Reliability analysis of a multi-stack solid oxide fuel cell from a systems engineering perspective

Abstract

Listen

Translate article

A reliability analysis methodology for a multi-stack solid oxide fuel cell (SOFC) system is presented based on physical modeling and experimental data. The constructed failure probability function comprises three operation phases: (i) as-fabricated, (ii) start-up, and (iii) constant power generation. In-house experimental data are used to capture the behavior during start-up and normal operation, including drifts of the operating point due to degradation. The physics-based model provides a theoretical structure, but alternatives are discussed as well which are particularly suitable for experimentalists. The failure probability function can be used to calculate the reliability of a multi-stack SOFC system. The effect of operating stacks under over-load conditions in terms of degradation is discussed. It is shown that the customized failure probability function better explains the dependency on operating conditions compared to standard parametric distribution functions. The originality of this work is mainly twofold: first, the construction of the failure probability function of a multi-stack SOFC using experimental data for degradation as well as start-up on a system level; second, the focus on technological implications covered by the methodology. Hence, this systems engineering methodology aims to provide a process for reliability analysis in which the strength of both approaches are utilized, namely keeping sufficient parameter-dependency by means of the physics-based approach together with the simplicity of stochastic methods. This methodology is not limited to SOFC but may also be applicable to other modular (electrochemical) systems. Besides references on SOFC from a theoretical and experimental perspective, the extended bibliography also includes references on reliability analysis and engineering design, which may act as a starting point for related system analyses.