抽水蓄能电站多倍叶频强振来源研究  

Study on source of strong vibration with multiple passing-frequency of blade in pumped storage hydropower plant

作　　者：王万鹏[1] 徐洪泉[1] 廖翠林[1] 安学利[1] WANG Wanpeng;XU Hongquan;LIAO Cuilin;AN Xueli(China Institute of Water Resources and Hydropower Research,Beijing 100038,China)

机构地区：[1]中国水利水电科学研究院,北京100038

出　　处：《水利水电技术（中英文）》2021年第7期132-142,共11页Water Resources and Hydropower Engineering

基　　金：中国水利水电科学研究院科研专项(HM0145B432016);国家自然科学基金项目(51309258)。

摘　　要：抽水蓄能电站机组和厂房振动问题非常突出,其振动频率多为2或3倍水泵水轮机转轮叶片通过频率,该频率的产生机理一直没有明确可信答案,强振问题迟迟得不到解决。为弄清该问题,在对国内十余个抽水蓄能电站运行稳定性调研的基础上,对电站强振频率、波形与水泵水轮机导叶前压力脉动频率、波形进行了对比研究,发现了二者之间的相同点及脉络联系,发现产生于导叶前的空化衍生压力脉动是引起厂房振动的根源。研究从无叶区压力脉动的幅值及频率特性入手,总结提出了无叶区压力脉动的传播规律,指出多倍叶频压力脉动并非直接源自转轮,而是发源于导叶前的空化衍生压力脉动。无叶区压力脉动主要以压力波方式由转轮向上游传播,在经过导叶进水边因脱流而产生的旋涡空腔时,使空腔产生膨胀-收缩循环变化,产生空化衍生压力脉动。每一个导叶前旋涡空腔产生一个叶频空化衍生压力脉动,所有散布在转轮周围的导叶前压力脉动会在导叶前测点叠加成一周期长短不一的压力脉动,其分析频率为多倍叶频,该倍数通常为转轮叶道对导叶的整数覆盖系数。这说明,没有导叶、固定导叶区域空化空腔的存在,就没有多倍叶频空化衍生压力脉动及机组和厂房强振。The problem of the vibration of powerhouse and pump-turbine unit with most of the vibration frequencies of 2 or 3 times the runner blade-passing frequency of the pump-turbine unit is quite prominent for pumped storage power plant,while no clear and credible answer is there to the generating mechanism of this frequency all along,thus the problem of the strong vibration is not solved for a long time.In order to make clear about this problem,a comparative study between the frequency and waveform of the strong vibration of the plant and the frequency and waveform of the pressure fluctuation in front of the guide vane of the pump-turbine is carried out on the basis of the operation stability investigations made on more than ten pumped storage hydropower plants in China,from which the similarities and the connections between both of them are found out,namely,the cavitation-induced pressure fluctuation in front of the guide vane is just the origin to cause the powerhouse vibration.Starting from the amplitude and frequency characteristics of the pressure fluctuation in the bladeless region,the propagation law of the pressure fluctuation in the vaneless region is summarized and put forward in the study,and then it is pointed out that the pressure fluctuation of the multiple blade-passing frequency does not originate directly from the runner,but from the cavitation-induced pressure fluctuation in front of the guide vane.The pressure fluctuation in the bladeless region mainly propagates in a form of pressure wave from the runner to the upstream region.When it passes through the vortex cavity at the inlet edge of guide vane caused by the separated flow,it makes the cavity generate the change of expansion-contraction cycle and then generates the cavitation-induced pressure fluctuation.One blade frequency cavitation-induced pressure fluctuation is to be generated in the vortex cavity in front of each guide vane,while all the pressure fluctuations in front of guide vanes scattered around the runner are to be superposed into pre

关 键 词：水泵水轮机 无叶区 压力脉传播 空化空腔 空化衍生压力脉动 

分 类 号：TV743[水利工程—水利水电工程]