Transforming heat-recovery system performance by exploiting multi component turbine flows

由于能源成本不断上涨，能源需求与英国发电能力之间的差距越来越大，英国人的生活水平正面临重大风险。填补这一差距需要技术创新，这些创新既负担得起，又可以在相当短的时间内实施。可以迅速提高效率的一个重要领域是改进对工业过程中释放的热量的管理。所有工业和发电过程都会产生热量，这些热量通常以高温废气的形式释放到环境中。人们正在开发新技术，以回收这些原本被浪费的能源，用于其他地方，如电力、供暖或制冷。如果在整个英国制造业应用，这些技术可以节省大约20个发电站的能源输出。热回收技术也用于生物质、地热、太阳热能等可再生能源和分散式发电。因此，热回收技术的发展对于减少我们的碳足迹以及提高英国的能源安全至关重要。热回收系统的工作原理是通过热交换器将热量传递到高压工作流体中。为了发电，工作流体驱动与发电机相连的涡轮。热回收系统通常使用制冷剂或长链碳氢化合物作为工质。这些工质的性质与传统上在涡轮机内使用的工质（例如航空发动机/燃气轮机内的空气或蒸汽轮机内的水蒸气）有很大不同，可以由几种成分组成，包括气体和液体的混合物。由于缺乏实验数据来验证现有的理论，人们对这些非常规工作流体在涡轮机中的行为知之甚少。这一点很重要，因为涡轮设计师需要精确的模型来开发高性能的机器，而模型中的不确定性会对开发成本和热回收系统的整体性能产生不利影响。还有一种潜力是利用这些工作流体的不寻常行为，例如它们在涡轮机中从液体变为气体的能力，这可以用来提高系统功率与尺寸比（功率密度），这是使用普通工作流体（如水）无法实现的。该项目将探索如何利用多组分流体的行为来提高涡轮机的性能。为了实现这一目标，这项工作将涉及开发模拟涡轮机内多组分流体的方法。该项目将使用实验和计算技术来模拟这些流动，并使用这项工作的结果来改进当前的计算方法。该项目涉及与GE合作，GE是热回收系统设计、制造和供应的全球领导者。通用电气将把这项工作的结果纳入他们的设计系统。这样，这个项目的成果将加速热回收技术的发展，这些技术将在世界范围内使用。

Living standards in the UK are at significant risk from the rising costs of energy and the increasing gap between demand and the UK's generating capacity. Plugging this gap requires technological innovations which are affordable and can be implemented over reasonably short time-scales. An important area where efficiency gains can be achieved quickly is improving the management of heat released from industrial processes. All industrial and power generation processes produce heat which is often released into the environment in the form of high temperature exhaust products. New technologies are being developed to recover this otherwise wasted energy for use elsewhere, such as electricity, heating or cooling. If applied across the UK manufacturing sector, these technologies could save the energy output of around 20 power stations. Heat-recovery technologies are also used for renewable power from biomass, geothermal, solar-thermal sources and in de-centralized power generation. The development of heat recovery technology is therefore important in terms of cutting our carbon footprint as well as increasing UK energy security. Heat recovery systems work by transferring heat into a high-pressure working-fluid, using a heat exchanger. In order to produce electricity, the working fluid drives a turbine which is connected to an electrical generator. Heat recovery systems often use working fluids which are refrigerants or long-chain hydrocarbons. The properties of these working fluids differ greatly from those which have traditionally been used within turbines (such as air within aero-engines/gas-turbines or water vapour within steam turbines) and can be made up of several components including mixtures of gases and liquids. There is very little known about the behaviour of these unconventional working fluids within turbines largely due to a lack of experimental data with which to test current theories. This is important because turbine designers require accurate models in order to develop high performance machines, and uncertainties in the modelling can have a detrimental impact on both the development costs and the overall performance of a heat recovery system. There is also a potential to exploit the unusual behaviour of these working fluids, such as their ability to change from liquid to gas across the turbine, which can be exploited to increase system power to size ratios (power density) in ways not possible using normal working fluids like water. The project will explore how the behaviour of multi-component fluids can be used to increase turbine performance. In order to achieve this, the work will involve developing methods to simulate multi-component fluids within turbines. The project will use experiments and computational techniques to model these flows and use the results from this work to improve current computational methods. The project involves a collaboration with GE who are global leader in the design, manufacture and supply of heat recovery systems. GE will incorporate the results of this work into their design systems. In doing so, the results from this project will accelerate the development of heat-recovery technologies which will be used world-wide.