Performance assessment of sustainable evacuated tube heat pipe solar collector driven seawater desalination system

Abstract

This study proposes a solar-powered humidification and dehumidification freshwater extraction system, analyzing its efficiency through heat transfer modeling. Despite extensive research on thermal desalination using various renewable energy sources, limited attention has been given to solar energy applications, particularly for humidification-dehumidification-based freshwater extraction and seawater recovery. The proposed system aims to be both economical and energy-efficient, leveraging low-grade solar energy for heating and utilizing natural water bodies as thermal reservoirs. The humidifier and condenser components were validated individually using data from existing literature, yielding an estimated maximum error of ±12 %. A parametric analysis highlights the impact of the exit temperature from an evacuated tube heat pipe solar collector on the system's performance, showing membrane energy exchange, water condenser energy exchange, and freshwater condensation rate of 0.91 kW/m², 0.21 kW/m², and 0.154 L/h-m², respectively, within the specified conditions and operating range. Performance analysis indicates that using cooling water from seawater, alongside enhanced effectiveness of condenser and optimized fluid flow rate ratio, improves the system's performance. The exit temperature from the solar collector emerges as a primary influence on the overall performance, and the correlation matrix of performance parameters is identified as a significant factor in system effectiveness. This research offers insights into solar-driven seawater recovery across various regions, acting as a reference for identifying solar energy hotspots.