This study numerically investigates three metal hydride–phase change material (MH-PCM) reactor designs for onboard hydrogen storage in heavy-duty fuel cell forklifts. Using a 3D COMSOL Multiphysics model validated against experimental data, we compare a conventional shell-and-tube layout (Design A) with two novel macro-encapsulated configurations: finned PCM (Design B) and spherical PCM-in-MH (Design C). Simulations under realistic, variable-load driving profiles, including intermittent and VDI60 heavy-duty cycles, demonstrate that Design C achieves 90% hydrogen absorption in just 44 min, outperforming Designs A and B due to superior heat transfer and uniform temperature distribution. During dynamic operation, the MH-PCM system reliably supplies hydrogen for up to 88 min under sustained load and ∼30 min under high-power VDI60 conditions. These results confirm that advanced MH-PCM integration enables fast refueling, effective thermal management, and robust load-following capability, which are key requirements for practical deployment in fuel cell material handling vehicles. • Investigation of novel MH-PCM hydrogen supply unit for FC electric vehicles. • 3D numerical model compared three reactor designs. • Encapsulated PCM reduced the H 2 storage time by 172 % compared to the conventional one. • MH-PCM supplies hydrogen between 30 and 88 min under heavy-duty operation.
Nyamsi et al. (2026) studied this question.