Tidal Stream Energy - Designing for Performance

该奖学金将在潮流能源研究方面发挥领导作用，通过提高性能、可维护性和可靠性的设计，促进成本和风险的降低，从而加快实现潮流能源的商业能源供应。潮流能源可以为英国和世界各地的可再生能源目标做出重大贡献，帮助实现减排和气候变化目标。流体动力潮流涡轮机发电的潜力被广泛接受，资源的可预测性是一个重大好处，将促进融入更广泛的电力系统。潮流能源提供了一种尚未开发的可再生能源；全球资源估计为每年100至500太瓦时，其中约20太瓦时/年在英国水域内。各种商业潮流系统正在开发中，重点是单个涡轮机的设计和控制。风能行业的知识和技术已经层出不穷。涡轮机的直径通常为15-20米，额定容量为1-2兆瓦，流速约为2-3米/S，设计用于深达40米的水流中。在接下来的几年里，法国和英国计划部署第一批小型潮流涡轮机阵列，每个阵列5-20兆瓦。但是，如果要在足够大的范围内部署潮流能，为商业电力市场做出贡献，就需要在性能、可靠性、可部署性、可维护性和经济可行性方面进行重大改进。这就要求增加每兆瓦装机的功率输出，减少每兆瓦装机的开支，并降低成本变化的风险。安装成本很高，而且变化很大，目前的成本估计为GB 200/兆瓦时，考虑到未来规模生产和部署的经济性，目前的成本降至GB 120/兆瓦时。当前潮汐发电场提案的假设和基础有时是含蓄的，即涡轮机将安装在水下风力涡轮机风格的农场的单个海底安装架上，涡轮机的位置相互作用最小。出于显著提高潮汐设施经济可行性的需要，这项提议将挑战这些假设，并寻求革命性的新解决方案，采用紧密耦合的涡轮机阵列形式，利用建设性干扰效应来增强阵列性能。众所周知，通过在部分跨越更宽通道宽度的多转子栅栏中排列涡轮机，可将性能提升高达35%(Nishino&Willden 2012)。该奖学金将寻求开发所需的基础科学、工程工具和转子设计，以实现这一显著的性能提升，并推断能源成本预计将降低约10%-20%。我们将利用分析、数值和实验活动相结合的方式，为设计用于在受限潮汐水道中运行的涡轮机、包含相互建设性干扰效应的多转子防潮栅栏、高速转子、抗空化设计以及流动和螺距控制策略提供理解、工程工具和设计指南。学术参与将通过传统的出版手段、期刊文章、国际会议和研讨会，以及积极参与英国学术海洋能源网络UKCMER和国际学术合作来实现。由此产生的涡轮机技术、工程模型和设计指南将与潮汐能源行业密切合作开发，以最大限度地发挥影响并加速实现潮汐水流的商业能源供应。

The fellowship will provide leadership in tidal stream energy research that will promote cost and risk reduction, through design for increased performance, maintainability and reliability, thus accelerating the realization of commercial energy supply from tidal streams.Tidal stream energy can make a substantial contribution to UK and worldwide renewable energy targets, helping to achieve emissions reductions and climate change objectives. The potential for energy generation by hydrokinetic tidal stream turbines is well accepted and the predictability of the resource is a significant benefit that will facilitate integration into the wider electricity system. Tidal stream energy offers an as yet largely untapped source of renewable energy; global resources are estimated at 100 to 500 TWh/yr, with around 20 TWh/yr estimated to be within the UK's waters. Various commercial tidal stream systems are under development with most emphasis on design and control of individual turbines. There has been some cascade of knowledge and technology from the wind energy industry. Turbines are typically 15-20 m in diameter, rated capacity 1-2 MW at flow speeds of around 2-3 m/s, and designed to be deployed in flows of up to 40 m depth. Over the next few years the first small scale tidal stream turbine arrays, 5-20 MW each, are planned to be deployed in France and the UK.However, significant improvements in performance, reliability, deployability, maintainability and thus economic viability are needed if tidal stream energy is to be deployed at a sufficiently large scale to contribute to commercial electricity markets. This requires that power output per MW installed is increased, expenditure per MW installed and the risk of cost variations are reduced. Installation costs are both high and extremely variable, with current cost estimated at £200/MWh reducing to £120/MWh accounting for future economies in scale production and deployment.The, sometimes implicit, assumption, and basis for current tidal farm proposals, is that turbines will be installed on individual seabed mountings in an underwater wind turbine style farm with turbines positioned to minimally interact with each other. Motivated by the necessity to dramatically improve the economic viability of tidal installations, this proposal will challenge these assumptions and seek revolutionary new solutions in the form of closely coupled turbine arrays using constructive interference effects to enhance array performance. It is known that there is a potential uplift in performance of up to 35% available through arraying turbines in a multi-rotor fence that partially spans the width of a much wider channel (Nishino & Willden 2012). This fellowship will seek to develop the underlying science, engineering tools and rotor designs required to deliver this significant performance uplift and the inferred expected reduction in cost of energy of circa 10-20%. A combination of analytic, numerical and experimental activities will be used to deliver the understanding, engineering tools and design guidelines for turbines designed to operate in confined tidal channels, multi-rotor tidal fences incorporating mutual constructive interference effects, high speed rotors, design against cavitation, and flow and pitch control strategies.This fellowship will involve close and sustained engagement with both the academic and industrial marine energy communities, internationally as well as within the UK. Academic engagement will be achieved through traditional publication means, journal articles, international conferences and workshops, as well as active participation in the UK academic marine energy network UKCMER, and in international academic collaborations. The resulting turbine technologies, engineering models and design guidelines will be developed in close cooperation with the tidal energy industry in order to maximise impact and accelerate the realization of commercial energy supply from tidal streams.