TY  - EJOU
AU  - Zhang, Haozhe 
AU  - Wang, Shengjie 
AU  - Song, Jiajia 
AU  - Chen, Zeqi 
AU  - He, Suoying 
AU  - Gao, Ming 

TI  - Finned-Tube Heat Exchangers for Accelerated Hydrogen Absorption in Metal-Hydride Storage Reactors
T2  - Fluid Dynamics \& Materials Processing

PY  - 
VL  - 
IS  - 
SN  - 1555-2578

AB  - This study develops and systematically evaluates a hierarchical tree-shaped finned-tube heat exchanger designed to enhance hydrogen absorption in porous metal-hydride (MH) storage reactors. The proposed architecture combines geometrically nested primary, secondary, and tertiary tubes with branched fins to redistribute cooling capacity from the reactor core towards peripheral regions where localized reaction dead zones develop. A validated two-dimensional transient model, incorporating Darcy-law porous-media flow, heat transfer between the MH bed and the aluminium heat-exchanger structure, and LaNi<sub>5</sub> hydriding kinetics, is employed to compare a series of discrete heat-exchanger geometries. The effects of tube-spacing ratio <i>α</i>, primary-tube radius <i>r</i><sub>0</sub>, tube-radius ratio <i>β</i>, secondary-fin included angle <i>θ</i>, fin-angle ratio <i>γ</i>, and fin-extension distance <i>δ</i> are examined under a common heat-exchanger structure volume fraction of <i>φ</i> ≤ 15%. The optimized configuration reduces the hydrogen absorption time from 490 s to 287.5 s, corresponding to a 41.33% reduction. In particular, extending the fins towards the reaction dead zones further reduces the absorption time from 329 s to 287.5 s, while increasing the heat-exchanger volume fraction by only 2.36 percentage points. Response-surface analysis provides further insight into the geometric interactions, revealing a statistically significant coupling between <i>θ</i> and <i>γ</i> (R<sup>2</sup> = 0.954, overall <i>p</i> &lt; 0.001), which governs the positioning of tertiary fins and the associated local heat-conduction pathways. The results demonstrate that the performance enhancement arises not simply from increasing heat-transfer area, but from spatially matching the heat-removal architecture to the heterogeneous reaction field.
KW  - Tree-shaped finned-tube bundle; porous media flow; heat and mass transfer; metal hydride; hydrogen absorption process; numerical simulation

DO  - 10.32604/fdmp.2026.088369