叶片包角对液力透平水力性能与压力脉动的影响  

Effect of Blade Envelope Angle on Hydraulic Performance and Pressure Pulsation of Hydraulic Turbines

作　　者：寇佳文 汪程鹏 王生辉 杨一帆 KOU Jiawen;WANG Chengpeng;WANG Shenghui;YANG Yifan(Mechanical and Electrical Engineering College,Hainan University,Haikou,China,Post Code:570228;The Institute of Seawater Desalination and Multipurpose Utilization,MNR,Tianjin,China,Post Code:300192)

机构地区：[1]海南大学机电工程学院,海南海口570228 [2]自然资源部天津海水淡化与综合利用研究所,天津300192

出　　处：《热能动力工程》2024年第8期49-57,共9页Journal of Engineering for Thermal Energy and Power

基　　金：海南省省重点研发计划(ZDYF2021SHFZ057);天津市自然科学基金重点项目(20JCZDJC00460);中央级公益性科研院所基本科研业务费专项资金项目(K-JBYWF-2021-T07,R-JBYWF-2021-T02)。

摘　　要：为探究叶片包角对液力透平能量回收效率和运行稳定性的影响,采用UG建立流体域的三维模型,通过CFX软件将包角在50°~120°区间内的液力透平在额定工况下进行数值计算并进行外特性分析,选择75°,80°和85°3个包角方案进行内流特性分析与压力脉动频谱分析。结果表明:液力透平的效率随包角的增大先增大后减小,在包角80°左右时效率最高;包角的改变对叶轮内部流场的影响较大,合适的包角可以降低叶轮工作流道内的湍动能,使高速流体冲击叶片后的能量转换更加充分;主频为7fn时蜗壳与隔舌处的压力脉动主要受动静干涉作用影响,主频为2fn时叶轮工作流道内主要受涡流影响,包角对蜗壳、叶轮的压力脉动影响较大,对隔舌影响较小;包角为80°时,监测点rv5处的峰峰值与包角85°时相比降低了9.78%,显著提升了液力透平运行的稳定性。In order to explore the influence of blade envelope angle on the energy recovery efficiency and operational stability of hydraulic turbines,a three-dimensional model of the fluid domain was established using UG.The hydraulic turbine with envelope angle in the range of 50°to 120°was numerically calculated and analyzed for external characteristics under rated conditions using CFX software.Three sets of envelope angle schemes,namely 75°,80°and 85°,were selected for internal flow characteristics analysis and pressure pulsation spectrum analysis.Research has found that the efficiency of a hydraulic turbine first increases and then decreases with the increase of the envelope angle,and the efficiency is highest at around 80°envelope angle;the change of the envelope angle has a significant impact on the flow field inside the impeller.An appropriate envelope angle can reduce the turbulent kinetic energy in the working flow channel of the impeller,making the energy conversion more complete after the high-speed fluid im热pacts the blade.Under a main frequency of 7fn,the pressure pulsation at the volute and tongue is mainly affected by the interference of dynamic and static forces;under a main frequency of 2fn,the working flow channel of the impeller is mainly affected by eddy currents.The envelope angle has a greater impact on the pressure pulsation of the volute and impeller,and a smaller impact on the tongue.When the envelope angle is 80°,the peak to peak value at monitoring point rv5 decreases by 9.78%compared with that at the envelope angle of 85°,significantly improving the operational stability of the hydraulic turbine.

关 键 词：液力透平 包角 内流特性 压力脉动 水力性能 

分 类 号：TV734[水利工程—水利水电工程] TK720[动力工程及工程热物理—流体机械及工程]