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臺灣能源期刊論文全文

臺灣能源期刊第7卷第1期內容

出刊日期:March, 2020

題目
9.5 MW離岸風力機之複合重力式基礎的初步評估
Title
The Preliminary Assessments of Hybrid Gravity Based Foundations for 9.5 MW Offshore Wind Turbines
作者
劉品瑄、朱棟樑、黃金城
Authors
Pin-Hsuan Liu, Tung-Liang Chu, Chin-Cheng Huang
摘要
本研究針對9.5 MW大型化參考離岸風力機結合複合重力式基礎與重力式基礎進行設計檢核與分析評估,並完成風、波浪載重相關理論與數值模擬之比較與探討。本研究首先使用SAP 2000分析軟體建立構架式風力機整體模型,並進行自然振動頻率、構件強度與基礎穩定性檢核,其次依據DNVGL-ST-0437 (2016)針對離岸風力機的設計載重情況(DLCs, Design Load Cases),並且採用我國彰濱外海風場地質條件、新竹浮標測站之風力與外埔潮位站波浪等環境參數進行負載分析,結果顯示,本研究參考之重力式基礎型式皆能符合要求。再者,水動力分析結果顯示,使用半經驗公式之Morison方程式獲得的波浪負載較ANSYS Fluent數值模擬保守,可見數值分析對重力式基礎設計有較佳的經濟性。接著在角形沉箱式重力式基礎於設計載重方向性差異分析中,負載方向性對角形沉箱與轉子與機艙配置位置影響不明顯;然而重力式基礎之大尺寸沉箱由於受波浪截面積較大,因此其受波浪負載較樁體、錐形區大。最後,於風、波浪負載對於重力式基礎穩定性分析之結果顯示,基礎水平滑動力主要以波浪控制,基礎傾倒彎矩主要以風力控制,顯示水動力與風力機空氣動力分析對重力式基礎的重要性。
關鍵字
離岸風力機,複合重力式基礎,水動力分析
Abatract
This research is focused on the validation and evaluation of Hybrid Gravity Based Foundation and Gravity Based Structure combining with large-scale 9.5 MW reference wind turbines. Firstly, SAP 2000 frame models are established for natural frequency, component safety margin and stability of the foundations evaluations. Meanwhile, the Design Load Cases (DLCs) suggested by DNVGL-ST-0437(2016) are applied to the frame models. The results show both the referred gravity based foundations satisfy the specific DLCs requirements and are applicable to the wind farms soil properties in Changhua, and the wind and wave conditions at Hsinchu buoy observation station and Waipu tide station. Secondly, 3D non-linear fluid models are made by adopting ANSYS Fluent for more precisely hydrodynamic simulations. The wave loads acting on the foundations obtained by the semi-empirical Morison equation seem to be more conservative than by numerical simulation, then appearing the numerical simulations will provide higher economic efficiency in support structures design. Moreover, in the load directional difference analysis, the polygonal caisson of gravity based structure merely causes influences in the shape of concrete caisson and rotor nacelle assembly position; however, the caisson would bear higher wave loads than shaft and cone components due to the larger fluid flowing area acting on it. Lastly, the comparisons between wave and wind loads are made by the stability analysis. The results show that the horizontal sliding and tilting are separately controlled by wave and wind, and emphasize the vitality of hydrodynamic and aerodynamic simulations for gravity based support structures for offshore wind turbines.
Keywords
Offshore wind turbine, Hybrid gravity based foundation, Hydrodynamic analysis. Received