【摘要】 金属蒸气对真空击穿和真空灭弧室绝缘性能均有影响。本研究旨在明确真空灭弧室在电压老炼产生场发射电流条件下，触头间隙金属蒸气的扩散规律及瓷壳内壁表面的沉积情况。本文通过仿真方法，采用直接模拟蒙特卡洛方法并采用兰纳-琼斯势估算碰撞截面，计算真空灭弧室内金属蒸气的运动，研究不同屏蔽罩位置和几何形状对金属蒸气的吸收效果及金属蒸气在瓷壳上沉积情况。计算了5种真空灭弧室多重悬浮屏蔽系统在电压老炼1.5 ms后屏蔽罩的吸收率与金属在瓷壳内壁上的沉积率，并分析了不同触头开距对金属蒸气的扩散及沉积影响。仿真结果表明：在远离触头区域，金属蒸气近似呈自由粒子运动状态，瓷壳内壁特定位置会形成沉积条带，该现象与触头间隙和屏蔽罩的相对位置密切相关。主屏蔽罩的主要作用是吸收金属蒸气，随着触头开距不断增大，屏蔽罩吸收的金属蒸气量先小幅上升后下降；当动触头位置接近主屏蔽罩边界时，金属蒸气吸收率显著降低。本研究成果可为真空灭弧室屏蔽罩设计及电压老炼下金属蒸气在瓷壳表面的沉积提供依据。更多还原

【Abstract】 The metal vapor affects the breakdown and insulation of vacuum interrupters. This study aims to clarify the diffusion law of metal vapo in the contact gap and the distribution of metal vapors deposition on the surface of ceramic under field emission current of voltage conditioning in vacuum interrupters. Via simulation methods, the motion of metal vapor in the vacuum interrupter was calculated using the direct simulation Monte Carlo(DSMC) method, with the collision cross-section estimated based on the LennardJones potential. The absorption effect of metal vapor by shields with different positions and geometric shapes, as well as the metal vapor deposition on the ceramic envelope, were systematically investigated. The absorption rates of the shields and the deposition rates of metal on the surface of ceramic are calculated after 1.5 ms of voltage conditioning for five types of multiple floating shield configuration in vacuum interrupters. Moreover, the influence of different contact gaps on the diffusion and deposition of metal vapor is determined. The simulation results show that in the region far from the contacts, metal vapor approximately as free particles, and deposition bands are formed at specific positions on the inner wall of the ceramic envelope. This phenomenon is closely related to the relative positions of the contact gap and the shields. The main function of the main shield is to absorb metal vapor. As the contact gap distance increases, the amount of metal vapor absorbed by the shields first slightly increases and then decreases. When the moving contact is close to the boundary of the main shield, the metal vapor absorption rate decreases significantly. This research results of this study can provide a theoretical basis and technical reference for the design of vacuum interrupter shields and the control of metal vapor deposition on the ceramic envelope surface during voltage conditioning.更多还原