Direct methanol fuel cell system reliability analysis

Abstract The article presents details of a reliability analysis for a Direct Methanol Fuel Cell system, focussing on both quantitative and qualitative methods. The system was analysed on an overall basis. The qualitative analyses presented include fault tree analyses, where four main causes of total system failure were outlined with their initiating failure modes. These included the Failure Mode, Event and Criticality analysis (FMECA) which focused on failures, causes, severity, frequency and the reaction or response to each issue. The results which included raw data for all combinations of failure were analysed in different ways and compared to the published study. It was found that for the system studied in this project, the most reliable configuration had a reliability figure of 0.98243 while the least reliable was 0.78358 compared to the published study which had a value of 0.9041. The main difference was that this study included redundancies (parallel pumps) and considered additional equipment (boost controller) compared to that of the published data. When altering the given system to match that of the published paper, the percentage error in reliability (2.1%) was very low, indicating that the differences were from configuration and analysis rather than the failure rate values.