小水深下浮式风机系泊系统配件特性研究

Characterisation of components for a floating wind turbine mooring system in small water depths

海上风能资源远超陆地,而我国海域随着离岸距离增加,大陆架水深增加幅度减缓,针对此特点,如何优化设计适应我国海域水深条件的系泊系统是目前发展浮式风机遇到的重大难题之一。本文以5MW-OC4半潜式浮式风机作为研究对象,浮式风机采用悬链线式系泊方式,使用SESAM软件在渤海某海域40 m水深下对浮式风机进行频域和时域计算。系泊配件在单独和组合使用时分别进行参数敏感性分析,再将浮筒和配重块组合使用对系泊系统进行优化。研究结果表明:浅水条件下,系泊配件组合使用和单独使用时改变相同系泊参数对浮式风机整体响应影响规律相同,但组合使用时改变系泊参数对系泊系统性能优化的效果要更明显,组合使用时更改配重块位置参数时均值的优化差值能达到15.7%,而纵荡、纵摇以及张力响应的优化差值基本都在10%以内,因此选择合理的配件组合方式可以显著改变浮式系统的整体特性并影响系统的安全性和成本。

Offshore wind energy resources is richer than land wind energy,and water depth of the continental shelf in China's waters increases slowly as the distance offshore increases.Based on the characteristics,how to optimize the design of mooring systems to adapt to the water depth conditions in China is one of the major problems encountered in the development of floating wind turbines.In this paper,a 5MW-OC4 semi-sub⁃mersible floating wind turbine was used as the research object,the floating wind turbine was moored by sus⁃pended chain lines,and the frequency domain and time domain calculations of the floating wind turbine were performed under 40 m water depth in a sea area of Bohai Sea using SESAM software.Mooring accessories were used separately and in combination for parameter sensitivity analysis,and then the mooring system was optimized by combining buoys and clump weight blocks.The results of the study show that under shallow wa⁃ter conditions,the combination of mooring fittings has the same effect on the overall response of the floating wind turbine as changing the same mooring parameters when used alone,but the effect of changing the mooring parameters on the optimisation of the performance of the mooring system is more obvious when used in combination,the optimisation difference in the mean value of the counterweight block position parameters when used in combination can reach 15.7%,and the optimisation difference in the longitudinal oscillation,longitudinal rocking and the tension response are all within 10%of each other.The optimisation difference of longitudinal oscillation,longitudinal rocking and tension response is basically within 10%.Therefore,choos⁃ing a reasonable combination of accessories can significantly change the overall characteristics of the floating system and affect the safety and cost of the system.