An integrated energy storage system consisting of Compressed Carbon dioxide energy storage and Organic Rankine Cycle: Exergoeconomic evaluation and multi-objective optimization

In this paper, an integrated energy storage system consisting of Compressed Carbon dioxide Energy Storage (CCES) and Organic Rankine Cycle (ORC) was proposed. Four criteria (system exergy efficiency, total cost rate of exergy destruction, total product unit cost, and total exergoeconomic factor) were defined to evaluate the system performance from exergy and exergoeconomic points of view. The influence of key parameters on system performance was analyzed, and multi-objective optimization of the system was conducted. The results showed that for the base case, the net power output, system exergy efficiency, and total product unit cost were 27.736 MW, 66.64%, and 20.34 $/GJ, respectively. Recuperator had the largest exergy destruction (39.17% of the total exergy destruction) and a higher value of investment cost rate, signifying its necessity of optimization. Sensitivity analysis demonstrated the monotonic effects of compressor inlet temperature, turbine inlet temperature, and minimum temperature difference in heat exchangers on system performance, but for pressure ratio or pump2 outlet pressure, there was an optimal value for the system performance within the range of values studied. Finally, multi-objective optimization recommended a 72.6% for system exergy efficiency, 452.35 $/h for total cost rate of exergy destruction, and 18.49 $/GJ for total product unit cost. (c) 2022 Elsevier Ltd. All rights reserved.