Design optimization and performance evaluation of spherical hydrogen storage reactor

Metal hydrides (MHs) have emerged as promising materials for H2 storage and transportation owing to their superior volumetric hydrogen storage density, with metal hydride reactors (MHRs) playing a pivotal role in hydrogen absorption/desorption processes. Herein, we propose a novel spherical hydrogen storage reactor (SHSR) based on spindle helical tubes. A reactor with a jacket (SHSR-J) was additionally developed to reduce the unfavorable heat transfer regions inside the SHSR. This reactor design has several distinct features, such as the ability to eliminate inhomogeneous blind heat exchange areas to realize isotropic mass transfer and reaction distributions and to uniformly withstand the instantaneous high pressure inside the MH reactor. Moreover, a sensitivity analysis was performed by numerical simulation to estimate the order of sensitivity of the structural parameters of the reactor, and a quadratic regression model for the operating parameters during H2 absorption in the SHSR-J was constructed by response surface analysis. According to the factor weight of these analysis parameters, both structural and operational parameters were individually explored and optimized in sequence by COMSOL Multiphysics. The results revealed that SHSR-J has superior heat transfer and reaction performance and can reach 90 % saturation of hydrogen absorption at 100 s under the optimum operating conditions. The efficient hydrogen storage and heat management capabilities of the SHSR-J are expected to significantly advance the adoption of hydrogen energy.