铜蒸气浓度对SF_6-Cu高温电弧物性参数的影响

Influence of Copper Concentration on Physical Property Parameters of High-temperature SF_6-Cu Arc

开关设备（例如高压SF6断路器）触头表面产生的铜金属蒸气会改变电弧等离子体的物理化学特性。因此在建立考虑金属烧蚀的流体仿真模型之前,需要确定含有金属蒸气的电弧等离子体的性质。文中基于吉布斯自由能最小化原理和Chapman-Enskog理论,计算了SF6-Cu混合气体电弧在0.6 MPa压强下、温度区间为300-30000K时的物性参数,包括平衡态粒子组分、统计热力学参数、输运系数和混合扩散系数,着重分析了铜蒸气浓度（最大90%）对上述物性参数的影响。结果表明少量的铜对物性参数无明显影响,但当铜蒸气浓度达到30%时则会显著改变上述参数。

The copper vapor resulting from electrode surfaces in switch devices, such as high-voltage circuit breakers, may modify the characteristics of arc plasmas. The corresponding properties of plasmas contaminated by the metallic vapor are therefore needed to be determined before setting up physical models considering the metal erosion. In this paper, the physical property parameters, including the equilibrium compositions, thermodynamic properties, transport coefficients, and combined diffusion coefficients of SF6-Cu mixtures are calculated at temperatures of 300-30,000 K and a pressure of 0.6 MPa based on the Gibbs energy minimization and Chapman- Enskog theory. The influences of copper proportion （up to 90%） on such properties are investigated. It is found that a small quantity of copper has no significant influence on the above thermo-physieal properties of SF6-Cu mixtures, while a large quantity of copper, can generally change these properties dramatically when the content is more than 30%.