A Novel Recompression S-CO2 Brayton Cycle with Pre-Cooler Exergy Utilization

This study examines the performance of a novel recompression supercritical CO 2 (S-CO 2 ) Brayton cycle of nuclear power plant with pre-cooler exergy utilization, which uses a transcritical CO 2 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-CO 2 and the presented new S-CO 2 recompression cycles were studied. Finally, the recompression S-CO 2 cycles were thermodynamically optimized using the Engineering Equation Solver software. Based on identical operating conditions, a comparison between the new S-CO 2 and a simple S-CO 2 cycle was also performed. It was found that both the first- and second-law efficiencies of the new S-CO 2 cycle are about 5.5 per cent to 26 per cent higher than that of the simple S-CO 2 cycle. The exergy destruction of the new S-CO 2 cycle is also about 6.7 per cent to 28.8 per cent lower than that of the simple S-CO 2 cycle.