大型风力发电机组流固耦合尾迹特性分析

发布时间：2018-01-15 08:07

本文关键词：大型风力发电机组流固耦合尾迹特性分析　出处：《上海电力学院》2014年硕士论文　论文类型：学位论文

【摘要】：随着社会的进步和发展，人类对能源的需求越来越大，而在常规能源的有限性以及当今世界环境日益恶化的形势下，可再生能源的利用无疑为人类寻求可持续发展提供了机会。风能作为一种可再生能源，取之不尽、用之不竭，具有广阔的应用前景和开发潜力，日益受到世界各国的重视。为了更有效的提高风能利用效率、减少基础设施成本，风电场的大型化是目前的发展趋势，而大型风电场中下游风力机常处于上游风力机的尾迹当中，使下游风力机的性能受到影响，为了合理设计风电场，提高风电场效率，开展大型风力机的流固耦合尾迹特性分析是非常有必要的。由于风力机是在复杂多变的环境条件下运行的，风力机会在风的作用下发生变形，同时这变形和运动又会反过来影响风的运动，从而改变风载荷的分布和大小，所以风力机与风场之间的双向流固耦合分析是必不可少的。此外，为了研究实际工作中复杂的运行环境对风力机的影响，应该考虑动态来流和塔影效应等因素对尾迹的影响。本文基于流固耦合理论，采用ANSYS+FLUENT方法和滑移网格技术对NREL5MW风力机的尾迹特性进行了系统分析。为了分析动态来流对尾迹的影响，本文选择了具有代表性的正常垂直风切变、极端垂直风切变、极端运行阵风和极端风向变化4种典型风况，通过UDF进行程序编译并作为入口边界条件，然后采用滑移网格技术进行计算。结果表明：在双向流固耦合情况下，，在近尾迹区，风力机的输出功率和轴向推力比未耦合情况更接近NREL设计值，在远尾迹区，在双向流固耦合情况下，轴向速度更早的在X=6D处达到来流速度，而湍流强度也提前在X=2D处出现拐点开始下降，在X=6D处达到9.8%，流场进入低湍流度区；在动态来流工况下，风力机的功率输出均出现不同程度的波动，尾迹结构也从叶根到叶尖处出现明显变形；塔影效应使风力机扭矩和功率均减小，塔架表面上的升力也出现激烈突变，将对塔架的疲劳寿命产生不利影响，从风力机下游6D处开始可以忽略塔影效应对风力机尾迹分布的影响；本文还提出大型风电场中下游风力机组纵向间距不少于6倍风轮直径和横向距离不少于2倍风轮直径的建议，这将对风电场的风力机组优化布置提供一定的参考依据。
[Abstract]:With the progress and development of society, human demand for energy is increasing, while the limited conventional energy and the world environment worsening situation, the use of renewable energy is the human sustainable development provides opportunities. Wind power as a renewable, inexhaustible, inexhaustible, and has a good application prospect the development of a wide range of potential, has attracted more attention around the world. In order to more effectively improve the wind energy utilization efficiency, reduce the cost of infrastructure, large-scale wind farm is the current trend of development, and the wind downstream of large wind farms in the upstream of the wind turbine machine wake, the performance of downstream turbines is affected, in order to reasonable design of wind farms, improve the efficiency of large-scale wind farm, wind turbine coupling characteristics of wake analysis is necessary.
Because of the wind turbine is running in the complex environment conditions, wind opportunities deform under the action of wind, which will in turn affect the deformation and movement of air movement, thereby changing the size and distribution of wind load, so the analysis of two-way flow solid coupling between the wind turbine and wind field is essential. In addition in order to study the complex operating environment, in the practical work of the wind turbine, should consider the dynamic flow and tower shadow effect influence on the wake. This paper based on the fluid solid coupling theory, the characteristics of wake ANSYS+FLUENT method and sliding mesh technique of NREL5MW wind turbine was analyzed by dynamic analysis. In order to flow influence on the wake, this paper chooses normal vertical wind shear are representative of the extreme vertical wind shear, 4 typical extreme wind conditions and extreme operating gust wind direction change, through the UDF into the trip In order to compile and as the entrance boundary conditions, and then using the sliding mesh technique were calculated. The results showed that: in the two-way flow solid coupling, in the near wake region, the wind turbine output power and axial thrust is closer to NREL than the design value coupling, in the far wake region, in the double to FSI case the axial velocity earlier at X=6D to the flow velocity, and turbulence intensity in advance at X=2D inflection point began to decline, reaching 9.8% at X=6D, flow into the low turbulence zone; in the dynamic flow conditions, the power output of the wind turbine are different degrees of fluctuation, from the root to the leaf blade structure at the tip of apparent deformation; tower shadow effect of the wind power and torque are reduced, the tower also appeared on the surface of the lift fierce mutation, will have an adverse effect on the fatigue life of the tower, it can be ignored from the downstream turbine 6D The tower shadow effect on wind turbine wake distribution; this paper also put forward the downstream in large wind farm wind turbine vertical spacing of not less than 6 times the diameter of the wind wheel and the horizontal distance of not less than 2 times the diameter of the wind wheel of the proposal, which will wind wind turbine layout optimization to provide some reference.

【学位授予单位】：上海电力学院
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM315

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