内外双层垂直轴水轮机性能研究

发布时间：2019-03-10 21:23

【摘要】：海洋是蕴藏着庞大资源的能量宝库,海洋能不但清洁环保,对生态环境影响甚微,且是一种取之不尽用之不竭的可再生绿色资源,人类所用能源的未来就在宽广的海洋之中。潮流能水轮机是将潮流动能转换为电能的装置,其中固定偏角垂直轴潮流能水轮机对不同的来流方向具有良好的适应性,且易于加工,成本较低,因而引起了广泛的关注。单层叶片垂直轴水轮机自启动困难、叶轮载荷波动大及低转速时效率低的缺点,影响了它的发展优势。因此,本文在传统固定偏角直叶片水轮机的内部增加一层叶片,应用CFD数值模拟方法,研究这种内外双层固定偏角直叶片垂直轴水轮机的性能。首先对单层垂直轴水轮机进行了二维数值模拟计算,通过与试验结果对比验证了数值模拟的正确性。在此基础上计算得到了单层垂直轴水轮机最佳密实度范围,及最佳叶片数,从而确定了内外双层垂直轴水轮机外层叶轮的尺寸。然后,采用二维和三维CFD数值模拟分析了速比、内外叶轮相位差、半径比、弦长比、展长比、内层叶片翼型及偏角、三维效应等参数对水轮机性能的影响。研究结果表明双层叶轮可有效提高水轮机的自启动性能和低转速下的效率,同时减小了叶片和叶轮的受力和转矩波动。最后,论文还对内外双层水轮机进行了单向流固耦合分析。计算结果表明,内层叶轮的受力状态要明显优于外层叶轮;水轮机的叶片变形量远小于主轴变形量;水轮机整体的最大应力出现在主轴根部,经过校核其结构是安全的。同时由于水轮机整体变形较小,因此无需对双层水轮机进行双向流固耦合分析。研究结果可为内外双层水轮机设计与优化提供借鉴。
[Abstract]:The ocean is a treasure house of energy containing huge resources. The ocean energy is not only clean and environmentally friendly, but also has little influence on the ecological environment, and is an inexhaustible renewable green resource. The future of the energy used by human beings lies in the wide ocean. Tidal turbine is a device that converts the kinetic energy of tidal current into electric energy, in which the fixed deviation angle vertical axis tidal turbine has good adaptability to different flow directions, and it is easy to be machined with low cost, so it has attracted wide attention. The disadvantages of single-story vertical shaft turbine such as the difficulty of self-starting, the large fluctuation of the impeller load and the low efficiency at low speed affect its development advantage. Therefore, in this paper, a layer of blade is added to the internal of the traditional fixed biasing blade turbine, and the performance of the vertical shaft turbine with the inner and outer fixed biasing angle is studied by using the numerical simulation method of CFD. First, a two-dimensional numerical simulation of a single-story vertical shaft turbine is carried out, and the correctness of the numerical simulation is verified by comparing with the experimental results. On this basis, the optimum compactness range and the optimum number of blades of the single-layer vertical shaft turbine are obtained, and the size of the outer impeller of the internal and external double-layer vertical shaft turbine is determined. Then, two-dimensional and three-dimensional CFD are used to simulate and analyze the influence of speed ratio, phase difference between inner and outer impeller, radius ratio, chord length ratio, aspect ratio, blade profile and deflection angle, and three-dimensional effect on the performance of hydraulic turbine. The results show that the double-layer impeller can effectively improve the self-starting performance and the efficiency of the turbine at low speed, and reduce the force and torque fluctuation of the blade and impeller at the same time. Finally, the unidirectional fluid-solid coupling analysis of internal and external double-layer turbine is carried out. The calculated results show that the stress state of the inner impeller is obviously better than that of the outer impeller, the blade deformation of the turbine is much smaller than that of the main shaft, and the maximum stress of the turbine appears at the root of the spindle, and the structure of the turbine is checked to be safe. At the same time, there is no need to analyze the bi-directional fluid-structure coupling of the double-layer turbine because the overall deformation of the turbine is small. The results can be used as reference for the design and optimization of internal and external double-deck turbine.
【学位授予单位】：哈尔滨工程大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TK730;P743.1

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