Thermodynamic analysis of geothermal energy based integrated systems for multigeneration

In this study, an integrated geothermal energy system is designed for electricity, drying, greenhouse heating, heating, cooling, clean water, hot water, and hydrogen production. In the design, Kalina cycle, Rankine cycle, drying plant, clean water production plant, greenhouse heating system, and hydrogen production plant are integrated. The mass balance equations, energy balance equations, entropy balance equations, and exergy balance equations were specified separately for each component used in the overall system. In the analysis, the energy and exergy efficiencies of the system were found to be 59.53% and 53.17%, respectively. The largest exergy destruction in the system occurred in the hydrogen production facility with 7856 kW. Electricity, drying, greenhouse heating, heating, cooling, clean water, hot water, and hydrogen production in the system are found to be 1951.4 kW, 2209 kW, 6176 kW, 11805 kW, 1709 kW, 12.33 kg/h, 4130 kW, and 0.015 kg/h, respectively. The environmental temperature, geothermal water flow rate, geothermal water temperature, and vapor generator pinch point temperature parameters are analyzed and the effects of the energy efficiency, exergy efficiency, useful outputs, and exergy destruction on the integrated system are investigated. It is observed that the increase in the ambient temperature, geothermal water flow rate, and geothermal water temperature have a positive effect on the system performance, while the increase in the vapor generator pinch point temperature has inverse effect.