摘要
水力发电中,冲击式水轮机是利用高水头资源的主要设备,六喷嘴冲击式水轮机内部流动复杂,分析困难。鉴于此,分析了六喷嘴冲击式水轮机内部流动过程,分析给水机构内部的流动状态对自由射流的影响机理。利用VOF模型准确捕捉气液交界面的特点,分析自由射流冲击转轮的流动过程,找出水斗力矩变化规律以及影响效率的流动损失,分析开度变化对不良流动的影响规律以及不良流动现象产生的原因,为优化改进多喷嘴冲击式水轮机的出力和效率提供依据。结果表明:流体在分叉管处产生漩涡,漩涡向下游发展,使自由射流的形状发生改变;21个水斗具有周期性变化,相互之间仅存在相位差,自由射流冲击水斗时存在两射流同时作用到同一水斗和背面打水等不良流动。
As a main equipment in hydraulic power generation,pelton turbine is widely adopted to utilize high water head.Yet the flow of 6-nozzle pelton turbine is complex and difficult to be analyzed.In view of this,this paper analyzed the internal flow process of 6-nozzle pelton turbine and analyzed the influence mechanism of the flow state inside the feedwater mechanism on the free jet and used the VOF model to accurately capture the characteristics of the gas-liquid interface,and analyzed the flow process of the free jet impact runner.The variation law of bucket torque and flow loss affecting efficiency were found out,and the influence law of opening variation on adverse flow and the causes of adverse flow phenomenon were analyzed,which provided a basis for optimizing and improving the output and efficiency of multi-nozzle impact turbine.The results show that the fluid generates a vortex at the bifurcated pipe,and the vortex develops downstream,which changes the shape of the free jet.The 21 buckets have periodic changes,and there is only phase difference between each other.When the free jet impinges on the bucket,there are bad flows such as two jets acting on the same bucket at the same time and hitting water on the back.
作者
魏鸿达
王洪杰
Wei Hongda;Wang Hongjie(Changchun Institute of Optics,Fine Mechanics and Physics,Chinese Academy of Sciences,Changchun 130033,China;School of Energy Science and Engineering,Harbin Institute of Technology,Harbin 150001,China)
出处
《机电工程技术》
2023年第4期65-71,共7页
Mechanical & Electrical Engineering Technology
关键词
冲击式水轮机
气液两相流
能量损失
不良流动
pelton turbine
gas-liquid two-phase flow
energy loss
bad-behaved phenomenon
