Design and performance analysis of a geothermal modular desalination system for sustainable water production

Seawater desalination has emerged as a critical solution to address global water scarcity; however, its widespread adoption faces challenges related to high energy consumption and environmental impacts. This study presents the design, thermodynamic analysis, and performance evaluation of a Geothermal Modular Desalination (GMD) system that utilises low-enthalpy geothermal energy as a sustainable heat source. The proposed system operates through a multi-effect distillation (MED) process optimised for energy efficiency and modular scalability. A comprehensive thermodynamic model was developed to evaluate mass and energy balances, heat transfer coefficients, and operational efficiency under varying conditions. Experimental and computational simulations were employed to assess the performance of heat exchangers, vacuum systems, and brine concentrators. Key parameters, including global heat transfer coefficients (GHTC) ranging from 1793 to 2616 W/m2K, were analysed to demonstrate thermal performance. Results indicate that the GMD system achieves an energy consumption of 1.5-1.8 kWh/m3 , significantly lower than conventional technologies such as Multi-Stage Flash (MSF) and traditional MED systems, which typically consume 80-120 kWh/m3 and 1.5-2.5 kWh/m3 , respectively. The modular design of the GMD allows scalability, simplified maintenance, and adaptability to diverse geographic and operational conditions. Furthermore, its integration with geothermal energy reduces greenhouse gas emissions and operational costs, positioning it as an economically and environmentally sustainable alternative for water production. This research highlights the GMD system's potential to enhance water security in arid regions while promoting renewable energy integration in desalination technologies.