T. Arunkumar

Experimental Study on Various Solar Still Designs

Humankind has depended for ages on underground water reservoirs for its fresh water needs. But these sources do not always prove to be useful due to the presence of excessive salinity in the water. In this paper, the fabrication of seven solar still designs such as spherical solar still, pyramid solar still, hemispherical solar still, double basin glass solar still, concentrator coupled single slope solar still, tubular solar still and tubular solar still coupled with pyramid solar still and their performance evaluation in converting brackish water into fresh water for drinking are presented. The experiment was constructed and tested during January to May 2011. All the solar stills were operated in the same climatic conditions to analyze the influence of the modifications on the productivity. From the observations, the compound parabolic concentrator-assisted tubular solar still shows the maximum yield.

Geometrical variations in solar stills for improving the fresh water yield—A review

AbstractWater consumption by humanity is one of the major yardsticks to assess its civilization. Humans depend on groundwater sources for drinking. Some of these underground water sources cannot be used for drinking due to pollution. To solve the issues related to drinking water, several methods are employed, and a promising one is solar desalination. This paper communicates a review of different geometrical shapes of solar still. The present study concludes that the geometry in the solar still significantly influences the yield of fresh water.

Experimental Study on a Compound Parabolic Concentrator Tubular Solar Still Tied with Pyramid Solar Still

Water is a nature’s gift and it plays a key role in the development of an economy and in turn for the welfare of a nation. Non-availability of drinking water is one of the major problem faced by both the under developed and developing countries all over the world. Around 97% of the water in the world is in the ocean, approximately 2% of the water in the world is at present stored as ice in polar region, and 1% is fresh water available for the need of the plants, animals and human life [1]. Researchers have been carried out in this method by Nij‐ meh, et al., [2], they have been investigated the regenerative, conventional and double-glasscover cooling solar still theoretically and experimentally. Several system parameters were also investigated with respect to their effect on the productivity, namely, water with and without dye in the lower basin, basin heat loss coefficient, and mass of water in the basins and mass flow rate into the double-glass cover. Thermal performances of a solar still cou‐ pled with flat plate heater along with an evaporator-condenser have been analyzed by Rene Tchinda, et al., [3]. They reported that the theoretical solar still productivity is in reasonably good agreement with the experimental distillation yields. Thermal performances of a regen‐ erative active solar distillation system working under the thermosyphon mode of operation have been studied by Singh and Tiwari for Indian climatic condition. It is concluded that (i) there is a significant improvement in overall performance due to water flow over the glass cover and (ii) the hot water available due to the regenerative effect does not enhance the out‐ put. They derived expressions for water and glass temperatures, hourly yield and instanta‐ neous efficiency for both passive and active solar distillation systems [4]. Chouchi et al., [5] have designed and built a small solar desalination unit equipped with a parabolic concentra‐ tor. The results show that, the maximum efficiency corresponds to the maximum solar light‐

Economic and exergy investigation of triangular pyramid solar still integrated to inclined solar still with baffles

ABSTRACT This paper presents the detailed exergy and economic investigation of triangular pyramid solar still under passive and active mode of operation. For validation, experiments were carried out at different water depth maintained inside the basin under a continuous flow of water from an inclined solar still. Results confirm that the effect of integration rises the exergy efficiency during the offshine period, whereas during the sunshine hours the exergy efficiency decreases when the maintained the depth of water inside basin decreases. Similar study on economic analysis shows that the net pay back period increases from 5.6 to 11.4 with an increase in the water depth at an average selling price of water Rs 5/kg in a standalone triangular pyramid solar still.

Effect of forced cover cooling technique on a triangular pyramid solar still

Abstract In the present study a triangular pyramid solar still is theoretically analysed by flowing air over the entire surface of the glass from the top to analyse the improvement in yield of fresh water. The effect of water mass and wind velocity was theoretically analysed. The results show that there is a significant improvement in the yield of fresh water to about 10.1 kg/m2 with a maximum velocity of air (U = 40 m/s) at a least water mass of 20 kg inside the basin. For practical cases the yield of fresh water depends on naturally occurring wind velocity and the results show that the improvement in yield is 104% with an increase in velocity from 0.5 to 4 m/s.

Effects of electric potential, NaCl, pH and distance between electrodes on efficiency of electrolysis in landfill leachate treatment

ABSTRACT This study investigated the effects of different parameters on the removal efficiencies of organic and inorganic pollutants in landfill leachate treatment by electrolysis. Different parameters were considered such as the electric potential (e.g., 24, 40 and 60 V), hydraulic retention time (HRT) (e.g., 40, 60, 80, 100 and 120 min), sodium chloride (NaCl) concentration (e.g., 1, 3, 5 and 7%), pH (e.g., 3, 7 and 9), electrodes materials [e.g., aluminum (Al) and iron (Fe)] and distance between electrodes (e.g., 1, 2 and 3 cm). The best operational condition of electrolysis was then recommended. The electric potential of 60 V with HRT of 120 min at 5% of NaCl solution using Al as anode and Fe as cathode (kept at a distance of 3 cm) was the most efficient condition which increased the removal efficiencies of various parameters such as turbidity, salinity, total suspended solids (TSS), total dissolved solids (TDS), biochemical oxygen demand (BOD), chemical oxygen demand (COD) and heavy metals (e.g., Zn and Mn). The higher removal percentages of many parameters, especially COD (94%) and Mn (93%) indicated that the electrolysis is an efficient technique for multi-pollutants (e.g., organic, inorganic and heavy metals) removal from the landfill leachate.

Annual Performance analysis of Single basin passive solar still coupled with evacuated tubes : Comprehensive study in climate conditions of Mahesana, Gujarat

ABSTRACT A solar still is very simple device to convert available brackish or saline water into drinkable water by use of solar energy. But due to its lower distillate output, it is not used widely for industrial and domestic potable water application. In the present research paper, annual performance analysis of a single-basin passive solar still with vacuum tubes (SBSWVT) is carried out in climate conditions of Mahesna, Gujarat, India, during July 2011–June 2012. From constant research work of 1 year, energy payback time of 176 days and cost of water produced of around 0.716 Rs per litre have been found.