Thermodynamic and economical analysis of geothermal energy powered organic rankine cycle and kalina cycle

In this study, thermodynamic and economic analyses of the Organic Rankine Cycle (ORC) and the Kalina cycle caused by geothermal energy were made to determine the optimal operating conditions. In the Organic Rankine Cycle which is sourced from geothermal energy, Turbine inlet temperature, turbine inlet pressure, geothermal source inlet temperature parameters and 21 different concentration pairs of isobutane-isopentane and R245faisopentane fluids are variable parameters of organic rankine conversion system from geothermal energy source. On the other hand, turbine inlet pressure, turbine inlet temperature, turbine outlet pressure, geothermal fluid inlet temperature and 7 different concentration pairs of ammonia-water fluids are variable parameters of the kalina cycle system. Thermodynamic values of fluids were obtained using REFPROP 8.0 program. The designs for the geothermal energy sourced ORC and Kalina cycle were evaluated using energy and exergy analysis methods. According of this, energy and Exergy yields were calculated for each design of the ORC and Kalina cycles caused by geothermal energy. In the next part of the study, cost analysis was performed for each design. The useful life of the system has been determined as 20 years and the economics of the geothermal energy sourced ORC and Kalina cycle are investigated using the net present value (NPV) method.