油入電力機器のアーク故障に起因する絶縁油の燃焼を想定した大型電気室内の圧力上昇解析

抄録

In this paper, we present an analysis of the pressure rise caused by combusting of oil resulting from a fault arc, assuming that the arc occurs in oil-filled equipment in a large electric room with an opening. In the analysis, we clarified that the location and volume of the arc fault and the location of the opening affected the pressure rise and the propagation around the arc fault. We found that the initial pressure rise (P_1st) at the floor adjacent to the wall and equipment was greater than those at other locations. In particular, P_1st was largest at the corner of the electric room owing to a superimposed pressure wave. Moreover, the value ofP_1st at the floor adjacent to the equipment was independent of the location of the opening. It was also found that P_1st decreased inversely propositionally to the distance between the floor adjacent to the wall and equipment and the location where the fault occurred. Also, the time to reach P_1st was decided by the distance in spite of part of arc fault, arc fault volume and location of the opening, and the pressure wave which occurs from the arc fault is propagated in air at sonic speed, The results would be utilized for a strength design of wall in an electric room.