Analysis of 3D Flow Field in Rotary-Gas High Voltage SF6 Circuit Breaker with Different Blade Nozzle

A 252kV single-break SF6 circuit breaker is taken as the investigation model in this paper, the 3D cold arc-quenching chamber calculation model of traditional nozzle without blade and six different nozzles with different blade contour are presented based on 3D N-S equations. The variations of the cold flow field parameters in arc-quenching chamber with different blade nozzles have been obtained using finite volume method (FVM) during the interrupting, and the effect on 3D flow field by different blade nozzles is analyzed emphatically. The influences of blade contour on gas flow velocity, pressure-temperature ratio and pressure in arc-quenching chamber are analyzed by changing the angle, number and the height of the blade in the circumstances of keeping flow unchanged, and the reasonable nozzle blade structure of circuit breaker is obtained.