Effect of printed circuit heat exchanger's different designs on the performance of supercritical carbon dioxide Brayton cycle

Several fin configurations have been proposed in the literature to address the poor hydraulic performance associated with the PCHEs. However, the effect of the heat exchangers with proposed channel geometries on the performance of supercritical carbon dioxide(sCO₂) power cycle is missing. In this context, the current study deals with the effects of different designs of the PCHEs varied by proposed channel configurations, heat exchanger's effectiveness and design value of inlet Reynolds number on the performance of sCO₂ power cycle. Moreover, a multi-object optimization study to find the best bargain between cycle's efficiency and heat exchanger's size is carried out using five different fin configurations (straight, zigzag, C-shaped, S-shaped, and airfoil fin channel configuration), heat exchanger's effectiveness and inlet Reynolds number as a design variable. Results shows that enhancement in the hydraulic characteristics for a channel geometry that comes at the cost of thermal performance may not benefit the system's efficiency. Optimization results suggest that C-shaped channel and zigzag channel geometries correspond to the cycle's maximum efficiency and heat exchanger's minimum size respectively. Optimization results further highlight that the comparison of channel geometries should be performed while in the setting of complete power generation cycle to account for all the variables involved.