压水堆吊篮下部防断支承组件流致振动分析

Flow-induced vibration analysis for the lower internals of PWR

对秦山核电厂堆芯下腔流场、堆内下部防断支承组件振动特性及全组件的流致振动进行了分析,特别对旋涡脱落致振进行了定量分析。分析结果表明防断支承组件初始结构的整体转动振动的固有频率与旋涡脱落频率相差较大,发生大幅振动的可能性不大;只有当部分连接件松动,整体结构转动振动的固有频率下降时,才很有可能发生大幅振动。

The velocity distribution of flow in the lower plenum of Qinshan Nuclear Power Plant was analyzed, as well as the natural frequencies and the flow-induced vibration of the lower internals in sequence, especially the quantitative analysis of the vortex shedding mechanism. By this analysis, it was showed that the vortex shedding frequency is a little far from the natural swirling frequency of the whole lower internals so that the possibility is low to occur the lock-in vibration of the lower internals with a large amplitude. Only when some of the connections are loosened and as a result the natural frequencies of the whole lower internals decrease, the large-amplitude vibration may occur. Results from this research have provided the important technical proofs for the recovery of Qinshan NPP, as well as the modification of Chashma Nuclear Power Plant.