Effect of O2 and H2O on the Degradation of SF6 by Pulsed DBD
SF6 is widely used in various high voltage electrical equipment because of its excellent insulation performance.However,SF6 is a strong greenhouse effect gas.The degradation of SF6 can greatly reduce the harm of SF6 to the atmos-phere.In this study,SF6 was degraded by pulsed dielectric barrier discharge plasma with the addition of O2 and H2O.The results showed that the addition of O2 could promote the discharge current,and the degradation of SF6 could be effectively promoted by the addition of appropriate amount of O2.With the increase of O2 content,the degradation rate and energy efficiency of SF6 first increased and then decreased.The reaction system obtained the highest degradation rate and energy efficiency of 58.40%and 5.24 g/kWh,respectively,when the input power was 45 W,the gas flow rate was 50 mL/min,the content of O2 was 1%and the content of SF6 was 2%.In the SF6/Ar/O2/H2O system,the addition of H2O could im-prove the degradation rate of SF6.When 1%H2O was added,the degradation rate of SF6 had the best degradation effect,but the degradation rate gradually decreased with the increase of H2O content.The degradation rate and energy efficiency of SF6 were 89.7%and 8.05 g/kWh,respectively,when 1%H2O and 1%O2 were added.In addition,the addition of O2 in-hibited the formation of SO2,while the addition of H2O promoted the production of SO2.At the same time,the product selectivity of SO2F2 gradually decreased with the increase of H2O content.In the SF6/Ar/O2 system,SO2F2 and SOF4 are the main components of the degradation products,and there are also decomposition products such as SOF2,SO2,SiF4 and SF4.In this paper,the decomposition path of O2 in SF6 is analyzed in detail according to the infrared spectra and decom-position products.