空化诱导的轴流式水轮机转轮径向振动特性研究  

Study on the Radial Vibration of Kaplan Turbine Runner Induced by Cavitation

作　　者：门羿 朱国俊[1] 冯建军[1] 王晓航[2,3] 张乐福 MEN Yi;ZHU Guojun;FENG Jianjun;WANG Xiaohang;ZHANG Lefu(Xi'an University of Technology,Xi'an 710048,China;Harbin Electric Machinery Co.,Ltd.,Harbin 150040,China;State Key Laboratory of Hydro-power Equipment(Harbin Institute of Large Electrical Machinery),Harbin 150040,China)

机构地区：[1]西安理工大学,西安710048 [2]哈尔滨电机厂有限责任公司,哈尔滨150040 [3]水力发电设备全国重点实验室(哈尔滨大电机研究所),哈尔滨150040

出　　处：《大电机技术》2023年第3期51-57,共7页Large Electric Machine and Hydraulic Turbine

基　　金：国家自然科学基金(52079108);国家自然科学基金(51909212)。

摘　　要：转轮的径向振动特性对水轮机转子系统的稳定性至关重要。为了研究空化对轴流式水轮机转轮径向振动特性的影响规律,本文首先搭建了包含激光测振仪(Laser Doppler Vibrometer,LDV)的非接触式振动测试系统,并结合高速摄影系统获得了不同空化状态下的转轮内部流场图像以及转轮径向振动信号。然后对转轮内部流动图像及振动信号进行了综合分析,结果表明:从无空化到空化初生阶段,空化系数的降低对转轮径向振动基本没有影响;空化初生以后,转轮径向振动的幅值会随着空化程度的加剧而急剧上升。转轮内部空化流动形态的转变是转轮径向振动频域特性改变的根源。从空化初生到完全空化阶段,转轮径向振动的能量会出现向低频区域迁移的趋势,增加机组共振的风险。本文的研究对轴流式水轮机稳定运行以及经济性具有重要意义。The radial vibration characteristics of the runner are very important to the stability of the turbine rotor system.In order to study the influence of the cavitation on the radial vibration characteristics of the runner of Kaplan turbine,a non-contact vibration testing system including Laser Doppler Vibrometer(LDV)is firstly established.Then the images of flow in runner and radial vibration signals of runners under different cavitation conditions are obtained by combining high-speed flow visualization system with the non-contact vibration testing system.Finally,the flow images and vibration signals of the runner are comprehensively analyzed.The results indicate that the reduction of cavitation number has no effect on the radial vibration of the runner from no cavitation to the inception of cavitation.After cavitation inception,the amplitude of runner radial vibration rises sharply with cavitation degree enhanced.The transition of cavitation flow pattern inside the runner is the source of the change in frequency domain characteristics of runner radial vibration.From the inception of cavitation to the complete cavitation,the energy of runner radial vibration tends to migrate to low frequency region,which increases the risk of unit resonance.The research results of this paper are of great significance to the stable operation and economy of Kaplan turbine.

关 键 词：轴流式转轮 空化 径向振动 时频分析 多重信号分类 

分 类 号：TK730.323[交通运输工程—轮机工程]