Optimal Design of Very Large Tidal Stream Farms: for Shallow Estuarine Applications

该项目由SuperGen Marine、埃克塞特水资源中心（非SuperGen）、宾夕法尼亚州立大学、aquscientific有限公司、丹麦水力研究所合作完成，并由Garrad Hassan合作伙伴指导。主要目标是引入一种新的混合优化方法，允许在环境影响下对海洋能源农场的布局和功率负荷进行多目标优化设计。它涉及一种新的，学术上极具挑战性的综合分析/数值/实验方法，以优化大型潮汐流能量捕获农场的性能。具体的应用重点涉及适合在浅层中流河口运行的潮汐涡轮机，但该技术可以应用于所有类型的海洋能源农场。优化的前提是将洪水风险降至最低，而进一步的环境影响，如泥沙运输驱动的结果，能够作为缓慢的时间尺度效应随后纳入。这项工作是对PERAWAT项目的补充，并拥有共同的主要合作伙伴。目前，大型潮汐流农场的技术水平是预先定义的大型农场设计的性能估计，而优化，需要许多性能计算，被认为是计算不现实的实际设计目的。本项目将通过采用以下组合来克服这一障碍：(i)一种新的混合方法，该方法通过参数化分析模型描述农场，该模型与河口的数值描述相匹配（ii）一种新的高效优化技术。模型参数定义了潮汐周期内的最佳水轮机位置和水轮机负荷因子，通过对农场模型和河口描述的匹配过程计算得到。基于采样表面函数的新型优化技术（在埃克塞特开创），可以大大减少需要估计的优化参数的数量。该方法利用了农场参数之间的空间依赖关系，其应用范围远远超出了潮汐流农场问题。从多目标优化的一个重要衍生是，它允许农场设计和环境影响的统一，到目前为止，这一直被视为相当独立的问题。分析和计算工作将借鉴埃克塞特正在进行的工作，包括埃克塞特/水科学有限公司获得的10kW规模近地面涡轮机模型和现场试验的现有实验数据。爱丁堡的一项实验研究将加强这一点。这将调查(i)数十个涡轮机的阵列（以注塑套件的形式制造）和（ii）在新的All Waters测试槽中，小组大型模型之间非常详细的相互作用。特别重要的是关于功率吸收和涡轮机几何形状之间的关系以及涡轮机相互作用的资料。这项工作的结果将是一个结合：新科学和实用技术，使大规模潮汐流农场设计优化的后续工具的发展成为现实，再加上传播工具，需要快速有效地将这些传递给缅因州可再生能源社区。这将影响投资者/工业供应商的信心，以及潮汐流研究界，从而允许随后创建一系列实用的设计工具，以帮助实现20:20和20:50的可再生能源目标。Garrad Hassan将指导该项目，并对工作进行尽职调查研究，以便向更广泛的利益攸关方传播。该项目包括一系列流程和专门的活动，旨在加强SuperGen Marine财团的运作，促进有效的影响途径，并围绕SuperGen未来的研究愿景进行了明确的规划。

This project is a collaboration between SuperGen Marine, the Exeter Centre for Water Resources (Non-SuperGen), Penn State University, Aquascientific Ltd., The Danish Hydraulics Research Institute and is mentored by Garrad Hassan partners. The primary goal is the introduction of a new hybrid optimisation approach that allows the multi-objective optimal design of the layout and power loadings of marine energy farms subject to environmental impacts. It involves a new, academically highly challenging integrated analytic/numerical/experimental, approach to optimising the performance of large tidal stream energy capture farms. The specific application focus involves tidal turbines suited to operating in shallow medium flow estuaries but the technique can be applied to all types of marine energy farms. Optimisation is subject to minimising flood risk, with further environmental impacts, such as sediment transport driven outcomes, being capable of subsequent incorporation as slow timescale effects. The work complements the PERAWAT project and has key partners in common. At present the state of the art in large tidal stream farms is the performance estimation of pre-defined large farm designs, while optimisation, requiring many performance calculations, is deemed to be computationally unrealistic for practical design purposes. The present project will overcome this barrier by employing a combination of :(i) a new hybrid approach which describes the farm via a parameterised analytic model, that is matched to a numerical description of the estuary (ii) a new highly efficient optimisation technique. The model parameters, which define the optimum turbine locations and turbine loading factors over tidal cycles, are computed via the process of matching of the farm model and estuary descriptions. The new class of optimisation technique (pioneered at Exeter) based upon sampled surface functions, allows a large reduction in the number of optimisation parameters which require to be estimated. This method exploits the spatial dependencies between farm parameters and has applications far beyond the tidal stream farm problem. An important spin off from multi-objective optimisation is that it allows the unification of farm design and environmental impact which until now have been treated as rather separated issues.The analytic and computational work will draw on a body of on going work at Exeter including existing experimental data on model and field trial 10kW scale near surface turbines obtained by Exeter/Aquascientific Ltd. This will be enhanced by an experimental study at Edinburgh. This will investigate (i) arrays of many tens of turbines, (manufactured in injection moulded kit form) and (ii) highly detailed interactions between small groups of large models in the new All Waters test tank. Of particular importance will be information on the relationship between power absorption and turbine geometry and on turbine interactions. The outcomes of the work will be a combination: of new science and practical techniques that make the development of follow on tools for large scale tidal stream farm design optimisation realistic, plus the dissemination tools required to rapidly and effectively deliver these to the maine renewable energy community. This will impact on: investor/industrial provider confidence, and on the tidal stream research community, allowing the subsequent creation of a range of practical design tools for helping deliver 20:20 and 20:50 renewable energy targets. Garrad Hassan will mentor the project and undertake a due diligence study on the work for the purposes of dissemination to the wider stakeholder community.The project includes a set of processes and dedicated events aimed at enahancing the operation of the SuperGen Marine consortium and promoting effective pathways to impact and has been planned explicitly around future research vissions of SuperGen.