Performance Evaluation of a Hybrid Power Generation System Integrating SOFC, Gas Turbine, and Supercritical CO₂ Cycle

To improve the efficiency of waste heat recovery and overall energy generation in solid oxide fuel cells (SOFC), we have developed a novel combined power generation system that integrates SOFC with a gas turbine (GT) and a dual expansion recompression supercritical carbon dioxide ($\mathbf{S C O}_{2}$) cycle. By creating a comprehensive model that incorporates both thermodynamic and economic performance and employing multiobjective optimization techniques, we successfully identified the configuration of design parameters, resulting in a system net power output of up to $5,151.1 \mathrm{~kW}$ while also achieving substantial economic benefits, with a unit exergy cost of merely 40.84 ${\$}$/GJ. This system offers a dual advantage: improved performance alongside effective cost management. The assessment showed that the integrated power generation system achieved a power generation efficiency of 59.46% and an exergy efficiency of 57.21%, reflecting effective energy conversion and quality retention. Further optimization improved exergy efficiency by 2.62% at the ideal design point and reduced unit costs by 1.07 ${\$}$/GJ, achieving both technical and economic enhancements.