Experimental study on the effect of H2O and O2 on the degradation of SF6 by pulsed dielectric barrier discharge

Abstract

SF6 has excellent insulation performance and arc extinguishing ability, and is widely used in the power industry. However, its global warming potential is about 23500 times that of CO2, and it can exist stably in the atmospheric environment, is not easy to degrade, and has great potential harm to the environment. Based on pulsed dielectric barrier discharge plasma technology, the effects of H2O and O2 on the degradation of SF6 were studied. Studies have shown that H2O and O2 can effectively promote the decomposition of SF6 and improve its degradation rate and energy efficiency. Under the action of pulse input voltage and an input frequency of 15 kV and 15 kHz respectively, when H2O has added alone, the effect of 1 % H2O is the best, and the degradation rate and energy efficiency of SF6 reach the maximum, which is 91.9 % and 8.25 g/kWh, respectively. The synergistic effect of H2O and O2 on the degradation of SF6 was similar to that of H2O. When the concentration of H2O and O2 was 1 %, the system obtained the best degradation rate and energy efficiency, which were 89.7 % and 8.05 g / kWh, respectively. At the same time, different external gases exhibit different decomposition product regulation capabilities. The addition of H2O can effectively improve the selectivity of SO2. Under the synergistic effect of H2O and O2, with the increase of O2 concentration, the degradation products gradually transformed into SO2F2.