Multi-objective thermodynamic and heat transfer optimization of a LaNi₅-based metal hydride hydrogen storage reactor
Journal of Energy Storage, cilt.178, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 178
- Basım Tarihi: 2026
- Doi Numarası: 10.1016/j.est.2026.123789
- Dergi Adı: Journal of Energy Storage
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Compendex, INSPEC
- Anahtar Kelimeler: Artificial neural networks, Entropy generation, Metal hydride, Multi-criteria decision-making, Multi-objective optimization, Thermal management
- Dokuz Eylül Üniversitesi Adresli: Evet
Özet
This study presents a comprehensive numerical and thermodynamic investigation of a LaNi₅-based metal hydride hydrogen storage reactor within a multi-objective optimization framework. A two-dimensional axisymmetric transient model was developed in ANSYS Fluent using user-defined functions to define hydrogen absorption kinetics, heat transfer, and thermodynamic irreversibilities. The effects of key operating and design parameters, including hydrogen supply pressure, convective heat transfer coefficient, and effective thermal conductivity enhanced through copper coating, were systematically examined. Reactor performance was evaluated in terms of filling duration, stored hydrogen mass, average reactor temperature, and entropy generation. A rank correlation-based sensitivity analysis was conducted to identify the dominant parameters governing reactor behavior. To identify the optimal reactor configuration, an ANN-based surrogate model was developed using the 84-case CFD dataset, achieving an average R2 of 0.984. The surrogate model was subsequently coupled with the Non-dominated Sorting Genetic Algorithm II (NSGA-II) to generate a continuous Pareto-optimal frontier, and the best-compromise design was selected using the TOPSIS multi-criteria decision-making method. The selected optimal configuration, obtained under a baseline weighting scheme that prioritizes filling duration, operates at a supply pressure of 7.65 bar, a convective heat transfer coefficient of 464 W/m2K, and a copper coating percentage of 38.4%, achieving a charging duration of 632.81 s with an entropy generation of 92.86 J/K and a stored hydrogen mass of 0.31 kg, validated against a numerical simulation with errors below 2%. To assess the robustness of this design choice, a sensitivity analysis was conducted for four alternative TOPSIS weighting scenarios, except the baseline design, revealing that prioritizing stored hydrogen mass over filling duration more than doubles the baseline charging time, while Scenario 3 achieves the lowest entropy generation, albeit with a modest increase in charging duration relative to the baseline. The findings highlight the critical role of entropy-based metrics, together with charging duration and storage capacity, in the multi-objective optimization of metal hydride reactor design.