Solid oxide fuel cell (SOFC) stacks face reliability challenges because multiple degradation mechanisms interact with operational and environmental variability. We develop a hierarchical Bayesian framework that couples a monotone area-specific resistance (ASR) growth law with a Weibull time-to-failure model and employs a Student-t observation layer to down-weight outliers. Using multi-cell data, the approach narrows to 95 % predictive-interval widths for ASR and lifetime by up to 33 % relative to a non-hierarchical baseline, and global sensitivity analysis identifies the ASR growth rate as the dominant driver (S1 ≈ 0.84). Scenario projections quantify operational effects: hot–humid climates raise failure probability to ≈56 % versus ≈46 % under cold–dry conditions, whereas moderate load variations are negligible within normal ranges. External validation on a ∼93 000 h record shows low root-mean-square and means absolute errors with near-nominal predictive-interval coverage. Collectively, these results establish a diagnostic-to-decision workflow for reliability modeling that improves confidence in lifetime predictions and supports data-informed operation and maintenance.

This study evaluates the thermodynamic performance of the following two CO₂ liquefaction processes for onboard carbon capture and storage (OCCS) on a 174,000 m³ LNG carrier: the Linde–Hampson and vapor compression refrigeration cycles. The cycles were designed based on realistic vessel operating conditions and compared using the specific energy consumption (SEC) as the primary performance indicator, alongside the coefficient of performance (COP). To enable a fair comparison of the two distinct cycles, a complementary COP metric was validated for the open-loop Linde–Hampson cycle by establishing a system-level definition of heat removal. The validity of this metric was confirmed by demonstrating that its optimal point (maximum COP) aligns with that of the primary metric (minimum SEC), ensuring thermodynamic consistency. The analysis reveals that the vapor compression cycle demonstrates superior performance, achieving an 8.35% higher COP and an 11.45% lower SEC than the Linde–Hampson cycle. This work provides a consistent methodology for the comparative assessment of open- and closed-loop liquefaction systems.

As environmental concerns increase globally, the International Maritime Organization has been strengthening regulations to limit pollution from ships, attracting increasing interest in ammonia as a zero-carbon marine fuel. This study aimed to establish safe bunkering procedures for ammonia-fueled ships through thermodynamic analysis. The research analyzed two bunkering scenarios, ship-to-ship and truck-to-ship, calculating the boil-off rate and return boil-off gas for each scenario. A thermal analysis showed that the ship-to-ship scenario generated 271.9 kg/h of return boil-off gas with a total heat ingress of 92.84 kW. The truck-to-ship scenario produced 243.95 kg/h of return boil-off gas with a total heat ingress of 84.4 kW. Based on these findings, comprehensive bunkering procedures were developed for both scenarios, consisting of 14 steps for ship-to-ship and 13 for truck-to-ship, addressing the unique challenges of ammonia handling. These procedures include evaporated gas recovery systems, ammonia catch systems, and nitrogen purging to minimize leakage and explosion risks. The results of this study contribute to the development of safety regulations for ammonia-fueled ships by establishing systematic operational procedures that consider the toxicity and corrosiveness of ammonia.