小型複合式風力發電機結構設計與分析

Abstract

現在一般商業用的風力發電機葉片形式多為水平軸式，雖然具有較高風能轉換效率，但是因葉片需直接迎風，並隨風向變化而旋轉風力發電機機身，長期使用下容易造成風機葉片受風力作用影響而斷裂情形。本研究欲改善此一問題，將自行設計複合式風力發電機葉片，將水平軸式風力發電機葉片以垂直軸式加以改良。實驗的主要目的，在使用計算流體力學軟體對加上外罩的三葉片風力發電機進行分析，以確認此複合式葉片運轉可行性。經由模擬分析後發現在葉片攻角36度時因推力值較高適合啟動葉片，而葉片攻角0度時比其他葉片攻角可獲得較高的風能轉換效率。藉由不同入口風速去測試風能轉換效率發現Cp值並未顯著變化，研判此複合式風力機內部具穩態流場特性。

Owing to the higher conversion efficiency of wind energy, the general commercial wind turbine blades are mostly horizontal axis types in recently. However, the blades need to against directly the wind flow, and follow the change of wind flow direction to rotate the fuselage of the wind turbine generator. So, it may cause the fracture situation of blades by strong wind force after a long-period operation. In order to improve this situation, this study will design a compound wind turbine blades system by modifying the vertical axis type blades. The main purpose of this study is to use the software with guards on the three-blade wind turbine analysis, and confirms the operation of this compound wind turbine blades system is feasible. The analysis result show, the blade angle of attack at 36° has higher thrust to starting the wind turbine. The blade angle of attack at 0° has higher energy transformation efficiency than other angles of attack. If we change wind velocity the energy transformation efficiency were not different, so we can have more steady flow field for this compound wind turbine.