中等水深10MW张力腿浮式风机基础设计及结构动力特性研究

Design and dynamic responses of a 10 MW tension leg platform floating wind turbine for moderate water depth

针对我国东南部海域中等水深(以60 m水深为例)及环境载荷特点,本文基于某10 MW海上风机,提出了一种小水线面、浅吃水、可自浮整体拖航运输安装的张力腿浮式风机基础结构。通过基础结构主要参数的优化设计及对其在工作海况和极端海况下的结构动力响应进行研究,验证其适宜性。研究结果表明,水深较浅会导致系泊系统较短,基础纵荡自振频率接近常见波浪频率范围,可能产生较大的共振响应,在不改变结构质量的情况下,可通过增大下部边立柱及浮筒的高度、减小其宽度以增大结构纵荡附加质量;当预张力较大时,纵荡自振频率较大,可能与一阶波浪载荷发生共振;应合理设置浮式风机基础质量,当基础质量较小时,可能引起较大的结构动力响应。

A 10 MW tension leg platform wind turbine with small water plane area,shallow draft,and self floating transportation and installation was proposed for moderate water depths(60 m in this paper)in Southeast China Seas.The suitability of the TLP wind turbine was verified based on the optimization design of the main parameters and the nonlinear dynamic analysis of its structural response under working and extreme sea states.The results show that a shallow water depth will result in a shorter mooring system,and the surge natural frequency will be close to the range of wave frequencies,which may cause a larger resonance response.Without changing the mass of the structure,the added mass of the surge motion can be increased by increasing the height and reducing the width of the lower columns and pontoons.When the pretension is larger,the surge natural frequency is larger,which may resonate with the first-order wave load.The mass of the system should be set reasonably,because when the foundation mass is small,it may cause larger dynamic responses of the floating wind turbine.