基于泄放阀泄放反力作用下的低温管系动态分析

应用CAESARII软件对某低温乙烯液体输送管系进行动态分析,校核了在泄放阀泄放反力作用下管系的位移、应力是否符合规范,并对管系结构进行了优化。结果表明:管系基频过低、应力超标,距离泄放阀最近端管系弯头纵向振幅较大,泄放阀泄放反力作用弯头位置横向振动剧烈,须重新对管系进行改进。提出改进方案:将管系中间位置约束改为固定支撑,以增大管系刚度;将距离泄放阀最近弯头处承重支撑改为弹簧支撑,以承担竖直方向的反冲力;在泄放阀进口管段设置阻尼约束,泄放阀出口管弯头位置加设承重支撑与限位,并调整限位与管系之间的间隙,找到最佳间隙为6.63 mm。据改进后的方案重新建模并分析,管系在X、Y、Z向的最大振幅分别减弱了88.12%、76.02%、99.86%。

Dynamic analysis of cryogenic piping based on effect of discharging reaction force of relief valve

The dynamic analysis was performed using CAESARII software of the cryogenic ethylene liquid transporting piping,the displacement and stress of the piping under the discharging reaction force of relief valve were checked to make sure that they conform to the specification,and the structure of the pipe was optimized.The result shows that,the basic frequency of the piping is extremely low,and the piping stress exceeds the standard,the longitudinal amplitude of the piping elbow near to the relief valve is large,the lateral vibration is obvious in the position of elbow on which the discharging reaction force of relief valve acted.The piping structure should be improved.First,the piping intermediate position constraint was changed into a fixed support to increase the stiffness of the piping.Second,the bearing support was changed into a spring support in the piping elbow which is the nearest to the relief valve to bear the vertical opposing force.Third,a damping constraint was set in the inlet piping of the relief valve,a bearing support with a limit was added in the outlet tube elbow of the relief valve,and the best spacing gap was found to be 6.63mm by repeatedly adjusting the gap between the limit and the piping.The maximum amplitude of X,Y and Z in the improved piping decreased by 88.12％,76.02％ and 99.86％ respectively according to the simulation.