Numerical thermofluid simulation of high current air arcs at fault point contaminated with metal vapor from evaporation of metal electrode in open air

Abstract

AbstractA numerical simulation was conducted to simulate behavior of an arc discharge in open air contaminated with metallic vapor for kA‐class high current. This simulation is concerned with a fundamental study on an arc discharge in a high‐energy arcing fault (HEAF), which can be found occasionally in electric equipment inside nuclear power plants. To understand phenomena in HEAF, it is useful to study air arc behavior at high fault currents, considering metallic vapor contamination from the metallic electrodes because the fault arcs often form in air between metallic parts in electric equipment. In this model, metal electrode evaporation and metal vapor contamination of the arcs were taken into account. Using this model, the temperature, pressure rise, and heat flux in arc plasmas established between Fe electrodes were calculated for ac currents of 3, 5, and 7 kApeak in open air. © 2019 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.