Energy and exergy analysis of a novel geothermal energy based system for power, desalination water and hydrogen production

The usage of multi-generation systems is quickly developing in the last decade. The current study develops a new geothermal based integrated system, double flash, organic Rankine cycle (ORC), proton membrane electrolyzer (PEM), reverse osmosis (RO) unit and domestic heat water. The configuration is designed to produce four outputs namely, power, heating, desalination water and hydrogen. The proposed multi generation system is evaluated from thermodynamic and exergy point of view. A comprehensive parametric study is done as well and then, the multi generation system is optimized for three viewpoints (net output power, thermal efficiency and exergy efficiency). The results show that the net output power, thermal and exergy efficiencies have optimum values in regard to two separator pressures. Also, optimization results from net output power viewpoint show that, the power generation, desalination water, thermal efficiency, exergy efficiency, hydrogen production and heating were obtained as 5091 kW, 41.75 kg/s, 15/58%, 43.44%, 2.83 kg/hr and 350.6 kW, respectively.