... The problem with conventional techniques like thermal, electrical and mechanical is their high energy consumption. Among the new techniques solar energy can be considered as the most efficient related to energy, economic and environmental aspects  . In solar stills powered systems heat is collected at the lower wall from solar irradiation transmitted through the transparent cover. ...
Numerical results of laminar double-diffusive natural convection in a trapezoidal shape solar distiller occupied with an air-vapor mixture are carried out. In the present paper, the distiller is subjected to cooling fluid with a cold free stream temperature from the upper wall that kept at low concentration. The lower distiller wall kept with hot temperature and high concentration. The finite volume method based on SIMPLE algorithm is employed to solve the governing equations. Outcomes are performed with a scope of Rayleigh number (10⁴ ≤ Ra ≤ 10⁶), free stream Reynolds number (10² ≤ Re∞ ≤ 10⁵), buoyancy ratio (N = 1, 2,5 and 10) and varying cooling fluid (air or water). The Prandtl (Pr), Schmidt (Sc) and Lewis (Le) numbers are fixed at 0.7, 0.62 and 0.89, respectively. The results revealed a considerable enhancement on the mass and heat transfer rates with increasing of Ra, N and Re∞. The effect of Re∞ is more pronounced with Ra = 10⁶. On the other hand, more vortices formed in the cavity as Ra and N augments and the maximum vortices number obtained when N = 5. Regarding the local Nusselt (NuL) and Sherwood (ShL) numbers, improvements are found both on the upper and lower cavity walls as Ra and N rise. The impact of N on NuL and ShL turns out significant with the higher value (N = 10).
... Many researchers have been reported different construction and optimization of tool and technique for enhancing the yield of single slope passive solar stills . Present development in solar stills, daily water distiller output/yield ranges from 1 to 7 liters per square meter of still basin area , hence for feeding potable water to a small community requiring 200 m 3 /d needs 3,00,000-20,00,000 m 2 land area to meet the demand of potable water. As a high capital cost, involved in solar distillation, due to the primary land and equipment hence accurate prediction of an expected distillate production unit is essential for the success of the project and doing optimization of capital investment and maximizing the production rate. ...
An experimental study has been performed to evaluate the single slope hybrid solar still integrated with heat pump (SSDHP). The purpose of this study is to determine the effectiveness of solar still and its modeling using artificial neural networks (ANNs) with the help of experimental data. Most influencing parameters (the solar radiation, glass cover temperature, basin temperature, water temperature and temperature of the evaporator) at an hour interval on the performance of hybrid solar still using ANNs model are discussed in this paper. Effect of an air compressor on the productivity of SSDHP and assess the sensitivity of the ANN predictions for different combinations of input parameters as well as to determine the minimum amount of inputs necessary to accurately model solar still a performance for the prediction of actual distiller output results. The experimental result SSDHP with air will give 100% higher yield as compared to the SSDHP without air but SSDHP dramatically maintains its lead by 25% at 9 h. While this duration maximum difference in yield of SSDHP with and without air observed that SSDHP with air gives 34.61% higher yield as compared to without air during 11 to 12 hour due to the influence of basin temperature. SSDHP with air was recorded 33.33% higher yield as compared to the SSDHP without air. For training, validation, test and all, value of R is equal to 0.99454, 0.99121, 0.99974 and 0.99374 respectively in ANNs proposed model which shows very good agreement with the experimental result. Satisfactory results for the SSDHP with air will pave the way to predict performance result for different climate regimes, with sufficient input data, the ANN method could be extended to predict the performance of other solar still designs also.
... 1(Kuram & Ozcelik, 2014). Solar stills are broadly classified into passive and active solar stills (Vishwanath Kumar, Kumar, Prakash, & Kaviti, 2015). Passive stills are further divided into basin type and inclined types. ...
The requirement of fresh water is growing exponentially in industrial as well as domestic sector, resulting in more pollution of natural water resources and creating a scarcity of drinking water. Additionally, the number of arid and desert regions on the world map which already face the shortage of rainfalls and ground water. The problem is substantially increased as most of the water bodies like rivers, lakes are saline and brackish which are not suitable for drinking purpose. In recent past, solar desalination has been found to be a sustainable and economical way of generating the fresh water to cater the need of drinking water at large. Much technological advancement in the field of solar stills has been made which can ably produce a large quantity of fresh water depending on the availability of solar radiation. Various desalination schemes have been utilized to utilise water from such available resources to convert the available water in to the drinkable water. Additionally, attention has also been put on developing efficient solar still with latent heat based thermal energy storage systems which can work in the absence of sunlight as well. In the present paper, a short review on solar stills utilising latent heat storage has been presented. The present study covers the design specifications, efficiency, merits and demerits of solar stills with latent heat storage system. A discussion on the future research outlook in the area of solar stills with latent heat storage has also been given, so as to make it more economically viable for generating sustainable potable water.
... Tiwari et al. (2003) conducted energy and economic analyses for PV/T and FPC active solar still. Prakash and Velmurugan (2015) reviewed the effect of factors like absorption area, water depth, heat storage, inlet water temperature etc. for improving the yield of solar stills using reflectors, FPCs etc. Viswanath Kumar et al. (2015) reviewed the performance of solar stills with passive and active mode of operation and described various design specifications of Nomenclature A w evaporative surface area (m 2 ) A g area of glass cover (m 2 ) A c area of collector (m 2 ) C unknown constant Gr ...
Effect of flat plate collectors (FPCs) in series on the distillate output and performance of solar still have been studied in active mode. The solar still has an effective basin area of 1 m2 and fixed cover inclination of 30°. Each FPC with an effective area of 2 m2 is attached with solar still. For the present study, experiments have been conducted for 24 h during the summer months for active solar distillation system. An effective collector inclination of 5° is used. Outdoor experiments were conducted at Kakinada (16°.93′N/83°.33′E), A.P., India, which has coastal climatic conditions. The aim of the present work is to study the effect of FPCs connected in series on the yield and distillation efficiency of an active solar still for the selected location. The results show that solar still, with two FPCs connected in series, provides 41% more distillate yield when compared to still with single FPC and the still efficiency is 0.47% more with two FPCs connected in series. The still with three FPCs connected in series has produced 89% more distillate yield when compared to still with single FPC. However, the still efficiency is 0.48% less with three collectors in series due to increase in area for radiation. The increase in distillate yield for the still with FPCs in series is due to the attainment of high water temperature.
Mankind has depended, for a long time, on underground water supplies for the freshwater needs. In any case, these sources are not generally helpful because of saltiness in the water. Utilizing solar stills in dry districts is one of the reasonable remedies to receive the potable water from inferior water sources. Development of the customary solar stills to improve the gainfulness has reliably been the stress of originators and investigators in the solar energy and associated areas. This paper presents the review on different types of solar stills, including basin stills, wick stills, concentrating collector stills, and so on. The working principles of these stills are discussed in detail.
This paper presents an outlook to enhance the productivity of a basin type double slope multi–wick solar still by introducing the wicks. The experimental data for different months are presented, and analyzed the effect of climatic and operational parameters on the performance of modified basin type double slope multi–wick solar still (MBDSMWSS). The study has been conducted at Motilal Nehru National Institute of Technology Allahabad (MNNIT Allahabad), Uttar Pradesh (U.P.), India. A significant increase in the heat input, yield, and overall thermal efficiency have been obtained. In the instantaneous efficiency equation, the yield output and the heat input to the solar still is modified as input from both the glass covers and transparent walls are considered for the modified solar still. The result shows that, the maximum yield is obtained as 9012 ml/day (4.50 l/m² day) for black cotton wick in comparison to 7040 ml/day (3.52 l/m² day) for the jute wick at 2 cm water depth in MBDSMWSS. Also, for same basin condition, the overall thermal efficiency of MBDSMWSS with the jute and black cotton wicks are 20.94% and 23.03%, respectively.
In this paper, an exergy analysis is performed for a double slope solar still equipped by thermoelectric heating modules to achieve a better thermodynamic performance. Thermoelectric modules were used as a water heater to increase the temperature of water and accordingly improve the performance of the solar still. The results are obtained by performing a series of experiments during ten days and nights under the climate conditions of Semnan (35° 33′ N, 53° 23′ E), Iran. Finally, an economic analysis has been performed to determine the production cost of water per liter. The obtained results showed that the heatsink temperature and heating created by thermoelectric cause an increase in the water temperature. This prevents reduction in production when the solar intensity decreases at afternoon. Moreover, it is observed that the exergy efficiency increases during the times of experiments. The maximum exergy efficiency of the system is about 25% and occurred at 3 p.m. Life cycle analysis also showed that the cost of distilled water for the day and night are 0.1422 and 0.237 $/L/m², respectively.
In this communication, existing design of single slope solar still has been modified, developed and tested. The modifications in conventional single slope solar still include (i) inside walls painted with white color (ii) attachment of water sprinkler with constant water flow rate of 0.0001kg/s on the glass cover. The performance of modified single slope solar still has been evaluated and compared with conventional solar still. Experiments have been carried out on both modified and conventional single slope solar still for 05cm water depth in the month of April at Jabalpur (Latitude 23o18’ N; Longitude 79o95’ E) India. The distilled water output was recorded 2940ml and 3541ml from conventional and modified solar stills respectively. Water productivity or yield of single slope solar still is increased by 20% from above modifications. The overall efficiency is increased by 21% over the conventional solar still.
Due to the greater growth of population and industrial developments especially from the early 20th century, people living in remote villages suffer with shortage of drinking water. People living in urban and rural areas depend on surface and ground water sources, where these sources are majorly polluted by industrial waste. The use of reverse osmosis technique and other conventional technique appears to be a costlier method and requires a very large land mass. An economical method of converting the saline water to portable water is by using solar energy. Solar still desalination is one method of converting saline water into potable water by evaporation and condensation. Many researchers carried out extensive studies on the solar still desalination technique and this paper communicates a detailed review about the existing desalination technique by solar energy.