A 2D transient mathematical model was established to separately describe the anode bubble dynamics and the bubbleinduced electrolyte motion in the rare earth electrolysis cell with horizontal electrode.Results indicat...A 2D transient mathematical model was established to separately describe the anode bubble dynamics and the bubbleinduced electrolyte motion in the rare earth electrolysis cell with horizontal electrode.Results indicate that with the increase in the anode inclined angle,the maximum bubble thickness is increased gradually.Furthermore,compared with the conventional anode,the inclined and chamfered anodes are conductive to the bubble length reduction and the bubble velocity improvement.Meanwhile,the bubble-induced electrolyte motion in the electrolysis cell can improve the distribution and transport process of oxyfluorides,thereby enhancing the current efficiency.Finally,a novel feeding method based on the electrolyte flow is proposed.展开更多
Arc flashes pose significant hazards to personnel working with energised power lines due to their high thermal risk,quantified by incident energy(IE)in joules or calories per area.Accurate estimation of IE is crucial ...Arc flashes pose significant hazards to personnel working with energised power lines due to their high thermal risk,quantified by incident energy(IE)in joules or calories per area.Accurate estimation of IE is crucial for ensuring safety.The most widely employed method for estimating IE from an arc flash is outlined in IEEE Std 1584-2018,which applies exclusively to three-phase AC arc flashes.However,limited research has explored alternative methods due to the complexities,costs,and preparation involved.Numerical simulations offer a viable alternative for studying arc flashes.This paper introduces a multiphysics simulation approach for determining IE by modelling three-phase AC arc flashes using the magnetohydrodynamics(MHD)theory.This study exclusively investigates horizontal electrodes in open-air(HOA)configuration due to the specific characteristics of the local power system configuration,which predominantly features overhead power lines,and the available test setup in the laboratory.The IE derived from simulations is compared with measurements from an arc flash laboratory based on IEEE Std 1584-2018 and with the IE calculated by the standard itself.The results indicate a significant alignment between this innovative approach and other methods for estimating IE for three-phase arc flashes.展开更多
In this work,the results of an experimental study of the impulse characteristic of practical ground electrodes consisting of horizontal conductors of various lengths and full-scale tower footings were reported.These e...In this work,the results of an experimental study of the impulse characteristic of practical ground electrodes consisting of horizontal conductors of various lengths and full-scale tower footings were reported.These electrodes were installed at an outdoor test site having nonuniform soil,with equipment facilities for generating low-and high-magnitude impulse currents.The tests on the horizontal electrode were used to determine the effective length,the voltage and current distribution along the electrode length and the effect of the injection point along the electrode.The tests on the tower footings were used to determine impulse resistance and demonstrate its non-linear variation with current magnitude.Computer simulations of the test electrodes using the electromagnetic field method showed good agreement with the measured result.展开更多
基金National Natural Science Foundation of China(52101165)Inner Mongolia Science and Technology Major Project(2020ZD0010)Key Research Program of the Chinese Academy of Sciences(ZDRW-CN-2021-3)。
文摘A 2D transient mathematical model was established to separately describe the anode bubble dynamics and the bubbleinduced electrolyte motion in the rare earth electrolysis cell with horizontal electrode.Results indicate that with the increase in the anode inclined angle,the maximum bubble thickness is increased gradually.Furthermore,compared with the conventional anode,the inclined and chamfered anodes are conductive to the bubble length reduction and the bubble velocity improvement.Meanwhile,the bubble-induced electrolyte motion in the electrolysis cell can improve the distribution and transport process of oxyfluorides,thereby enhancing the current efficiency.Finally,a novel feeding method based on the electrolyte flow is proposed.
基金CPFL Group,Grant/Award Number:PD-00396-3104/2024Federal University of Santa Maria+3 种基金Electrical Engineering Graduate Program of UFSMNational Institute of Science and Technology—Distributed GenerationSmart Grids Institute of UFSMCoordenação de Aperfeiçoamento de Pessoal de Nível Superior—Brazil—Financing Code 001。
文摘Arc flashes pose significant hazards to personnel working with energised power lines due to their high thermal risk,quantified by incident energy(IE)in joules or calories per area.Accurate estimation of IE is crucial for ensuring safety.The most widely employed method for estimating IE from an arc flash is outlined in IEEE Std 1584-2018,which applies exclusively to three-phase AC arc flashes.However,limited research has explored alternative methods due to the complexities,costs,and preparation involved.Numerical simulations offer a viable alternative for studying arc flashes.This paper introduces a multiphysics simulation approach for determining IE by modelling three-phase AC arc flashes using the magnetohydrodynamics(MHD)theory.This study exclusively investigates horizontal electrodes in open-air(HOA)configuration due to the specific characteristics of the local power system configuration,which predominantly features overhead power lines,and the available test setup in the laboratory.The IE derived from simulations is compared with measurements from an arc flash laboratory based on IEEE Std 1584-2018 and with the IE calculated by the standard itself.The results indicate a significant alignment between this innovative approach and other methods for estimating IE for three-phase arc flashes.
文摘In this work,the results of an experimental study of the impulse characteristic of practical ground electrodes consisting of horizontal conductors of various lengths and full-scale tower footings were reported.These electrodes were installed at an outdoor test site having nonuniform soil,with equipment facilities for generating low-and high-magnitude impulse currents.The tests on the horizontal electrode were used to determine the effective length,the voltage and current distribution along the electrode length and the effect of the injection point along the electrode.The tests on the tower footings were used to determine impulse resistance and demonstrate its non-linear variation with current magnitude.Computer simulations of the test electrodes using the electromagnetic field method showed good agreement with the measured result.
