摘要
当混流式水轮机在涡带区工况即部分负荷运行时,诱发的压力脉动偏大,易引起机组各部件的振动、噪声甚至出力波动,影响机组的安全稳定运行。以大型中低水头混流式水轮机为研究对象,针对模型试验中出现的涡带区压力脉动突然增大及振动噪声现象,进行模型试验和三维全流道非定常数值计算(CFD)研究。结果表明:引起涡带区压力脉动突增的原因是1.35倍转频的频率成分,由粗且不稳定的尾水涡带引起;优化转轮和补气能够破坏粗且不稳定的尾水涡带,从而消除1.35倍转频的频率成分,大大降低涡带区的压力脉动幅值;匹配不同的泄水锥能够减弱尾水涡带的强度(使涡带稍微变细),涡带区的压力脉动幅值有所下降,但未能破坏涡带的形状,不能消除1.35倍转频的频率成分。研究成果为改善涡带区压力脉动提供了新的思路,在实际工程中可根据实际情况采用合适的措施。
When a Francis turbine operating in part-load,namely in a case of vortex zone,excessive pressure pulsations appear,which can lead to vibrations,noise,and power fluctuations,adversely affecting the unit′s safe and stable operation.In response to the sudden increase in pressure pulsation vibration,and noise in the vortex zone during model experiments,we investigated a large-scale medium-low-head Francis turbine operating in part-load in the vortex zone,and model tests and three-dimensional unsteady simulations(CFD)were employed to analyze the phenomena.The results revealed that the primary cause of the pressure pulsation surge was the 1.35 times rotational frequency pulsation induced by the thick and unstable vortex rope.Optimization of the runner and air supply were found to disrupt the unstable vortex rope,eliminating the 1.35 times rotational frequency component and significantly reducing pressure pulsations in the vortex zone.Additionally,matching different runner cones could weaken the intensity of the vortex rope(slightly narrowing the vortex rope),thus reducing the pressure pulsation amplitude,however,this modification cannot break the vortex and therefore the 1.35 times rotational frequency component remained.These findings can provide valuable insights for mitigating pressure pulsations in the vortex zone.In practical engineering,appropriate measures can be taken according to the actual situation.
作者
叶长红
袁玲丽
谭军
龚莉
刘芮麟
邓祥平
YE Changhong;YUAN Lingli;TAN Jun;GONG Li;LIU Ruilin;DENG Xiangping(Wujiangdu Power Plant of Guizhou Wujiang Hydropower Development Co.,Ltd.,Zunyi 563104,China;Research and Development Center,Dongfang Electric Machinery Co.,Ltd.,Deyang 618000,China)
出处
《人民长江》
北大核心
2025年第2期158-166,182,共10页
Yangtze River
基金
国家自然科学基金项目(11972220)。
关键词
混流式水轮机
涡带区
压力脉动
模型试验
数值模拟
Francis turbine
vortex zone
pressure pulsation
model test
numerical simulation
