真空断路器铜铬金属蒸气等离子体非局部热力学平衡态物性参数分析

Analysis of Physical Properties Parameters of CuCr Metal Vapor Plasma under Non-Local Thermodynamic Equilibrium State for Vacuum Circuit Breaker

真空断路器在大电流故障开断过程中,以真空为介质条件的灭弧系统内所产生的金属蒸气电弧等离子体组氛与电极材料特性密切相关。为了研究开断过程中金属蒸气等离子体物性参数的变化,以真空断路器CuCr25~CuCr75触头电极材料为研究对象,建立非局部热力学平衡模型,研究铜铬合金不同配比下金属蒸气等离子体粒子组氛分布。采用统计热力学方法求得等离子体热力学参数,分析不同合金配比下比焓和比定压热容分布;利用Chapman-Enskog法计算等离子体输运参数,探究铜铬合金材料配比对电导率的影响。

In the large current-breaking process of the DC vacuum circuit breaker,the metal vapor arc plasma generated in the vacuum interrupter is closely related to the material properties of the contact electrode.In order to study the variation of metal vapor plasma physical properties parameters in the process of breaking,the non-local thermodynamic equilibrium model of vacuum arc plasma was established to obtain the composition distribution of particles of metal vapor plasma of CuCr25~CuCr75 contact.Moreover,using the statistical thermodynamic method,the thermodynamic parameters of metal vapor plasma were calculated,and the distribution of specific enthalpy and isobaric specific heat capacity with different alloy ratios were illustrated.Furthermore,the Chapman-Enskog method was used to calculate the transport parameters to investigate the effect of alloy ratio on the conductivity.