Open Access

ARTICLE

Finned-Tube Heat Exchangers for Accelerated Hydrogen Absorption in Metal-Hydride Storage Reactors

Haozhe Zhang¹, Shengjie Wang¹, Jiajia Song¹, Zeqi Chen¹, Suoying He¹, Ming Gao^1,2,*

1 School of Nuclear Science and Energy Engineering, Shandong Engineering Research Center for High-efficiency Energy Storage and Hydrogen Utilization, Shandong University, Jinan, China
2 Rizhao Research Institute of Shandong University, Rizhao, China

* Corresponding Author: Ming Gao. Email:

Fluid Dynamics & Materials Processing 2026, 22(9), 6 https://doi.org/10.32604/fdmp.2026.088369

Received 02 July 2026; Accepted 09 September 2026; Issue published 28 September 2026

Abstract

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 LaNi₅ hydriding kinetics, is employed to compare a series of discrete heat-exchanger geometries. The effects of tube-spacing ratio α, primary-tube radius r₀, tube-radius ratio β, secondary-fin included angle θ, fin-angle ratio γ, and fin-extension distance δ are examined under a common heat-exchanger structure volume fraction of φ ≤ 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 θ and γ (R² = 0.954, overall p < 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.

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Keywords

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