流致振动差压式测振装置的研究

为解决管束流致振动试验中,现有接触式振动测量方法的应用局限性,提出一种基于测量受激对象换热管两侧压差脉动频率原理的测振装置,即差压式测振装置。差压式测振装置解决了传统接触式传感器对换热管外部流场的干扰问题以及安装空间受限的问题。为了验证差压式测振装置的有效性,分别进行了单管和换热管束两类流致振动测试试验。试验结果表明,差压式测振装置能在复杂的流动环境中准确捕捉到换热管受到的各类激振形式的频率,而且单管流致振动试验结果表明差压式测振装置所测得的周期性涡激振动频率与理论值偏差在5%以内。因此,差压式测振装置的研制与应用对于流致振动试验的测试以及换热管振动的长期监测均有很重要的意义。

Research on differential pressure vibration measurement device for flow induced vibration test Ma Pingchang1, Li Hong1, Lin Dan2, Zhang Liang2, Wang Liwen3

Abstract:The contact vibration measurement method has application limitation in the flow induced vibration test of the tube bundle. To solve this problem, a new measurement device, named as the differential pressure vibration measurement device, is designed. Based on the principle of measuring the pressure differential fluctuation frequency on both sides of the heat exchange tube, the differential pressure type vibration measuring device can measure the excitation frequency of the external fluid force of the heat exchange tube. Differential pressure vibration measurement device solves the problem of interference of the traditional contact sensor to the external flow field of the heat exchange tube and the problem of limited installation space. To verify its effectiveness, the single tube flow induced vibration test and the heat exchange tube bundle flow induced vibration test are carried out respectively. Experimental results show that the designed device can accurately capture the frequency of all kinds of vibration forms of the heat exchange tube in the complex flow environment, including pump vibration, natural vibration, periodic vortex vibration and two phase flow vibration characteristics. Experimental results of single tube flow induced vibration test show that the periodic vortex induced vibration frequency measured by the designed device is within 5% of the theoretical value. Therefore, the development and application of the differential pressure vibration measuring device is of great significance for the measurement of the flow induced vibration test and the long term monitoring of the vibration of the heat exchange tube.