Unveiling the electrochemical-thermoacoustic integration performance based on an ammonia fueled protonic ceramic fuel cell and a thermoacoustically driven cryocooler

To enhance overall energy utilization in ammonia fueled protonic ceramic fuel cells (NH3-PCFCs), this work proposes a novel electricity-cooling cogeneration system by directly coupling an NH3-PCFC with a thermoacoustically driven cryocooler (TDC). A steady-state mechanistic model is developed, including ammonia cracking kinetics, electrochemical and thermal transport processes of the NH3-PCFC, and thermoacoustic heat-to-cooling conversion in the TDC. After independent validation of the sub-models, the hybrid system is predicted to deliver a peak power density of 3672.43 W m−2 with a corresponding energy efficiency of 41.84%. Parametric analysis indicates that the NH3-PCFC operating temperature, electrolyte thickness, and hydrogen utilization jointly determine both stack output and recoverable heat availability; while the TDC cooling temperature and cooling efficiency primarily regulate energy cascading and cooling performance, thereby shaping system-level energy and exergy behaviors. Local sensitivity analysis identifies electrolyte thickness as the dominant performance driver. Finally, an NSGA-II based multi-objective optimization is performed to construct the Pareto frontier between power density and energy efficiency. A compromise solution achieves 5908.66 W m−2 with an energy efficiency of 56.98%. Overall, the results indicate that electrochemical–thermoacoustic integration can substantially improve energy cascading and utilization, and provide quantitative guidance for the design and operation of NH3-PCFC/TDC cogeneration systems.