EXPERIMENTAL AND NUMERICAL INVESTIGATION ON THE EFFECT OF PCM AND EXTERNAL REFLECTORS ON THE PERFORMANCE OF A CONVENTIONAL SOLAR STILL

Enhancing the stepped solar still performance using internal and external reflectors

This study primarily focuses on comparative experimental analysis on standalone conventional solar still (CSS), inclined solar still (ISS), and integrated conventional and inclined solar still (CSS‐ISS) for different parameters that affect the freshwater yield. For enhancing the freshwater yield only a few studies are available on still‐still integration. The present novel study provides a greater improvement in improving the freshwater yield by integrating ISS with CSS. This experimental work mainly concentrates on the importance of water depth (d w) and mass flow rate of water ( m w) in the solar still. Water depth inside the conventional still varied from 0.02 to 0.06 m whereas, water is constantly flown with a mass flow rate of 8.33 kg/hour in an ISS with baffles. The experimental result shows that the accumulated freshwater yield from CSS‐ISS, ISS, and CSS were 6.2, 5.04, and 4.24 kg, respectively. CSS‐ISS and ISS produced 46.23% and 18.87% higher productivity than the CSS. From the experimental investigation, it is also identified that the water temperature is significantly improved by 20% using integration as compared with CSS without integration under the same water depth of d w = 0.02 m. The overall improvement in yield was higher in the case of CSS‐ISS. The deviations between experimental and theoretical values of yield from the conventional and modified solar still were in the range of ±7%.

Utilizing a single slope solar still with copper heating coil, external condenser, phase change material, along with internal and external reflectors — Experimental study

Solar desalination is one of the mostsustainable solutions to produce freshwater from brackish water. The present research work aims to experimentally investigate the effect of a V-shape concentrator integrated with solar still (SS). The V-shape concentrator integrated with the conventional solar still (CSS) is used to supply the saline water at elevated temperature to the basin of SS, which augments the freshwater yield compared to CSS. The experimental investigation was performed at different brackish water depths of 0.01, 0.02, and 0.03 m, respectively. The SS system was evaluated based on water yield, energy, exergy, concentrator efficiency, and economicanalysis. The freshwater yield of the solar still integratedwith V-shape concentrator (SSVC) was found to be 5.47, 5.10, and 4.89 L/m2.day, whereas the yield of the CSS was 3.73, 3.27, and 2.91 L/m2 .day at thewater depths of 0.01, 0.02, and 0.03 m, respectively. The daily energy and exergy efficiency of CSS were 38.5, 33.5, and 29.4% and 1.9, 1.5, and 0.97 % in the case of 0.01, 0.02, and 0.03m water depth , respectively. However, the integration of concentrator significantly augmented the energy efficiency to 57.4, 51.7, and 44.9% and exergy efficiency to 3.8, 3.3, and 2.8% for the respective water depths . Life cycle studies demonstrated that the freshwatercost per liter for CSS and SSVC were 0.0102 $ and 0.0117 $ respectively, at a water depth of 0.01 m. It was concluded that the addition of V-shape concentrator and minimum water depth is useful to augment the energy efficiency, exergy efficiency, and yield of the SS in the very economical way.

Experimental investigation on the impact of thermal energy storage on the solar still performance coupled with PV module via new integration

The aim of this study is to experimentally investigate the impact of several design parameters on the performance of an active solar still that is typically used to produce desalinated water. Thus, a solar still with 1 × 1 m2 basin area and 1 m height has been designed and constructed to carry out the experiments. This solar still was integrated with a photovoltaic unit to generate electricity to power two circulation pumps (CPs) and one electric heater (EH). These CPs and EH were immersed in the water basin to increase the turbulence intensity and temperature of the water molecules in the still basin and hence increase the water productivity. The impact of varying the water depth, circulating the basin water via CPs, and heating the basin water via EH on the solar still performance has been evaluated in a conventional solar still (CSS), an active solar still (CSS with CPs), and another active solar still (CSS with CPs and EH). The experimental results revealed that the water productivity increases as the water depth decreases: the daily productivity of the CSS with CPs increased by approximately 10% when the water depth was decreased from 6 to 3 cm. Moreover, compared to that of CSS at a water depth of 3 cm, the daily water productivity increased approximately 20% and 24% in cases of CSS with CPs and CSS with CPs and EH, respectively. Finally, an economic study was carried out to confirm the feasibility of the solar still. This study illustrated that the constructed solar still is economically feasible, and the estimated benefit-cost ratio is 4.1.

Enhancement of discs’ solar still performance using thermal energy storage unit and reflectors: An experimental approach

Augmentation of the basin type solar still using photovoltaic powered turbulence system

This study conducts an experimental assessment to investigate the influence of black gravel and cylindrical cement fins as thermal heat storage materials in a single-slope solar still. The trials are performed under the meteorological conditions of North-East, Silchar (24.76°N, 92.80°E), India. The performance of each modification is evaluated experimentally and compared to a conventional solar still (CSS) at three different water depths in the basin: 2 cm, 4 cm, and 6 cm. The study assessed the cumulative distillate output, along with a 4E analysis (energy, exergy, economic, and ecological analyses) of the solar stills. The outcomes show that at a 2 cm water depth, the daily yield and efficiency of the solar still with black gravel (SSBG) are 27% and 18% higher, respectively, when compared to the CSS. Additionally, the solar still with cylindrical cement fins (SSCCFs) achieved the highest daily production of 4462.4 mL/m2 with an efficiency of 41.5%. The cost assessment disclosed that the cost per liter of distillate water produced by SSBG and SSCCF is 18% and 23% lower, respectively, than the CSS at a water level of 2 cm. Moreover, the SSCCF improved carbon credits by 26% and enhanced carbon emission mitigation by 110.87% compared to the CSS at the same water depth. Solar stills equipped with energy storage provide a cost-effective solution for tackling water scarcity.

Experimental investigation on single basin tilted wick solar still integrated with flat plate collector

Improving the performance of a hybrid solar desalination system under various operating conditions

Experimental investigation on the negative effect of the external condenser on the conventional solar still performance

The lack of drinkable, safe water is one problem that governments around the world are dealing with. There are many methods for desalinating saltwater, such as solar distillers, which can be used in remote places without access to traditional energy sources to produce distilled water. In this manuscript, two solar stills [conventional solar still (CSS) and CSS with high thermal conductivity material (HTCM)] were researched at the "School of Mechanical Engineering, B.S. Abdur Rahman Crescent Institute of Science and Technology, Vandalur, Chennai, India," under the same climatic condition. The HTCM (silicon carbide) works as a sensible heat energy storage material, which was placed at the basin of the CSS. The silicon carbide used in the present research is used to enhance the freshwater production during lower solar intensity period and furthermore after evening time. It has been found that the maximum fresh water production from the CSS is 1.5kg/m2 and the CSS with HTCM is 2.9kg/m2. The daily yield production from the CSS with HTCM is 93.7% higher compared to the CSS. The study also has shown that the maximum daily thermal efficiency of the CSS is 13.43% and the CSS with HTCM is 26.09%. The CSS with HTCM produced 94.3% higher thermal efficiency as compared to the CSS.

Employing convex shape absorber for enhancing the performance of solar still desalination system

Although numerous improvements have been introduced in solar still technology to enhance its performance by using nanofluids, phase change materials, and design alteration, more attention needs to be paid to the role of sound agitation in enhancing solar still productivity. The present study aims to determine how the inclusion of sound agitation can enhance the performance of a solar desalination system. The experiment was performed in Coimbatore, India, in May 2024, where a conventional solar still (CSS) and modified solar still (MSS) with sound agitation were employed. The Taguchi method and analysis of variance (ANOVA) were used to evaluate the impact of several parameters, such as sound level, wave type, and water depth, on the productivity of the solar desalination system. The results indicated that wave type had the maximum impact on the output, while water depth and sound level exerted a secondary effect. The optimal parameters combination was wave type equal to square wave, water depth equal to 5 mm, and sound level equal to 90 dB. Regression analysis revealed accurate quantitative relationships between the input factors employed and the output, and the MSS system performed better than CSS, where the most significant improvement in distillate was 36.09% and 72.1% to evaporative heat transfer coefficient. Meanwhile, the average improvement concerning the evaporative heat transfer coefficient was 95.84% during the experiment. Thus, it can be concluded that the present experiment revealed the role of acoustic agitation in enhancing a solar desalination system’s thermal efficiency and productivity.