Thermodynamic Performance Study on the Recompression Supercritical CO₂-Based Binary Mixture Brayton Cycle with Turbine Reheating

This study devotes to the augmentation of power generation performance within the recompression supercritical CO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>-based binary mixture Brayton cycle incorporating turbine reheating. The CO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>-C<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf>H<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">8</inf> and CO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>-Kr binary mixtures are employed as the working fluids, and the effects of varying fluid composition ratios and turbine reheating effectiveness are investigated on the power cycle efficiency and specific net work under normal and extreme operational conditions. The findings reveal that both the thermal efficiency and the specific net work can be markedly enhanced by optimizing the weight ratio of the binary mixtures and enhancing turbine reheating effectiveness. The CO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>-Kr cycle exhibits a more pronounced advantage in thermal efficiency, whereas the CO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>-C<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf>H<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">8</inf> cycle displays superior specific net work performance. This research presents innovative strategies to enhance thermoelectric conversion efficiency within sCO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> Brayton cycles and provides valuable insights for selecting appropriate binary mixture working fluids tailored to different operational scenarios.