Enhancement of efficiencies of cryogenic energy storage packed bed using a novel Referred-Standard-Volume optimization method

• Published in: International journal of heat and mass transfer Vol. 224; p. 125367
• Main Authors: She, Xiaohui, Wang, Xingyu, Han, Peng, Li, Yongliang, Wang, Chen
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.06.2024
• Subjects: Cryogenic energy storage packed bed; optimization method; Reference-Standard-Volume; Reference-Standard-Volume; Cryogenic energy storage packed bed; optimization method
• ISSN: 0017-9310; 1879-2189
• DOI: 10.1016/j.ijheatmasstransfer.2024.125367

•A Reference-Standard-Volume optimization method is proposed to improve CESPB.•The best aspect ratio of CESPB is 2–4 considering efficiencies and pressure drop.•The volume multiple is given at 1.1 with the highest exergy efficiency of 63.72 %.•The thermal and exergy efficiencies are increased by 2.03 % and 3.65 %, respectively. Cryogenic liquids (e.g., liquid air, liquid hydrogen, liquid carbon dioxide) have gained popularity in electricity storage due to their high energy density, no geographical constraints, and environmental friendliness. The cryogenic energy storage packed bed (CESPB) is widely employed as a cold recovery device to enhance the round-trip efficiency of cryogenic energy storage systems. Nonetheless, the cycle efficiencies of CESPB remain relatively low, with limited research investigating efficient methods for determining the design parameters. To address this, a novel optimization method named as the Reference-Standard-Volume (RSV) approach is introduced to enhance the thermodynamic performance of CESPB. In this paper, the complete optimization process of CESPB is illustrated, presenting the optimization outcomes in the view of heat and mass transfer. The findings reveal that a larger aspect ratio leads to the higher efficiencies but increased pressure drops. An optimal aspect ratio of 3 and a volume multiple of 1.1 is identified, achieving the highest exergy efficiency of 63.72 %. Meanwhile, increasing charging/discharging time enhances heat transfer in CESPB, however, it leads to an increase in external cold dissipation, which gives an optimal charging/discharging time of 3/3 h. By implementing the RSV optimization method, the percentage increase of discharging efficiency, thermal efficiency, and exergy efficiency of CESPB is 2.08 %, 2.03 %, and 3.65 %, respectively. These research outcomes offer valuable reference and guidance for future CESPB design and research.