﻿ 半潜式浮式风机系统湿拖过程动力响应研究
 舰船科学技术  2022, Vol. 44 Issue (18): 116-121    DOI: 10.3404/j.issn.1672-7649.2022.18.023 PDF

1. 中船风电工程技术(天津)有限公司，天津 300450;
2. 天津大学 水利仿真与安全国家重点实验室，天津 300072

Dynamic response of semi-submersible floating wind turbine during wet-towing operation
LI Ya-jie1, MIN Ye1, ZHANG Kun-peng1, LIU Li-qin2, YV Yong-jun2, MENG Chun-lei2
1. CSSC Wind Power Engineering Technology (Tianjin) Co., Ltd., Tianjin 300450, China;
2. State Key Laboratory of Hydraulic Engineering Simulation and Safety, Tianjin University, Tianjin 300072, China
Abstract: The motion and cable tension of wet towing of the floating wind turbine systems were studied. The hydrodynamic model of floating wind turbine system was established, and the hydrodynamic forces of floating foundation were calculated based on three-dimensional potential flow theory. Having considered wind, wave and current loads, the key parameters such as floating foundation motion, wind- turbine flange inclination, cabin acceleration and towing cable tension during towing were calculated. The influence of cable length, wave height and wave period on the calculation results was analyzed. The results show that within a given ranges of environmental parameters, the motion of the floating turbine meets restrictive conditions. The shorter the towed cable, the greater the towed cable tension under the same environmental parameters. The towed cable tension of 600 m and above is relatively stable and less affected by wave parameters. Finally, the limiting operating wave parameters of different cable lengths are presented. This study provides some suggestions for the wet-towing operation of the floating wind turbine.
Key words: floating wind turbine     wet towing of floating wind turbine     the motion of wind turbine     cable dragging force
0 引　言

1 计算原理与方法

 $\Delta \varPhi =\dfrac{{\partial }^{2}\varPhi }{{\partial} {x}^{2}}+\dfrac{{\partial }^{2}\varPhi }{{\partial }{y}^{2}}+\dfrac{{\partial }^{2}\varPhi }{{\partial} {z}^{2}}=0。$ (1)

1）海底不可穿透条件，海底上的法向流速为0，即

 $\dfrac{\partial \varPhi }{\partial z}=0,\text{ }z=-{h}_{0}。$ (2)

2）自由表面条件，即在平均水面上

 $g\dfrac{\partial \varPhi }{\partial z}+\dfrac{{\partial }^{2}\varPhi }{\partial {t}^{2}}=0。$ (3)

3）物面边界条件，即在浮体表面法向流速与浮体法向运动速度一致，即

 $\dfrac{{\partial \varPhi }}{{\partial N}} = U \cdot N。$ (4)

 $p = - \rho \left( {\dfrac{{\partial \varPhi }}{{\partial t}} + gz + \dfrac{1}{2}{{\left| {\nabla \Phi } \right|}^2}} \right)。$ (5)

 ${F = } - \iint\limits_{{S_0}} {p{n}}{\rm{d}}{S_0}。$ (6)

 $\varPhi ={\varPhi }_{w}+{\varPhi }_{d}+{\displaystyle \sum\limits_{j=1}^{6}{\varPhi }_{j}}。$ (7)

 $p = - \rho \left( {\dfrac{{\partial {\varPhi _w}}}{{\partial t}} + \dfrac{{\partial {\varPhi _d}}}{{\partial t}} + \displaystyle \sum\limits_{j = 1}^6 {\dfrac{{\partial {\varPhi _j}}}{{\partial t}} + gz} } \right)。$ (8)

 $q=\dfrac{1}{2}{\rho }_{a}{U}_{T,Z}^{2}。$ (9)

 ${F_w} = q\displaystyle \sum\limits_1^n {{C_z}{C_s}{A_n}}。$ (10)

2 算例分析 2.1 动力学建模

 图 1 拖船布置方式 Fig. 1 Arrangement of pullboats

 图 2 浮式风机水动力模型及坐标系 Fig. 2 Hydrodynamic model and coordinate system of the floating wind turbine
2.2 计算结果及分析

 图 3 浮式基础运动（3 m有义波高） Fig. 3 Floating foundation motion (3 m significant wave height)

 图 4 风机顶部法兰运动极值 Fig. 4 Extreme value of the fan top flange motion

 图 5 风机机舱重心加速度 Fig. 5 Acceleration of the center of gravity of fan cabin

${F_{l2}} = {F_{l2}} = \dfrac{{{F_{w}}}}{2}/\cos \theta$ ，其中 $\theta$ 为龙须缆与主缆的夹角，以下给出龙须缆的受力。

 图 6 主拖缆张力 Fig. 6 Main towing cable tensions
3 安全作业环境窗口

 $R = 1.2{k_m}\varphi dL{v^2}\dfrac{\rho }{2}。$ (11)

4 结　语

1）在有义波高1.5～3 m、谱峰周期4～12 s范围内，浮式基础运动、风机法兰倾角、风机机舱加速度都满足给定的限制条件，浮式风机运动在安全范围内。

2）分析波浪参数和拖缆长度对浮式风机拖航运动的影响，结果表明，有义波高、谱峰周期对浮式风机运动、风机法兰倾角、机舱加速度都有显著的影响；拖缆长度对浮式风机纵荡和纵摇、风机法兰倾角有一定的影响，对浮式风机垂荡、风机机舱加速度影响很小。

3）随着有义波高和谱峰周期的增加，缆张力增大，缆越短相同环境参数下拖缆张力越大，200 m长拖缆的张力受波浪参数影响非常显著。相对而言，600 m及以上缆长的张力相对较为稳定，其受波浪参数影响较小。

4）给出了不同缆长可以作业的波浪参数限制条件，缆越长、有义波高越低，所允许的谱峰周期越大，即作业的窗口越大。缆长是拖航的重要参数，实际中应根据环境条件实时调整拖缆长度以保证拖航作业安全。

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