A novel recompression S-CO₂ Brayton cycle with pre-cooler exergy utilization

摘要

This study examines the performance of a novel recompression supercritical CO₂ (S-CO₂) Brayton cycle of nuclear power plant with pre-cooler exergy utilization, which uses a transcritical CO₂ cycle to enhance the performance of this new cycle. More attention was paid to irreversibilities generated in the combined cycle. Individual models were developed for each component through the application of the first and second laws of thermodynamics. The effects of the turbine inlet temperature, compressor pressure ratio, maximum cycle pressure, main compressor inlet temperature, and also environment temperature on the first- and second-law efficiencies and also on the exergy destruction of the S-CO₂ and the presented new S-CO₂ recompression cycles were studied. Finally, the recompression S-CO₂ cycles were thermodynamically optimized using the Engineering Equation Solver software. Based on identical operating conditions, a comparison between the new S-CO₂ and a simple S-CO₂ cycle was also performed. It was found that both the first- and second-law efficiencies of the new S-CO₂ cycle are about 5.5 per cent to 26 per cent higher than that of the simple S-CO₂ cycle. The exergy destruction of the new S-CO₂ cycle is also about 6.7 per cent to 28.8 per cent lower than that of the simple S-CO₂ cycle.