天然气管线压力脉动激振分析

ANALYSIS ON PRESSURE PULSATION-INDUCED VIBRATION OF GAS PIPELINES

动力机械对管线内的流体提供一定的激发,使管流处于脉动状态。脉动状态的流体遇到弯头、异径管、控制阀、盲板等管线元件,会产生一定的、随时间而变化的激振力,在这种激振力作用下管线和附属设备就要产生振动。为此,对一段包含复杂约束、管道附件的天然气管线进行了动态分析,计算出了作为外加激励的气流压力脉动激发的管线动力响应。计算结果表明,压力脉动能激发相当大的管线振动,在管线设计时,必须考虑压力脉动的影响,并提出了控制管线振动的措施。这些措施包括调整管线模态频率,模态形状,减小弯头转角,在最大管线位移位置处添加减振器、或阻尼器、或支撑等。

Some induction provided by power machines to the fluid in the pipeline forces the fluid flowing in the pulsation state. The fluid in the pulsation state will produce the induced force, which will change along with time, when the fluid encounters the units of the pipeline such as elbows, substitutes, control valves, blinds etc. Under the action of the induced force, vibration will happen in the pipe-line and the auxiliary equipment. So the dynamic analysis is conducted for a section of pipeline including complex restraints and auxiliary equipment, and the dynamic response of the pipeline section induced by the additional gas-flowing pressure pulsation is calculated. The results show the pressure pulsation can induce rather large vibration of the pipe-line. Therefore, the influence of the pressure pulsation should be considered and the measures to control the pipeline vibration should be proposed when the pipeline design is made. The measures include adjusting the modal frequencies and shapes of the pipeline, reducing the bend angles of elbows, and building additional snubbers, dampers or supports at the locations of maximum displacement of the pipeline, etc.