高压SF_6自能膨胀式断路器无载开断过程中灭弧室内气流场的数值分析

Numerical analysis of gas flow field during no\|load interruption in H.V. SF 6 auto\|expansion circuit breaker

本文以质量守恒定律、动量守恒定律和能量守恒定律为基础 ,数值分析了 SF6 自能膨胀式断路器无载开断过程中灭弧室内的气流场。气流场的变化分为三个阶段。在第一阶段中 ,膨胀室内气体压力、密度增加 ,为下一阶段吹弧做好准备。在第二阶段中 ,动静弧触头之间的区域形成滞止区 ,气流场在空心动弧触头及导电杆内达到超音速流 ,这些有利于电弧的熄灭。在第三阶段中 ,主喷口扩张区与喉部之间存在超音速流 ,影响介质恢复强度 ;在静弧触头边缘存在激波 。

The cold gas flow field in the interrupter of high voltage SF 6 auto\|expansion circuit breaker is investigated by numerical method based on the laws of mass, momentum and energy conservation. The change of the flow field is divided into three stages. The pressure and density are increased in the storage gas chamber at first stage. The arc is blown when the auxiliary nozzle is opened. The stagnation region emerges between moving contact and fixed contact, and there is supersonic flow at second stage. The dielectric strength is increased. At third stage, the supersonic flow in nozzle has influence on the dielectric strength. The shock wave counteracts the energy of arc to dissipate in the edge of fixed contact.