Effects of different heat transfer enhancers in PCM-based latent thermal energy storage for hydrogen storage in activated carbon bottle

This study presents a numerical simulation of a packed bed reactor filled with activated carbon for hydrogen storage, incorporating phase change material (PCM) with various heat transfer enhancers. The simulations were performed using the Fluent ANSYS. The main goal is to explore the use of PCM as a heat manager (reactor coolant) and optimize its performance by investigating the effects of various enhancers, including nanoparticles (NP), metal foam (MF), and fins, on the melting efficiency of PCM in activated carbon beds. Outcomes showed that the hydrogen adsorption capacity of 25 mmol/g was found to be independent of the type of PCM enhancer used in the system. The results showed that the MF provided the best cooling performance of the activated carbon bed, with a surface heat flux of 2750 W/m2 and a surface heat transfer coefficient of 410 W/m2K, while fins provided the highest melting rate of the PCM. In the presence of fins, metal foam, and nanoparticles, the fusion rate of PCM has been enhanced by 64, 32, and 8%, respectively, compared to pure PCM. These findings provide valuable insights into the design of packed bed reactors for hydrogen storage and can be used to optimize the thermal performance of the system. Based on the obtained findings, it is recommended that future studies on H2 storage in solid beds should be focused on the optimization of fins, metal foams, use of other nanoparticles, integration of composite PCMs, adoption of chemically modified or nanoporous carbon beds, and possibly the employment of hybrid enhancers.