Advanced thermal management of metal hydride
reactors

Oussama Rejeb, Christophe Vial, Abdelmajid Jemni, Tarik Kousksou, Nour-Eddine Fenineche, Maamar Bettayeb, Chaouki Ghenai

► To cite this version:

Oussama Rejeb, Christophe Vial, Abdelmajid Jemni, Tarik Kousksou, Nour-Eddine Fenineche, et al. Advanced thermal management of metal hydride reactors. 15th International Conference on Hydrogen Production (ICH2P-2024) ICH2P, Dec 2024, Sharjah, United Arab Emirates. hal-04859703

HAL Id: hal-04859703

https://hal.science/hal-04859703v1

Submitted on 30 Dec 2024

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# Advanced thermal management of metal hydride reactors: a numerical study on optimized fin geometries

¹ Oussama Rejeb¹, Christophe Vial¹, Abdelmajid Jemni², Tarik Kousksou³, Noureddine Fenineche⁴, Maamar

Bettayeb ⁵,⁶, Chaouki Ghenai ⁷,⁸*

1. Université Clermont Auvergne, Clermont Auvergne INP, CNRS, Institut Pascal, F-63000, Clermont-Ferrand, France

2. Université de Monastir, Ecole Nationale d'Ingénieurs de Monastir (ENIM), LESTE, LR99ES31, 5000, Monastir, Tunisia.

3. Laboratoire SIAME, Université de Pau et des Pays de L'Adour/E2S UPPA, EA4581, 64000 Pau, France

4. ICB-PMDM UMR 6303, CNRS, Université Bourgogne Franche-Comté, UTBM, Belfort, F-90010, France

5. Department of Electrical Engineering, University of Sharjah, Sharjah, United Arab Emirates.

6. Center of Excellence in Intelligent Engineering Systems (CEIES), King Abdulaziz University, Jeddah, Saudi Arabia.

7. Department of Sustainable and Renewable Energy Engineering, College of Engineering, University of Sharjah, Sharjah, United Arab Emirates

8. Sustainable Energy Development Research Group, Research Institute for Science and Engineering (RISE), University of Sharjah, P.O. Box 27272, Sharjah, United Arab Emirates.

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## Context

### Hydrogen Storage Mode

Compressed

Liquefied

Solid (Hydride)

<figure><img src="image_4.png" /></figure>

<figure><img src="image_5.png" /></figure>

<figure><img src="image_6.png" /></figure>

High-pressure

High energy (Cryogenic) needed

Thermal management

## Contribution

* Safe Hydrogen Storage: Solid storage ensures safety.

* Passive Thermal Management: Effective heat regulation.

* Optimized Fin Geometries: Different fin shapes for better heat transfer.

* Developed a Dynamic Model for the LaNi5 material with a cylindrical reactor coupled with fins.

## System Description

<figure><img src="image_7.png" /><figcaption>(a) Rectangular Fins</figcaption></figure>

<figure><img src="image_8.png" /><figcaption>(b) Triangular Fins</figcaption></figure>

<figure><img src="image_9.png" /><figcaption>(a) Rectangular Fins</figcaption></figure>

<figure><img src="image_10.png" /></figure>

LaNi5 cylindrical reactor coupled with fins

### Mathematical Part

#### Kinetics Reaction

$$ \frac{dX_{abs}}{dt} = Cst_{abs} \ln\left(\frac{P}{P_{eq,abs}}\right) \exp\left(\frac{-E_{act}}{RT_{abs}}\right) (X_{lim,abs} - X_{abs}) $$

#### Energy equation

$$ (C_{p,can}m_{can} + C_{p,MH}m_{MH}) \frac{dT_{abs}}{dt} = -Cst_{x} \frac{\Delta H}{M W_{H_2}} \frac{dX_{abs}}{dt} - A\eta_{0,fin}h_{air}(T_{ex} - T_{abs}) $$

## Validation

<figure><img src="image_11.png" /></figure>

Validation: Comparing the results provided by the numerical model with experimental data available in the literature.

## Results

<figure><img src="image_12.png" /></figure>

The variation in hydrogen storage capacity (%wt) for parabolic fins, rectangular fins, and triangular fins.

## Conclusions

**Model Development:** A lumped transient model for a finned LaNi5 cylindrical reactor integrates kinetics, energy, and mass transfer.

**Thermal Control:** Parabolic fins outperform rectangular and triangular designs, reducing the charging time.

**Efficiency Boost:** Fins enhance the reliability of metal hydride hydrogen storage, supporting sustainable energy solutions.