Multiparameter optimization and configuration comparison of supercritical CO2 Brayton cycles based on efficiency and cost tradeoff

Supercritical CO2 Brayton cycle has high efficiency, compactness, and excellent power generation potential. In the design of the cycle, some parameters, such as recuperator pinch point temperature difference (ΔTrec,pp), turbine inlet temperature (Ttur,in), and maximum cycle pressure (pmax), are often preset without optimization. Furthermore, different preferences on efficiency and cost tradeoff can significantly affect the optimal design of the cycle, and the influence of different parameters on the design condition and the optimum cycle configuration becomes unclear as the preference changes. In this study, different preferences on efficiency and cost tradeoff are considered, and the effects of cycle configuration and optimization parameter addition on the tradeoff are investigated. In addition, four configurations under different preferences on tradeoff are recommended. Results show that the design condition parameters ΔTrec,pp decrease and Ttur,in and pmax increase as the preference of thermal efficiency (Wth) increases. Different optimized parameters affect the results of the design point and cycle performance. In addition, the simple recuperative cycle and reheating cycle are recommended when low cycle initial cost dominates (Wth 0.701). The decision maker can select appropriate configuration according to specific preferences.