中文摘要：

为提高高压SF6断路器中介质恢复和开断能力,提出了涡流冷却气吹技术。在高压SF6断路器中构造新型轴流式涡流喷口结构,使气体在开断过程中动能径向交换,形成沿径向温度梯度,实现高压气流能量分离。以550 k V SF6断路器为例,采用有限体积法,建立3维气流场物理数学模型,研究了容性小电流开断下,喷口上游构造的＂X＂形导流片对灭弧室内气流参数的影响。并基于流注理论,对有、无导流片结构的断路器介质恢复特性进行数值计算与定量分析。结果表明：导流片结构改变流体运动形态,形成大旋转曲率强旋流动,有效实现能量分离,且能延长气流滞留时间,提高气流利用效率;新型轴流式喷口结构具有更高的介质强度恢复特性。

英文摘要：

To improve the dielectric recovery and current interruption ability of high-voltage SF6 circuit breakers （HV SF6 CBs）, we proposed a technology of vortex gas flow cooling. A novel axial vortex chamber structure was constructed at the nozzle of a HV SF6 CB to induce the energy exchange of turbulent gas flow in the radial direction during the interrup- tion,consequently, the temperature gradient could be formed along the radial direction to further realize the energy separation of the high-pressure gas flow. Taking a 550 kV SF6 CB as the example, we used the finite volume method to build a 3-D flow field-mathematical model under the small capacitive current interruption, and studied the influence of X-shaped guide blade structure on the flow field. Based on the streamer theory, the gas dielectric recovery characteristics in the chamber in the presence and absence of X-shaped guide blade nozzles were also calculated and compared. The re- suits show that the X-shaped guide blade shifts the form of axial flow into strong rotary blow that forms energy separation effect and it prolongs the time of airflow in the chamber and increases the efficiency of the air flow. Moreover, the gas di- electric recovery characteristic is improved with the novel axial flow nozzle structure.