摘要
水电机组在调频、调峰及调节新能源波动的过程中经常偏离最优工况运行,由此带来的尾水管涡带和压力脉动问题备受关注,这严重限制了机组的调节能力。本文采用RANS-LES方法,模拟了混流式水轮机变速运行模式下的尾水管涡带和压力脉动分布特性。结果表明:在消涡转速附近,尾水管涡带减小明显,偏离消涡转速时,尾水管涡带将增强;从消涡转速增加到最佳转速,虽然涡带增多、压力脉动幅值有所增大,但效率也随之提高;在最佳转速运行时,水轮机效率最高,相对传统恒速运行模式,可以提高7%左右。研究结果可以为水电机组的运行管理提供参考。
Vortex ropes and pressure pulsations in a hydropower unit-under regulating operation of frequency,peak load,or new energy fluctuation-severely restrict regulation capability of the unit and have attracted much attention.In this work,a RANS-LES method is used to simulate the vortex ropes and pressure pulsations in the draft tube of a Francis turbine under the mode of variable-speed operation.The results show that the strength of vortex ropes is decreased obviously near the vortex elimination speed(VES)but increased when the speed deviates from VES.From VES to the optimal speed,turbine efficiency is increased,though the number of vortex ropes and the amplitude of pressure pulsations are increased.At the optimal speed,the turbine achieves its highest efficiency,7%higher than that in the conventional fixed-speed operation mode.
作者
王彤彤
张昌兵
谢婷婷
曹文哲
WANG Tongtong;ZHANG Changbing;XIE Tingting;CAO Wenzhe(College of Water Resource&Hydropower,Sichuan University,Chengdu 610065)
出处
《水力发电学报》
CSCD
北大核心
2021年第9期95-101,共7页
Journal of Hydroelectric Engineering
关键词
混流式水轮机
变速运行
尾水管涡带
压力脉动
稳定性
Francis turbine
variable-speed operation
vortex rope in the draft tube
pressure pulsation
operation stability
