離岸風機沉箱型重力式基礎之可行性研究

Abstract

本研究以英國及丹麥近年來離岸風場開發遭遇問題分析為基礎，針對國內離岸風電發展目前面臨之困難與瓶頸，如相關工程技術、建購成本、地質與結構互制之安全性、環境影響及海事工程產業與市場需求等條件，嘗試從產業與學術觀點整合提出創新的解決方案，為國內發展離岸風場提供另一種選擇。因此，提出沉箱型重力式基礎配合上部結構與風機在陸上預組裝之構想，並以拖航方式運輸進行沉放安裝，過程中為了避免海上瞬間的風浪，以及沉箱浸水至重心與浮心交會深度時，易發生扶正力矩不平衡而產生傾倒現象，故採用錨碇系統作為輔助。同時也利用計算力學軟體ANSYS-FLUENT 進行模擬，針對沉箱型重力式基礎在沉放過程時，探討本基礎附近的流場與壓力場分佈情形。此外，也針對本基礎在未來工程施工上進行可行性評估，以驗證本構想之可行性。

This study proposes innovative solutions, which are based on the analysis of the problems faced in wind farm development in the United Kingdom and Denmark in recent years, to the current difficulties and bottlenecks of domestic and overseas offshore wind power development by integrating industrial and academic viewpoints. Such difficulties and bottlenecks include engineering and technological challenges, construction and purchasing costs, safe interactions between geological and structural features, environmental influence, conditions of the marine engineering industry, and market demand. Furthermore, this study provides alternatives for developing domestic offshore wind power. Therefore, this study use a caisson gravity foundation paired with superstructures and turbines preassembled onshore, transported by towing, and installed by submergence. In sinking installation, the center of buoyancy and gravity meeting will lead the righting moment losing and the pre-assembling offshore wind turbines(POWT)capsizing in slight environmental loading such as wind, current and waves. To avoid and control this risk, a temporal mooring system is needed. A simplified and feasible mooring solution is suggested. And we also use the computational fluid dynamics(CFD)software ANSYS-FLUENT that is applied to simulate the distribution of the velocity, pressure and flow field. Then we can understand the distribution of the underwater foundation, even make advance precautions. In addition, we also do the feasibility assessment of the foundation .This study results indicated that an optimal solution that can enable Taiwan to develop offshore wind power while promoting the domestic marine engineering industry.