Industrial waste heat recovery using supercritical carbon dioxide cycles (SCOTWOHR)

使用超临界二氧化碳循环回收工业废热 (SCOTWOHR)

• 批准号: EP/V001752/1
• 负责人: Abdulnaser Sayma
• 金额: $ 97.84万
• 依托单位: City, University of London
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2021
• 资助国家: 英国
• 起止时间: 2021 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FV001752%2F1
• 关键词: Industrial; waste; heat; recovery; using

Increased pressure on reducing the carbon footprint from energy intensive industry such as glas, iron and steel, cement and oil and gas, with substantial waste heat streams is leading to the need to develop efficient and cost-effective waste heat recovery technologies. With waste heat stream at temperatures typically below 500 deg C, and low flow rates that mean commercially available steam power generation systems are unsuitable, attention is focused on other waste heat recovery technologies. Thus, significant research efforts have focused on the next generation of thermal-power systems, operating with novel working fluids such as organic fluids and supercritical carbon dioxide (sCO2). The ORC, which uses an organic working fluid, has been proven for conversion of heat between approximately 100 and 350 deg C into electricity, and commercial systems are available. However, ORC systems remain associated with high investment costs, whilst organic fluids are often flammable, unstable at high operating temperatures, and associated with a detrimental environmental impact. Alternatively, CO2 is an extremely promising candidate with benefits including low cost, is non-flammable and has a lower environmental impact than organic fluids. It facilitates compact components owing to high fluid densities, and high cycle efficiencies can be obtained at moderate heat-source temperatures. Despite its significant potential, sCO2 systems for waste heat recovery applications have not been commercialised yet, due to significant technical challenges that need to be overcome. This includes the development of suitable heat exchangers and turbomachinery, as well as the identification of optimal systems that adequately address the trade-off between performance and complexityThe focus of this proposal is to conduct original research to improve the fundamental understanding of the performance sCO2 cycles and the design aspects of the key components, namely compressors, expanders and heat exchangers. Computational and experimental methods will be used to investigate the performance and design characteristics across a wide range of operating conditions. These studies must account for the complexities of using sCO2 that exhibit complex fluid behaviour not observed in conventional fluids such as air and steam, in addition to considering the high-speed flows, and two-phase conditions close to the critical point at the compressor inlet, and the corrosive nature of sCO2 with low level of humidity to the heat exchanger materials. Ultimately, the results from these studies will improve the existing scientific understanding, and will facilitate the development of new performance prediction methods for the cycle and components. Understanding these aspects will not only lead to improved performance prediction, but could also lead to improved component design in the future. Within this project the new prediction methods will be used to investigate and compare the performance of different cycle architectures and component designs. The results from these comparisons will enable the identification of the optimal systems that can operate across a wide range of heat input and load conditions, and therefore best facilitate improvements to sCO2 systems. The primary outcomes of this research will be improved fundamental understanding of the performance of sCO2 cycles and component designs and validated performance models for compressors and expanders. Furthermore, recommendations will be made on the most appropriate system configurations that offer improvements to operational aspects, thus enabling the future commercialisation of small-scale sCO2 technology for waste heat recovery. Therefore this project has the potential to stimulate investment and create new jobs within the low carbon energy market, whilst positively contributing to the UK's existing research portfolio in waste heat recovery from energy intensive industry.

减少玻璃、钢铁、水泥、石油和天然气等能源密集型行业的碳足迹的压力越来越大，这些行业有大量的废热流动，这导致需要开发高效和具有成本效益的废热回收技术。由于废热流动的温度通常低于500摄氏度，以及低流量意味着商业上可用的蒸汽发电系统不适合使用，因此人们将注意力集中在其他废热回收技术上。因此，重要的研究工作集中在下一代热力系统上，使用有机液体和超临界二氧化碳(SCO2)等新型工质运行。ORC使用有机工质，已被证明可以将大约100℃到350℃之间的热量转换为电能，并且有商业系统可用。然而，ORC系统仍然伴随着高昂的投资成本，而有机液体通常是易燃的，在高温下不稳定，并与有害的环境影响有关。或者，与有机流体相比，二氧化碳具有成本低、不可燃、对环境的影响小等优点，是一种非常有前途的候选材料。由于高流体密度，它有利于紧凑的部件，并且在中等热源温度下可以获得高的循环效率。尽管SCO2系统具有巨大的潜力，但由于需要克服重大的技术挑战，用于废热回收应用的SCO2系统尚未商业化。这包括开发合适的热交换器和透平机械，以及确定充分考虑性能和复杂性之间权衡的最佳系统。这项建议的重点是进行原创性研究，以提高对性能、SCO2循环和关键部件(即压缩机、膨胀机和热交换器)的设计方面的基本了解。计算和实验方法将被用来研究在广泛的操作条件下的性能和设计特性。这些研究必须考虑到使用SCO2的复杂性，这些复杂的流体行为在空气和蒸汽等常规流体中没有观察到，此外还考虑了高速流动和接近压缩机入口处临界点的两相条件，以及低湿度的SCO2对热交换器材料的腐蚀性。最终，这些研究的结果将提高现有的科学认识，并将有助于开发新的循环和部件的性能预测方法。了解这些方面不仅可以改进性能预测，还可以改进未来的组件设计。在该项目中，将使用新的预测方法来调查和比较不同循环架构和部件设计的性能。这些比较的结果将有助于确定能够在广泛的热输入和负载条件下运行的最佳系统，从而最好地促进对SCO2系统的改进。这项研究的主要成果将是增进对SCO2循环性能的基本了解和组件设计，以及经过验证的压缩机和膨胀机性能模型。此外，还将就最合适的系统配置提出建议，以改善操作方面，从而使小规模的SCO2废热回收技术能够在未来实现商业化。因此，该项目有潜力刺激投资并在低碳能源市场创造新的就业机会，同时为英国现有的从能源密集型行业回收余热的研究组合做出积极贡献。

项目成果

DYNAMICS OF SCO2 HEAT TO POWER UNITS EQUIPPED WITH DUAL TANK INVENTORY CONTROL SYSTEM

配备双罐库存控制系统的 SCO2 热力发电装置动态

• 发表时间: 2021
• 期刊: International Seminar on ORC Power Systems
• 作者: Marchionni M.