封闭容器内部短路燃弧爆炸压力效应计算

摘要

Internal short-circuit arcing explosion in a medium-voltage (MV) switchgear poses a serious hazard to the safety of equipments,buildings and personnel.In the present work,to find out an appropriate method to calculate the pressure effect resulting from the internal arcing explosion,we analyzed the energy balance mechanism of the internal arcing in the switchgear,presented an indirect coupling analysis method based on CFD through the analysis of the thermal-mechanical effect of the arcing process,and verified the method by the actual arcing in a closed container.The results show that the relative error of the average pressure rise between measurement and calculation is about 2％.The arc size has less effect on the pressure rise.In the closed container,the pressure rise approximately increases linearly with the increase of the arc energy.The installation of a negative pressure room can reduce the pressure in the arcing room 60％,thereby effectively restraining the pressure rise in the switchgear caused by the internal short-circuit arcing explosion.%中压开关设备内部短路燃弧爆炸对设备、建筑物以及工作人员的安全带来了严重威胁.为提出合适的数值计算方法对短路爆炸引起的压力效应进行计算,对开关设备内部短路燃弧的能量平衡机制进行了分析;通过分析燃弧过程的热-力效应,提出了基于CFD法的间接耦合分析方法,并开展了实际封闭容器内部短路燃弧实验验证了算法的可行性.研究结果表明:实验测量与模拟计算获得的平均压强仅相差2％左右;电弧尺寸对压力升的影响较小;封闭容器内部压力升随电弧能量的增大近似线性增大;安装负压室后燃弧室的压强可降低60％左右,因此,增设负压室可有效抑制开关设备内部短路爆炸引起的压力升.