Higher Distillate Yield Research Articles

Experimental study of mono and hybrid nanofluids on square pyramid solar still.

The lower productivity of square pyramid solar still is the prime impediment to its worldwide applicability. In the present study, efforts have been made to improve the productivity of square pyramid solar still using mono and hybrid nanofluid. The experiments were carried out with two similar square pyramid solar stills at a 1cm depth of basin fluid (saline water, mono, and hybrid nanofluid) under the climate of location (20.61°N 72.91°E). Copper (Cu) and aluminum oxide (Al2O3) nanoparticles were chosen to prepare mono and hybrid nanofluid. The 0.1% weight concentration of mono and hybrid nanofluid was prepared for experimentation. The hybrid nanofluid was prepared for the different mixing proportions of Al2O3-Cu such as 80:20, 60:40, 50:50, 40:60, and 20:80. For the case of use of mono-nanofluid, the performance of square pyramid solar still with Cu nanofluid was higher than Al2O3 nanofluid. The total productivity of 1640 mL/m2 and diurnal average efficiency of 17.00% were achieved for square pyramid solar still with Cu mono-nanofluid than saline water. A higher distillate yield was achieved for the square pyramid solar still with hybrid nanofluid than the mono-nanofluid and saline water. The diurnal average efficiency of 34.50% and maximum distillate output of 2644 mL/m2 were obtained for the square pyramid solar still with Al2O3-Cu hybrid nanofluid for the mixing ratio of 20:80. The efficiency and distillate output were higher by 27.41% and 25.19% for the square pyramid solar still with Al2O3-Cu (20:80) hybrid nanofluid than the square pyramid solar still with saline water. The distillate yield decreases with a decrease in the proportion of Cu nanoparticles.

Investigation and performance analysis of solar still with energy storage materials: An energy- exergy efficiency analysis

Researchers have attempted different Energy storage materials (ESM) in solar stills (SS) to improve distillate yield. In this experimental work, an attempt was made to increase the distillate yield & efficiency of SS, using good absorbing and heat transfer capacity of ESM. A comparison was made between a conventional solar still (CSS) and a solar still with energy storage materials (SSWESM) in this experiment. Different energy storage materials like black color glass ball (BCGB), black granite (BG) and white marble stone (WMS) were used in equal quantity during experimental work. CSS and SSWESM had daily distillate yield of 1.4 kg/m2 and 2.5 kg/m2, respectively. The ESM boosts water evaporation during the day and releases heat at night, resulting in a higher distillate yield than CSS. Meanwhile, the exergy efficiency (ƞexe) of CSS and SSWESM were 4.99% and 12.55% respectively. Also the SSWESM gives 72.6% more daily efficiency (ƞ) than CSS.

Performance evaluation of single slope solar still augmented with the ultrasonic fogger

The surface area of basin water exposed to the incident solar radiations plays a vital role in the performance of a conventional solar still (CSS). This research article presents a new method to increase the distillate yield of CSS by augmenting it with an ultrasonic fogger/humidifier. Experimental and theoretical investigations are performed on CSS and CSS augmented with Ultrasonic fogger (MSS). The heat transfer coefficients were evaluated by using a thermal model which is based on regression analysis. The ultrasonic fogger has increased the water surface area and introduced the turbulence in the basin water, which results in the better performance of MSS over CSS. There has been an improvement of 97% in the value of evaporative heat transfer coefficient for MSS in comparison to CSS. MSS gives 33.26% higher distillate yield from 11:00 to 18:00 h in contrast to CSS. The augmentation of ultrasonic fogger has increased the mean thermal efficiency of MSS by 31.04%. It has been observed that the MSS yields remarkably when the direct solar radiations are falling on it. The per liter cost of potable water produced from MSS is 9.89% lower than its CSS counterpart.

Experimental investigation of modified single slope solar still integrated with earth (I) &(II):Energy and exergy analysis

In this article, an attempt has been made to examine the experimental and theoretical results of two newly developed Modified single slope solar stills integrated with earth (MSSIE) viz. MSSIE(I) and MSSIE(II), using Dunkle, Kumar & Tiwari, Clark, modified Spalding's mass transfer theory and Tsilingiris models. In MSSIE(II) the polythene covering has substantially elevated the energy of nearby ground which results in 11.2% higher distillate yield than MSSIE(I). Kumar & Tiwari model gives good agreement with the results obtained from the experimentation. It has deviation of 3.53 and 4.03% for MSSIE(I) and MSSIE(II) respectively. Total internal and exergy efficiency (Kumar & Tiwari model) of MSSIE(II) leads by 5.06 and 76.64% as compared to MSSIE(I) respectively. Maximum exergy destruction has been recorded in the basin area. MSSIE(II) shows a reduction of 2.96% in exergy destruction as comparison to MSSIE(I). From experimental and theoretical results it has been observed that, the proposed model (MSSIE(II)) maintain its lead throughout the experimentation and hence can be a good option for potable water production in coastal areas.

Augmentation of distillate yield in “V”-type inclined wick solar still with cotton gauze cooling under regenerative effect

AbstractWater flowing over bare glass is not evenly distributed over the width of the glass cover. Effective temperature reduction in the glass cover is not possible in this case. Thin cotton gauze is used over the glass cover to solve this problem. The amount of water required to cool the glass cover is low and the flowing water is collected and fed into a hot water reservoir. Water from the hot water reservoir is directed to the wick absorber by a drip valve. The system was tested in two ways (i) regenerative effect with cotton gauze (ii) regenerative effect without cotton gauze. The inclined wick absorber ensures that the surface is always wet due to capillary action and there were no dry spots. Excess flow in the wick absorber is pumped back to the hot water reservoir. Due to low thermal inertia of the wick and regenerative effect, the system has quick start-up times, as well as higher operating temperatures. This resulted in higher distillate yield than simple solar stills. Since the hot water reserv...

Experimental and theoretical analysis of single sloped basin type solar still consisting of multiple low thermal inertia floating porous absorbers

This paper presents the experimental and theoretical work, conducted in central India at Rewa (M.P.) (24°32″N, 81°18″E) to analyse the performance of modified basin type solar still, incorporating multiple low thermal inertia porous absorbers, floated adjacent to each other on the basin water with the help of thermocol insulation. The porous absorbers were made up of ordinary blackened jute cloth. Multiple floating absorbers of smaller width ensured that the absorber surface was always wet due to capillary action and there were no dry spots. Due to low thermal inertia of the porous absorber, quicker start-up times, as well as higher operating temperatures were achieved resulting in higher distillate yield. Also, the increase in the evaporation surface area further aided the performance. In order to evaluate the improvement obtained by the modification, the performance of the modified still was compared with a conventional basin type solar still of same size, under similar operating conditions on both clear and partially clear days. The results indicate that on clear days, about 68% more distillate output was obtained by the modified still, whereas it was nearly 35% more on cloudy days. Since the basin water beneath the floating insulation remained warm enough during the off shine hours, reasonable amount of nocturnal distillate output was also obtained from the modified still. A twin reflector booster was constructed by placing two plane mirrors mutually perpendicular to each other. On applying the twin reflector booster with the modified still an increase in the yield by 79% was obtained over the modified still without booster. The basin water depth does not have any significant effect on the performance of the modified still; therefore the modification can be effectively applied on deep basin stills also. Results obtained from the thermal model have fair agreement with the experimental values. The effect of wind transfer coefficient, base heat loss coefficient and the floating insulation heat transfer coefficient has also been theoretically analysed.