洋流電廠力學設計與分析

Mechanical Design and Analysis of the Ocean Current Power Plant

吳鎮宇(Chen-Yu Wu)

指導教授 ： 陳發林

國立臺灣大學/工學院/應用力學研究所/碩士(2021年)

https://doi.org/10.6342/NTU202101074

摘要

本論文意在開發一款新型淺海渦輪發電廠之佈放程序與運作概念，使用的部件包含了浮筒、渦輪發電機、纜繩、萬向接頭、中空槓桿與吸力錨(suction pile)等等。首先對於電廠的設計概念做出示意動畫預覽，並以此目標來做各項設定進而計算出靜態與動態的力平衡分析與位移狀態，最後以滿足此運作情形之條件來設計各項機件，進而架構出五台渦輪發電機組並以3420kW的功率持續供電。
本研究以降低成本為目標做設計，因此採用易於安裝與拆卸的吸力錨，以及五組共用單一錨錠的方式來設廠。透過數值軟體(MATLAB)計算，得出組間間距越長將使得組間應力越大、淨浮力將會對應到電廠所能停滯的深度，而結果顯示在距離海床30m以內，能夠大幅降低組間的應力，故設定電廠運作位置約為距離海床20m，且得出每組浮筒扣除機件重量後的淨浮力須為497.5kN。因為渦輪機的結構設計會導致渦輪機承受的應力與轉子位置相關，故在考慮相位角後將成為動態問題。分別給予五組渦輪機轉子不同的起使角設定後，將產生組間應力與位移的變化和不對稱問題，但是本電廠是以中間組為中心來對稱兩邊的渦輪機以求得平衡，故須提供反向的組間應力差來使中間組停留不動。接著透過觀察各組的位移，可得各組組間方向位移幾乎為零，而高度則有隨著往海流流向移動時而降低的情形發生。
最後藉由應力的分析結果來對機件做出設計以滿足需求。得到纜繩的直徑、浮筒規格、錨錠在不同海床下的參考尺寸。盼望未來這款新型洋流發電廠能對再生能源產業做出貢獻，成為後人發展技術與設計的參考，推動全球綠能產業的研究。

關鍵字

力學設計 ； 吸力錨 ； 淺海型電廠 ； 黑潮發電 ； 力學分析 ； 海事工程

並列摘要

The purpose of this thesis is to develop a new type of neritic turbine power plant deployment procedures and operational concepts. The components used include buoyancy, turbine generators, cables, universal joints, hollow column and suction piles, etc. First, make a schematic animation preview of the design concept of the power plant, and use this goal to make various settings to calculate the static and dynamic force balance and displacement analysis, and finally to meet the conditions of this operating situation to design various parts. In turn, five turbine generator sets were constructed and continuously supplied with a power of 3420kW.In this study, the design goal is to reduce the budget. Therefore, choosing a suction anchor that is easy to install and five groups of common anchors were used to set up the factory. Through numerical calculations, it is concluded that the longer the distance between groups, the greater the stress between groups, and the net buoyancy will correspond to the depth at which the power plant can stagnate. The results show that within 30m from the seabed, the stress between groups can be greatly reduced. Therefore, it is assumed that the operating position of the power plant is approximately 20m away from the seabed, and the net buoyancy of each group of buoys after deducting the weight of the parts must be 497.5kN. Because the structural design of the turbine will cause the stress on the turbine to be related to the position of the rotor, it will become a dynamic problem after considering the phase angle. After five groups of turbine rotors are given different starting angles, there will be changes in stress and displacement between groups and asymmetry problems. However, this power plant uses the middle group as the center to symmetrical the turbines on both sides to achieve balance, so it is necessary to provide the reverse stress difference between the groups keeping the middle group stationary. Then, by observing the displacement of each group, the directional displacement between each group is almost zero, and the height decreases as it moves toward the ocean current way. Finally, the mechanical parts are designed to meet the stress analysis results. Obtain the diameter of the cable, the specification of the buoy, and the reference size of the anchor in different soil properties. It is hoped that this new type of ocean current power plant can contribute to the renewable energy industry in the future.

並列關鍵字

Mechanical Design ； Suction Anchor ； Neritic Power Plant ； Kuroshio Power Generation ； Mechanical Analysis ； Maritime Engineering

參考文獻

[1] F. Chen, The Kuroshio Power Plant, Springer, 2013.

[2] J. VanZwieten, F. R. Driscoll, A. Leonessa, and G. Deane, “Design of a prototype ocean current turbine—Part I: mathematical modeling and dynamics simulation,” Ocean Engineering, vol. 33, no. 11-12, pp. 1485–1521, 2006.

[3] F. R. Driscoll, G. M. Alsenas, P. P. Beaujean, S. Ravenna, J. Raveling, E. Busold, and C. Slezycki, “A 20 KW open ocean current test turbine,” OCEANS 2008, 2008.

[4] C. W. Finkl and R. Charlier, “Electrical power generation from ocean currents in the Straits of Florida: Some environmental considerations,” Renewable and Sustainable Energy Reviews, vol. 13, no. 9, pp. 2597–2604, 2009.

[5] https://www.theguardian.com/environment/2009/jan/05/tidal-wave-power