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
寇佳文 1汪程鹏 2王生辉 1杨一帆1
作者信息
- 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
- 折叠
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.
Abstract
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 calcu-lated 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 analy-sis 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 in-side 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-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Key words
hydraulic turbine/envelope angle/internal flow characteristics/pressure pulsation/hy-draulic performance引用本文复制引用
基金项目
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)
中央级公益性科研院所基本科研业务费专项资金项目(R-JBYWF-2021-T02)
出版年
2024
NETL
NSTL
万方数据