Regenerative Fuel Cell System

The objective of the work was to develop and define the performance and life characteristics of regenerative fuel cell technology for space applications. The report describes the system, analyses, component configurations, test results and conclusions derived from this work effort for this initial developmental program phase. Laboratory-type evaluation electrolysis single-cells 3 x 3 inch size were fabricated and operated on performance and life tests to determine the design parameters in unit design. Full-size fuel cell units were assembled and tested, with the final 8-cell stack completing 975 hours of testing at the design current density 10 ASF and 180F cell temperature. An electrolysis stack configuration was designed and several single and 3-cell stacks were performance tested to develop the design concept. A complete 150 - 200 watt breadboard regenerative fuel cell system was designed and fabricated. The system was performance tested to demonstrate the system energy efficiency approximately 33, which compared favorably with a predicted energy efficiency of 38. Two daily mission cycles 12 minutes and 16.5 minutes fuel cell discharge durations were completed in the regenerative system prior to an electrolysis unit failure. This testing demonstrated the technical feasibility of an integrated regenerative system approach. Additional hardware development is required to demonstrate system reliability and successful completion of a 45 day eclipse season mission test. Author