摘要
电弧高温是机械绝缘节(简称“绝缘节”)烧损碳化导致其无法满足轨道电路绝缘要求的主要原因。基于磁流体动力学理论,考虑电磁场、热场、流场以及电弧物性参数的影响,在COMSOL软件中建立绝缘节电弧的多物理场耦合模型;通过仿真求解不同电弧作用次数、电弧电流以及电弧移动速度下的电弧温度分布,分析绝缘节碳化规律与钢轨温升规律。结果表明:在较低电弧电流下,随着电弧作用次数的增加,绝缘节温度升高、碳化程度加剧,钢轨表面温升则不明显,绝缘节在电弧作用1~2次时未出现碳化,作用3次时出现碳化且碳化率为15.2%,作用6次时碳化率升至69.4%,而钢轨表面温度在电弧作用6次时仅升高142.2 K;电弧电流越大,绝缘节发生碳化的程度也越高,钢轨表面温度也随之升高,绝缘节在电弧电流为40~60 A时未出现碳化,80 A时出现碳化且碳化率为33.5%,电弧电流大于等于120 A时碳化率升至100%,而钢轨表面温度在电弧电流由40 A增至180 A时升高440.8 K;电弧移动速度越快,电弧对绝缘节和钢轨的传热影响越小,越有利于降低绝缘节的碳化,电弧移动速度从10 m·s^(-1)增至20 m·s^(-1)时,绝缘节碳化率降低16.7%,钢轨表面温度降低116 K。
High arc temperature is the main reason for the burning loss and carbonization of mechanical insulation joints(referred to as insulation joints),resulting in their failure to meet the insulation requirements of rail circuits.Based on the magneto-hydrodynamics theory,considering the influences of electromagnetic field,thermal field,flow field and arc physical parameters,the coupling model for the multi-physical field of the insulation joint arc is established in COMSOL software.The arc temperature distribution under different arc action times,arc currents and arc moving speeds is solved by simulation to analyze the law of carbonization of the insulation joint and the temperature rise of the rail.The results showed that,under the lower arc current,with the increase of arc action times,the temperature of insulation joints rose,the degree of carbonization intensified,while the temperature rise of rail surface was not obvious.The insulation joint did not occur carbonization under the arc action of 1 to 2 times,while occurred carbonization under the action of 3 times with the carbonization rate of 15.2%.When the carbonization rate rose to 69.4%,the rail surface temperature only increased 142.2 K under the arc action of 6 times.The higher the arc current,the higher carbonization degree of the insulation joint,and the higher the rail surface temperature.The insulation joint did not occur carbonization with the arc current from 40 to 60 A,while occurred carbonization with that of 80 A with the carbonization rate of 33.5%.The carbonization rate rose to 100%when the arc current was greater than or equal to 120 A,while the rail surface temperature increased 440.8 K with the increase of arc current from 40 to 180 A.The faster the arc moved,the smaller the effect of the arc on the heat transfer between the insulated joint and the rail,which was more conducive to reducing the carbonization of the insulation joint.When the arc moving speed increased from 10 to 20 m·s^(-1),the carbonization rate of the insulated joint was reduce
作者
张友鹏
郑泽荣
李军丽
赵斌
ZHANG Youpeng;ZHENG Zerong;LI Junli;ZHAO Bin(School of Automatic and Electrical Engineering,Lanzhou Jiaotong University,Lanzhou Gansu 730070,China)
出处
《中国铁道科学》
EI
CAS
CSCD
北大核心
2023年第3期155-163,共9页
China Railway Science
基金
国家自然科学基金资助项目(51967010)
兰州交通大学青年科学研究基金资助项目(2019033)。
