基于桨叶调节的轴流转桨式水轮机模型飞逸数值模拟  

Numerical simulation of runaway transients of Kaplan turbine model based on blade regulation

作　　者：周大庆[1] 郭优[1] 姜德政[2] 

机构地区：[1]河海大学能源与电气学院,江苏南京211100 [2]中国长江电力股份有限公司,湖北宜昌443002

出　　处：《水利水电科技进展》2016年第4期13-19,共7页Advances in Science and Technology of Water Resources

基　　金：国家自然科学基金(51339005;51106042)

摘　　要：为了研究不同桨叶启闭规律对轴流转桨式水轮机飞逸过程的影响,采用三维非定常数值方法模拟了5种桨叶控制方式下的轴流转桨式水轮机模型飞逸过程,对比分析了转速、流量、力矩和压力脉动等参数随时间变化特性及桨叶表面压力分布和尾水管内流场演变规律。结果表明：以桨叶静止工况下的最大逸速为基准,在±10°内启闭桨叶对最大逸速影响范围为-6.6%~5.0%;在飞逸过程中打开桨叶会加剧外特性参数波动,尾水管中心部最大负压值可达初值的2.86倍,产生的偏心螺旋涡带诱发强烈低频脉动,不利于机组稳定;关闭桨叶可降低水流流速,减小压力脉动及改善尾水管流态,但需探究合理关闭方式以避免过大的转速最大上升值。In order to study the effect of different laws regarding the opening and closing of the blade on the runaway transient of a Kaplan turbine, the runaway transient of a Kaplan turbine model in five blade control modes was simulated using the three-dimensional unsteady numerical method. Changes of the rotation speed, flow rate, torques, and pressure fluctuation with time were analyzed, and the pressure distribution on the blade surface and inner flow patterns in the draft tube were examined. The results show that, compared with the maximum runaway speed under the fixed blade conditions, the variation of the maximum runaway speed ranges from -6. 6% to 5. 0% when the blade angle is changed from -10° to 10°. Opening blades during the runaway transient increases characteristic parameter fluctuations, causes the maximum negative pressure at the central area of the draft tube to reach 2. 86 times the initial value, and produces an eccentric spiral vortex rope, which induces strongly low-frequency fluctuation and is adverse to the unit stability. Closing blades can reduce water velocity, alleviate pressure fluctuation, and improve the flow pattern in the draft tube, but reasonable closure modes should be investigated in order to avoid an excessive increase in the runaway speed.

关 键 词：轴流转桨式水轮机 飞逸过程 桨叶调节 启闭规律 三维非定常数值模拟 

分 类 号：TK730[交通运输工程—轮机工程]