初探大氣紊流模式與風機性能之評估

Abstract

再生能源一直是目前大家所關注的議題，在台灣，風能目前是最有發展潛力的再生能源，由於台灣西部為數一數二的最佳風場，近幾年也有許多發展風能強盛的國家來台投資。雖然高風速會得到風能效益高，但風機之間產生的紊流擾動，使得產生功率反而減小，並且造成風機損壞，尤其在風機葉片上。 本研究有中尺度及微尺度模擬資料做討論。中尺度資料由數值天氣預報系統 (WRF 模式) 以2015年9月東北季風剛發生時，進行福海地區風況重建，以GFS-FNL作為初始資料預測各個風機輸出功率，願能適時減少碳排放，並模擬紊流動能分布，觀察加入風場後，整個風場對於紊流動能的影響及趨勢，屬於大氣尺度的觀察；微尺度以頻譜模型為基礎，由中尺度WRF模擬結果中幾個重要變數(輪軸高度上的風速、風切值及紊流強度)作為微尺度TurbSim輸入參數，模擬出相似實際天氣狀況之風機紊流入流場，再以微尺度FAST將此入流場與風機模塊結合，模擬此入流場對風機的影響，在本文研究上以風機葉片為研究主軸，並將數據分析其頻譜分布，更清楚瞭解其意義，屬於工程尺度的觀察。 總結，希望藉由本文研究呈現風機架設在福海地區預測風輸出功率及風況紊流特徵，並專注研究在紊流對風機葉片根部的影響，由大氣尺度到工程尺度並結合，達到一貫化風能模擬，願能提供未來福海地區架設風機時的依據，並再加以討論，如何達到風機受紊流損害最小。

Sustainable energy has always been an issue of concern to everyone. In Taiwan, wind energy is currently the most renewable energy source with potential for development. Since Taiwan Strait is one of the best wind farms in the world, there are also many countries that have developed wind power strongly want to invest in Taiwan in recent years. Although high wind speeds will result in high wind energy efficiency, the turbulence disturbances generated between the wind turbines will result in a reduction in power generation and cause wind turbine in damage, especially on the blades. There are mesoscale and microscale simulation data for discussion in this study. The mesoscale simulation by conducting the Weather Research and Forecast model (WRF model). The reconstruction of wind conditions in the Fuhai area was performed during September 2015 when the northeast monsoon occurred, and GFS-FNL was used as the initial data to forecast the output power of the wind turbines. The micro-scale simulation by conducting TurbSim which is a kind of statistical based on Kaimal model. In order to make relation between two different scale simulator, several important variables (wind speed, turbulent intensity at the hubheight, and wind shear ) from the mesoscale WRF simulation results are used as micro-scale TurbSim input parameters to simulate the wind turbulence that is similar to the actual weather conditions. The turbulent inflow field combine with wind turbine module by conducting FAST to simulate the effect of this inflow field on the wind turbine. In this report, the main study is on the blades of wind turbine, is a small scale observation, and make the data to spectrum distribution for understanding its meaning more clearly. In conclusion, it is hoped that this report will forecast wind power output in the Fuhai area and study the wind turbulence characteristics and focus on the impact of turbulence on root of blades. From the atmospheric scale to the engineering scale and combined to achieve consistent wind energy simulation. Furthermore, attempting to provide the basis for installation of wind turbines, and further discuss how to achieve the minimum wind turbine damage caused by turbulence.