Dynamic optimization of airflow rate for air-cooled PEMFC under multi-operating conditions

Air-cooled proton exchange membrane fuel cells (PEMFCs) are promising for small aircraft and portable power systems, yet their performance is limited by the inherent trade-off between heat removal and membrane hydration. Most existing studies optimize static parameters, whereas dynamic airflow regulation remains insufficiently explored. This work experimentally identifies the optimal airflow for a 48-cell open-cathode air-cooled PEMFC stack under three representative operating conditions: variable current loads, hydrogen supply configurations, and purge durations, each with distinct thermal and humidification requirements. Results indicate that a 40% fan duty cycle balances cooling and parasitic power at low-to-medium loads (0–450 mA/cm2). At high loads (450–550 mA/cm2), 60%–80% fan duty improves thermal management despite reduced membrane water content. For hydrogen feeding, 40% duty fits single-path supply and 60% suits dual-path operation, mitigating hydrogen gradients and improving voltage uniformity. A 40% fan duty is optimal for 1–2 s purges, while 60% prevents heat buildup for 3 s purges. This study reveals airflow-stack performance coupling and supports dynamic optimization for lightweight power engineering.