混流式水轮机全流道仿真研究与压力脉动分析

发布时间：2018-03-11 10:42

本文选题：仿真数值计算　切入点：混流式水轮机　出处：《昆明理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：水力发电中,水轮机占据着水电站的枢纽位置,随着国家积极发展大型水电建设,混流式水轮机成为了应用最广泛的一种水轮机。以某水电站混流式水轮机为本文的仿真研究对象,通过对水轮机流场进行三维建模的方法,以计算机为实验平台,采用全流道仿真模拟计算方法对水轮机内部流动状况进行研究。首先介绍本文的研究背景与意义,水轮机内部流动的研究方法,且简要概述国内外混流式水轮机全流道仿真研究的研究现状;其次展开对CFD软件的介绍和计算中所用到的基本理论知识,着重讨论几种湍流的分析计算方法的优劣性;然后结合专业建模软件运用专业CAD软件Pro/Engineer对水轮机全流道的各个过流部件进行三维实体建模,运用专业网格划分软件ICEM对全流道网格进行划分,实现CAD/CFD技术的融合,蜗壳、导叶、转轮等均采用非结构体网格划分,尾水管流场部分采用结构体网格划分。最后采用选择Realizablek-ε模型作为本次仿真计算模型,针对水轮机的8个不同工况进行仿真数值计算,分析各个过流部件的计算结果,包括蜗壳、活动导叶、转轮、尾水管的速度场与压力场分布,并在此基础上进行非稳态模拟计算,最后得到了尾水管的压力脉动时域分布,分析其压力脉动特性,并推断产生压力脉动原因,找出机组稳定运行区间,为实际工程中的机组稳定性运行提供理论基础,并且为找出不同工况下运行与尾水管压力脉动强度的关系做了初步的探索。
[Abstract]:In hydroelectric power generation, hydraulic turbines occupy the pivotal position of hydropower stations. With the active development of large-scale hydropower construction in the country, Francis turbine has become the most widely used hydraulic turbine. Taking the Francis turbine of a hydropower station as the object of this paper, through the method of three-dimensional modeling of the turbine flow field, the computer is used as the experimental platform. This paper introduces the research background and significance of this paper, and introduces the research method of the internal flow of the turbine. The research status of Francis turbine full-channel simulation at home and abroad is briefly summarized. Secondly, the basic theoretical knowledge used in the introduction and calculation of CFD software is introduced, and the advantages and disadvantages of several turbulence analysis and calculation methods are emphatically discussed. Then combining with the professional modeling software, using the professional CAD software Pro/Engineer to carry on the three-dimensional entity modeling to each flow passage parts of the hydraulic turbine, and using the professional grid division software ICEM to divide the whole flow channel grid, realize the integration of CAD/CFD technology, volute. The guide vane, runner and so on are divided by non-structural mesh, and the flow field of draft tube is divided by structural grid. Finally, the realizablek- 蔚 model is selected as the simulation model, and the simulation numerical calculation is carried out for 8 different working conditions of the turbine. The distribution of velocity field and pressure field of volute, active guide vane, runner and draft tube are analyzed. Based on this, unsteady state simulation calculation is carried out, and the time domain distribution of pressure pulsation of draft tube is obtained. The characteristics of pressure pulsation are analyzed, and the causes of pressure pulsation are inferred, and the stable operation interval of the unit is found out, which provides a theoretical basis for the stable operation of the unit in practical engineering. In order to find out the relationship between operation and pressure pulsation intensity of draft tube under different working conditions, a preliminary exploration has been made.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TV734.1

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