Double Slope Solar Stills Research Articles

Enhancing the solar still performance with nano-coated seashells and surface-modified absorber plates for clean water production

The study focuses on enhancing the thermal efficiency and water productivity yield of a double slope solar still (DSSS) by integrating a roughened corrugated copper plate, and nano-coated seashells. The surface-modified absorber plate, combined with small and larger-sized conch shells, intends to enhance thermal absorption, thermal transfer, and water evaporation. Four different SS are considered in this study, namely (i) CSS, (ii) corrugated absorber plate with shot blasting (CSBSS) (iii) corrugated absorber plate with small conch shell (CSBSSS), and (iv) corrugated absorber plate with big conch shell (CSBBSS) incorporated SS. The corrugation process and the conch shells’’ addition enhance the absorption, improving heat transfer, maintaining water temperature, reducing heat loss, promoting efficient water evaporation, and augmentation of durability and adaptability of the solar still system. The increased heat flux was observed in the corrugated copper plate (6400.7 W/m2), compared with the flat plate (4723.8 W/m2), suggests that the corrugated design is more capable of capturing and transmitting solar energy effectively through ANSYS software. The daily productivity of CSS was 1468 ml/m2/day, and CSBSS achieved 1708 ml/m2/day. Promoting the implementation of corrugation and the integration of conch shells, CSBBSS and CSBSSS systems exhibited improved yields, reaching 2002 and 2193 ml/m2/day, respectively. CSBSS, CSBSSS, and CSBBSS showed thermal efficiencies surpassing CSS by 6.41 %, 35.53 %, and 24.48 %, respectively. The average exergy efficiencies attained for CSS, CSBSS, CSBSSS, and CSBBSS were 1.653 %, 2.451 %, 3.91 %, and 3.29 %, respectively at an 8 % interest rate.

Performance enhancement of double slope solar still using cylindrical fins: Experimental and numerical analysis

This study explores the enhancement of a double slope solar still (DSSS) by integrating cylindrical fins on the absorber plate to improve heat transfer efficiency and water productivity. The experimental setup, made from galvanized iron sheets and insulated with a wooden box, features a glass cover angled at 34° for optimal solar radiation absorption. Testing was conducted in Gabes, Tunisia, evaluating solar radiation, wind speed, ambient temperature, and water productivity. Measurements were taken from 9:00 a.m. to 6:00 p.m., focusing on distillate yield, temperatures, and heat transfer coefficients. Both experimental and numerical analyses examined the effect of fin diameter on temperature distribution, heat transfer coefficients, and energy efficiency. Results demonstrate that the addition of fins significantly enhances both absorber and water temperatures, with the largest fin diameter (80 mm) achieving a 14.07 % increase. A validated Computational Fluid Dynamics (CFD) model showed a maximum temperature deviation of less than 3.5 °C from experimental data. The study recorded a peak energy efficiency of 71.03 % and a cumulative water productivity of 3252.55 mL/m2.

Experimental investigation of the effects of different nanoparticles on the performance of single basin double-slope solar stills

Abstract The study focuses on the development of a thermal model for a single basin double-slope solar still and compares the effects of varying volume concentrations of nanoparticles on its performance. The efficiency of single basin double-slope solar still is improved by using strip-grooved fin absorber shapes and a combination of nanoparticles (Al2O3, CuO, Ag, Fe2O3, and ZnO) in water depths from 0.01 to 0.05 m. The nanoparticles are present in different volume concentrations of 0.10%, 0.15%, 0.20%, 0.25%, and 0.30% in saline water within the basin. The strip-grooved fins are used to increase the surface area available for evaporation and serve as an important material for storing thermal energy, which is then transferred to the fluid mass in the basin, increasing its temperature. On the other hand, nanoparticles are used to improve the heat transfer of saline water in the basin and enhance its absorption of solar radiation. The experiment revealed that without the presence of nanofluid, the distillation efficiency of strip-grooved fin was 26.93%. The distillation production efficiency of strip-grooved fins combined with nanoparticles Al2O3, CuO, Ag, Fe2O3, and ZnO were 36.13%, 35.58%, 34.60%, 32.44%, and 29.71%, respectively. Furthermore, the economic analysis showed that the overall costs per liter of freshwater produced by single basin double-slope solar still with strip-grooved fin and the combination of single basin double-slope solar still with strip-grooved fin and Al2O3 were reduced by 0.0368 and 0.0309$/L, respectively.

A CFD and experimental analysis of a double-slope solar still with channel integration

Freshwater scarcity is a critical global issue, particularly in arid regions. Solar stills provide a sustainable solution for water desalination using solar energy, yet traditional designs often exhibit limited efficiency. This study examines the performance of a Double Slope Solar Still (DSSS) integrated with a square-shaped conventional channel (CCDSSS) to enhance water evaporation and production. Experiments were conducted in Chengalpattu, Kattankulathur (latitude 12.8° N, longitude 80.03° E) along with three-dimensional simulations using Computational Fluid Dynamics (CFD) and were validated against literature and experimental data. The CCDSSS system achieved a water productivity of 3.084 lm−2day−1, which is 25.67 % higher than the DSSS system’s 2.454 lm−2day−1. It also keeps a uniform temperature within still and enhances vapor velocities, resulting in higher evaporation rates and productivity. Optimal performance was observed with a 10 mm water depth, showing a 24.41 % increase in yield compared to a 30 mm depth. Despite higher initial costs, the CCDSSS system offers a shorter payback period of 238 days compared to 289 days for the DSSS system. This study provides detailed insights on the effect of channel attachment in DSSS highlighting significant improvements in both solar still efficiency and economic performance.

Comparative study on productivity of double slope solar still using different wick and energy storage materials

The aim of the proposed study is to evaluate the efficiency of Double Slope Solar Still (DSS) using different wick and energy storage materials. In the study, wick materials such as jute, cotton and sponge were used in combination with energy storage materials such as mild steel, cast iron and copper. The experiments were conducted using DSS with different combinations of wick and energy storage materials to determine the efficient performance combination. The results show that sponge and copper have higher efficiency with wicks and energy storage materials. The results show that the maximum amount of water produced in a single day was 3147 ml when the DSS system was used with a combination of sponge and copper materials. This range shows an increase of 17.47 % and 12.44 % over the DSS with jute and copper and the DSS with the combination of cotton and copper respectively. The DSS showed the highest average energy efficiency when used in conjunction with a combination of sponge and copper, namely 51 % of the average efficiency. This corresponds to an increase of 18.60 % and 10.86 % compared to the combination of DSS with jute and copper and the combination of DSS with cotton and copper respectively. The best evaporation heat transfer coefficient of 345 W/m2K was determined for the combination of DSS with sponge and copper. Average exergy efficiency is also maximum of 3.076 % for the DSS with sponge and copper materials, which is higher than other investigated combinations. The proposed system has an energy payback period of 1.26 years, an energy production factor of 0.78, a life cycle efficiency of 6.9 % and a cost of $0.031 per litre of water produced in the environmental economic analysis.

Experimental and computational modeling analysis of double slope solar still with a trapezoidal channel for preheating

In specific locations in India, water scarcity is an important issue, therefore several efforts are made to produce treated water so that rural and urban areas have access to safe and sustainable drinking water. The solar still method is the most affordable water purification option available in these hot areas. This research aims to enhance the performance of passive double-slope solar stills by analyzing the effects of preheated water on evaporation and yield rates. A new method was adopted to maintain the lowest water depth in the basin of a solar still by using a channel attachment to move the feed water. Additionally, the study investigates the impact of a trapezoidal channel attachment within the solar still, a first-time innovation, on its efficiency and yield rate. Computational fluid dynamics and experimental data collected on February 10, 2024, in Kattankulathur was analyzed to assess temperature variations and yield rates. A three-dimensional full-scale simulation was carried out using Ansys Fluent with a two-phase (evaporation and condensation) model, where the flow in the channels of the rate varied from 0.87 × 10-4 to 5.21 × 10-4 Ls−1 and the highest yield is achieved at flow rate of 1.74 × 10-4 Ls−1. The accuracy of the simulation technique was evaluated by comparing it to experimental data, and found a good match. The results demonstrated that solar still with trapezoidal channels significantly increased the overall yield rate. Optimal performance was achieved under specific environmental conditions, with a cumulative yield of 2.45 Lm−2 at a basin water depth of 10 mm, marking a 37.64 % increase over the conventional solar still. Economic analysis indicated a reduction in the payback period to 299 days, affirming the system’s cost-effectiveness. The trapezoidal channel design is limited to a cross-section of 10 mm2, and positioned at a 17° angle on the middle sidewall to minimize the shadow formation on the basin of still and maintain high yield and evaporation–condensation rates. The novelty of this work is to integrate trapezoidal channels on the double slope solar still and to optimize its design and flow rate to maximize the overall production.

Enhanced water production and improving solar water distillation efficiency of double-slope solar stills: Modeling and validation

Solar distillation is a promising technology for producing clean water using renewable energy, especially in regions with water scarcity and contamination. This study investigates the impact of design modifications on the efficiency of a double-slope solar still coupled with evacuated tubes and external reflectors. Using Matlab software analysis, key findings indicate that packing factors, temperature control, and solar radiation exposure all contribute to the system’s optimal performance. Solar radiation levels directly correlate with production rates, emphasizing the need for effective sunlight exposure. The system’s ability to rely on stored heat at night enhances its practicality. This study shows how to make solar stills more efficient at producing clean water. It is found that the best way to do this is to use PV cells with a packing factor of 0.25. A packing factor of 0.25 outperforms other factors, significantly increasing water production and system efficiency. With this optimal factor, the system achieved a remarkable thermal efficiency of 83.5 % and a maximum daily production of 19 L per square meter during peak solar radiation hours. The system’s overall efficiency is 94 % increased by 13 % over the highest value recorded in previous studies. Furthermore, the system’s productivity increased by 40 % from the highest value recorded in previous studies. The amount of electrical energy produced is directly proportional to the packing factor, by the power of 41.1 W-hours (Wh) at a PV cell with a packing factor of 0.25.

Experimental investigation of the effect of angled fins on the energy and exergy efficiencies of solar stills: A comparison between double slope and pyramid solar stills under Tunisia weather conditions

Solar stills play a crucial role in addressing the scarcity of potable water, particularly in remote areas. However, traditional solar still designs are often inefficient, with limited productivity and high energy consumption. One approach to enhancing the efficiency of solar stills is to use finned absorber plates, which can increase the heat transfer area and improve heat transfer rates, thereby enhancing evaporation and overall productivity. This study investigates the impact of different configurations of angled fins on the energy and exergy efficiencies of solar stills, focusing on Pyramid Solar Still (PSS) and Double Slope Solar Still (DSSS) designs. Energy efficiency was calculated over several days to determine the effect of the number of angled fins ((3 × 3), (3 × 5), and (3 × 7) fins) on the performance of both solar stills and to compare the two configurations. The most favorable results were obtained using an absorber plate featuring (7 × 3) angled fins in PSS. The desalination systems equipped with finned absorber plates with (7 × 3) angled fins achieved approximately 43.22 % and 46.25 % greater productivity for the PSS and DSSS, respectively, compared to absorber plates without fins. In this configuration with (7 × 3) angled fins, the PSS system recorded an energy efficiency of 37.84 %, while the DSSS system achieved a rate of 31.93 %. The PSS desalination system with an absorber plate without angled fins achieved an energy efficiency of 26.18 %, while the similarly equipped DSSS system attained an energy efficiency of 22.39 %. Regarding exergy efficiency, the PSS showed an average daily exergy efficiency without angled fins of 1.94 %, but using (7 × 3) angled fins boosted this to 2.66 %, the highest value observed. Likewise, the DSSS’s exergy efficiency started at 1.54 % without fins but reached 2.15 % with (7 × 3) fins. Overall, though, the PSS consistently outperformed the DSSS in terms of both energy and exergy efficiency across the various absorber plate configurations. These findings underscore the effectiveness of using finned absorber plates to enhance the evaporation rate and improve the overall efficiency of solar stills.

An experimental comparison for thermos-economic performance of five different designs of solar stills

Five different solar stills (SSs) have been tested in this experimental study. Hemispherical SS, tubular SS, pyramid SS, double slope SS, and conventional SS are the five SS systems. The primary goal is to determine which SS will perform more effectively at the testing location. Initially, the SSs were evaluated with no changes and the outcomes were contrasted with those of the conventional SS. Secondly, exterior reflectors have been added to four SSs. Third, hemispherical SS and tubular SS with reflectors have been utilized with phase change material (PCM) combined with Ag-Nanoparticles. Lastly, tests using reflectors, fan, and external condensers have been conducted on the hemispherical SS and tubular SS. The findings showed that the increase in productivity for hemispherical SS, tubular SS, pyramid SS, and double slope SS without modifications are 107 %, 97 %, 66.5 %, and 30 % greater than that of conventional SS, respectively. Furthermore, the results depicted that employing reflectors improved the productivity rise for tubular SS, hemispherical SS, pyramid SS, and double slope SS to be higher than conventional SS's productivity by 168 %, 153 %, 113 %, and 85 %, respectively. Besides, the effect of employing PCM-Ag with hemispherical SS and tubular SS (with reflector) is increasing their productivity to be 202 % and 212 % higher than conventional SS's production, respectively. Also, the hemispherical SS and tubular SS with reflector, fan, and a condenser showed 217 % and 236 % higher productivity than conventional SS. The actual cost of producing water for the conventional SS, hemispherical SS, and tubular SS with reflectors and fan is 0.0244, 0.012, and 0.013 $/L, respectively.

Enhancing performance of Double-Slope solar stills through optimization of heat addition methods: a comprehensive analysis

Enhancing performance of Double-Slope solar stills through optimization of heat addition methods: a comprehensive analysis

Energy matrices, enviro-economic and characteristic equation-based performance analyses of photovoltaic thermal compound parabolic concentrator (PVT-CPC) coupled solar still equipped with heat exchanger using SWCNTs and MWCNTs–water nanofluids

In this paper, effect of single wall carbon nanotubes (SWCNTs) and multiwall carbon nanotubes (MWCNTs)- water based nanofluid have been studied to examine the performance, long-term feasibility andenviro-enviro-economic analysis of partially covered series connected N- photovoltaic thermal (PVT)-compound parabolic concentrator (CPC) collectors coupled double slope solar still (DSSS) equipped with helically coiled heat exchanger (HE). Analysis have been carried out by developing thermal modelling of the proposed system. Instantaneous gain and loss efficiencies; annual thermal energy/exergy, and productivity – is investigated for optimized parameters of the proposed system in detail. Gain efficiency of the proposed system is found to be approximately 25-30% higher using CNT-NPs as compared to the system without using NPs. Annual thermal energy and exergy of CNTs, particularly SWCNTs water-based nanofluid (thermal energy- 2491.55 kWh, thermal exergy-894.67 kWh) have been found to be greater in comparison to basefluid (thermal energy -2185.76 kWh, thermal exergy-772.18 kWh). Also, results give higher value of CO2 mitigation using CNT-NPs both on the basis of energy (SWCNT-5.082t, MWCNT-4.787t) and exergy (SWCNT-1.83t, MWCNT-1.76t) respectively. SWCNT-NPs shows better performance due to their better TPPs; also PVT-CPC collector integrated DSSS equipped with HE is more viable practically.

Theoretical study of a double-slope solar still with solar air heater condenser

Despite their limited water production and efficiency, double-slope solar stills are an appropriate solution for water scarcity in hot arid regions. Numerous studies have focused on enhancing the effectiveness of double-slope solar stills. In this context, this study introduces a double-slope solar with a solar air heater condenser (DSSS-SAHC). The back cover of a conventional double-slope solar still was replaced by a glass air heater in order to recover the still’s thermal losses in heating air. The transient performance of the DSSS-SAHC was investigated numerically under real weather conditions and compared to the performance of a conventional double-slope solar still (CDSSS) with the same aspects. The impact of various weather and operation factors on the DSSS-SAHC performance was investigated at air flows of 0.01 and 0.1 kg/s to account for both natural and forced air circulation, respectively. The results revealed an increase of about 15% and 6% in the thermal efficiency of the DSSS-SAHC over that of the CDSSS, respectively, at air flows of 0.1 and 0.01 kg/s despite the DSSS-SAHC distillate was insignificantly greater than that of the CDSSS at both air flows. In addition, the water distillate of the DSSS-SAHC increased as the solar irradiance increased, the ambient wind and ambient temperature had contrary effects on the efficiency, and the initial saline water level had a negligible impact on the overall performance

Productivity Augmentation of Solar Stills by Coupled Copper Tubes and Parabolic Fins

A solar still is an eco-friendly device that makes use of ample solar energy for the purification of water. The main objective of this research is to increase the yield output of a double-slope solar still (DSSS) by coupling the basin liner with copper tubes and parabolic fins. In this work, the experiments were supervised for nine days with three different cases. For these experiments, copper tubes with thickness of 2 mm, outer diameter of 32 mm, inner diameter of 28 mm, and parabolic fins with 30 mm diameter and 50 mm height were considered. In the first case, non-coated copper tubes (NCCTs) were used, in the second case, coated copper tubes (CCTs) were employed, and in the last case, coated copper tubes with a combination of parabolic fins (CCTPFs) were used. The MSS (case-III) demonstrated a substantial yearly productivity enhancement of 57.79%, establishing its superiority in terms of output because of its higher daily distillate yield of 1215 mL/day in contrast to CSS. When compared, case III—CCTPF—performed better than case II—CCT—by 35.75%. The CSS and MSS both contributed to a decrease in the pH of the saline water, which went from 8.18 to 7.64 and 7.23, respectively. In comparison to the MSS and CSS, which had 0.428 mg/L and 0.569 mg/L of fluoride ions, respectively, brine water had a fluoride ion level of 0.734 mg/L. Total dissolved solids (TDS) concentration before desalination was 440 ppm and it was minimized to 20 ppm with MSS and 55 ppm with CSS, respectively, post-desalination. The corresponding cost per liter (CPL) of MSS and CSS is USD 0.053 and USD 0.040, respectively.

Experimental study with thermal and economical analysis for some modifications on cylindrical sector and double slope, single basin solar still

Solar stills are considered one of the most thermally eco-friendly and promising solutions for producing potable water in sunny and arid regions. However, they suffer from a disadvantage in terms of their low productivity. Therefore, this study aims to investigate the performance of cylindrical sector solar stills and compare them with double-slope solar stills. The study also presents the enhanced performance of a thermo-economic system by integrating cost-effective and readily available materials. The experiments were conducted in Egyptian climate conditions, with a water depth of 2 cm in the stills basin, using different materials. Under the same operating conditions, the results showed that the accumulated productivities of the cylindrical sector solar stills (CSSS) and double slope solar stills (DSSS), using black fiber and black dye, were 3514 ml/m2 and 3029 ml/m2, respectively, representing an increase of 16.01%. Furthermore, the daily thermal efficiency of the CSSS and DSSS, using black fiber and black dye, were 30.42% and 26.32%, respectively, showing an increase of 15.58%. The cost per liter (CPL) of potable water produced by CSSS, using black dye with black natural-fiber, was approximately 0.0119 US$/L, while it was 0.0137 US$/L for DSSS. Additionally, the payback periods for CSSS and DSSS were 92 days and 106 days, respectively. In all scenarios studied, the daily accumulated productivities and thermal efficiency of CSSS were greater than those of DSSS.

Mathematical analysis of optimized requisites for novel combination of solar distillers

This study examines the impact of variable Evacuated Annular Tube Collectors (EATCs) on performance, both with and without the use of parabolic concentrators. The study aims to address the irregular use of EATCs by utilizing novel parabolic solar receivers (PSRs) to enhance the performance of the recommended double slope solar still (DSS) in comparison to conventional or PSR-assisted single sloped systems. The DSS-EATC-PSR system has been improved with the inclusion of basin mass temperature (11.4 %) while adhering to a 30° inclination of the basin cover and EATC tubes. An increase in natural thermo siphon circulation has been achieved with improvement of 28.1 % and 0.1 % for DSS-EATC-PSR in comparison to single slope solar still (SSS) with EATC and SSS-EATC-PSR, respectively. The daily energy-exergy efficiencies of the system exhibit a slight decrease of 8.4 % and 4.7 % for overall and exergy, respectively, compared to the conventional solar still system. The daily yield has demonstrated a 4.6 % improvement compared to the SSS system, while maintaining a minimal promotion price of $0.07 per liter. This has been achieved despite a noticeable increase in production cost. The CO2 mitigation results in a higher environmental revenue compared to the SSS system by 5.9 % and 14.6 %. The cost analysis of the DSS system indicates a reduction of 6.6 % in expenses. Additionally, the productivity of the systems has been observed to exceed 100 %, thereby confirming the feasibility of the proposed systems.

Performance improvement of single and double effect solar stills with silver balls/nanofluids for bioactivation: An experimental analysis

The implementation of bioactivation nanofluid in single and double slope solar stills (SDESS) is an important aspect from thermo-economic point of view. Based on efficient thermal modelling, a comparative analysis of nanofluids is also suggested for design optimization of solar stills. To develop SDESS observations, the data is taken for the period from January 2021 to April 2022, at KLEF in India. To create green TiO2 nanoparticles using eco-friendly bleaching chemicals and jackfruit peel (Bioactivation), a green nanoscale approach is used. The performance of the double-effect solar distiller (DESD) is demonstrated using various TiO2/Jackfruit peel nanofluids (TJPN) (5%, 10%, 15%, 20%, 25%, and 30%) with silver colour balls. The SDESS results are presented as energy (41%) and exergy (5.63%), with the TJPN having the highest efficacy (20%) based on water depth of 0.8 cm. With a water depth of 0.8 cm over the course of a 12-hour observation period, the total SDESS efficiency result is 7.35 kg/m2 per day and TJPN for 30%. An economic analysis of SDESS is found with the cost of concentration that portable water (per litre) and appraised around 0.0726$ by reimbursement term of 14 months. The average thermo-enviro-economics analysis of SDESS is 3.35 (exergy) and 4.71% (Energy). For 0.8 cm of water depth and an analysis of the weather for good life cycle units, SDESS concentrates 7.97 tonnes of CO2 emissions. Additionally, the analysis of TJPN optimization by the SDESS is done for 5%, 10%, 15%, 20%, 25%, and 30% and is based on the theoretical yield at the maximum water temperature and water depths of 0.6, 0.8, 1 and 1.2 cm.

Experimental investigation of double slope solar still integrated with PCM nanoadditives microencapsulated thermal energy storage

Transparent covered slope solar stills are trending but characterised with low productivity, heat losses and high energy consumption, which are setbacks in practice. In this study, double slope solar still (DSSS) integrated with PCM-TES is presented. PCM was microencapsulated with epoxy resin composite using vacuum mould-filled techniques. Conventional DSSS and DSSS-TES data collected have been compared to establish the influence of TES on productivity. Daily average temperature of the glass cover, humid air, saline water, still basin absorber and TES cavity for the DSSS-TES attained are 65.2 °C, 77.5 °C, 82.4 °C, 79.5 °C and 68.4 °C, respectively. DSSS-TES has yielded higher production, with 7.5 Litres of potable water daily and extension in operation period by 3 h has been achieved. In addition, condensation and evaporation rates increased with increase in production by 105%. Integration of TES with the system has reduced the heat losses while leakages from PCM nanocomposite have been prevented by microencapsulated insulator. No trace of metals, bacteria and organic contaminants has been found in desalinated water. A payback period of 0.8 year has been recorded based on all-year-round operations. Findings are in good agreement with existing models. Moreover, sensorial characteristics obtained conform to WHO standards.

An experimental comparison study between four different designs of solar stills

In this experimental work, four different solar stills (SSs) have been tested. The SS systems are conventional SS (CSS), Double Slope SS (DSSS), Pyramid SS (PSS) and Tubular SS (TSS). Finding out which design will perform better at the testing site is the main objective. To minimize the shadow effect inside the DSSS and PSS the water basin has been elevated and the performance have been compared with the CSS. Additionally, phase change material mixed with Ag Nano particles has been employed with TSS, elevated basin DSSS and elevated basin PSS. The results indicated that, the productivity rise/thermal efficiency for DSSS, PSS and TSS are 28.5%/38.2%, 66%/43.7% and 96.5%/48.2%, respectively. But in case of DSSS and PSS with elevated basin the productivity rise/thermal efficiency showed 40.5%/40% and 84.5%/46.4%, respectively. Finally, the productivity rise/thermal efficiency for PSS with elevated basin and PCM showed the highest values of 116.4%/51.3%. The productivity for TSS is superior to those for the tested solar stills. In contrast to PSS, the TSS's manufacturing is more complicated and costly. Also, environmental and economic analyses have been considered, the achieved costs of the distilled freshwater were 0.024 and 0.019 $/L for the CSS and PSS (elevated basin and PCM), respectively. The environmental parameter of elevated basin PSS with PCM-Ag and CSS was 14.7- and 6.67-tons CO2 per year, respectively.

Experimental investigation on the performance improvement of double-slope solar still by different shapes of the channel integration.

An experimental investigation has been done for the performance enhancement of double-slope solar still (DSSS) by incorporating channels of different shapes. There are five solar stills including one conventional solar still, and four others modified with square (Sq), rectangular (Rect), triangular (Tri), and trapezoidal (Trap) channel are used. The temperature difference between the channel inlet and outlet, basin, and glass cover was measured at an optimum basin water depth of 2cm. It is found that incorporating the channels inside the still enhances the basin water surface temperature. Results demonstrate that the best yield rate was achieved from the trapezoidal shape channel inserted in double-slope solar still (DSSS + Trap). DSSS + Sq, DSSS + Rect, DSSS + Tri, and DSSS + Trap channels increased the yield rate by 4.35%, 13.04%, 20.28%, and 30.43% compared to conventional double-slope solar still. Energy and exergy analysis was calculated for different days in the modified solar still. The cost per liter of distillate water was least ($0.034) for DSSS + Trap system with a payback period of 6.5months. Moreover, it is observed that the modified double-slope solar still with trapezoidal channel attachment has reduced 5.33 tons CO2 for its life cycle. Furthermore, water samples collected during experimental have a drinking quality as per requirements of the World Health Organization standards.

Influence of basin water depth in the distillate yield of traditional and developed passive single basin double slope solar still

PurposeThe purpose of this paper is to understand the effect of basin water depth towards the cumulative distillate yield of the traditional and developed single basin double slope solar still (DSSS).Design/methodology/approachModified single basin DSSS integrated with solar operated vacuum fan and external water cooled condenser was fabricated using aluminium material. During sunny season, experimental investigations have been performed in both conventional and modified DSSS at a basin water depth of 3, 6, 9 and 12 cm. Production rate and cumulative distillate yield obtained in traditional and developed DSSS at different water depths were compared and best water depth to attain the maximum productivity and cumulative distillate yield was found out.FindingsResults indicated that both traditional and modified double SS produced maximum yield at the minimum water depth of 3 cm. Cumulative distillate yield of the developed SS was 16.39%, 18.86%, 15.22% and 17.07% higher than traditional at water depths of 3, 6, 9 and 12 cm, respectively. Cumulative distillate yield of the developed SS at 3 cm water depth was 73.17% higher than that of the traditional SS at 12 cm depth.Originality/valuePerformance evaluation of DSSS at various water depths by integrating the combined solar operated Vacuum fan and external Condenser.