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

Abstract

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.