Comparative Experimental Study Between Conventional Stepped Solar Still and an Active Stepped Solar Still Incorporated with a Water Circulation System (original) (raw)

Effect of Depth of Water on the Performance of Stepped Type Solar Still

The research work carried out so far in the field of solar desalination is related to the single basin type solar still only. The effect of changes in design, climatic and operational parameters on the distillate yield has been studied but limited to the single basin type solar still. The increase in productivity by connecting a flat plate collector which is called as active solar desalination has also been studied but limited to the single basin type solar still. Present study deals with a stepped type solar still to improve the performance of single basin type solar still by increasing the production rate of distilled water. The modifications in the design of single basin type solar still are introduced by replacing the flat basin by a stepwise structure. The stepped type solar still selected in this case has 8 number of steps of size 620 mm(L) x 100 mm(W) and total absorber area equal to 0.5093 m 2 . The characteristic feature of stepped type solar still is that it provides an additional 40% absorber area as compared to the single basin type solar still.

PERFORMANCE & ANALYSIS AND OPTIMIZATION OF STEPPED TYPE SOLAR STILL

As water shortage is becoming a major problem of national as well as international concern, desalination will increasingly be required to meet growing demands of fresh water. Desalination technologies have developed rapidly during the past several decades for desalting a variety of raw waters such as seawater, brackish ground water, industrial waste water etc.The present study aims to improve the solar still performance and to increase its distillate yield. So it is necessary to evaluate some important parameters affecting the system productivity. The effect of depth of water, glass cover thickness, Different depths of saline water over the basin (5 mm, 7.5 mm and 10 mm); different thicknesses of the glass cover (3.5 mm and 4 mm); are tested under the same climatic conditions. The study aims to introduce the applicability of a stepped type solar still to determine the various parameters that influence the performance of stepped type solar still. To vary the depth of water in the basin of stepped type solar still. To vary glass cover thickness of stepped type solar still. Presentation of the optimized results obtained after detailed analysis of the data generated for various configurations of solar stills. Keywords: Depth of solar stil glass cover thickness enhancement of productivity etc.

3E enhancement of freshwater productivity of solar still with heater, vibration, and cover cooling

2022

This study focused on experimentally increasing the productivity of freshwater from solar stills. The performance of a single solar still system could be augmented with the combination of an electric heater, vibration motion, and thermoelectric cooling. The study investigated the effect of combining two of these components and finally combining all of them on freshwater productivity. The electric heater and vibration motion are used to enrich the evaporation rate while thermoelectric coolers are used to enhance the condensation rate, leading to high freshwater productivity. The proposal, construction, and testing of two identical solar stills performed under the local climate conditions of the city of Alexandria in northwestern Egypt during the summer and winter times. The two solar stills had a 1 m2 base area. An electric heater of 450 W was placed inside the modified solar still. The modified solar still was fixed on four coiled springs. A 1 hp power DC motor, an inverter, a contr...

Influence of Various Basin Types on Performance of Passive Solar Still: A Review

International Journal of Renewable Energy Development

Passive solar still is the simplest design for distilling seawater by harnessing solar energy. Although it is undeniable that solar still is a promising device to provide an additional freshwater source for global increasing water demand, low thermal efficiency along with daily distillate yield are its major disadvantages. A conventional solar still can produced 2 to 5 L/m2day. Various studies have been carried out to improve passive solar stills in terms of daily productivity, thermal efficiency, and economic effectiveness. Most of the researches that relate to the daily output improvement of passive solar still concentrates on enhancing evaporation or/and condensation processes. While the condensation process is influenced by wind velocity and characteristics of the condensed surface, the evaporation process is mainly affected by the temperature of basin water. Different parameters affect the brackish water temperature such as solar radiation, design parameters (for example water ...

Experimental Investigation of Double Slope Solar Still for the Climatic Condition of Sultanpur

International Journal of Engineering and Technology, 2017

A single basin double slope solar still of 1 m 2 basin area is fabricated from an acrylic sheet of 3.5 mm. The condensing glass covers of 3.5 mm thickness with 30° tilt angle are used. In the present work, an attempt has been made to investigate the effect of the various parameters on the productivity of solar still like water depth, wind velocity, solar radiation, etc. The solar still experimentally tested under the climatic condition of Sultanpur (26.26° North, 82.07° East) in the month of March and April. For the present study, the experiments are conducted for both orientation East-West and North-South of solar still. The hourly temperature has been recorded for water, basin liner, and glass surfaces. It is seen that the production rate increases with increase in wind velocity and cooling of glass covers. The production of 75 ml (from16:30 hrs. to 17:00 hrs.) found for the temperature difference of 9.2°C after cooling the covers. The yield is 20.46% higher when basin water depth is 2 cm as compared to 4 cm basin water depth from 8:00 hrs. to 17:00 hrs. The results indicated that the production of distilled water increases with the increase in wind velocity, cooling the glass covers and the decrease in water depth. Keyword-Solar still, acrylic, solar desalination, East-West and North-South orientation. I. INTRODUCTION Next to the oxygen, the fresh water is essential for sustaining the human life. About 97 % of water available earth are brackish or saline and 2 % of water available in the form glaciers. Thus, only 1% of the earth, water are potable i.e. drinkable [1-4]. Much of the world's population does not have access to safe drinking water, which is the main cause of waterborne diseases that kill on the average more than 6 million children each year. Hence, we must find new and reasonable ways of producing pure water from brackish/saline water. Solar distillation is a good method for water purification and requires solar energy for its operation which is environmentally friendly and free [5-7]. The construction and operation of a solar still are very simple. There is a black painted basin, which contains brackish water and it's covered by a transparent cover. The incident solar radiation falls on the black pained basin and the brackish water gets evaporated and it's condensed on condensing cover and gets collected [8-10]. A.A. Al-Karaghouli and W.E. Alnaser reported that the production of a double slope, solar still is greater than the single basin solar still [11]. M.M. Morad et al. has conducted an experiment and reported that the passive solar still production rate is increased when there is cooling of condensing cover [12]. T. Rajaseenivasan and K. Kalidasa Murugavel have carried out their experiment and concluded that the production rate is maximum when basin water depth is minimum. They have also reported that the production of a double basin solar still is higher than the single basin solar still [3]. M. Zeroual et al. has presented the result of an experiment carried out with a solar still that the average daily output of a double slope, solar still is improved by 11.82% when the north glass is cooled by water on flowing on it [13]. V.K. Dwivedi and G.N. Tiwari have reported that the thermal efficiency of double slope passive solar still is higher than the double slope active solar still [14]. Margarita Castillo-Tellez et al. conducted an experiment and based on experimental results they concluded that the rate of production of solar still will be increased when wind velocity increase up to a certain limit, they reported that the wind velocity should not be greater than 5.5 m/s for their experimental setup [15]. G.N.Tiwari et al. reported that the East-West orientation of DSSS has a greater production rate than the single slope, solar still in summer condition because the sun is at a higher position in summer condition [16]. It is clear from the above literature review numerous studies were published on a double slope solar still desalination system. The main objective of doing this project is to study the effects of various parameters like water depth, wind velocity, cooling of condensing glass covers and solar radiation etc. on the productivity of DSSS for the climatic condition of Sultanpur and also to study the orientation is good for the Sultanpur climatic condition.

Experimental Investigation of Modified Solar Still Productivity under Variable Climatic Conditions

International Journal of Design & Nature and Ecodynamics, 2020

Conversion of untreated water into drinking water using solar distillation technology can be considered as the most viable methods in the dry climate regions and remote areas. The productivity of solar stills influences by various conditions such as design, operational and environmental conditions. The current paper includes a practical investigation of the effects the climatic conditions on the fresh water production from modified single-slope solar still in Russia. Results analysis showed that the mechanism of heat transfer and mass transfer within the solar still depend on environmental parameters. The heat transfer coefficients have been gradually increased from the early morning after 08:00 am and reached the highest value at the noon then decrease gradually afternoon to reach the lowest value at 20:00 pm. The maximum value of coefficient of heat transfer by evaporation found to be 12.1 W/m 2. K at 17:00 pm on 19.06.2019, then 9.9 W/m 2. K at 17:00 pm on 18.06.2019, and 2 W/m 2. K at 18:00 pm on 17.06.2019. Therefore, a noticeable improvement in the fresh water productivity from solar still has been observed with increasing solar radiation intensity, ambient temperature and decreasing relative humidity. The amount of production during a cloudy day was 287 ml/m 2 , 620 ml/m 2 for a partial cloudy day and 950 ml/m 2 during a sunny day.

A Review of Different Solar Still for Augmenting Fresh Water Yield

Journal of Environmental Science and Technology, 2015

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.

Analytical Comparison and Evaluation of Single Slope Single Basin Stepped Type Solar Still

International Journal of Advance Research and Innovative Ideas in Education, 2017

Concern for environment and ever increasing demand for energy, combined with relentless advancement in renewable energy innovations, are interested in the new opportunities to accomplish in the field of use of renewable energy resources. Till date, solar energy is the most clean, cheap and inexhaustible among all renewable resources. The power from the sun is many times larger than the present rate of energy consumption on the earth. Solar still is one of the finest ways to harness the solar power. A simple and effective device which is applied for obtain distilled water from the saline water with the solar desalination process is known as solar still. The conventional still produces 2–3 l fresh water per day (9AM to 5PM) but the output of stepped solar still is quite high compared to the conventional. There are various scientists and researchers who investigated the effect of design parameters, climate parameters and operational parameters to review the effect of these parameters w...

Performance analysis of modified solar still with forced water circulation

Thermal Science, 2017

This work is aimed to enhance the evaporation rate of water in the basin and the condensation rate of water vapour on the glass cover of a solar still. The evaporation rate is enhanced by supplying more solar thermal radiation and the condensation rate of water vapour is improved by removing more thermal energy from the glass cover. For enhancing the evaporation rate of water, the evacuated tubes were integrated with the stepped basin to increase the water surface area exposed to solar radiation. The internal and external reflectors reflect solar radiation on the water of the stepped still basin and inside the evacuated tubes. The forced water circulation maintains the thin film of water on the basin. Water sprinkling on the glass cover removed more thermal energy from it. As a result, the condensation rate was high. Comparisons between the modified stepped solar still with conventional solar still was carried out to evaluate the performance under the same climatic conditions. The productivity of the modified stepped solar still with reflectors and sprinkled glass cover cooling was 8660 ml/day.

DEVELOPMENT AND PERFORMANCE EVALUATION OF A SOLAR WATER STILL

The availability of potable water is a necessity for human existence. A simple laboratory scale solar water still capable of holding 75 litres of water has been developed and evaluated. The highest temperature in the solar still occurred at the vapour region and reached up to 66°C. The productivity of the solar still varies with the depth of water in the still. The results of the productivity were 67.4 ml/m 2 h, 54.2 ml/m 2 h and 43.4 ml/m 2 h for depths of 20 mm, 40 mm and 60 mm respectively. The efficiency of the solar still was found to vary with the depth of water in the basin. The highest efficiency obtained for the solar still was 29.1% at a depth of 20 mm. Characterization of water quality before and after distillation in the solar still showed a reduction in chemical and microbiological constituents after distillation which was comparable to standard drinking water. The solar still could be developed at a small-scale workshop at reasonably cheap costs. Further work to improve the productivity of the solar water still is proposed. INTRODUCTION Supply of potable water is a major problem particularly in developing countries. The problem often faced is that protected or improved sources, such as boreholes and treated urban supplies, can still be contaminated such that microbiologically unsafe water is delivered [1]. Of major concern is the populace dwelling in rural regions of developing countries who do not have access to these improved sources and are at higher health risks as they depend on the natural sources like rivers, streams and springs which are often contaminated. The ability to be able to treat water on a domestic scale will therefore be of immense benefit. Nigeria lies within a high sunshine belt and solar radiation is fairly well distributed within the country. The annual average total solar radiation varies from 12.6 MJ/m 2-day in the coastal latitudes to 25.2MJ/m 2-day in the far north [2]. This vast amount of solar energy could be utilized in purifying water domestically. Solar distillation has been largely used in desalination. It involves utilizing solar energy for heating of water to cause evaporation. The vapour produced, then, condenses to produce distilled water. Gomkali and Datta [3] designed a simple solar still with a double-sloped glass cover plate which had an annual average productivity of 2.5 l/m 2-day and at an efficiency of 28%. Naim [4] also devised a single-stage solar desalination spirally-wound module which had maximum distillation efficiency of 34% and with a productivity of 575 ml/m 2-h. Medugu and Malgwi [5] designed and tested a solar still and claimed that the instantaneous efficiency increases with the increase of solar radiation and with increase of feed water temperature. Tarawneh [6] studied the effect of water depth on the performance evaluation of a solar still and stated that decreased water depth has a significant effect on increased water productivity, noting that the productivity of