Enhanced Multi-Generation Geothermal System for Sustainable Energy, HHO, and Freshwater Production
DOI:
https://doi.org/10.66279/s2a24j87Keywords:
Geothermal Energy, HHO, Alkaline electrolyzer, ANSYS Fluent, DesalinationAbstract
The growing demand for sustainable energy, clean water, and green fuels has increased interest in integrated renewable-energy systems, which can produce multiple valuable outputs from a single energy source. In this paper, a laboratory-scale geothermal-based multi-generation system was designed, developed, and experimentally investigated for the production of electricity, HHO gas, and desalinated freshwater. The proposed system is composed of a geothermal steam generator, a steam turbine coupled with a DC generator, an alkaline water electrolyzer, and a waste-heat-assisted solar still combined by a thermal cascading configuration. The steam turbine for electricity generation was driven by the superheated steam generated from the geothermal heat source. In order to improve the performance of the solar desalination unit, the electricity generated was then used to produce HHO using an alkaline electrolyzer, and the low-pressure turbine exhaust steam was recovered in a submerged heat exchanger. In addition, a three-dimensional Computational Fluid Dynamics (CFD) simulation was performed using ANSYS Fluent to study the fluid flow and heat transfer behavior and to validate the experimental results. The experimental results showed the stable operation of the integrated system with an average electrical power output of about 31 W, which is enough to run the electrolyzer continuously. The maximum efficiency in the four-cell alkaline electrolyzer was about 79%, and the time of HHO production was decreased compared to the two-cell. The recovered turbine exhaust heat improved desalination performance significantly with increased freshwater productivity to 8.6 L day-1. Water quality analysis indicated a significant reduction of total dissolved solids (TDS) to about 76 ppm, indicating the production of high-quality fresh water. The maximum deviation between numerical and experimental results was approximately 6%. The results demonstrate the technical feasibility of integrating geothermal power generation, HHO production, and desalination on a single platform.
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