Enhancing hydrogen storage efficiency in metal hydride tanks through conical heat exchangers and phase change material integration

This study proposes an innovative approach to enhance the thermal management of metal hydride (MH) hydrogen storage systems by integrating a conical heat exchanger and phase change material (PCM) jacket. Magnesium-based MH reactors offer high hydrogen storage capacities, but their performance is limited by poor thermal conductivity, which hinders charging and discharging processes. The conical coil heat exchanger design improves heat transfer, reducing hydrogen charging time by 30% compared to conventional helical coils. Additionally, incorporating a PCM jacket optimizes the thermal performance, achieving up to a 69% reduction in charging time. The PCM absorbs excess heat during hydrogen charging and releases it during discharging, further improving the reactor's charging/discharging rate. Sensitivity analyses on hydrogen inlet pressure, heat transfer fluid temperature, and Reynolds number are performed, identifying optimal operating conditions. The proposed design is validated using experimental data, confirming its effectiveness in reducing charging and discharging times. To address the long-term thermal behavior of the PCM, future studies are recommended to experimentally validate PCM thermal stability over multiple hydrogen charging/discharging cycles. This integrated system offers a promising solution for enhancing hydrogen storage in clean energy applications, contributing to the development of more efficient and sustainable hydrogen fuel technologies. • Conical heat exchanger reduces hydrogen charging time by 30% in MH tanks. • Phase change material integration cuts charging time by up to 69%. • Sensitivity analysis identifies optimal hydrogen inlet pressure and thermal conditions. • Novel design improves thermal management for efficient hydrogen storage.