Energy, exergy, exergoenvironmental, and economic assessments of the multigeneration system powered by geothermal energy

Abstract

In this article, a new geothermal powered multigeneration system is proposed and analyzed via energy, exergy, economic, and exergoenvironmental points of view as well as parametric study to see the effects of main parameter variations. This multigeneration system includes a new configuration of the organic Rankine cycle with two evaporators and expanders, heater, NaClO system, and reverse osmosis. The products of this proposed system are electricity, hydrogen, heating, potable water, and salt. Due to theoretical analysis, this system produces 1.264 GWh of electrical energy, 15.93 GWh heating, 1919 Ton salt, 86400 m3 of potable water, and 4.397 × 107 m3 of hydrogen, annually with 60% and 21% of the system energy and exergy efficiencies. The organic Rankine cycle and reverse osmosis systems have the highest and lowest percentage of exergy destruction rates. The economic analysis reveals that the system payback period is 5.3 years. The system's net present value is 668.2 million US$. The exergoenvironmental analysis shows that the exergoenvironmental, environmental damage effectiveness, and the exergy stability factors for the proposed system are 0.86, 4.414, and 0.8, respectively. The parametric study shows that increasing the geo-fluid mass flow rate, increases the system's electrical power production and exergy efficiency while decreases the system exergy efficiency.