In this study, the novel trigeneration systems based on the atmospheric and pressurized SOFC are proposed and investigated. The proposed systems include the SOFC based top cycles and an innovative bottom cycle which combines a transcritical CO₂ cycle, a transcritical organic Rankine cycle, and a LNG cold energy utilization system. The mathematical model is developed, and the energetic, exergetic and economic analysis is conducted accordingly. Then, the effects of key parameters, such as current density, operating temperature, steam-to-carbon ratio (STCR) on system performance are evaluated. Under design conditions, the results show that the electrical efficiencies, the overall system efficiencies, the exergy efficiencies, and the total cost rate of the integrated systems can reach 57.14%, 59.56%, 55.12%, 16.73 $/h for the atmospheric system and 68.1%, 68.8%, 65.7%, 19.84 $/h for the pressurized system, respectively. Parameter study shows that the thermodynamic performance of pressurized system is significantly better than that of the atmospheric system, but economic cost is much higher. SOFC inlet temperature has a positive effect on the pressurized system performance, while this positive effect is found when the inlet temperature is less than 510 °C for atmospheric system. Besides, the multi-objective optimization by using genetic algorithm (NSGA-II) for the novel trigeneration systems has been performed. And the technique for order preference by similarity to an ideal solution (TOPSIS) based on entropy weight is performed to choose the final optimum design point of the combined systems. The multi-objective optimization results demonstrate that the exergy efficiency and the total cost rate achieve the values of 56.1%, 16.82 $/h and 66.83%, 12.02 $/h for atmospheric and pressurized system, respectively, at the optimal balance point selected by the TOPSIS method.

在这项研究中，提出并研究了基于大气和加压SOFC的新型三代发电系统。拟议的系统包括基于SOFC的顶部循环和创新的底部循环，该底部循环结合了跨临界CO ₂循环，跨临界有机朗肯循环和LNG冷能利用系统。建立了数学模型，并进行了能量，能量和经济分析。然后，关键参数的影响，例如电流密度，工作温度，蒸汽碳比（STCR））对系统性能进行评估。在设计条件下，结果表明集成系统的电气效率，整体系统效率，火用效率和总成本率可以达到57.14％，59.56％，55.12％，16.73美元/小时。加压系统分别为68.1％，68.8％，65.7％，19.84 $ / h。参数研究表明，加压系统的热力学性能明显优于大气系统，但经济成本要高得多。SOFC入口温度对加压系统的性能有积极影响，而对于大气系统，当入口温度低于510°C时，就会发现这种积极影响。除了，利用遗传算法（NSGA-II）对新型三代发电系统进行了多目标优化。然后执行基于熵权的类似于理想解决方案（TOPSIS）的顺序偏好技术，以选择组合系统的最终最佳设计点。多目标优化结果表明，在选择的最佳平衡点上，大气压和加压系统的火用效率和总成本率分别达到56.1％，16.82美元/小时和66.83％/ 12.02美元/小时。 TOPSIS方法。