(283d) Dynamic Modeling and Simulation of Ammonia Borane Hydrogen Storage Systems

Out of the materials available for chemical hydrogen storage in PEM fuel cell applications, ammonia borane (AB, NH3BH3) has a high hydrogen storage capacity (upto 19.6% by weight for the release of three hydrogen molecules). Therefore, AB was chosen in our chemical hydride simulation studies. A new systems concept based on augers, ballast tank and reactor, hydrogen heat exchanger and H2 burner was designed and implemented in simulation. One dimensional models based on conservation of mass, species and energy were used to predict important state variables such as reactant and product concentrations, temperatures of various components, flow rates, along with pressure, in various components of the storage system. Control signals to various components are governed by a control system which is modeled as an independent subsystem. Various subsystem components in the models were coded as C language S-functions and implemented in Matlab/Simulink environment. System simulation results for vehicle start-up and transient drive cycle cases are presented.