Thermodynamic and Transport Characteristics of High Temperature Atmospheric Air Arcs containing Two Different Metal Vapor of Cu, Fe and Al

Abstract

Serious fault of high energy arcing fault (HEAF) can occur in electrical equipment. When a large current is supplied to a possible arc discharge, a sudden temperature rise and a pressure rise would occur inside the arc, which will cause serious damage to the power board and switchboard leading to fire accident. It is not realistic to consider and experimentally verify all the individual switchboard events, but the theoretical explanation of experimental observation data such as current-voltage characteristics and damage degree are necessary. The arc characteristics should be described with melting and vaporization of metal conductors, because it can directly influence on the arc performance due to changes in thermodynamics and transport characteristics. The present work provides the theoretical calculation results on thermodynamic and transport characteristics under atmospheric air from 300 K to 30,000 K considering two different metal vapor contamination of Cu, Fe and/or Al. Equilibrium compositions of air with two different metal vapor were calculated through the Gibbs free energy minimization method. Then, mass density, enthalpy, specific heat, electric conductivity, thermal conductivity and viscosity from 300 K to 30,000 K of air with/without metal vapor were calculated. These numerical calculation data would be very important for theoretical studies of atmospheric arcs of HEAF and thermal plasmas, and for the design of arc devices.