Author: Zhiguo Qu (Xi'an Jiaotong University) - Accurate prediction of the effective thermal conductivity (ETC) of metal hydride (MH) bed is crucial for ensuring the precision of numerical simulations in MH reactors. Existing ETC models for predicting the MH beds suffer from inaccuracies, necessitating the development of more precise ETC models for the design and optimization of MH reactors. This study, based on a three-dimensional model, analyzes the thermal conduction paths of MH beds through mathematical modeling and considers the Smoluchowski effect to establish a powder bed thermal conductivity integral model (TCI model). Experimental validation shows that the TCI model's predicted values, compared with experimental data under atmospheric air and dynamic pressure conditions, exhibit maximum mean absolute percentage errors (MAPEs) of less than 7% and 8%, respectively. Subsequently, the predicted values of the TCI model and five other ETC models were compared with experimental data. It was found that the TCI model exhibited the smallest MAPE across varying porosities, temperatures, atmospheres, and mixed conditions. Finally, based on the TCI model, the effects of particle size, MH bed temperature, and bed porosity on the ETC of the MH bed were systematically investigated. The TCI model proposed in this study provide theoretical support for heat transfer analysis in MH reactors and offer significant guidance for the development and optimization of hydrogen storage systems.
