Structure and performance optimization of a MgH2 based array hydrogen storage reactor

Metal hydride (MH) is a promising type of solid-state hydrogen storage material, known for its inherent safety, stability, and efficient hydrogen absorption and desorption capabilities. However, MH hydrogen storage reactors suffer from issues such as high heat transfer resistance and slow reaction rates, urgently requiring an efficient thermal management technology. This paper investigates a novel optimized design of an arrayed MgH2 hydrogen storage reactor, aiming to increase heat transfer area, rationalize the distribution of array units, and enhance reaction efficiency. Under the premise of determining the reasonable amount of PCM in the reactor, the influence of the number and distribution pattern of the reactor's array units on the heat transfer and absorption performance were discussed. The results demonstrated a 2.6-fold increase in the H2 absorption rate of the nine-unit array reactor compared to the traditional reactor with one unit. Due to the existence of heat transfer enhancement limits, for a nine-unit array reactor, further increasing the heat exchange area, such as adding copper fins, has almost no further enhancement effect on absorption rate. However, the decentralized distribution of array units optimized the PCM usage of each array unit, resulting in an additional 54.6 % increase in hydrogen absorption rate.