Operating performance and energy flow modeling for a hundred-kilowatt proton exchange membrane fuel cell stack test system

This study presents a comprehensive system-level analysis model for evaluating performance characteristics of a hundred-kilowatt proton exchange membrane fuel cell (PEMFC) test system. Unlike conventional power-focused systems, the test system has a more complex architecture and numerous balance of plants (BOPs). The developed model integrates detailed input-output traits of each system component. The energy efficiency ratio (EER) and energy conversion efficiency (η) are introduced as metrics for assessing net power consumption and conversion capability of the test system. By simulating various operational scenarios (considering temperature, load current, cathode pressure, humidity, and PEMFC power), the model predicts the behaviors of BOPs and energy flow relations. The changing rules of the EER and η are also investigated. An increase in temperature, current, and cathode pressure leads to an improvement in EER. Increasing operating temperature, cathode pressure, and humidity can enhance η. Key findings suggest optimal conditions for system self-sufficiency include an operating temperature below 90 °C, load current over 1200 mA cm⁻², and air humidity under 90%. Furthermore, the PEMFC power is advisable to configure between 50% and 100% of the test system's maximum power. These insights are pivotal for improving the design and functionality of PEMFC testing equipment, further contributing significant advancements to fuel cell technology.