Effect of energy storage medium (black granite gravel) on the performance of a solar still
TL;DR: In this paper, a detailed experiment has been conducted on a single-basin solar still which is modified with energy storage medium of black granite gravel for absorbing the excess heat energy from solar radiation during the noon hours.
Abstract: In this study, a detailed experiment has been conducted on a single-basin solar still which is modified with energy storage medium of black granite gravel. An attempt has been made to utilize the maximum amount of solar energy and to reduce the heat loss from the sides and bottom of the still. The conventional still is modified with an energy storage medium of black granite gravel of 6 mm size which is provided in the basin for different (quantity) depths. The black granite gravel functions as energy storage medium and also as an insulation layer to reduce the bottom and side loss coefficients. The black gravel is used for absorbing the excess heat energy from solar radiation during the noon hours. Due to this, the heat accumulated in the space between the water and glass surface is reduced and hence the temperature difference between the water and glass surfaces increases. The depth (quantity) of the gravel layer in the basin will influence the performance of the still and some of the parameters like basin temperature, water temperature, glass temperature and still productivity. This study deals with the effect of aforesaid parameters on the performance of the still. An attempt has been made to optimize the still performance for the above-mentioned parameters. A mathematical model is developed to estimate the water, gravel, and inside glass temperatures theoretically and to estimate the hourly and daily yield. To show the effectiveness of the modification, its performance is compared with the conventional still under the same climatic condition. It is found that the still yield is increased by 17-20% with almost no cost for this modification as black granite gravel is very cheap. Error analysis was done by comparing the theoretical and experimental results to show the validity of the mathematical model. It is found that the maximum percentage of discrepancy for all the parameters is about ±18%. Theoretical value of yield per day has 8% discrepancy over experimental value.
Citations
More filters
TL;DR: In this article, the authors explore the implementation of thermal energy storage in district heating and cooling systems, highlighting their potential in combination with district heating, taking into account the research maturity of each type technology.
209 citations
TL;DR: In this paper, the authors analyzed the many studies on factors that affect the performance of solar stills and showed that the distillation productivity was significantly influenced by ambient conditions (e.g., ambient temperature, insolation, wind velocity, dust and cloud cover), operating conditions, and design conditions, such as different passive/active designs, slope of the cover, materials selection, storing materials, reflectors, insulation, gap distance and sun tracking system).
Abstract: Reasonable amounts of fresh water can be produced via inexpensive and sturdy solar stills in places that are exposed to solar radiation and have a brackish water. This work intends to analyze the many studies on factors that affect the performance of solar stills. The results showed that the distillation productivity of solar stills are significantly influenced by ambient conditions (e.g., ambient temperature, insolation, wind velocity, dust and cloud cover), operating conditions (e.g., depth of water, various dyes, salt concentration and inlet temperature of water), and design conditions (e.g., different passive/active designs of solar stills, slope of the cover, materials selection, storing materials, reflectors, insulation, gap distance and sun tracking system). It was also determined that the performance of solar stills was improved through the increase in solar radiation, ambient air temperature, wind speed, and water absorptivity. This also rings through with the decrease in water depth, thickness of cover, gap distance between water surface and condensing cover. It was also determined that both internal and external reflectors are capable of increasing the amount of absorbed solar radiation on the basin liner. The potential output of a basin type still can potentially increase to almost 70–100%. On top of this, the utilization of a sun tracking system was determined to be way more effective in improving the performance of solar still. This translate to the fact that solar stills being able to produce potable water at a very economical cost. Due to the existence of different methods of cost estimation, it is not possible to determine a universal, comparable price per technology; the cost per liter of distilled water obtained from the basin type solar still is ranged from 0.035 to 0.074$/liter. This study proved the fact that distillation productivity of solar still is heavily influenced by climatic, operational, and design parameters. Its output can be further improved via operational and design conditions, as climatic conditions are beyond our control.
190 citations
TL;DR: In this paper, a review of factors affecting solar still production (climatic conditions, operations and design parameters) and enhancement techniques (wicks, internal condensers, internal and external reflectors, phase change materials, Stepped solar still and a new method improved the solar still yield by using nanoparticles) has been argued.
189 citations
TL;DR: In this paper, the effects of nanoparticle-enhanced phase change material (NPCM) on solar still operation and performance were investigated, where three types of nanoparticles (TiO2, CuO and GO) were impregnated individually at 0.3 weight% in paraffin.
187 citations
TL;DR: In this paper, a v-corrugated absorber solar still with built-in phase change material (PCM) is presented, which allows for the expansion of melting wax through a net of tubes extended inside the storage tank.
170 citations
References
More filters
TL;DR: In this paper, the performance of a solar still with different size sponge cubes placed in the basin was studied experimentally, and the results showed that the daily production of such a still can be greatly enhanced using sponge cubes.
248 citations
TL;DR: Using black rubber or black gravel materials within a single sloped solar still as a storage medium is examined in this article, and the experimental results showed that using black gravel of 20-30 mm size improves the productivity by 19% at the conditions of 20 l/m2 brine volume and 15° of glass cover angle.
239 citations
TL;DR: In this paper, a regenerative solar desalination unit is modeled and its performance evaluated, and the results of the simulations show that the productivity of the regenerative still is 20% higher compared to the conventional still.
236 citations
TL;DR: In this article, the effect of using different absorbing materials in a solar still, and thus enhancing the productivity of water, was studied, and it was shown that using an absorbing black rubber mat increased the daily water productivity by 38%. Using black ink increased it by 45%.
194 citations
TL;DR: In this paper, the main parameters affecting solar still performance under the weather conditions of the Suez Gulf area are investigated and a general equation is developed to predict the daily productivity of a single sloped solar still.
186 citations