水泵水轮机S特性对相继甩尾水最小压力的影响  

Influence of S characteristics of pump-turbine on minimum pressure in draft tube during successive load rejection

作　　者：王皓臻 俞晓东[1] 林文雯 李朋宇 刘昌太 WANG Haozhen;YU Xiaodong;LIN Wenwen;LI Pengyu;LIU Changtai(College of Water Resources and Hydropower Engineering,Hohai University,Nanjing 210098,China)

机构地区：[1]河海大学水利水电学院,南京210098

出　　处：《水力发电学报》2024年第6期113-122,共10页Journal of Hydroelectric Engineering

基　　金：国家自然科学基金(52179062)。

摘　　要：为探究水泵水轮机全特性曲线S特性与尾水压力最小值的联系,基于新丰抽水蓄能电站的过渡过程数值仿真模型模拟了尾水最不利相继甩工况。通过调整机组运行轨迹线附近开度线斜率,对比分析并总结S区形状变化对相继甩工况尾水压力极值的影响规律,提出了一种图形指标,能够应用在抽蓄前期设计中评价S特性对尾水压力影响优劣,并验证其准确性。结果表明,相继甩工况后甩机组流量变化率第一波下降时,机组运行轨迹线呈现完整倒S形,S区形状变化改变了机组流量变化率的大小,导致出现在靠近轨迹线S形下拐点前的尾水压力极值发生变化,给出的图形指标形状越趋近于竖向细长的规则长方形,相应的尾水最小压力的改善效果越好。To explore the relationship of the full S characteristic curve of a pump-turbine and the minimum pressure in its draft tube,we conduct numerical simulations of successive load rejection which is most unfavorable to the draft tube flow for the Xinfeng pumped storage power station.By adjusting the opening curve slope near the unit’s operating trajectory,a comparative analysis and a summary are made on the influence of changes in the S zone shape on the extreme pressure in the draft tube under successive rejection conditions.We formulate a graphical indicator that is applicable in the early design phase of such stations to evaluate the impact of S-shape characteristics on draft tube pressure,and verify the calculation accuracy.The results show that for the first decrease of the unit’s flow caused by the rejection,the operating trajectory presents a complete inverted S-shape.This shape change will cause a change in the slope of the unit’s flow variations,and further result in a change in the extreme draft tube pressure that occurs near the S-shape inflection.The more the graphical indicator shape obtained approaches a vertically slender regular rectangular shape,the better the improvement of the corresponding minimum draft tube pressure.

关 键 词：抽水蓄能电站 水泵水轮机全特性曲线 S特性 相继甩 尾水最小压力 

分 类 号：TK743[动力工程及工程热物理—流体机械及工程]