Tidal Stream Energy - Designing for Performance

该奖学金将在潮汐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，促进降低成本和风险，从而加速实现潮汐流的商业能源供应。潮汐流能源可以为英国和全球可再生能源目标做出重大贡献，有助于实现减排和气候变化目标。流体动力潮汐流涡轮机发电的潜力已被广泛接受，资源的可预测性是一个重大的好处，将有助于融入更广泛的电力系统。潮汐能提供了一种尚未开发的可再生能源;全球资源估计为100至500 TWh/年，其中约20 TWh/年估计在英国的沃茨内。各种商业潮汐流系统正在开发中，其中大部分重点放在单个涡轮机的设计和控制上。风能行业的知识和技术已经出现了一些级联。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/秒，设计用于部署在水深达40米的水流中。在接下来的几年中，第一批小规模潮汐流涡轮机阵列，每个5-20 MW，计划在法国和英国部署。然而，如果要以足够大的规模部署潮汐流能量以促进商业电力市场，则需要在性能、可靠性、可部署性、可维护性以及经济可行性方面进行显著改进。这要求增加每兆瓦装机的功率输出，降低每兆瓦装机的支出和成本变化的风险。安装成本既高又极不稳定，目前的成本估计为200英镑/兆瓦时，考虑到未来的规模生产和部署经济，降低到120英镑/兆瓦时。目前潮汐发电场提案的假设和基础有时是隐含的，即涡轮机将安装在水下风力涡轮机式发电场的单个海底安装件上，涡轮机的位置应尽量减少相互影响。由于需要大幅提高潮汐装置的经济可行性，本提案将挑战这些假设，并寻求革命性的新解决方案，即采用相长干涉效应的紧密耦合涡轮机阵列，以提高阵列性能。众所周知，通过将涡轮机布置在部分跨越更宽通道宽度的多转子围栏中，可以获得高达35%的性能提升（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，并推断预计将能源成本降低约10- 20%。分析、数值和实验活动的结合将用于提供以下方面的理解、工程工具和设计指南：设计用于在封闭潮汐通道中运行的涡轮机、结合相互建设性干扰效应的多转子潮汐围栏、高速转子、抗气蚀设计、以及流量和螺距控制策略。该奖学金将涉及与学术界和工业界海洋能源界的密切和持续接触，在国际上，以及在英国。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.