Thermodynamic and thermoeconomic analyses of an organic Rankine cycle adapted gas turbine cycle using S-CO2

In this study, a model of an organic Rankine cycle (ORC) adapted gas turbine cycle using supercritical CO2 (S-CO2) as working fluid is performed. Thermodynamic analyses of system are carried out using Aspen Plus and EES programs. As a result of the thermodynamic analyses, electricity production capacity, energy and exergy efficiencies of proposed system are evaluated as 1530.88 kW, 23.30 % and 59.60 %, respectively. For the thermoeconomic analysis of the system, specific exergy costing method, SPECO, is applied as widely used one among the second law based methods. Unit exergetic cost of electricity production for 1 kWh is found to be 7.28 cent and the total cost of electricity production for 1530.88 kWh is found to be 114.43 $. The annual return from the system of the ORC adapted gas turbine cycle using S-CO(2)which has total investment cost of 3,033,300 $ is evaluated as 741,146 $ taking into account the difference between the cost of electricity production and sale price of electricity. As a result of the thermoeconomic analysis, the payback period of system is found to be 4.09 years.