THE Three Gorges Dalian Zhuanghe (300 megawatt) offshore wind farm will be built in the sea of Zhuanghe, Dalian, Liaoning province. Once operational, the plant will supply an annual on-grid energy capacity of 714 million kilowatt hours, meeting the annual electricity demand of 450,000 households.
When compared with coal-fired power plants on the same scale, the Three Gorges wind farm will annually save about 230,000 tons of coal, reduce 55,300 tons of ash and slag, and reduce the emission of 6,000 tons of sulfur dioxide and 637,000 tons of carbon dioxide. Shanghai Investigation, Design & Research Institute Co., Ltd. (SIDRI) is responsible for the overall survey and design of this large project with Goldwind Science & Technology optimizing the anti-ice design for the integrated offshore wind turbine support structure.
The understaffed team faced several challenges, including a complicated design and a short design cycle. The most critical challenge, however, was the presence of floating ice during winter months, which added a complexity previously unseen in the field of offshore wind power in China.
To help the structures withstand the impact of the floating ice, engineers needed to collaborate to design an anti-ice cone that would protect the single-pile foundation in the winter yet not adversely impact wave force performance in non-winter months.
A SACS interface with the turbine manufacturer (GH)Bladed produced an integrated design for the support structure, enabling engineers to balance the anti-ice design for winter and the wave force performance in non-winter seasons, and optimize the entire support structure. A multidiscipline design team (covering hydraulic, electrical, structural, HVAC, water, drainage, architecture, and construction) used OpenBuildings, OpenPlant, ProSteel, SACS, MicroStation, and Navigator for their modeling work. ProjectWise was used to manage the documentation and models and to facilitate collaboration from the contributing engineers.
The integrated design process using Bentley’s open modelling and simulation applications helped SIDRI complete the project three months ahead of schedule, while improving the design quality. SACS helped the Goldwind engineers streamline their workflow, reducing design time by 200 working days.
This first-of-its-kind project lays the foundation for future integrated design methods for China’s offshore wind anti-ice design projects. As well as the substantial environmental benefits, the project realized an RMB 50 million savings in overall project costs, and it is expected that at least RMB 5 million in savings will be achieved on each subsequent project.
“Using Bentley’s SACS, we were able to develop an effective and integrated design for the support structure for the offshore wind turbine,” said Yiming Zhou, design delivery manager of Offshore Wind Power Design Research Institute.
“SACS has helped us effectively reduce the fatigue load of infrastructure design by more than 30%, saved the cost of designing supporting structures by more than 10% on average, and achieved a savings of RMB 50 million in supporting structure costs. The method we used has also contributed to promoting the wind power development in China’s ice area.”