Experimental analysis of patterned floating absorbers integrated thermal storage facilitating interfacial evaporation

Abstract

Conventional solar-driven desalination methods yield low water productivity as a portion of the available energy is wasted for bulk heating. Furthermore, like any solar device, desalination is restricted by the availability (i.e., during night-time) and intermittent nature of solar flux. As a remedy, in this work, (a) interfacial evaporation, which is one of the best emerging energy-efficient technology that can help rectify the drawback of the conventional methods, and (b) the inclusion of thermal energy storage materials, which can supplement the energy needed for evaporation during the off-sunshine hours are selected for further investigations. The cumulative impact of the Solar Interfacial Evaporation (SIE) system incorporated with Phase Change Material (PCM) and different patterned floating absorbers is presented. As an extension, the system is introduced with Thermoelectric Generator (TEG) modules for cogeneration (i.e., desalination and open circuit voltage (OCV)). Primarily, under a controlled environment, this system is subjected to three different solar flux conditions, and the resulting water production is determined. Under 2-Sun conditions, the SIE-PCM approach yielded a higher evaporation rate of 2.3 kg/m2-h, 59 % higher than the SIE system without PCM. Also, under off-sunshine conditions, the SIE-PCM system yielded the highest evaporation rate of 0.5 kg/m2-h. Energy and exergy analysis indicated that the 36 square patterned absorbers yielded higher efficiencies than other tested configurations. The findings revealed that the cogeneration strategy yielded a low OCV showing its lack of potential in the proposed system.