摘要
以南水北调某泵站为模型,对该泵站大型轴流泵反向发电发生空化条件现象进行全流道数值模拟。对反向发电工况下空化现象进行定常与非定常研究,并与试验结果做比较,得出了水泵反向发电时发生不同空化条件下的气泡体积分布规律,并预测了叶片发生空化的发展特性。在反向发电工况下对三个监测面的压力脉动进行研究,得出压力脉动幅值在导叶进口处最小,转轮出口处幅值最大,约为转轮进口处7倍,水流受转轮转动影响严重,主频为转频。不同空化数下转轮前后的压力脉动幅值随着空化系数减小而增大,压力脉动主频不受空化系数影响。空化数越小,叶片受到的径向力减小,轴向力增加,加剧转轮的不稳定性。为确保轴流泵反向发电运行的稳定与高效,应使得装置在较高的空化系数下运行。
Taking apumping station of South-to-North Water Transfer Project as a model,we conducted full-channel numerical simulation of the cavitation conditions of large-scale axial flow pumps in the pumping station during reverse power generation.We studied the steady and unsteady cavitation phenomena under the condition of reverse power generation,and compared the experimental results.We obtained the bubble volume distribution law under different cavitation conditions,and predicted the development characteristics of blade cavitation.The pressure fluctuation of the three monitoring surfaces was studied under the condition of reverse power generation.The results showed that the pressure fluctuation amplitude was the smallest at the guide blade inlet and the largest at the runner outlet,which was about 7times of that at the runner inlet.The water flow was seriously affected by the runner rotation and the main frequency was the frequency of the runner.The amplitude of pressure fluctuation before and after the runner would increase with the decrease of the cavitation coefficient under different cavitation numbers,and the main frequency of pressure fluctuation was not affected by the cavitation coefficient.The smaller the cavitation number,the less the radial force of the blade,the greater the axial force,increasing the instability of the runner.To ensure the stable and efficient operation of the axial flow pump in reverser power generation,the device should be running under a high cavitation coefficient.
作者
周颖
郑源
汪昊蓝
唐魏
陈明炤
赵梦晌
尕藏才让
ZHOU Ying;ZHENG Yuan;WANG Haolan;TANG Wei;CHEN Mingzhao;ZHAO Mengshang;GAZANG Cairang((School of Water Conservancy and Hydropower Engineering,Hohai University,Nanjing210098,China)
出处
《南水北调与水利科技》
CAS
北大核心
2019年第1期178-185,共8页
South-to-North Water Transfers and Water Science & Technology
基金
国家自然科学基金(51579080)~~
关键词
轴流泵
反向发电
压力脉动
叶频
空化
axial flow pump
reverse power generation
pressure pulsation
blade frequency
cavitation
作者简介
周颖(1995-),女,江苏盐城人,主要从事流体机械及水利水电工程研究。E-mail:1007422002@qq.com;通讯作者:郑源(1964-),男,山东日照人,教授,博士生导师,主要从事流体机械及水利水电工程研究。E-mail:zhengyuan@hhu.edu.cn
