Design and topology optimization of a dual-side fin-and-tube-integrated metal hydride reactor for enhanced hydrogen absorption performance

Metal hydride reactors (MHRs) are promising H₂ storage systems because of their high volumetric capacity and reversibility, but their performance is limited by internal heat and mass transfer bottlenecks. This study proposes a topology-optimization-driven dual-side fin-and-tube-integrated reactor (DFTR@TO), in which conductive fins are distributed between the inner and outer heat-transfer boundaries to form an efficient heat-conduction network. A numerical framework based on the UCVM kinetic model was established to describe the coupled hydrogenation process, and the volumetric hydrogen storage rate, R_v, was introduced as a performance metric. Compared with inner-side and outer-side fin configurations, the dual-side fin arrangement increased R_v by approximately 47% and 6%, respectively. After structural, topological and operating optimization, DFTR@TO achieved 90% hydrogen saturation within 80 s, with R_v=0.398 (Formula presented).