Simulation of a thermally coupled metal-hydride hydrogen storage and fuel cell system

For the first time, the dynamic behavior of a thermally coupled hydrogen storage and fuel cell system was studied using experimentally validated models of a metal-hydride hydrogen storage system and a proton exchange membrane (PEM) fuel cell stack. Two specific situations were studied: in the first scenario, the fuel cell and metal hydride bed were thermally coupled; in the second scenario, they were thermally uncoupled. The results from these simulations clearly exposed unique and subtle behavior associated with thermally coupled systems that could not be easily gleaned from simulating each device alone, as revealed from studying the uncoupled case. The most important result exemplified the importance of providing waste (excess) energy from the PEM fuel cell to the metal hydride bed to facilitate the removal of hydrogen during a discharge process. A detailed parametric study is forthcoming.