基于原型观测的梯级泵站管道振源特性分析

发布时间：2018-08-31 07:42

【摘要】：以景电二期3泵站2号输水管道为对象,结合原型试验观测数据,研究该类型泵站结构的振源组成及其对管道的影响。首先,对连接2号管道的4号、5号机组正常运行和开关机过程中引起的管道结构振动频率进行识别统计,确定其动荷载来源;然后,分析统计不同工况下管道结构主要部位达到峰值时各分频所占比例,计算不同工况下各频带能量对总能量的贡献率。计算结果表明:机组稳定运行时,叶频和转频倍频引起的振动比例达73.4%,是管道振动的主振源低频所占比例为12%左右;机组开机过程中,低频水流脉动所占比例增加到33.7%,叶频所占比例保持40%左右,叶频和低频是主要振源;机组关机过程中,低频水流脉动引起的振动比例达73.3%,水体-管道耦合引起的高频振动达21.7%左右,低频水流和高频是主要振源,且低频对管道顺水流方向振动影响较大。研究结果有助于从量级上评价管道振动的原因及引起振动的各分频贡献率,以期为管道结构主动控制和安全运行提供依据。
[Abstract]:Taking the No. 2 water conveyance pipeline of Jingdian No. 3 pumping Station as an object, the vibration source composition of the structure of this type pump station and its influence on the pipeline are studied in combination with the observation data of prototype test. First of all, the vibration frequency of pipeline structure caused by normal operation of Unit 4 and Unit 5 connected with No. 2 pipeline and the process of switching machine are identified and statistics, and the source of dynamic load is determined. This paper analyzes the proportion of frequency distribution when the main parts of pipeline structure reach the peak value under different working conditions, and calculates the contribution rate of each frequency band energy to the total energy under different working conditions. The results show that when the unit is running stably, the ratio of vibration caused by blade frequency and frequency doubling is 73.4%, and the proportion of low frequency of main vibration source of pipeline vibration is about 12%. The proportion of low frequency water flow pulsation increased to 33.7 and the proportion of leaf frequency remained about 40%. Leaf frequency and low frequency were the main sources of vibration. The ratio of vibration caused by low frequency water flow pulsation is 73.3%, and the high frequency vibration caused by water-pipeline coupling is about 21.7%. Low frequency water flow and high frequency flow are the main sources of vibration, and the low frequency has a great influence on the flow direction vibration of pipeline. The results are helpful to evaluate the cause of pipeline vibration and the contribution rate of each frequency of the vibration in order of magnitude, and to provide the basis for the active control and safe operation of the pipeline structure.
【作者单位】：华北水利水电大学水利学院;
【基金】：国家自然科学基金(51679091) 华北水利水电大学研究生教育创新计划基金(YK2015-02)资助
【分类号】：TV675

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