中等水深复杂环境载荷下张力腿式浮式风机结构动力学特性研究

Large offshore floating wind turbine foundation design and construction technology has become an important breakthrough orientation in the innovation of China's energy technology revolution. The environment conditions in moderate water depth of China south-eastern seas are complex and changeable. Structural dynamics coupling problems of floating wind turbines caused by the external environment loads are intricate. In previous studies, it was found that water depth and extreme water level have significant effects on the structural dynamics and strength of tension leg platform wind turbines. This project will be conducted progressively through foundation optimization design, dynamic response and structural strength. First, in view of the characteristics of moderate water depth, the project intends to develop a suitable form of tension leg floating wind turbine through the optimization and influence research on main parameters of the support platform and mooring system. Second, in view of the frequent typhoons and storm surges, the dynamic model and theoretical analysis method considering wind, wave and extreme water level effects will be established. And third, it is proposed to establish a dynamic analysis method of structural strength of the substructure based on multi-body dynamics and to compare with the strength analysis of quasi-static result in frequency domain. The project strives to reveal the interaction and influence mechanism between the complex environmental loads and the structural dynamics of floating wind turbines and to find out the structural failure modes of tension leg platform wind turbines considering the nonlinear load effects. The successful implementation of the project will provide an important theoretical basis and technical support for the study on tension leg platform wind turbines in moderate water depth.

海上浮式风机基础设计建设技术已经成为我国能源技术革命创新的重要突破方向。我国东南部中等水深(50m-100m)海域环境条件复杂多变，外界载荷导致浮式风机结构动力学问题错综复杂。前期研究发现水深和极端水位对张力腿式浮式风机结构动力影响显著。本项目拟通过张力腿式浮式风机基础优化设计、结构动力响应、强度分析方法三个方面展开研究：(1)对中等水深处张力腿式浮式风机支撑平台、系泊系统等主要参数优化及影响研究，提出适宜的张力腿式浮式风机形式；(2)针对台风、大浪、风暴潮频发的特点，建立风-浪-极端水位影响的张力腿浮式风机结构动力模型及分析方法；(3)基于多体动力学建立支撑平台结构强度动力分析方法。研究风机系统在复杂环境载荷作用下发生结构动力响应的机理；探明考虑载荷非线性效应的支撑平台结构失效模式两个关键科学问题。为中等水深海域张力腿式浮式风机的研究提供重要的理论基础和技术支撑。

海上浮式风机的设计与建造涉及到空气动力学、波浪力学、结构动力学及风机系统控制等多个学科的交叉。设计方面的创新和对数值模拟及试验的研究可以帮助增加建造及运行过程中的安全性，减少各环节的成本，推进海上浮式风机的发展。围绕我国浮式基础设计技术创新发展方向，本项目在前期的基础上从支撑平台优化设计、结构动力响应、强度分析方法三个方面开展研究，目前取得了以下研究进展：（1）针对我国东南部海域中等水深及环境载荷特点，通过对STLP-5MW及STLP-10MW浮式风机支撑平台、系泊系统等主要参数的设计优化及影响研究，提出了适宜的张力腿式浮式风机形式；（2）针对台风、大浪、风暴潮频发的特点，建立了考虑风-浪-极端水位影响的浮式风机动力模型及分析方法，揭示了复杂环境载荷下张力腿式浮式风机结构动力响应的机理；（3）建立浮式风机支撑平台结构强度时域分析模型，重点研究了在复杂环境载荷作用下支撑平台结构内部及重点连接处应力变化问题，基本探明了张力腿式浮式风机支撑平台结构失效模式关键问题，可以为推进我国海上张力腿式浮式风机的发展提供了重要参考。