Research on the applicability of isothermal compressors to supercritical carbon dioxide recompression cycle for nuclear energy

Isothermal compressors have significant application potential in the supercritical carbon dioxide (sCO₂) cycle. In this study, two recompression cycle models (conventional and modified) integrated into lead-cooled fast reactors and an isothermal compressor model are established. The effect of different inlet conditions on the performance of the isothermal compressor and the applicability of the two layouts to the isothermal compressor are analysed. Results show that the isothermal compressor significantly reduces the compression work but dissipates a large amount of heat under high-temperature and low-pressure inlet conditions. The sCO₂ recompression cycle using an isothermal compressor both increases its specific power and reduces its overall heat exchanger size. The modified layout is more suitable for isothermal compressors than the conventional layout. Exergy analysis reveals that the use of the isothermal compressor augments the irreversibility of the high-temperature recuperator by 8.75% for the traditional layout, while only 0.68% for the modified layout.