Performance optimization of metal hydride hydrogen storage reactors based on PCM thermal management

• Published in: Applied energy 2023-05, Vol.338, p.120923, Article 120923
• Main Authors: Ye, Yang, Zhu, Hongxing, Cheng, Honghui, Miao, Hong, Ding, Jing, Wang, Weilong
• Format: Article
• Language: English
• Subjects: Metal hydrides; Phase change materials; Thermal management; Volumetric hydrogen storage capacity
• ISSN: 0306-2619; 1872-9118
• DOI: 10.1016/j.apenergy.2023.120923

•PCM's amount and properties affect the heat transfer and H2 absorption rate.•The increased absorption pressure can reduce the PCM's minimum consumption.•The reactor's volumetric H2 storage capacity was systematically analyzed.•The optimization method of the volumetric H2 storage capacity was obtained. Metal hydrides (MH) are considered promising hydrogen storage materials. In applications, the heat transfer characteristics of MH hydrogen storage reactors are closely related to their storage performance. Phase change materials (PCM) were proven to integrate with MH reactors for effective thermal management. Nevertheless, the PCM based MH reactors (MH-PCM reactors) still need to overcome the heat transfer resistance and the loss of volumetric hydrogen storage capacity caused by the PCM volume proportion. The present work established a mathematical model to describe the transfer and reaction process in the MH-PCM reactor. Various parameters were discussed in the current work. It was found that the increased PCM's amount and latent heat have a restricted effect on the enhancement of heat transfer and absorption reaction rate. The higher PCM's thermal conductivity and hydrogen supply pressure effectively enhanced the heat transfer and reaction rate. Furthermore, the increased absorption pressure can improve PCM's sensible heat storage capacity, which provides a new approach for optimizing PCM consumption. Finally, the quantitative relationship among the volumetric hydrogen storage capacity, the volume fraction and thermophysical properties of PCM, and the absorption pressure were established by systematic analysis, which provides an essential theoretical basis for the optimization of MH-PCM reactors.