Numerical study of the arc-quenching performance of eco-friendly C4F7N/CO2/O2 gas mixtures

Abstract In response to the increasing demand for environmentally sustainable alternatives to SF 6 gas in arc-quenching applications, comparative studies are performed in the present work to explore the arc-quenching performance of a novel eco-friendly gas mixture composed of C 4 F 7 N, CO 2 and O 2 . Through a combination of experimental studies and numerical modelling, the arc dynamic characteristics are firstly evaluated for ternary C 4 F 7 N/CO 2 /O 2 gas mixtures with different mixing ratios. The results demonstrate that the variations in the volume concentrations of C 4 F 7 N and O 2 only have an insignificant influence on the arc performance, which is attributed to their similar thermophysical properties. Under the same operation conditions, the flow field distributions of the C 4 F 7 N/CO 2 /O 2 gas mixture differ from those of SF 6 and lead to a noticeable gap in its arc-quenching performance in comparison with SF 6 . Further analysis is performed on the effects of gas-filling pressure to assess whether the performance of C 4 F 7 N/CO 2 /O 2 gas mixture can be improved or not. Our findings suggest that a 6% C 4 F 7 N/84% CO 2 /10% O 2 gas mixture, when used at a higher filling pressure, is a more optimal choice. Finally, the decomposition characteristics of the C 4 F 7 N/CO 2 /O 2 gas mixture are compared to support the evaluation of its arc-quenching performance.