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

拟议的项目标题是“一种创新的氧气燃烧超临界二氧化碳发电循环，用于高度灵活的发电”。上面提到的电力循环也被称为Allam循环，是一种新的系统，承诺与传统循环一样有效，能够匹配或改善它们的电力成本(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，导致富氧燃料燃烧。驱动涡轮发电机的燃烧产物的主要成分是二氧化碳(CO2)，其中大部分随后重新引入动力循环。由于剩余的二氧化碳可以被捕获并运输储存，Allam循环发电本质上包括碳捕获和促进能量存储，这是近期电力供应最理想的两个特征。爱丁堡大学的研究引入了使用胺溶剂的燃烧后捕获(PCC)的传统电厂灵活运营的概念(Lucquiaud等人，2008年；Chalmers等人，2009年)。通过使用临时溶剂储存，要么绕过二氧化碳吸收塔，要么将溶剂再生和储存的能源惩罚从高电价时期转移到低电价时期。与胺溶剂存储相同，空分装置中的氧气生产是一个非常耗能的步骤，可以与燃氧煤发电的主要发电过程脱钩(IEAGHG，2012)。氧气生产和发电的脱钩可以通过使用液氧存储来实现，可以弥补空分装置启动时间较慢的问题，从而在风力发电资源产量较低的情况下实现更便宜的发电。当风力发电量高时，电力循环在最低负荷下运行，将净零输出返回电网，并保持大量二氧化碳流向运输和存储系统。研究将涉及使用gPROMS软件对发电厂进行建模，并纳入流程优化和强化。将对当前设计的潜在改进进行评估，例如，使用液氧存储来补偿ASU启动时间较慢的情况。还将考虑到与电力网络和二氧化碳传输网络的整合，以提供一项将先进的操作灵活性概念应用于Allam循环发电厂的全面的同类研究。

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.