Concentrated solar power (CSP) is one of the most promising power technologies. The power cycle block accounts for about one-third of the capital expenditure in the CSP system and has a direct and significant impact on the conversion efficiency of the CSP system. It is necessary to employ a highly efficient and compact power cycle in the CSP system to improve system efficiency and reduce system costs. The supercritical CO₂ Brayton cycle (SCO₂-BC) system has more compact equipment, higher cycle efficiency, and a lower cost relative to the conventional steam Rankine cycle, which is a promising energy conversion cycle for the CSP system. A printed circuit heat exchanger (PCHE) is one of the most significant components in the SCO₂-BC system based on concentrated solar power, whose performance significantly affects the efficiency and compactness of the system. To improve the performance of PCHE with semicircular-straight channels, rib structures placed on the top flat wall of the semicircular channel are proposed, which are achieved by the double-sided etched heat transfer plates, and the effects of the distributions of rib structures on the performance of channels are also investigated by simulation. The thermal-hydraulic performance of the conventional semicircular channel and the semicircular channel with different rib structures are compared. The results indicate that rib structures placed on the top flat wall of the semicircular channel lead to an apparent increase in turbulence kinetic energy in channels and improve the synergy between velocity and temperature gradient fields, leading to heat transfer enhancement. Among the channels with different rib structures, the comprehensive performance of the semicircular channel with the spacing distribution of short rib structures (channel DR3) is the best, which is relatively 19.3 – 19.8% higher than that of the conventional semicircular channel. When the channel DR3 is adopted in PCHE, the effectiveness of PCHE could reach 98.4 – 98.7%, the efficiency of the SCO₂ Brayton cycle system based on solar power could be increased by 15.3%, and the compactness of the system could be improved by 3.8%. This present work is of great significance for deepening the understanding of PCHE heat transfer mechanisms and performance optimisation, as well as improving the overall performance and compactness of large-scale SCO₂-based power systems.

This work has received funding from the National Energy Group Major Pilot Project-China (GJNY2030XDXM-19-10) and the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement no. [882628].

The paper (Zengxiao Han, Jiangfeng Guo*, Xiulan Huai, Theoretical analysis of a novel PCHE with enhanced rib structures for high-power supercritical CO₂ Brayton cycle system based on solar energy, Energy 270 (2023) 126928) can be found in: https://doi.org/10.1016/j.energy.2023.126928 (Elsevier) and https://www.researchgate.net/publication/368526367_Theoretical_analysis_of_a_novel_PCHE_with_enhanced_rib_structures_for_high-power_supercritical_CO2_Brayton_cycle_system_based_on_solar_energy (ResearchGate)