极浅水多体波浪能发电装置锚泊系统设计

采用三维势流理论对多体波浪能发电装置进行频域水动力计算,分析极浅水效应和多体间相互作用对单体发电装置的水动力性能的影响。利用Orcaflex软件建立多体波浪能发电装置数值模型,浮体间采用铰接进行连接,并利用弹簧单元模拟发电液压缸的弹性阻尼作用。为极浅水多体波浪能发电装置设计合理的锚泊方案,采用时域动态耦合方法进行分析,同时考虑极浅水效应、多体影响和二阶低频力,根据API规范对自存工况下的锚泊缆强度进行校核,并对确定选用的锚泊方案进行敏感性分析。通过对计算结果进行分析,发现在进行浅水多浮体锚泊设计时,低频波浪载荷、多体相互作用和海底摩擦不可忽视；对于极浅水的锚泊系统设计,Lazy wave 型锚泊形式优于传统悬链线式锚泊。上述研究工作为近海极浅水海域新型海洋能发电装置锚泊系统的设计提供了新的参考和思路。

Analysis and design of the multi-body wave energy converter mooring system in ultra-shallow water

In this paper, hydrodynamics of the multi-body wave energy converter are analyzed in frequency domain based on potential flow theory. The effects of ultra-shallow water and multi-body interactions on the hydrodynamics of single device are considered. The numerical models of wave energy converter are simulated in Orcaflex. The connection between two power hydraulic cylinders is hinged connection and the spring element is adopted to model the elastic damping effect of two power hydraulic cylinders. Different mooring systems are designed in this paper and are analyzed in time domain by dynamic coupled method. Shallow water effect, multi-body interactions and second-order low frequency wave forces are considered in analysis. The mooring systems are checked according to API 2SK rule and the sensitivity analysis is performed. The results show that the second-order low frequency forces have effect on performance of mooring systems and the multi-body interactions and seabed friction are negligible. Lazy wave mooring system is better than catenary mooring system in ultra-shallow water. The present work provides a novel reference of mooring system design of new types of wave energy converter in shallow water inshore.