大扩散角进水流道水力诊断及优化  

Hydraulic Diagnosis and Optimization of Inlet Flow Passage with Large Diffusion Angle

作　　者：黄幸 翟禹鑫 王为术 郭嘉伟 甄娟 HUANG Xing;ZHAI Yuxin;WANG Weishu;GUO Jiawei;ZHEN Juan(Jiangxi Datang International Fuzhou Power Generation Co.,Ltd.,Fuzhou 344000,Jiangxi,China;School of Electric Power,North China University of Water Resources and Electric Power,Zhengzhou 450045,Henan,China)

机构地区：[1]江西大唐国际抚州发电有限责任公司,江西抚州344000 [2]华北水利水电大学电力学院,河南郑州450045

出　　处：《水力发电》2022年第3期82-88,112,共8页Water Power

基　　金：河南省科技创新人才计划资助项目(154100510011)。

摘　　要：为解决大型火电站循环泵顽固性振动,采用雷诺时均N-S方程和Realizable k-ε湍流模型,对1000 MW超超临界火电机组并联泵循环水流道与循环泵内水力状况进行FLUENT三维数值诊断性分析,模拟研究了进水流道内的流体流动形态、流速分布以及泵体周围和喇叭口周围流场的水力问题,并依此对循环水道进行了优化整流方案研究。研究结果表明,循环水流道前池过短且为不规范矩形,由引水段冲入的流体无法在前池内得到充分发展扩散,吸水室内水流流态严重偏流乃至贴壁流动,近壁流体流速差可达0.3 m/s;喇叭口处截面流速严重不对称,循环水泵周围流场紊乱,来流两侧水流流速差异过大,流速差最大可达0.5 m/s,进水条件恶劣。采取针对性优化整流方案后,进水流道内水流流态分布更加均匀,水泵进水条件得到显著改善。In order to solve the stubborn vibration of circulating pump in large thermal power plant,the Reynolds time averaged Navier-Stokes equations and Realizable k-ε turbulence model are used to simulate the 3-D flow hydraulic conditions of circulating water channel and parallel circulating pump of 1 000 MW ultra supercritical thermal power unit by FLUENT.The fluid flow pattern and velocity field distribution in the inlet flow passage are numerically studied.The hydraulic problems of the flow field around the pump casing and around the trumpet are also numerically studied.Moreover,the optimal rectification scheme of the circulating waterway is studied.The research results show that,(a) because the fore bay of the circulating water channel is too short and irregularly rectangular,the fluid flushed from the diversion structures cannot be fully developed and diffused in the forebay,the flow pattern of the water in the inlet sump is severely biased or even flows close to the wall,and the velocity difference of the fluid near the wall can reach 0.3 m/s;and(b) the cross-sectional flow velocity at the bell mouth is seriously asymmetrical,the flow field around the circulating water pump is turbulent,and the flow velocity difference between the two sides of the incoming flow is too large with a maximum difference up to 0.5 m/s.The water inlet conditions are bad.After adopting a targeted optimization rectification scheme,the flow pattern distribution in the inlet flow channel is more even,and the water inlet conditions of the pump are significantly improved.

关 键 词：进水流道 数值模拟 循环水泵 振动 水力不均 整流措施 

分 类 号：TV732[水利工程—水利水电工程]