Tackling the global blockage problem in a wind-farm due to interactions between turbulent wakes

解决风电场由于湍流尾流之间的相互作用而导致的全局堵塞问题

• 批准号: 2895226
• 金额: --
• 依托单位: Imperial College London
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2023
• 资助国家: 英国
• 起止时间: 2023 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2895226
• 关键词: Tackling; global; blockage; problem; wind

With rising concerns about the global climate and the impact of continued use of fossil fuels, renewable sources of energy have received much attention of late. Despite this attention, and considerable progress, there remain many challenges to fully exploit the energy available in the wind. A wind turbine produces usable electricity by extracting energy from the wind. This produces a wake, an area of slower moving air immediately behind the turbine. One turbine is good, but to satisfy our energy needs on limited land (or sea) we need many carefully arranged turbines (called a wind farm). This can be a problem, as downwind turbines will sit in the wake of upstream turbines. This lower energy wake means there is less energy to be extracted by the following turbine(s), as well as increased structural loading, reducing energy yield and increasing costs. In the wind industry, it is often useful to think of an individual turbine and base the performance of the wind farm at a specific site on this individual turbine. We know that we must account for the wakes of the turbines when we account for the performance of the wind farm. This, however, is not the complete picture. With the increased installation of wind farms, more information about their operation has become available and a deficit energy production has been identified. This deficit is small, but considering the costs involved in designing, constructing and operating a wind farm for a period of 20 years this small deficit can result in significant financial consequences. The source of this deficit has proven to be subtle and elusive until recently. The influence of the wind farm on the energy yield is more complex than the combination of wakes. The presence of the wind farm itself changes the wind encountered at the wind farm's site. The wind farm acts as an obstacle, a blockage, to the wind, and like the concept of the path of least resistance, the wind in a manner tries to avoid the wind farm. This manifests itself as the leading upwind turbines receiving wind at a lower speed than they would in the absence of the wind farm. This is referred to as Global Blockage. One would expect that global blockage would be subject to considerable academic and industrial interest, which it indeed has received. But this has been completed in a somewhat ad hoc manner, focusing on disparate aspects of the problem. The nature of this project is to complete a thorough and rigorous investigation of global blockage, and to identify and characterise the principal exacerbating aspects of wind farm design that result in blockage. There remains a degree of uncertainty on the precise definition and quantification of wind farm blockage, this project will have to identify from literature or create such definitions. The investigation will be experimental in nature, taking place in the wind tunnels at Imperial College London, namely the 10ft x 5ft Low Speed National Wind Tunnel Facility. As alluded to previously, the energy lost to blockage is only a small percentage (around 2%) of the total energy yield of the wind farm. With the influence of blockage being so small, considerable care must be taken to ensure any results are distinguishable from measurement uncertainty. As the need to go carbon neutral increases and the necessity of wind energy increases, high wind yield locations such as the North Sea will become in increasing demand. With more and more farms being developed, global blockage is only going to play an increasingly less subtle role. The potential results of this investigation could have important bearing on the design of future wind energy projects. Characterisation of blockage may allow for it to mitigated and increase energy yields or if it cannot be mitigated, it will allow for a more accurate picture to be developed of the financial viability of a particular wind energy project.

随着人们对全球气候和化石燃料持续使用的影响的担忧日益加剧，可再生能源最近受到了极大的关注。尽管受到了这样的关注，并取得了相当大的进展，但要充分利用风能，仍然存在许多挑战。风力涡轮机通过从风中提取能量来产生可用电力。这会产生尾流，这是涡轮机后面运动较慢的空气区域。一台涡轮机是好的，但为了满足我们在有限的陆地(或海洋)上的能源需求，我们需要许多精心安排的涡轮机(称为风电场)。这可能是一个问题，因为顺风涡轮机将紧随上游涡轮机。这种较低的能量尾迹意味着下一个涡轮机(S)可以提取的能量更少，同时增加了结构负荷，降低了能量产量，增加了成本。在风电行业，考虑一台单独的涡轮机，并根据这台单独的涡轮机在特定地点的风力发电场的性能通常是有用的。我们知道，当我们考虑风电场的性能时，我们必须考虑涡轮机的尾迹。然而，这并不是全部情况。随着风电场装机容量的增加，人们可以获得更多关于风电场运营的信息，并发现了电力生产的不足。这一赤字很小，但考虑到设计、建设和运营一个风力发电场20年的成本，这一小小的赤字可能会导致重大的财务后果。直到最近，这种赤字的来源一直被证明是微妙和难以捉摸的。风电场对发电量的影响比尾迹的组合更为复杂。风力发电场本身的存在改变了风力发电场现场遇到的风。风电场对风起到了障碍、阻挡的作用，就像最小阻力路径的概念一样，风在某种程度上试图避开风电场。这表现为领先的迎风涡轮机在没有风力发电场的情况下接收风速较低。这被称为全球阻塞。人们预计，全球封锁将受到学术界和工业界相当大的兴趣，而这一点确实得到了关注。但这是以一种有点特别的方式完成的，重点放在问题的不同方面。该项目的性质是完成对全球阻塞的彻底和严格的调查，并确定和描述导致阻塞的风力发电场设计的主要加剧方面的特征。风电场阻塞的准确定义和量化仍然存在一定程度的不确定性，该项目将不得不从文献中确定或创建这样的定义。这项研究将是试验性的，在伦敦帝国理工学院的风洞中进行，即10英尺x 5英尺的低速国家风洞设施。如前所述，堵塞造成的能量损失仅占风电场总发电量的一小部分(约2%)。由于堵塞的影响如此之小，必须相当小心地确保任何结果都能与测量不确定度区分开来。随着碳中和需求的增加和风能需求的增加，北海等高风能产区的需求将会增加。随着越来越多的农场被开发，全球封锁只会发挥越来越不那么微妙的作用。这项调查的潜在结果可能会对未来风能项目的设计产生重要影响。确定堵塞的特征可以缓解和增加能源产量，或者如果不能缓解，它将允许对特定风能项目的财务可行性进行更准确的描述。