The integration of wave energy converters(WECs) with floating breakwaters has become common recently due to the benefits of both cost-sharing and providing offshore power supply. In this study, based on viscous comput...The integration of wave energy converters(WECs) with floating breakwaters has become common recently due to the benefits of both cost-sharing and providing offshore power supply. In this study, based on viscous computational fluid dynamics(CFD) theory, we investigated the hydrodynamic performances of the floating box and Berkeley Wedge breakwaters, both of which can also serve as WECs. A numerical wave flume model is constructed using Star-CCM+software and applied to investigate the interaction between waves and wave energy converters while completing the verification of the convergence study of time and space steps. The effects of wave length on motion response and transmission coefficient of the floating box breakwater model are studied. Comparisons of our numerical results and published experimental data indicate that Star-CCM+ is very capable of accurately modeling the nonlinear wave interaction of floating structures, while the analytical potential theory overrates the results especially around the resonant frequency. Optimal damping can be readily predicted using potential flow theory and can then be verified by CFD numerical results. Next, we investigated the relationship between wave frequencies and various coefficients using the CFD model under optimal damping, including the motion response, transmission coefficient, reflection coefficient,dissipation coefficient, and wave energy conversion efficiency. We then compared the power generation efficiencies and wave dissipation performances of the floating box and Berkeley Wedge breakwaters. The results show that the power generation efficiency of the Berkeley Wedge breakwater is always much higher than that of the floating box breakwater. Besides, the wave dissipation performance of the Berkeley Wedge breakwater is much better than that of the floating box breakwater at lower frequency.展开更多
针对大规模光伏、风电并网给电力系统安全运行和可再生能源消纳带来的巨大挑战,提出了一种风光水一体化发电系统中长期多目标优化运行方法。首先,提出了一种考虑水库防洪、供水、蒸发、库区降雨等因素的水电站库容模型并分析了对混合系...针对大规模光伏、风电并网给电力系统安全运行和可再生能源消纳带来的巨大挑战,提出了一种风光水一体化发电系统中长期多目标优化运行方法。首先,提出了一种考虑水库防洪、供水、蒸发、库区降雨等因素的水电站库容模型并分析了对混合系统的影响,其次,建立了风光水一体化系统收益最大和总功率输出波动性最小的多目标优化运行模型。并且利用改进的基于模拟退火算法的改进非支配排序遗传算法(improved non-dominated sorting genetic algorithm based on simulated annealing,SA-NSGA-II)对优化模型进行求解,对SA-NSGA-II算法的改进主要有在变异阶段引入改进的模拟退火方法,在非支配排序阶段采用新的排序方法和拥挤距离公式,大幅提高了求解效率。最后,将该方法应用于龙羊峡水光互补项目-青海湖风电场,验证了其有效性。展开更多
基金financially supported by the National Natural Science Foundation of China(51409066,51761135013)High Technology Ship Scientific Research Project from the Ministry of Industry and Information Technology of the People's Republic of China-Floating Security Platform Project(the second stage,201622)the Fundamental Research Fund for the Central University(HEUCF180104,HEUCFP201809)
文摘The integration of wave energy converters(WECs) with floating breakwaters has become common recently due to the benefits of both cost-sharing and providing offshore power supply. In this study, based on viscous computational fluid dynamics(CFD) theory, we investigated the hydrodynamic performances of the floating box and Berkeley Wedge breakwaters, both of which can also serve as WECs. A numerical wave flume model is constructed using Star-CCM+software and applied to investigate the interaction between waves and wave energy converters while completing the verification of the convergence study of time and space steps. The effects of wave length on motion response and transmission coefficient of the floating box breakwater model are studied. Comparisons of our numerical results and published experimental data indicate that Star-CCM+ is very capable of accurately modeling the nonlinear wave interaction of floating structures, while the analytical potential theory overrates the results especially around the resonant frequency. Optimal damping can be readily predicted using potential flow theory and can then be verified by CFD numerical results. Next, we investigated the relationship between wave frequencies and various coefficients using the CFD model under optimal damping, including the motion response, transmission coefficient, reflection coefficient,dissipation coefficient, and wave energy conversion efficiency. We then compared the power generation efficiencies and wave dissipation performances of the floating box and Berkeley Wedge breakwaters. The results show that the power generation efficiency of the Berkeley Wedge breakwater is always much higher than that of the floating box breakwater. Besides, the wave dissipation performance of the Berkeley Wedge breakwater is much better than that of the floating box breakwater at lower frequency.
文摘针对大规模光伏、风电并网给电力系统安全运行和可再生能源消纳带来的巨大挑战,提出了一种风光水一体化发电系统中长期多目标优化运行方法。首先,提出了一种考虑水库防洪、供水、蒸发、库区降雨等因素的水电站库容模型并分析了对混合系统的影响,其次,建立了风光水一体化系统收益最大和总功率输出波动性最小的多目标优化运行模型。并且利用改进的基于模拟退火算法的改进非支配排序遗传算法(improved non-dominated sorting genetic algorithm based on simulated annealing,SA-NSGA-II)对优化模型进行求解,对SA-NSGA-II算法的改进主要有在变异阶段引入改进的模拟退火方法,在非支配排序阶段采用新的排序方法和拥挤距离公式,大幅提高了求解效率。最后,将该方法应用于龙羊峡水光互补项目-青海湖风电场,验证了其有效性。
