Sequential topology generation based on stage-wise concept and multi-objective integrated optimization of supercritical CO2 cycle

Supercritical carbon dioxide (sCO2) cycles have emerged in recent years as a highly promising technology for heat recovery power generation. Rational arrangement of the structural layout of the power generation system is key to improving overall efficiency. To address the search limitations in cycle layout design caused by empirical assumptions, this study proposes a sequential cycle topology generation mechanism based on the theoretical framework of decomposing the series-parallel relationships among cycle components, thereby effectively expanding the search space of the topology model. By facilitating data interaction between the cycle topology generation model and the heat exchanger network (HEN) superstructure model, the proposed method enables simultaneous multi-objective optimization of both structural layout and operating parameters for the sCO2 cycle heat recovery system considering multiple pinch temperature differences. The proposed method has been validated, optimized, and comparatively analyzed using case studies from the literature. A multi-objective Pareto frontier was obtained, yielding thermal efficiencies ranging from 23 % to 39 %. The proposed method achieves a maximum net power output of 40.08 kW, representing improvements of 36.9 % and 41.3 % compared over the baseline cases of 28.32 kW and 29.24 kW, respectively. The results indicate that the optimization framework provides important insights for topology generation in thermodynamic cycles and the integration of heat recovery systems.