Comparative study on the thermodynamic and economic performance of novel absorption power cycles driven by the waste heat from a supercritical CO2 cycle

Abstract

In this study, the investigation on the performance improvement of the recompression supercritical carbon dioxide (sCO2) power cycle by integrating with two novel absorption power cycles (APC) are carried out. Comparative study, parametric analysis, single-objective and multi-objective optimizations on the thermodynamic and economic performance are conducted quantitatively for two proposed sCO2/APC systems and an original sCO2/APC system. Comparative study results indicate that the proposed APC3 subsystem can generate the highest mass flow rate of working fluid with the highest reheated temperature across the turbine, contributing to the highest net power output. Besides, the working fluid produced by the proposed APC2 subsystem is nearly the same as that of the original APC1 subsystem, but the net power output of APC2 subsystem is still slightly higher than that of APC1 subsystem due to the reheated working fluid with more potential to generate power of APC2 subsystem. In addition, the optimization results reveal that all APC subsystems studied here are able to improve the stand-alone sCO2 system performance in thermodynamics and economics, and two proposed sCO2/APC systems can further improve the overall performance of the original sCO2/APC system. In detail, the improvement of 0.31% and 2.35% for the exergy efficiency and 0.21% and 2.43% for the total product unit cost can be achieved by the sCO2/APC2 system and sCO2/APC3 system, respectively, compared with the sCO2/APC1 system.