Exergic Analysis of an ISCC System for Power Generation and Refrigeration

Abstract

Exergic analysis has become an effective method of thermodynamic behavior evaluation for power systems. The current study focuses on an integrated solar–gas combined cycle (ISCC) system for electric power generation and refrigeration. Exergic analysis of the ISCC system is conducted by using the gray-box model as well as the Ebsilon software. The results show that under the rated working condition, the total exergy loss and overall exergy efficiency of the ISCC system are 119.078 MW and 44.63 %. The two largest exergy losses exist in the combustion chamber and solar DSG system, which are 56.45 MW and 28.52 MW, respectively. The LiBr–H2O absorption chiller system, HRSG, steam turbine and condenser have the same grade exergy losses. When the solar intensity augments, though the solar DSG system has an increase in the exergy efficiency, its exergy loss also increases, leading to the increase in the total exergy loss as well as the decrease in the overall exergy efficiency of the ISCC system. Therefore, further optimizations of the ISCC system should focus on the improvements of the solar DSG system and combustion chamber. The economic and ecological evaluations demonstrate that the ISCC system is economically feasible and ecologically friendly.