Design optimization and numerical investigation of multi tube metal hydride reactor for large capacity hydrogen storage application

The efficient operation of a metal hydride based hydrogen storage system primarily depends on the configuration of the storage reactor. Both the total weight and effective performance are crucial for large capacity hydrogen storage systems. Therefore, the present work is centered around the development of a lightweight, compact, and efficient MH reactor capable of accommodating a large hydrogen inventory. In this perspective, a disc finned multi tube reactor (DFMTR) design is proposed, and its behaviour is numerically analyzed. Five reactor configurations are studied using 3D COMSOL modeling to visualize the impact of various fin structures during the absorption and desorption half cycles. The DFMTR model shows remarkably higher performance by saving 38% and 31% time to store and release hydrogen compared to the baseline reactor. Further, the design methodology is discussed, and the geometrical and operational parameters are optimized to achieve the excellent performance of the proposed reactor. Furthermore, the portable design approach for scaling up the capacity of the storage system is discussed and recommended. Moreover, the proposed reactor design is compared with recent studies of the literature, and found that this reactor saved 22.1%, 50%, 52.1%, and 8.7% of time to store 90% hydrogen compared with tapered finned multi tube reactor, tube bundle reactor, radial finned reactor, and pin fin reactor, respectively. The authors believe that the proposed large capacity reactor has the potential to deliver outstanding performance, and this research will be instrumental in the construction of compact, effective metal hydride reactors with significant hydrogen storage capacities.