摘要
针对混流式水轮机转轮叶片出水边与上冠连接处应力过大、容易出现裂纹的问题,采用在该处添加补强三角块以改善该处的应力分布。本文主要研究了两个计算工况下,不同尺寸三角块对转轮应力的改善情况,同时分析了对转轮的变形、叶片压力分布、尾水管涡量、水轮机效率的影响。结果表明:在两个计算工况下,当三角块两个边长为转轮标称直径的5.7%时,水轮机其他水力性能基本不变,且转轮的最大应力值降低分别为26.9%和29.5%,且最大应力位置转移到了叶片出水边与三角块出水边相接的转角处,叶片出水边和上冠连接处的应力明显减小,这对于改善转轮叶片出水边与上冠连接处的应力、避免焊缝处裂纹的发生和水轮机的安全稳定运行均具有重要的意义。
In view of the problem of excessive stress and cracks at the junction between the outlet of the blade and the crown of Francis runner,the reinforcement triangle block is added to improve the stress distribution at the junction.In this paper,the effect of triangle blocks of different sizes on the stress improvement of runner under two calculation conditions is studied.The influence of triangle blocks on the deformation of runner,the pressure distribution of blade,the vorticity of draft tube and the efficiency of turbine are analyzed.The results show that under two calculation conditions,when the two sides of the triangle block are 5.7% of the nominal diameter of the runner,the other hydraulic performances of the turbine remain basically unchanged,and the maximum stress of the runner decreases by 26.9% and 29.5%,respectively.The maximum stress position shifts to the corner where the outlet edge of the blade joins the outlet edge of the triangle block,with the stress at the junction of the outlet edge of the blade and the upper crown decreasing significantly.It is of great significance to improve the stress at the junction between the outlet edge of runner blade and the upper crown,avoiding the cracks at the weld seam and to the safe and stable operation of the turbine.
作者
赵道利
陈涛
孙维鹏
梁武科
马薇
ZHAO Daoli;CHEN Tao;SUN Weipeng;LIANG Wuke;MA Wei(Institute of Water Resources and Hydroelectric Engineering,Xi’an University of Technology,Xi’an 710048,China;Electric Power Research Institute of Yunnan Power Grid Co.,Ltd.,Kunming 650217,China)
出处
《西安理工大学学报》
CAS
北大核心
2020年第2期230-236,244,共8页
Journal of Xi'an University of Technology
基金
国家自然科学基金资助项目(51839010)
陕西省自然科学基础研究计划资助项目(2018JM5087)。
关键词
混流式水轮机
转轮
三角块
应力
变形
Francis turbine
runner
triangular pieces
stress
deformation
作者简介
第一作者:赵道利,男,硕士,副教授,研究方向为水力机组优化设计与振动分析。E-mail:zhaodaoli@126.com。
