Operational and safety analyses of a commercial PEMFC system

• Published in: International journal of hydrogen energy Vol. 33; no. 15; pp. 4147 - 4160
• Main Authors: Gerbec, Marko, Jovan, Vladimir, Petrovčič, Janko
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.08.2008; Elsevier
• Subjects: Applied sciences; Energy; Energy. Thermal use of fuels; Equipments for energy generation and conversion: thermal, electrical, mechanical energy, etc; Exact sciences and technology; Fuel cells; Hydrogen; PEM fuel cell; Process safety; Reliability; Process safety; Reliability; Hydrogen; PEM fuel cell; Fires; Safety analysis; Explosions; Fault tree analysis; Maintenance; Proton exchange membrane fuel cells; Hazard
• ISSN: 0360-3199; 1879-3487
• DOI: 10.1016/j.ijhydene.2008.04.063

A commercial, transportable proton-exchange-membrane fuel-cell (PEMFC) system rated at 7 kW nominal power was the subject of an operational (reliability, availability, and maintainability) and process-safety analysis. The scope of the analysis included the system start-up to engine-run mode, the maintenance tasks, as well as the continuous power-production mode, carried out with a hazard and operability (HAZOP) study and a failure-scenarios' development. The failure and process-safety risks were categorized and the probabilities were assessed with a fault-tree analysis (FTA) using equipment-failure-rate data from the literature, if available. The results led to similar conclusions to those previously reported in similar studies, and the most important equipment/devices with respect to reliability and safety aspects were identified. While the most important uncertainty in the complete analysis comes from the generic equipment failure-rate data used, about three failures in the first year of operation are estimated together with an availability of about 98% (a point value figures, confidence interval analysis was also made). The process-safety analysis revealed four potential accident scenarios involving hydrogen releases, fires and explosions. Finally, detailed suggestions and recommendations for changes/improvements with respect to the reliability/availability, maintainability and safety aspects of the system analysed are presented.