管道振动分析与减振对策.doc

浙 江 科 技 学 院 本科学生毕业设计（论文） 题 目 管道振动分析与减振对策 　　　　 系 别 机械与汽车工程学院 专业班级 材料成型及控制工程A班 姓 名 学 号 指导教师 2006 年 6 月 6 日 摘 要 在石油化工等工矿企业中，广泛使用管道输送流体。在一定压力和流速的流体作用下这些管道壁上均会产生流体动压力。非定常的管流会引起管道的振动也就是管流脉动。管流脉动是引起管道及附属设备的振动的主要原因，导致管道结构和管路附件产生疲劳破坏，甚至造成严重事故，是管路系统的主要故障。 某炼化公司的甲胺泵管线振动强烈，已多次引起安全阀根部和导压板根部焊缝撕裂，连接法兰密封失效，高压高浓度的甲胺液外泄。本文对在单泵运行和双泵同时运行时的某炼化厂的高压甲胺泵管线振动分别进行了测试，通过对各个管路系统的不同测点的振动频谱分析，给出了振动的起因是压力脉动。当压力脉动的频率或者其倍数正好与管线的固有频率接近而导致共振时，管线就会发生强烈的振动。不发生共振时，管线振动就较小。因此提出了相应的减振措施：在现有支承架与管子的中间垫上防振橡胶垫，改变管线的固有频率，使压力脉动的频率及其倍频与管线的固有频率不相吻合。在泵的出口处加装蓄能器或者空气罐，用来吸收压力脉动，并根据条件设计了蓄能器。 关键词： 管流脉动 振动 甲胺泵管路 Abstract Pipes were widely used to transport liquid in many petrochemical factories and che- mical plant. Under the pressure of fluid with certain pressure and velocity, the fluid dyna- mic pressure pulsation will be created in the wall of the pipe. When the fluid flows in un- unsteady condition the unconstant flow would excite pipe abnormal vibration -it was also called flow pulsation. Flow pulsation, the main reason for the vibration of pipe and attac- ched equipment, educed the fatigue failure of pipe and attached equipment, which even result in fatal accident. In a refinery, the intensive vibration of the methylamine bump pipeline had caused many problems, for example tearing of welding line at the root of safety valve, seal failures of connecting flange which causing leakage of methylamine fluid with high pressure and concentration. In this paper, the vibration was tested to investigate the vibration fault on methylamine bump pipeline in a refinery when single pump or double pumps worked. By spectrum analysis of different measuring point, the cause of strong vibration was found out: pipe would vibrate strongly if the frequency of the pressure pulsation or multiple of it amount to the natural frequency of the pipeline. And in other case, the vibration would not be strong. Acco