An innovative oxy-fired supercritical CO2 power cycle for highly flexible electricity generation

拟议的项目名称是“一个创新的氧燃烧超临界二氧化碳动力循环高度灵活的发电。上面提到的动力循环也被称为Allam循环，是一种新型系统，有望与传统循环一样高效，能够匹配或改善其电力成本（Netpower，2016）。该循环使用空气分离装置（ASU）将氧气从空气中分离出来，从而产生氧燃料燃烧。驱动涡轮机发电机的燃烧产物的主要成分是二氧化碳（CO2），其中的大部分随后被重新引入到动力循环。由于其余的二氧化碳可以被捕获并运输储存，因此Allam循环发电固有地结合了碳捕获以及促进能量储存，这是不久的将来电力供应的两个最理想的特征。爱丁堡大学的研究引入了使用胺溶剂的燃烧后捕获（PCC）的传统工厂灵活运行的概念（Lucquiaud等，2008;查尔默斯等，2009）。CO2吸收器被绕过，或者溶剂再生和储存的能量损失通过采用临时溶剂储存从高电价时代转移到低电价时代。与胺溶剂储存一样，空分设备中用于氧气生产的空气分离是一个非常耗能的步骤，可以与主要发电工艺脱钩，如针对氧燃烧煤发电提出的建议（IEAGHG，2012年）。通过使用液氧储存可以实现氧气生产和发电的解耦，可以补偿ASU的缓慢启动时间，从而在风力资源的低产量时期实现更便宜的发电。当风力发电量很高时，电力循环以最低负荷运行，以使电网的净零输出恢复，并保持大量的二氧化碳流量到运输和储存系统。该研究将涉及使用gPROM软件对发电厂进行建模，并结合过程优化和强化。将对现有设计的潜在改进进行评估，例如，使用液氧储存来补偿ASU的缓慢启动时间。与电网和二氧化碳运输网络的整合也将被考虑在内，以提供一个全面的首次研究，将先进的运营灵活性概念应用于Allam循环发电厂。

The proposed project title is 'An innovative oxy-fired supercritical CO2 power cycle for highly flexible electricity generation.' The power cycle referred to above is also known as the Allam Cycle, and is a novel system which promises to be as efficient as conventional cycles, with the ability to match or improve upon their cost of electricity (Netpower, 2016). The cycle uses an Air Separation Unit (ASU) to isolate the oxygen from the air, resulting in oxy-fuel combustion. The main constituent of the combustion products which drive the turbine generator is carbon dioxide (CO2), the majority of which is then reintroduced to the power cycle. As the rest of the CO2 may be captured and transported for storage, Allam Cycle power production inherently incorporates carbon capture as well as facilitating energy storage, two of the most desirable characteristics of near-future electricity supplies.Research from the University of Edinburgh introduced the concept of flexible operation of conventional plants with Post Combustion Capture (PCC) using an amine solvent (Lucquiaud et al, 2008; Chalmers et al, 2009). The CO2 absorber is either bypassed or the energy penalty of solvent regeneration and storage is shifted from times of high electricity prices to low electricity prices by employing interim solvent storage. In the same way as amine solvent storage, air separation for oxygen production in the ASU is a very energy intensive step that can be decoupled from the main power generation process, as proposed for oxy-fired coal power generation (IEAGHG, 2012). The decoupling of oxygen production and power generation, which is achievable via the use of liquid oxygen storage, can compensate for the slow start-up time of the ASU, allowing for cheaper electricity generation in times of low production from wind power resources. When power generation from wind is high, the power cycle operates at minimum load to return net zero output to the grid and maintain a substantial CO2 flow to the transport and storage system.The study will involve the use of gPROMs software to model the power plant, with the incorporation of process optimisation and intensification. Potential improvements to the current design will be evaluated, for example, the use of liquid oxygen storage to compensate for the slow start-up time of the ASU. Integration with the electricity network and the CO2 transport network will also be accounted for to provide a comprehensive first-of-a-kind study applying an advanced operational flexibility concept to Allam Cycle power plants.