Development and analysis of geothermal energy-based low-grade heat utilization in an integrated form for multigeneration with hydrogen

Abstract

Multigeneration systems offer more effective solutions compared to other conventional energy production sys-tems. Also, geothermal energy plays a crucial role in changing fossil-based energy infrastructure to a renewable source. In this piece of scientific work, a novel geothermal energy-based multigeneration plant for generating power, fresh water, liquid hydrogen, heat, cooling and hot water is designed and investigated for possible implementation. In the design of the present system, a Kalina cycle is integrated into multigeneration plant, along with liquid hydrogen production subsystem, freshwater production subsystem, thermoelectric generator, domestic water heater, and organic Rankine cycle with a vapor compression refrigeration subsystem. According to the thermodynamic analyses performed here, energetic and exergetic efficiencies of the present multi-generation system are obtained as 46.87% and 44.13%, respectively. The total exergy destruction rate of the presently developed plant is 20,947 kW, in which the highest exergy destruction rate is observed for the Kalina cycle with about 5800 kW. Furthermore, the highest exergy efficiency occurs in the liquid hydrogen production plant as 54.17%. Moreover, eight key parameters affecting the multigeneration plant efficiency are investigated for evaluation.