Overreliance on fossil fuels for energy demands contributes to global warming and climate change. Therefore, it becomes imperative to transition to emission-free alternative fuels. While renewable sources like solar, wind, and hydropower offer clean energy solutions, their implementation is geographically limited and requires substantial initial investments. Hydrogen emerges as a promising fuel option to fulfill this need, as it possesses three times more energy content per unit mass compared to conventional gasoline fuels. However, the low density of the hydrogen enables its storage and transportation challenging. Solid-state storage in metal hydride (MH) materials offer higher storage densities than conventional gas and liquid storage methods at moderate pressure and temperatures. The heat-driven hydrogen storage in MHs necessitates a heat transfer system because of the poor thermal conductivity of MH and temperature-dependence reaction kinetics.
The investigations up to date have considered various heat transfer systems and improved the hydrogen charging/discharging performance in MH reactors. However, a systematic investigation leading to an optimal design has been missing in these studies. Therefore, the current research fills this gap by undertaking a systematic approach to optimize the MH reactor, which includes step-by-step design enhancements, enabling a more thorough and comprehensive investigation.
The present study started with a simple heat transfer system with only heat transfer fluid (HTF) tubes in the MH reactor. Then, its performance is systematically improved by adding fins and changing their configuration to arrive at an optimal design. Further, topology optimization is introduced to generate the fin structure in the MH reactor. Various topological fin structures are generated by varying the number of HTF tubes and fin volume ratio in the reactor.