基于CFD混流式水轮机泵叶及泵盖联合降压研究

为研究泵板装置对混流式水轮机上冠流道泄漏水影响,基于CFD商业软件平台,结合新疆红山嘴一级电站4号水轮机,以泵板装置为研究对象,将主轴密封真空度、泄漏量、上冠间隙进口与梳齿环出口压差作为3个研究指标.首先在模型准确基础上对泵板装置内泵叶角度和泵盖高度2个相关结构分别进行数值分析,其次对其联合优化结构数值模拟.研究表明,...

RESEARCH ON COMBINED PRESSURE REDUCTION OF PUMP BLADE AND PUMP COVER OF FRANCIS TURBINE BASED ON CFD

Based on the CFD commercial software,this work studies the effect of the pump plate device of the No.4 turbine in Xinjiang Hongshanzui First-Level Power Station on the leakage of the upper crown runner of the Francis turbine.The pressure difference at the outlet of the comb ring serves as three indicators.The vacuum degree of the main shaft seal,the leakage amount,and the pressure difference between the inlet of the upper canopy clearance and the outlet of the comb ring are taken as three indicators.First of all,the two related structures of the pump blade angle and the pump cover height in the pump plate device are numerically analyzed based on the accurate model,and then,the numerical simulation of the joint optimization structure is carried out.The results show that the optimization of pump blades and pump cover has significant positive effects on the vacuum degree of the shaft seal,that is when the pump blades are inclined at 30°and the adjustment height ratio of the pump cover is between 0.0272 and 0.1086,all three indicators can meet the design requirements.Tthe leakage in the upper canopy is closely related to the structure of the pump blades and the pump cover,and the impact of the height ratio of the pump cover is more obvious.This study provides a reliable theoretical basis for actual engineering such as modification of main shaft seal and reduction of leakage in power plants.