【摘要】 为了实现海上船舶对长续航与绿色高效的双重需求目标，提出了一种基于氨燃料固体氧化物料电池(SOFC)的全电力推进系统。利用COMSOL软件对SOFC内部的传热、传质与电化学反应过程进行数值模拟分析，重点研究了变工况下内部流场演变及镍氮化引发的性能衰退机制。结果表明:在去除系统辅机耗功后，推进系统净输出功率达95.86 k W，系统效率为42.11%;当船舶在变工况下运行时，随着燃空比(F/A)从0.046增至0.125，系统功率从31.84 k W升高至110.17 k W，效率从13.99%提升至48.39%，燃料通道入口温度升高，氨气分解吸热引起的温差从46 K减小至14 K，温度分布更均匀，进而提升SOFC整体性能;当F/A从0.087降至0.046时，入口处镍氮化风险区域扩大，肋片两侧局部区域镍氮化势能较高;低氨气流速和低温易引发直氨型SOFC的镍氮化，导致SOFC效率降低0.6%～5.87%。更多还原

【Abstract】 Addressing the dual imperatives of extended endurance and green,high-efficiency operation for future offshore ships,a safe,highly efficient,and compact ammonia-fueled solid oxide fuel cell( SOFC) all-electric propulsion system was proposed. Comprehensive numerical simulations of internal heat and mass transfer as well as electrochemical processes within the SOFC were conducted using COMSOL multiphysics software. Particular emphasis was placed on elucidating the evolution of the internal flow field under variable operating conditions and on quantifying performance degradation induced by nickel nitriding. The results demonstrate that after accounting for auxiliary power consumption of system,the proposed propulsion system delivers a net output power of 95. 86 k W with an overall system efficiency of 42. 11%,fully satisfying the power requirements of the target ship. Under variable operating conditions,as the fuel-to-air ratio( F/A) increases from 0. 046 to 0. 125,system power rises from 31. 84 to110. 17 kW,and efficiency improves from 13. 99% to 48. 39%. Concurrently,the inlet temperature of the fuel channel increases,and the temperature difference caused by endothermic ammonia decomposition decreases from 46 to 14 K,resulting in a more uniform temperature distribution and enhanced SOFC performance. When the F/A ratio decreases from 0. 087 to 0. 046,the risk area for nickel nitriding at the inlet expands,with localized high-potential nitriding regions occurring on both sides of the ribs. Low ammonia flow rates and low temperatures are prone to inducing nickel nitriding in direct ammonia SOFC,leading to SOFC efficiency reductions of 0. 6% to 5. 87%.更多还原