Dielectric barrier discharge (DBD), H₂, SF₆ degradation, product analysis, Electrical engineering. Electronics. Nuclear engineering, TK1-9971

Sulfur hexafluoride (SF6) is the most widely used gas insulation dielectric in power system, Currently, SF6 degradation technology based on non-thermal plasma faces issues with high content of difficult-to-treat byproducts like SO2F2. This study proposes improving the SF6 destruction and removal efficiency (DRE) through tandem DBD degradation and investigates the impact of adding H2 on the tandem DBD degradation of SF6 and its decomposition products. The results show that under conditions of 2% initial SF6 concentration, 1.5% H2, 150 mL/min gas flow rate, and 80W input power, the DRE in the first-stage tube is 73.2%, reaching 78.02% in the second-stage tube, and the DRE of SF6 in the dual-stage tandem reaches as high as 82.82%. In terms of decomposition products, there is no difference in the types of products formed in the two reaction tubes when H2 is added, and the main products are SO2F2, SO2, SOF2, and SOF4. The addition of H2 will inhibit the formation of S-O-F gas products, improves DRE and significantly regulates the distribution of degradation products, reducing the amount of SO2F2 generated in the second-stage tube and making SO2 the main product. Adding H2 with a concentration of 2.5 % can avoid the formation of SO2F2 in the second-stage tube. This study provides guidance for efficient SF6 degradation and product control.