THERMODYNAMIC AND ECONOMIC ANALYSIS OF GEOTHERMAL ENERGY POWERED KALINA CYCLE

In this study, thermodynamic and economic analysis have been carried out to the determination of optimum design parameters of Kalina Cycle. The optimization of four key parameters (turbine inlet pressure, geothermal water outlet temperature at evaporator, condenser pressure and ammonia mass fraction) is also conducted. The thermodynamic properties of the medium temperature geothermal resource in the Simav region are used in the system designs. The energy efficiency and exergy efficiency of the system are evaluated through the thermodynamic analysis. Also, the system has been investigated economically with the net present value method. As a result of the exergy analysis, it is determined that the maximum exergy destruction occurs in the evaporator within the total exergy destruction of the system. In the system design with 90 % ammonia mass fraction, the exergy destruction in the evaporator constitutes 66.5 % of the total exergy destruction in the system. The geothermal water outlet temperature at evaporator, ammonia mass fraction, turbine inlet pressure and condenser pressure of the most effective geothermal energy powered Kalina Cycle are determined as 353.15 K, 90 %, 4808 kPa and 700 kPa, respectively. The energy efficiency and exergy efficiency of this system are calculated as 13.04 % and 51.81 %, respectively. Also, the net present value of this system is calculated as 119.377 Million US$ and it is seen that it is suitable for investment in economic terms.