摘要
海上风电结构一体化安装技术实现了基础结构与塔筒及风机的海上整体安装,与传统的风电结构安装方法相比有较大优势。海上风电结构的浮运设计是海上风电结构一体化安装技术的一个重要组成部分,本文采用海洋工程设计软件MOSES气垫模块对风机运输船进行模拟,对风机运输船浮运影响因素进行分析,分析了风电机组结构浮态对风机运输船浮运的影响,同时对风电运输船的耐波性进行了研究。
经过对比分析,风电运输船浮运过程中,当风电机组结构吃水增大,不利于浮运安全。当吃水在4m以下时,吃水深度对风电运输船浮运影响较小,因而吃水在4m可设为安全吃水深度。同时风电机组结构内外液面高度差越大,浮运越平稳,安全。但风电机组结构内外液面高度差应有一个限值,以保证风电机组结构有一定的水封高度(内液面高度),防止内部气体溢出,产生严重侧倾,影响风电运输船的浮运平衡。
随浪浮运较顶浪浮运更平稳。在顶浪浮运时应保证风电机组结构内有一定的水封高度,防止风电机组结构内气体逸出,造成运输船倾覆。波高对风机运输船浮运有较大影响,当波高增大至接近极限波高时,钢吊缆张力突然变大同时舱内气压值变化剧烈。应通过对钢吊缆张力及舱内气压值的观测,对风机运输船在较大波浪作用下的稳定进行评估,及时采取相应措施保证浮运的稳定。
在浮运作业时,海上风浪较小,可适当减小风电机组结构吃水,同时在保证舱内水封高度足够的情况下适当增大风电机组基础结构各舱内气压,从而使得风电运输船浮运更加平稳。当风电运输船需经受较大风浪时,为确保运输船的安全,需及时对风机运输船的浮态进行调整,此时需增大风电机组结构吃水同时减小风电机组基础结构各舱内的气压值,以保证舱内水封高度满足最小水封高度的要求。
Integrated installation technology with offshore wind-power structure achieved the overall installation of foundation and wind turbines. This new installation method had greater superiority than the traditional installation method. The floating analysis is an important component of the integrated installation technology. In this paper, ocean engineering software MOSES was used to simulate the transport ship and the influence factors were analyzed. The effect of initial floating state of the transport ship and the seakeeping capability of the ship were studied.
After a comparative analysis, during the floating of the wind-power structure transport ship, when the draft of wind turbine structure decreased, floating was more stable. When the draft was below 4m, the effect of draft of the wind turbine structure was not significant and the draft of 4m can be set as a safe draft. At the same time, when the draft difference between inside and outside wind turbine structure was greater, floating was more stable. But the draft difference should be limited to ensure the inside draft are deep enough which can prevent the overflow of the inner gas.
The floating of the transport ship under following waves is safer than under head waves. During head waves, the inside draft of the wind turbine structure should be deep enough to prevent the overflow of the inner gas. The impact of wave height on towing force and vertical motion is great. When the ship was about to capsize, the tension of cable tension and the air pressure of the foundation changed abruptly which can help us to assess the condition of the ship. Some certain measures could be taken immediately.
When the wind and wave are small, the draft of the wind turbine structure can be decreased and inner air pressure of the foundation can be increased to make the transport ship float more smoothly. However, when the wave height was more than 2m, the draft of the wind turbine structure can be increased and inner air pressure of the foundation can be decreased to ensure the height of inside draft, which is Critical for the safety of the transport ship.
引文
[1]姜谦,2010-1015年中国海上风力发电行业投资分析及前景预测报告,中投顾问
[2]Sim on-Philippe Breton, Geir Moe.Status, plans and technologies for offshore wind turbines in Europe and North America, Renewable 2009 (34) : 646~654
[3]Kokkinowrachos K. et al. Drift forces on one and two-body structures in regular waves. Boss 1982, 467~487.
[4]Seidl,L.H., Development of an Air Stabilized Platform, University of Hawaii, Department of Ocean Engineering technical report submitted to US Department of Commerce, Maritime Administration, 1980, pp: 88 and appendices
[5]Chakrabarti,S.K., Scale effects on a unique launch sequence of a gravity-based structure,Applied Ocean Research, 1995, 17(1): 33~41
[6]Evans,D.V., Power from water waves, Annual Review of Fluid Mechanics, 1981, 13: 157-187 Devices, Journal of Offshore Mechanics and Arctic Engineering, 1997, ASME 119(4): 210~218
[7]Kim,D.S.,Iwata,I., Dynamic behavior of tautly moored semi-submerged structure with pressurized air-chamber and resulting wave transformation Coastal Engineering in Japan, 1991, 34(2): 223~242
[8]Kim,D.S.,Iwata,I., Nonlinear Interaction of second order Stokes waves and two-dimensional submerged moored floating structure, International Journal of Offshore and Polar Engineering, 1994, 4(2): 88~96
[9]Lee,C.-H.,Newman,N.J.,Nielsen,F.G. Water interactions with an oscillating water column,Proc.6th Int. Offshore and Polar Engineering Conference, 1996, vol 1, Los Angeles, pp: 82~90
[10]别社安,时忠民,王翎羽,气浮结构的静浮态分析,中国港湾建设,2000,6:18~23
[11]别社安,时忠民,王翎羽,气浮结构的小倾角浮稳性分析,中国港湾建设,2001,1:31~35
[12]别社安,时忠民,王翎羽,气浮结构的运动特性研究,中国港湾建设,2001,2:18~21
[13]刘树杰、王忠涛、栾茂田,单向荷载作用下海上风机多桶基础承载特性数值分析,海洋工程,2010,28(1):31~35
[14]孙曦源,栾茂田,唐小微,饱和软黏土地基中桶形基础水平承载力研究,岩土力学,2010,(2):667~662
[15]徐继祖、王翎羽,吸力锚到筒型基础平台——关于近海吸力式基础的工程经验和技术思考,中国海上油气(工程),2002,14(1):2~5
[16]徐宝,丁红岩,刘建辉,筒型基础结构浮态运动力特性的试验研究,中国海洋平台, 2007,22(1):34~37
[17]刘建辉,筒型基础海洋平台气浮拖航性能研究,[博士学位论文],天津;天津大学,2008
[18]丁红岩,刘建辉,筒型基础海洋平台拖航研究——波浪影响分析,船舶力学, 2009,2:19~26
[19]丁红岩,王高峰,刘建辉,多筒基础平台自浮拖航系拖点位置试验分析,天津大学学报,2007,40(5):548~553
[20]Ohkusu M. On the heaving motion of two circular cylinders on the surface of a fluid. Reports of Research Institute for Applied Mechanics, 1969, XVII, 58: 167~185
[21]Ohkusu M. Wave effects on multiple bodies. Hydrodynamics in ship and ocean Engineering, 2001, 3~26
[22]Kodan N. The motions of adjacent floating structures in oblique waves [A]. Proceedings of the Third International Offshore Mechanics and Arctic Engineering Symposium [C]. New Orleans, LA: ASME, February 1984, 1: 206~231
[23]Kagemoto H, Yue D K P. Interaction among multiple three-dimensional bodies in waves: an exact algebraic method. J. Fluid Mech., 1986, 166: 189~209
[24]Fang M C, Kim C H. An analysis of water shipping between two floating platforms in the beam waves. Journal of Offshore Mechanics and Arctic Engineering, 1987, 109; 179~185
[25]Faltinsen O M, Michelsen F C. Motions of large structures in waves at zero Froude number. Proc. Intl. Symp. on the Dynamics of Marine Vehicles and Structures in Waves, 1974, 91~106
[26]Van Oortmerssen G. Hydrodynamic interaction between two structures, floating in waves. Proc, 2nd Intl. Conf. on Behavior of Offshore structures(BOSS’79), London, 1979, 339~356
[27]Matsui, T. and Tamaki, T.,“Hydrodynamic interaction between groups of vertical axisymmetric bodies floating in waves,”Int. Symp. on Hydrodynamics in Ocean Engineering, Trondhem, pp. 817~836 (1981)
[28]Choi, Y. R. and Hong, S. Y.,“An analysis of hydrodynamic interaction of floating multi-body using higher-order boundary element method”, Proc. 12th Int. Offshore and Polar Engineering Conference, Kitakyushu, pp. 303~308 (2002)
[29]宁德志,滕斌,勾莹,快速多极子展开技术在高阶边界元方法中的实现,计算力学学报,2005,22(6),700~704
[30]勾莹,快速多极子方法在多浮体和水弹性问题中的应用,[博士学位论文],大连;大连理工大学,2006
[31]沈庆,陈徐均,系泊多浮体系统波浪运动响应的动力学分析,解放军理工大学学报,2002,1(4):31~36
[32]李跃,沈庆,陈徐均,波浪环境中作业起重船悬吊载荷的摆振分析,建筑机械,2003,8:55~58
[33]陈超核,王杰德,多浮体组合结构的波浪荷载响应计算,工程力学增刊,1996,354~358
[34]孙昭晨,王环宇,铰接多浮体耦合解析计算,船舶力学,2009,13(1):34~39
[35]别社安,徐元锡,祝业浩,增强结构气浮稳性的分舱及优化分析,中国港湾建设,2003,1:1~4
[36]别社安、徐元锡、祝业浩等,大圆筒结构的充气浮运方法,港工技术,2001(1):21~23
[37]施内克鲁特,咸培林(译),船舶水动力学,上海:上海交通大学出版社,1997,1~62
[38]Ultramarine Inc. Reference Manual for Moses. 2009
[39]李云波,船舶阻力,哈尔滨:哈尔滨工程大学出版社,2005
[40]刘培林,赵君龙,孙丽萍等,深水平台上层模块海上吊装多浮体响应分析,中国造船,2011,52(1),157~163