直叶片竖轴风机桨距控制策略优化研究

发布时间：2018-12-17 20:29

【摘要】：面对能源危机以及全球环境污染等问题的日趋严重化，可再生能源的开发和发展已经迫在眉睫。风机作为一种将风能转化为电能的装置，是目前开采风能的重要工具。根据风机的主轴方向，可将其分为水平轴风机和垂直轴（竖轴）风机。由于水平轴风机采能效果高，技术已相对成熟，而垂直轴风机因其较低的风能采集效率一直未受重视。近年来，小型垂直轴风机适应复杂风场的能力，以及大型垂直轴风机开发的潜力，促使垂直轴风机又逐渐受到青睐。论文将以升力型直叶片垂直轴风机为研究对象，立足于桨距角能显著改变叶片气动性能的特点，旨在提高其自启动性能和风能利用效率。传统双面多流管（Double-Multiple-StreamTube, DMST）风机性能评估方法具有原理简单，计算高效的特点。论文在对直叶片垂直轴风机变桨距的气动力分解、计算原理详细阐述的基础上，，对传统的DMST程序进行了三方面改进：（1）加入动态失速的修正；（2）加入可变桨距角的影响；（3）提高程序收敛性。改进后的程序提高了垂直轴风机性能评估的精度和收敛性，并可用于变桨距风机的计算。在DMST平台的基础上，结合遗传算法建立了直叶片垂直轴风机桨距角优化计算模型。得到了不同叶尖速比下的最优桨距角曲线，即主动桨距角控制的最优策略。通过对切向和法向力系数及风能利用率曲线的分析也表明优化后的风能利用率有明显提升。主动桨距控制策略的研究成果适用于方便安装独立控制装置的大型垂直轴风机上，而被动桨距控制装置适用于在城镇中或水下流场复杂的低成本小型垂直轴风机。 CFD数值模拟了变桨距风机运转的流场，同样证明了桨距控制对采能效率提升的有效性。此外，基于最优桨距角曲线设计了一套被动桨距控制机构。可通过调节该机构构件的尺寸使风轮转动过程中的桨距角与优化的桨距角相近。对比分析表明，被动桨距控制机构能够提高风能利用率以及启动性能。
[Abstract]:In the face of energy crisis and global environmental pollution, the development and development of renewable energy is imminent. Fan, as a device to convert wind energy into electric energy, is an important tool for exploiting wind energy. According to the spindle direction of the fan, it can be divided into horizontal shaft fan and vertical (vertical axis) fan. Because of the high energy recovery effect of horizontal shaft fan, the technology has been relatively mature, but the vertical axis fan has not been paid attention to because of its low wind energy collection efficiency. In recent years, the ability of small vertical shaft fan to adapt to complex wind field and the potential to develop large vertical shaft fan make vertical shaft fan become more and more popular. In this paper, the vertical shaft fan with lift straight blade is taken as the research object, which is based on the characteristic that the pitch angle can change the aerodynamic performance of the blade significantly, in order to improve its self-starting performance and wind energy utilization efficiency. The traditional double-sided multi-flow tube (Double-Multiple-StreamTube, DMST) fan performance evaluation method has the characteristics of simple principle and efficient calculation. On the basis of the aerodynamic decomposition and calculation principle of variable pitch of vertical shaft fan with straight blade, this paper improves the traditional DMST program in three aspects: (1) adding the modification of dynamic stall; (2) the influence of variable pitch angle is added; (3) the program convergence is improved. The improved program improves the accuracy and convergence of the performance evaluation of the vertical shaft fan and can be used to calculate the variable pitch fan. Based on the DMST platform and genetic algorithm, a model for calculating the pitch angle of vertical fan with straight blade is established. The optimal pitch angle curve under different tip speed ratio is obtained, that is, the optimal control strategy of active propeller pitch angle. The analysis of tangential and normal force coefficient and wind energy utilization curve also shows that the optimized wind energy utilization rate is obviously improved. The research results of active pitch control strategy are suitable for large vertical shaft fans which can easily install independent control devices, while passive propeller pitch control devices are suitable for low cost and small vertical shaft fans with complex flow field in towns or underwater. The flow field of variable pitch fan is numerically simulated by CFD, which also proves the effectiveness of pitch control in improving energy recovery efficiency. In addition, a passive pitch control mechanism is designed based on the optimal pitch curve. By adjusting the size of the component of the mechanism, the pitch angle in the wind wheel rotation process is close to that of the optimized pitch angle. The comparison and analysis show that the passive pitch control mechanism can improve the wind energy utilization and start-up performance.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM614

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