Thermodynamic performances of a novel multi-mode solar-thermal-assisted liquid carbon dioxide energy storage system

• Published in: Journal of energy storage 2024-09, Vol.97, p.112843, Article 112843
• Main Authors: Jiang, Haowen, Wang, Jiangjiang, Xu, Hangwei, Yao, Zibo, Tian, Yuyang
• Format: Article
• Language: English
• Subjects: Liquid carbon dioxide energy storage system; Multi-mode; Organic Rankine cycle (ORC); Solar-thermal-assisted; Thermodynamic analysis
• ISSN: 2352-152X
• DOI: 10.1016/j.est.2024.112843

Liquid carbon dioxide energy storage is an efficient and environmentally friendly emerging technology with significant potential for integration with renewable energy sources. However, the heat recovery and utilization during compression and expansion are not implemented well. This paper proposes a multi-mode solar-thermal-assisted liquid carbon dioxide energy storage system integrated with the organic Rankine cycle. Three operation modes of normal operation mode, heat distribution operation mode, and solar thermal power generation mode are developed to achieve flexible control of the system under both normal and extreme environmental conditions. Thermodynamic performance analysis of the system under normal operation mode shows that compared to traditional system with energy storage density of 8.55 kWh/m3, the overall efficiency of the coupled system increases from 49.5 % to 62.1 %, with an energy storage density reaching 21.74 kWh/m3. The impact of key parameters such as temperature and pressure on system performance is discussed. Furthermore, an analysis of the heat flow distribution ratio under the heat distribution mode was conducted, indicating optimal system performance at a heat flow ratio of 6:4. Comparative analysis of the system performance under various operating conditions for the three operation modes was performed, elucidating the operational strategies of each mode. •A multi-mode solar-assisted liquid carbon dioxide energy storage system is proposed.•Solar thermal assistance enhances the energy release capability during the expansion process.•The energy density reached 21.74 kWh/m3, which is more than twice that of traditional LCES systems.•The distribution of exergy loss in the system is analyzed.•The influence of temperature and pressure on the system performance is discussed.