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.

由于玻璃、钢铁、水泥、石油和天然气等能源密集型行业存在大量废热流，因此减少碳足迹的压力越来越大，因此需要开发高效且具有成本效益的废热回收技术。由于废热流的温度通常低于500摄氏度，而低流量意味着商业上可用的蒸汽发电系统不适合，因此人们的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电系统上，这些系统使用新型工作流体，如有机流体和超临界二氧化碳（sCO2）。ORC使用有机工作流体，已被证明可以将大约100到350摄氏度之间的热量转化为电能，并且可以使用商业系统。然而，ORC系统仍然与高投资成本相关，而有机流体通常是易燃的，在高温下不稳定，并且与有害的环境影响有关。另外，二氧化碳是一种极有前途的候选者，其优点包括成本低、不易燃，并且比有机流体对环境的影响更小。它有利于紧凑的组件，由于高流体密度，高循环效率可以在适度的热源温度下获得。尽管具有巨大的潜力，但由于需要克服重大的技术挑战，用于余热回收应用的sCO2系统尚未商业化。这包括开发合适的热交换器和涡轮机械，以及确定最佳系统，以充分解决性能和复杂性之间的权衡。本提案的重点是进行原创性研究，以提高对性能sCO2循环的基本理解和关键部件的设计方面，即压缩机，膨胀器和热交换器。计算和实验方法将用于研究在各种操作条件下的性能和设计特征。这些研究必须考虑到使用sCO2的复杂性，它表现出在空气和蒸汽等传统流体中观察不到的复杂流体行为，此外还要考虑高速流动、压缩机入口接近临界点的两相条件，以及sCO2在低湿度条件下对热交换器材料的腐蚀性。最终，这些研究的结果将改善现有的科学认识，并将促进新的循环和组件性能预测方法的发展。了解这些方面不仅可以改进性能预测，还可以改进将来的组件设计。在这个项目中，新的预测方法将用于调查和比较不同周期架构和组件设计的性能。这些比较的结果将有助于确定可以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。本研究的主要成果将提高对sCO2循环性能和组件设计的基本理解，并验证压缩机和膨胀机的性能模型。此外，还将就最适当的系统配置提出建议，以改进操作方面，从而使用于废热回收的小型二氧化碳技术在未来实现商业化。因此，该项目有可能刺激投资并在低碳能源市场创造新的就业机会，同时对英国现有的能源密集型工业废热回收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.