Experimental investigation of humidification-dehumidification desalination system based on double-ends open evacuated tube solar air heater with inbuilt heat storage unit

Abstract

The scarcity of freshwater has become an increasingly serious concern for society. The adoption of small-scale and decentralized desalination techniques presents a viable solution to the issue of water scarcity by overcoming the challenges inherent in large-scale desalination techniques. The solar-based humidification-dehumidification (SBH-DH) process is considered to be a very appropriate approach for small-scale desalination. However, the available SBH-DH system was only operational during sunshine hours. The current study involves the experimental investigation of a novel SBH-DH system that incorporates a solar air heater (4.687 m2) based on phase change material (PCM), a humidifier having cellulose as packing material, and a dehumidifier. The performance of the SBH-DH system with and without phase change material is compared using a parametric study. The use of PCM increases the operating time by 3 h. But the yield of the system with PCM does not change significantly in comparison to the system without PCM. Moreover, the cost of the obtained yield increased by 41.4 %. Additionally, the thermal energy and exergy efficiencies of the system with PCM are estimated at three distinct flow rates. The results reveal that a higher air flow rate leads to greater mean energy efficiency (36.2 %) and exergy efficiency (4.40 %).