Numerical simulation of two-dimensional gas flow in puffer-type SF 6 circuit breaker during short current interruption

The paper presents a model to analyze the convection-stabilized local thermodynamic equilibrium electric arc occurring in the arc-quenching chamber of puffer-type circuit breakers during a short-current interruption, which is described with the axial-symmetric Euler´s equations and coupled with a one-dimensional electric field. Employing the modified fluid in cell (FLIC) method, the gas flow has been calculated during both loading and nonloading interruption in a 550 kV two-break puffer-type circuit breaker. At the same time, the phenomenon of thermal block and back flow caused by the arc have been simulated for the sake of the analysis of effects of the arc on gas flow. Furthermore, the paper has also calculated the effects of nozzle structure on gas flow, which makes it possible to optimize the design of the breaker