高性能3kW風光互補整合系統實場開發之研究

Abstract

本研究建立一組並聯系統的四顆薩伯紐斯風車進行發電，同時建立一組太陽能發電系統於並聯系統底部正前方，且太陽能板安裝之傾斜角為23度，用以引導氣流撞擊風車系統，並將此系統安裝於竹北農村開放環境中用以整合發電。本研究內容可以分為兩大部分：首先，利用流體力學套裝軟體Fluent進行氣流場與系統性能的分析，其中包含單顆薩伯紐斯風車葉片的最佳重疊比、四顆薩伯紐斯風車之並聯系統及並聯系統與太陽能電池導流板之最佳間距比較。實驗中，在不同風速與風車轉速的情況下，觀測風車周速比(TSR)、功率係數(Cp)及發電量的關係。最後，所獲得之實驗結果與數值模擬進行詳細比較與分析。 由數值模擬結果顯示，薩伯紐斯風車在重疊比0.15得到最佳效能，且太陽能導流板的加入結果如預期，有助於風車並聯系統效率的提升。其中無太陽能導流板之並聯系統最大Cp值為0.289，發生在TSR 0.8之情況下；而有導流板之並聯系統最佳間距為50公分，且最大Cp值則為0.389，亦發生在TSR 0.8時，相差1.34倍。由速度向量分佈圖可知，太陽能導流板發揮其功用，有效引導風力機組下方氣流撞擊風車並提升風車之效能。 另一方面，由實驗結果顯示，在戶外開放的環境之下，風速與風車的轉速變化極大，故藉由不同季節之白天及夜晚情況下，反覆量測得到Cp與周速比之關係。以竹北實驗場所量測平均風速約6.99±1.52 m/s，其變異係數為21.7% 。四顆薩伯紐斯風車並聯系統，最佳發電效率為20.7%，並且一天可以產生8.25度的電力。最後本研究中3kW之風力與太陽能互補系統，利用四顆薩伯紐斯風車並聯系統與太陽能板模擬的最佳間距結果進行實驗，結果顯示，並聯風力發電系統添加導流板使風力系統效率提升10.1%，最佳發電效率是21.7％，並且風光互補系統一天可以產生14.55度的電力，此電力足以提供3個一般家庭於冬天使用。

The present study established four Savonius wind rotors into a parallel system, installed at a rural open field in Zhubei city of HsinChu County, to generate electric power by using the wind power. Meanwhile, a solar panel, which can generate power by solar energy, was set up in front of the bottom of the parallel system to guide the air flow impinging on the rotors. The solar panel is inclined 23° from the horizon. This dissertation is separated into two parts. First, a computational fluid dynamics (CFD) software, Fluent, was used to analyze the flow fields and the system performance, including the best overlap ratio of one single Savonius wind rotor, performance of four Savonius wind rotors in parallel system and optimal spacing of the parallel system with solar panel deflector. Then, experiments were carried under the various wind velocities and rotational speeds of wind rotors to deduce the relationship between tip-speed ratio (TSR) and power coefficient (Cp). The analyses for the results of numerical simulations experiments are discussed in detail and, finally, a comparison is given. For the numerical simulate results, the optimal performance is found to occur at overlap ratio equal to 0.15, which is adopted for all parametric studies, and the addition of solar panel deflector to parallel system can enhance the performance as expected. The maximum Cp value of parallel system without deflector is 0.289 at TSR 0.8, whereas such value is 0.389 at TSR 0.8 under the best spacing of 50 cm between the parallel system and deflector. The augment of Cp is 1.34 times. From velocity vector distribution, it can be seen that the deflector can guide the underneath air flow to impinge on the rotors to gain an extra wind power. On the other hand, the experimental results show that the wind velocity and rotational speed of wind rotors have large fluctuation in open field. Therefore, the present study repeated the experiments in day and night for different seasons to measure Cp and TSR. The measured average wind speed is 6.99±1.52 m/s with a coefficient of variation of 21.7% in plant. The four Savonius wind rotors in parallel system can generate 8.25 kWh per day, whose optimum power generation efficiency is 20.7%. The 3kW wind and solar hybrid integration system, which applies the best simulation conditions to the design of experiment, can generate power of 14.55 kW∙hr per day that can sufficiently provide power usages for three general families in winter, and the corresponding optimum power generation efficiency is 21.7%. From the result of Cp curve, it can find that the deflector indeed can improve the system performance up to 10.1%.