超高水头机组水轮机工况甩负荷过程不稳定流动研究  

Study on Unstable Flow of Ultra-high Head Unit in Load Rejection Process under Turbine Mode

作　　者：洪佳礼 李远余 陆荣 谢学东 李明明 田杰 樊红刚[3] HONG Jiali;LI Yuanyu;LU Rong;XIE Xuedong;LI Mingming;TIAN Jie;FAN Honggang(Xizang Datang Zara Hydropower Development Company Limited,Chengdu 610000,China;College of Intelligent Systems Science and Engineering,Harbin Engineering University,Harbin 150001,China;State Key Laboratory of Water and Sediment Science and Water Conservancy and Hydropower Engineering,Department of Energy and Power Engineering,Tsinghua University,Beijing 100084,China;Harbin Electric Machinery Company Limited,Harbin 150040,China)

机构地区：[1]西藏大唐扎拉水电开发有限公司,成都610000 [2]哈尔滨工程大学智能科学与工程学院,哈尔滨150001 [3]清华大学能源与动力工程系水沙科学与水利水电工程国家重点实验室,北京100084 [4]哈尔滨电机厂有限责任公司,哈尔滨150040

出　　处：《大电机技术》2025年第1期82-90,共9页Large Electric Machine and Hydraulic Turbine

基　　金：国家自然科学基金(51879140)。

摘　　要：由于电网调节的需求,水电站机组需要频繁地启动与关闭。在停机过程(甩负荷)中,水轮机内部将产生极其不稳定的流动,诱发旋涡、强压力脉动等现象,进而导致机组剧烈振动,可能损坏相关设备。为了研究甩负荷过程中机组内部流态及压力脉动特性,本文采用一维与三维耦合方法对水泵水轮机甩负荷过程进行了仿真分析,并采用变分模态分解方法对压力脉动信号进行处理。研究结果表明:当机组甩负荷后,转轮内流量首先迅速减小,然后出现回流现象,叶轮内部存在严重的二次流,导致流动变得极其不稳定;上冠和无叶区出现来回震荡的压力波,压力信号表现出宽频特征,其中直流分量与转速变化规律相似,高频压力脉动的主频为转频及其倍频;尾水管内存在螺旋状的涡带,其大小与转速密切相关。Due to the demand of power grid regulation,the units of hydropower station need to be started and shut down frequently.During shutdown(load rejection),extremely unstable flow will occur inside the turbine,inducing vortices,strong pressure fluctuations and so on,which will lead to severe vibration of the unit and damage to relevant equipment.To study the flow regime and pressure fluctuation during load rejection of units,the one-dimensional and three-dimensional coupled method is used to simulate the load rejection process of pump turbine,and the variational mode decomposition is utilized to process the pressure fluctuation signal.The results show that during the load rejection process of the pump-turbine,the flow rate first decreases rapidly,and then the reverse flow phenomenon occurs,there is a serious secondary flow inside the impeller,and the flow becomes extremely unstable;There are pressure waves oscillating back and forth in the crown and vaneless area,and the pressure signal shows broadband characteristics.The variation of DC component is similar to that of rotating speed,the dominate frequency of the high frequency pressure pulsation is rotation frequency and its multiple;There is a spiral vortex band in the draft tube,and its size is closely related to the rotating speed.

关 键 词：水泵水轮机 过渡过程 数值模拟 不稳定流动 变分模态分解 

分 类 号：TK733.8[交通运输工程—轮机工程]