PEMFC‐System Model for BOP Configuration Analysis

Abstract

A suitable design for the balance of plant (BOP) of fuel cell systems is essential and depends on the specific requirements of the stack, or stacks, as well as the application. System models can help to analyze the feasibility of different system designs during the preliminary design phase and offer the basis to derive the requirements for the different components making up the final system design. This paper will present the development of such a system model for a stationary fuel cell system, which will be built up in the project H2OptiLifeCycle. The system model is a coupling of the individual component models, with a focus on the fuel cell stack model and the humidifier models. A 1D finite element model of a fuel cell membrane electrode assembly (MEA) is simplified to a Simscape‐Block to model the behavior of the MEA, including reaction kinetics, diffusion, ionic conductivity, and water transport. This model is also the starting point for the development of the humidifier models, which are then validated against measurement data from the manufacturer. This system model is subsequently used to study three different designs regarding the humidification of the stack. The reference system design uses a single humidifier in the cathode subsystem of the stack, while the second configuration consits of two humidifiers, where the anode humidifier is supplied with a portion of the cathode exhaust in order to humidify the fuel flow to the stack. Finally, the third configuration uses only one humidifier in the anode subsystem. All three configurations are tested in simulation with the Autostack Industry load cycle, to confirm that the achieved humidification of the fuel cell is sufficient. Furthermore, the efficiency of all three configurations is evaluated.