Thermal analysis of a main compression intercooling supercritical CO2 cycle cascaded with flash tank enhanced compression-absorption refrigeration cycle

This study develops a unique electric power generation and refrigeration system that integrating two cascade compression-absorption refrigeration (CCAR) sub-systems as heat recovery systems for the recompression with main compression intercooling supercritical CO2 Brayton (RMCIB) cycle. Two heat recovery systems utilize heat waste from the topping power cycle's pre-cooler and inter-cooler to create cooling load, enhancing overall system performance. In order to investigate the integrated system's thermal performance, comprehensive parametric analyses are conducted in Python programming language under various boundary scenarios; such as temperature at turbine's entrance, temperature at compressor's entrance, minimum pressure, intermediate pressure, pressure ratio, evaporator temperature and pinch temperature at generators' hot and cold ends. The results indicate that turbine inlet temperature (TIT) significantly increases thermal efficiency, while compressor inlet temperature (CIT) adversely affects system performance. Besides, exergy destruction occurring throughout the components of the proposed system is analyzed. Thermodynamic optimization reveals thermal and exergy efficiencies of 54.23 % and 65.34 %, with the RMCIB subsystem's energy efficiency improving by 15.38 % and 2nd law efficiency by 3.35 % through CCAR integration. Under optimal conditions, the system produces 64 MW net work and 12 MW cooling load from 100 MW of input heat. Most exergy destruction occurs in the RMCIB subsystem, with heaters and recuperators contributing 10 % and 11.5 % of losses, respectively.