- 學位論文
垂直軸雙胞胎風力機研製與其效率量測
Development and Working Efficiency Measurements for the Twin Rotor Vertical Axis Windmil
摘要
本論文主要工作為開發具雙獨立轉軸之垂直軸雙胞胎風力機，利用雙軸套筒將內外轉軸獨立開來，達到互不干擾運作之目的以利用二次風能，並量測其整體的轉換效率。結構上，內轉軸連接阻力型葉片，而外轉軸連接升力型葉片，當氣流通過風力機的時候，會先被外部的升力型葉片捕捉部分風能，而剩下的風能將會被內葉片捕捉達到有效利用風能之目的。本垂直軸雙胞胎風力機在設計演進上可以區分成三代，第一代側重在概念及葉片型式的確立；第二代則是著重於雙軸套筒之改良並確定其機構設計；第三代則是改良葉片參數以改善風力機整體的轉動情形。此外，本工作亦利用LabVIEW軟體來自動化監控與量測轉動資訊，如：葉片轉速、尖速比及效率等等。實驗結果顯示，改良設計參數後的二階Savonius葉片在尖速比1.05時，有最佳效率19.5%，外葉片方面則是利用半圓形阻力型葉片與不同葉片數量的Clark-Y外葉片做一系列的量測，結果顯示，三片外葉片有較好的表現，在尖速比為1.13時，其效率為6.5%。內外葉片結合運轉方面，本論文分別以兩片及三片Clark-Y外葉片與Savonius內葉片結合來量測內外獨立運轉時，風力機的整體效率。量測結果顯示，不管外葉片數量如何，在內外葉片反向對轉時，結果對內葉片有利但對外葉片不利；而在內外葉片同方向運轉時，則是對內葉片不利但對外葉片有利。本實驗在內葉片與三片Clark-Y外葉片結合並反向運轉的情形下測試，整體效率的表現較佳，最佳效率出現在風速為8m/s時，整體轉換效率為21.6%。
並列摘要
This article is focused on developing the twin-rotor vertical axis windmill to capture the so-called secondary wind energy and performing its working efficiency measurements using LabVIEW program. Structurally, the inner and outer rotors are separated by twin-rotor mechanism so that the two rotors can be operated independently. In process, the inner and outer rotors were built in drag-type and lift-type blades respectively. The input wind energy can first be captured by the outer turbine and the inner turbine will capture the rest of wind energy which is also called the secondary wind energy. In this work, the twin-rotor vertical axis windmill can be distinguished from three generations in mechanical design. The first generation is focused on developing the twin-rotor mechanism idea and choosing the turbine blades type. The second one is to adjust the mechanism so that inner and outer turbines can be operated independently. The third generation concentrates on blades design to increase the working efficiency. Moreover, this work also used encoders and LabVIEW program to monitor the relevant information automatically, such as RPM, TSR and working efficiency of twin-rotor vertical axis windmill. The results show that modified two-steps Savonius rotor has the best working efficiency of 19.5% at TSR = 1.05. For the outer turbine of semicircular drag-type with different number of Clark-Y blades, the results show that the outer turbine with three Clark-Y blades has working efficiency of 6.5% at TSR = 1.13. Moreover, this work used two and three outer blades to combine with the inner turbine as the twin-rotor vertical axis windmill for working efficiency measurements. The results show that when the inner and outer turbines turn contrarily with any number of outer blades will received benefit for the inner turbine and disadvantage for the outer turbine, when the inner and outer turbines turn in same direction also with any number of outer blades will received the opposite result, i.e. disadvantage for the inner turbine and advantage for the outer turbine. Finally, this work accomplishes the twin-rotor mechanism. The results show that the inner turbine integrated with three blades outer turbine and turning contrarily received the best working efficiency of 21.6% at wind speed 8 m/s.