Modeling of power cycles suitable for geothermal water temperatures in Afyon province, thermodynamics and thermoeconomics analysis

In this study, a Kalina cycle was designed based on the temperature data of the AFJET ORC (Organic Rankine Cycle) Geothermal Power Plant, which is actively generating electricity in the province of Afyonkarahisar, and the thermodynamic and thermoeconomic performance of the cycle was thoroughly analyzed. The main objective of the study is to evaluate the feasibility and efficiency of the Kalina cycle system by utilizing medium-temperature geothermal resources. Accordingly, the geothermal source temperature was assumed to be 110 °C, and the source mass flow rate was taken as 150 kg/s. Considering the thermophysical properties of the working fluid, an ammonia-water mixture, the system parameters were modeled using computer software, and the analyses were carried out with Engineering Equation Solver (EES). Parametric optimization was performed in the study. As a result of the analyses, the energy efficiency of the Kalina cycle was calculated as 11,7%, and the exergy efficiency was found to be 57,5%. Additionally, the net electricity production of the cycle was determined to be 3,70 MW, and the unit electricity generation cost was calculated as 0,0120$/kWh.