定桨定速型风力发电机结构的风动力分析

发布时间：2018-09-18 14:37

【摘要】：本文选取GCN1000S型号的风力发电机为研究对象，首先对风力发电机的基本翼型性能参数进行数据采集，然后利用基本翼型参数通过插值方法得到GCN1000S型号风力发电机的性能参数，并通过数值模拟方法对叶片截面翼型升阻力系数进行检验，得到实际可靠的机翼数据，由此建立二维计算模型。依据叶素动量理论（BEM方法）进行数值分析，得到风力发电机的功率曲线和效率曲线。通过功率曲线与参考曲线进行对比发现二者吻合较好，从而验证了模型的正确性。在此基础上，，利用该二维模型对风力发电机结构附近的流场进行了计算，得到测风仪处的流场速度与来流风速存在较大差别，这些表明厂家原来将测风仪处的风速作为来流风速的做法是不恰当的，需要进行修正。为了得到测风仪处的流场速度与来流风速之间的明确关系，需要进一步开展风机结构附近流场分布的三维精确分析。首先，根据厂家提供的‘Solidworks-模型’导入风机结构的几何构型，藉由当前该领域的圆盘理论建立了流场分析的准三维模型。在划分恰当的离散网格后，通过CFD方法进行了求解，依次计算出在不同来流风速条件下，风机结构附近流场流速分布情况以及测风仪处风速的大小，得到该型号风力发电机测风仪处风速约为来流风速的80%左右。为了更进一步精确地确定测风仪处的流场速度与来流风速之间的比例系数，我们基于三维CFD方法开展了风机功率计算和绕流流场数值仿真，使用三种不同旋转模型进行数值求解，得出滑移网格模型预测的风力机功率曲线结果在趋势上更接近实测结果，确定测风仪处的风速与来流风速的比值约在86%-93%之间。通过对测风仪风速与来流风速进行这样修正后，所得到的风力发电机功率曲线在数值大小和趋势上都更加接近于实测结果。本文对风力发电机的设计和计算分析具有重要的指导意义。
[Abstract]:In this paper, the GCN1000S wind turbine is selected as the research object. First, the basic airfoil performance parameters of the wind turbine are collected, and then the performance parameters of the GCN1000S wind turbine are obtained by interpolation method using the basic airfoil parameters. The lift and drag coefficients of the blade section airfoil are calculated by numerical simulation method. According to the blade element momentum theory (BEM) numerical analysis, the power curve and efficiency curve of the wind turbine are obtained. By comparing the power curve with the reference curve, it is found that they are in good agreement, thus verifying the correctness of the model. The two-dimensional model is used to calculate the flow field near the structure of the wind turbine. It is found that there is a great difference between the velocity of the flow field at the anemometer and that of the incoming wind, which indicates that it is inappropriate for the manufacturer to take the wind speed at the anemometer as the incoming wind speed and needs to be revised.
In order to get a clear relationship between the velocity of the flow field and the velocity of the incoming wind, it is necessary to carry out a further three-dimensional accurate analysis of the flow field near the fan structure. Three-dimensional model. After dividing the appropriate discrete grid, the CFD method is used to solve the problem. The flow velocity distribution near the fan structure and the wind speed at the wind meter are calculated in turn under different wind speed conditions. The wind speed at the wind meter is about 80% of the wind speed at the wind turbine. Based on the three-dimensional CFD method, the power calculation and the numerical simulation of the flow field around the wind turbine are carried out. Three different rotating models are used to solve the problem. The power curve predicted by the sliding grid model is closer to the actual measurement in trend. The results show that the ratio of wind speed to incoming wind speed is about 86%-93% at the anemometer, and the power curve of the wind turbine is more close to the measured value and trend after the anemometer wind speed and incoming wind speed are corrected in this way.
This paper has important guiding significance for the design and calculation analysis of wind turbines.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM315

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