固氮性能的影响，以液相固氮的形式考察了总氮浓度TNC和固氮能耗EC的变化情况，并通过分析DBD气相产物变化规律揭示了DBD固氮的反应机理。研究发现，不同条件下的DBD气相产物会处于臭氧模式、过渡模式和氮氧化物模式三种模式之一，而各实验条件下的EC最小值均处于过渡模式，分析其原因在于该模式下可以有效生成NO₂和N₂O₅，提升可溶性氮的占比进而促进了固氮效果。EC的最小值在电压为18 kV、气流量为8 L/min时取得，为31.69 MJ/mol。

Study on nitrogen fixation performance and mechanism analysis of dielectric barrier discharge under different operating parameters

Dielectric barrier discharge (DBD) is a typical low-temperature gas discharge plasma method, which can generate a large area of ​​discharge plasma under mild conditions for nitrogen fixation, and has the characteristics of green environmental protection, high efficiency and energy saving. The energy consumption for nitrogen fixation of DBD on the high side, however, has a large optimization space. The influence of regulated voltage and gas flow rate on performance of DBD nitrogen fixation was explored to investigate the variation of total nitrogen concentration (TNC) and energy consumption (EC) in the form of liquid nitrogen fixation. Besides, the reaction mechanism of DBD nitrogen fixation was revealed by analyzing the variation rule of DBD gas phase products. It was found that DBD gaseous phase products under different conditions were in one of the three modes of ozone mode, transition mode and nitrogen oxide mode, and the minimum EC of each experimental group were all in transition mode. The reason was analyzed that NO₂ and N₂O₅ could be effectively generated under this mode, which improved the proportion of soluble nitrogen and thus promoted the nitrogen fixation effect. The minimum value of EC is 31.69 MJ/mol when the voltage is 18 kV and the gas flow is 8 L/min.