Search

• The performance of modified hemispheric solar still was investigated. • Multi additives were applied: V-corrugated basin, black cotton wick, paraffin wax PCM, and sheep fat PCM. • The freshwater productivity was maximumly augmented by 39.6 %. • The thermal performance improvement reached 39.75 % (energy) and 44.04 % (exergy). • The freshwater price was reduced by 17.5 % using all additives. Solar still is a developing solar desalination method that has been introduced to face the shortage of freshwater with low energy consumption. However, this method is challenged by its low productivity. Therefore, the following work aimed to improve the freshwater productivity and reduce the produced water price. Herein, the performance of a hemispheric solar still equipped with four alternative combinations was experimentally studied; and its thermo-economic performance was assessed. The experimental work had four stages, firstly the distiller's flat basin was replaced by a V-corrugated basin. Secondly, the corrugated basin was covered with a black cotton wick material. Thirdly, paraffin wax, as a phase change material (PCM), was contained under the wick-coated corrugated basin for latent thermal storage purpose. Finally, paraffin was replaced with sheep fat PCM. Each modified distiller was compared to a conventional one from 8 A.M. until 9 P.M. under the climate conditions of Suez City, Egypt lies at (29. 5825 °N, 32.5734°E) in terms of the thermal performance, daily productivity, and freshwater price. The four cases showed increasing in the daily productivity by ratios of 11 %, 25.7 %, 34.1 %, and 39.6 % respectively. The fourth case showed the best water productivity and thermal performance. It had daily productivity of 4737.5 mL/m2 and 45 % thermal efficiency. Furthermore, the thermal performance in terms of the thermal and exergy efficiencies improved by 39.75 % and 44.04 %, whereas the average total heat transfer coefficient increased by 5.5 %. Moreover, the freshwater price was 0.0137 $/L, likewise, 17.5 % cost reduction. [ABSTRACT FROM AUTHOR]

In this study, a paraffin/aluminum foam (AF) composite for thermal regulation of a photovoltaic (PV) system was performed. A comparative performance evaluation of three PV systems, i.e., PV without any modifications, PV incorporated with paraffin wax as phase change material PCM (PV-PCM), and PV incorporated with enhanced PCM comprising AF embedded in PCM (PV-PCM/AF) was performed. Outdoor experiments were conducted in summer and winter weather conditions of Benha city, Egypt, located at (latitude 30.466° North and longitude 31.185° East). The comparative analysis of the three PV configurations based on electrical efficiency, exergy efficiency, energy payback time, exergoeconomic, and enviroeconomic parameters was presented and discussed. The findings revealed that, against the unmodified PV configuration, the electrical efficiency of PV-PCM and PV-PCM/AF systems in summer was enhanced by 9% and 14%, respectively. While, the corresponding enhancement in winter was 3.7% and 4.8%, respectively. Also, it was found that the cost of electricity generation for PV-PCM and PV-PCM/AF systems was 0.1165 and 0.1145 $/kWh, respectively, against 0.1162 $/kWh for the PV system. Finally, it can be concluded that PV-PCM/AF is the most effective system based on exergy efficiency, exergy cost, and CO 2 avoidance rates. • A comparative 4 E performance analysis of PV, PV-PCM, and PV-PCM/AF was performed. • Using AF with PCM shortened the melting time by 37%. • Using AF with PCM enhanced the average electrical efficiency by 14%. • PV-PCM/AF is the most effective system based on exergoeconomic parameter and CO 2 mitigations. [ABSTRACT FROM AUTHOR]