主蒸汽隔离阀管系地震响应特性分析研究

Analysis on Seismic Response Characteristics of Main-Steam Isolation Valve System

目前核级阀抗震评估领域极少关注激励与阀门响应的动态特性。以国产主蒸汽隔离阀及其邻近部分管道为研究对象,利用三角级数叠加法反演了其所在楼层加速度谱的人工时程波,通过PSD函数分析振动波的频率成分,并分别利用反应谱法、时程分析法计算其地震响应。结果表明:楼层振动不同于地面震动,主要振动频带为0~10 Hz;主蒸汽隔离阀管系相对响应频率集中在其基频附近,主蒸汽隔离阀受载接近于单频;约束与较大的相对运动是管系产生较高应力的主要原因,管系响应对激励频率成分的敏感性远大于对幅值的敏感性。本文采用动力法进行主蒸汽隔离阀管系抗震分析,可为更大口径主蒸汽隔离阀的设计提供指导。

At present,little attention is paid to the dynamic characteristics of excitation and valve response in the field of seismic evaluation of nuclear grade valves.By taking the domestic main-steam isolation valve system and part of piping adjacent to it as the research object,the artificial time-history wave of the acceleration spectrum of the floor where they are located was inverted by the trigonometric series superposition method.The frequency components of the vibration wave was analyzed by the PSD function.The seismic response was calculated respectively using the response spectrum method and the time-history analysis method.The results show that the floor vibration was different from the ground shaking,and the main vibration frequency band of floor vibration was 0~10 Hz.The relative acceleration response frequency of the main steam isolation valve was concentrated near its fundamental frequency and the actual load of the valve was close to the single frequency excitation.Constraints and large relative motion were the main causes of higher stress in the piping system.The sensitivity of piping system response to excitation frequency was much greater than that of excitation amplitude.In this paper,the seismic analysis of the main steam isolation valve system was carried out using the dynamic method,which can provide guidance for the design of larger diameter main steam isolating valve.