A Holistic Conceptual Synthesis and Analysis of Fuel Cell System Architectures Using 1D Coupled Thermofluid and Electrochemical Lumped Parameter System Simulation

Abstract In this work, several fuel cell system architectures are described and analyzed. The architecture variability includes uncoupled/coupled cooling and aspirant systems, the inclusion or exclusion of an energy recovery turboexpander on the exhaust, and, for those that include a turboexpander, the inclusion or exclusion of thermal recuperation. It is recognized a-priori that certain architectures will have specific advantages over others. It is also recognized that there are several performance metrics that may be sought. They include power system efficiency, gravimetric power density, volumetric power density, and specific cost per capacity. The analyses carried out in this work lead to a novel way to minimize the cost of a fuel cell power system. Specifically, knowing that the fuel cell proper represents the highest cost component of a fuel cell based power system, it is shown that one can optimize for maximum “bang for the buck” in a surrogate fashion in a holistic system analysis. The key to being able to achieve this is having a reliable electrochemical analysis model of a cell coupled with an overall system simulation model. Thus, for a variation of parameters, it can be predicted how relative fuel cell stack specific power density changes with parameter variation. The outcome of this paper is a documentation of several integrated fuel cell system architectures with a parametric analysis and resulting performance metrics of each system when independently optimized for efficiency, power density, and fuel cell specific power capacity, showing an improvement of about 15% over a simple baseline.