Experimental and Numerical Simulation of Solar Still for the Production of Drinking Water in Desert Areas of Southern Algeria

2018 ◽  
Vol 26 (03) ◽  
pp. 1850024
Author(s):  
Mekki Zerouali ◽  
Fouad Khaldi ◽  
Zina Belkhiri

Solar distillation is a simple method used for the production of drinking water from saline or brackish water. This method proposes a solution for the production of fresh water in arid and desert areas, where a large solar field is available and also the existence of underground sources of saline water. A solar distiller with a single basin and double slopes is theoretically examined. The theoretical model is based on the resolution of equations of heat and mass transfer dependent on time for glazing cover, water film and absorber basin. For validating the results of the theoretical model, a comparison with the experimental results was carried out. A series of experimental tests on a solar distiller with double slopes in the climatic conditions of Ouargla in Algeria were performed. The tests were carried out on 19th February 2009. The amount of water distilled was 2.7 liters, after a day’s work. The results show that the cooling of the glazing cover leads to increase in the amount of distilled water of about 17% in comparison with the reference case. In addition, we found a good agreement between the results of the theoretical model and the experimental data.

Author(s):  
R. Vesipa ◽  
C. Camporeale ◽  
L. Ridolfi

Precipitation of calcium carbonate from water films generates fascinating calcite morphologies that have attracted scientific interest over past centuries. Nowadays, speleothems are no longer known only for their beauty but they are also recognized to be precious records of past climatic conditions, and research aims to unveil and understand the mechanisms responsible for their morphological evolution. In this paper, we focus on crenulations, a widely observed ripple-like instability of the the calcite–water interface that develops orthogonally to the film flow. We expand a previous work providing new insights about the chemical and physical mechanisms that drive the formation of crenulations. In particular, we demonstrate the marginal role played by carbon dioxide transport in generating crenulation patterns, which are indeed induced by the hydrodynamic response of the free surface of the water film. Furthermore, we investigate the role of different environmental parameters, such as temperature, concentration of dissolved ions and wall slope. We also assess the convective/absolute nature of the crenulation instability. Finally, the possibility of using crenulation wavelength as a proxy of past flows is briefly discussed from a theoretical point of view.


2016 ◽  
Vol 19 (3) ◽  
Author(s):  
NASIR SUBRIYER

<p>The declining water quality in Sriwijaya University has been caused by the presence of heavy metal contents such as Iron (Fe) and Zinc (Zn) in the treatment and distribution of water. A simple method is proposed in this work to minimize the heavy metal content in water by using filtration technology. This research was carried out using ceramic filter made of 77.5% natural clay, 20% fly ash, and 2.5% iron powder. The results showed an increase in the quality of raw water that is in accordance with the requirement of drinking water standard. The rejection percentage of TDS, Iron (Fe) and Zinc (Zn) content in feed water tended to be high and met the regulation number 492/MENKES/PER/IV/2010 for standards of drinking water in Indonesia.</p>


2019 ◽  
Vol 6 (2) ◽  
pp. 91-102
Author(s):  
R. Sivakumaran ◽  
P. Jdihesh

The world is facing the state of being scarce of fresh or drinking water and it is the major problem and global challenge. Along with air and food, water is a basic necessity for human. Solar energy is the biggest source of energy available on earth. A solar distillation is one of the methods for purifying salt water to drinking water. In this method fresh water is obtained by exposing a small layer of salt water to solar radiation and the water vaporized from the basin is condensed on the bottom side of a taper transparent cover. It can be collected in receiving troughs at the end of the still. For this research, a solar still has been designed, fabricated and tested under the climate condition of Coimbatore (11.01680 N, 76.9550 E), India from December 2016 to March 2017. The still basin area was 1m2 and the glass cover of still is inclined at 13 degree based on the city latitude. Solar still is integrated with thermal system such as solar photovoltaic system and then with solar pond in order to preheat the feed water thereby increasing the productivity considerably. Experiments were carried out on the still using different parameters and tested for performance. The results showed that the daily production of the conventional solar still was 2 Lit/m2/day and integrated with photovoltaic system and solar pond was 3.1 Lit/m2/day and 2.54 Lit/m2/day respectively.


Water ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2387
Author(s):  
José Garcés-Vargas ◽  
Wolfgang Schneider ◽  
Andre Pinochet ◽  
Andrea Piñones ◽  
Francisco Olguin ◽  
...  

The Valdivia River estuary (VRE) located in south-central Chile is known as one of the largest estuarine ecosystems on the Pacific coast. This research aims to determine the intra-tidal and sub-tidal variability of saline intrusions into the VRE between November 2017 and March 2019 derived from salinity sensors located along the VRE. Complementary hydrographic measurements were conducted during flood and ebb conditions of the spring and neap tides for each of the four seasons of the year along the central axis of the VRE. The results of the salinity time series showed that saline intrusions (values greater than 0.5 Practical Salinity Units) occurred ~20 km from the estuary mouth, when the total flow of the Cruces and Calle-Calle rivers (main tributaries of the estuary) was low, around 280–300 m3 s−1. During the same period, the best co-variability was observed between the saline intrusions and the mixed-semidiurnal tide and the fortnightly and monthly periods of the tide. Regression analyses indicated that salinity intrusion length (L) is best correlated to discharge (D) with a fractional power model L α D−1/2.64 (R2 = 0.88). The decreasing discharge trend, found between 2008–2019, implies that saline water intrusions would negatively impact the Valdivia’s main drinking water intake during the low rainfall season under future climate conditions.


2019 ◽  
Vol 9 (24) ◽  
pp. 5345
Author(s):  
Shijie Jiang ◽  
Yinfang Shi ◽  
Yannick Siyajeu ◽  
Ming Zhan ◽  
Chunyu Zhao ◽  
...  

Material extrusion (ME), an additive manufacturing technique, can fabricate parts almost without geometrical limitations. With the growing application of ME parts, especially in actual working conditions, the dynamic characteristics are needed to be studied to accurately determine their reliability. This study provides an experimental validation of the theoretical model for predicting the dynamic characteristics of ME plates fabricated with three different key processing parameters, i.e., extrusion width, layer height and build direction. The model is set up based on the bidirectional beam function combination method, and a series of experimental tests are performed. It is found that different processing parameters result in the material properties of the samples to vary, thus leading to different dynamic characteristics. Through the comparison between predictions and measurements, it is shown that the influencing trend of the processing parameters is predicted precisely. The theoretical model gives reliable predictions in dynamic characteristics of ME plates. The natural frequency discrepancy is below 13.4%, and the predicted mode shapes are the same as the measured ones. This present work provides theoretical basis and technical support for further research in improving the dynamic performance of ME products, and helps extend the applications of this technique.


Electronics ◽  
2019 ◽  
Vol 8 (8) ◽  
pp. 858 ◽  
Author(s):  
Sadeq D. Al-Majidi ◽  
Maysam F. Abbod ◽  
Hamed S. Al-Raweshidy

Maximum power point tracking (MPPT) techniques are a fundamental part in photovoltaic system design for increasing the generated output power of a photovoltaic array. Whilst varying techniques have been proposed, the adaptive neural-fuzzy inference system (ANFIS) is the most powerful method for an MPPT because of its fast response and less oscillation. However, accurate training data are a big challenge for designing an efficient ANFIS-MPPT. In this paper, an ANFIS-MPPT method based on a large experimental training data is designed to avoid the system from experiencing a high training error. Those data are collected throughout the whole of 2018 from experimental tests of a photovoltaic array installed at Brunel University, London, United Kingdom. Normally, data from experimental tests include errors and therefore are analyzed using a curve fitting technique to optimize the tuning of ANFIS model. To evaluate the performance, the proposed ANFIS-MPPT method is simulated using a MATLAB/Simulink model for a photovoltaic system. A real measurement test of a semi-cloudy day is used to calculate the average efficiency of the proposed method under varying climatic conditions. The results reveal that the proposed method accurately tracks the optimized maximum power point whilst achieving efficiencies of more than 99.3%.


2018 ◽  
Vol 7 (4.24) ◽  
pp. 688
Author(s):  
R. Gnanasekaran ◽  
Ramya. K ◽  
D. Yuvaraj ◽  
Noorul Jamela

Drinking Water scarcity is one of the leading issue in our growing world. The atmospheric air contains large amount of water in the form of water vapor, fog, mist etc.In which 30% of water is wasted.Under this situation the climatic conditions of many regions are suitable for generating water. This moisture content is processed by condensation principle to produce fresh water that may be used as distilled water in laboratory and further purification leads to drinking water purity level. Here cooling is produced by Peltier effect and hot air is passed to cooling medium and when it reaches dew point it start condensing water from air. The obtained water from air contain excess of contaminants such as bacteria, nitrate, nitrate, odor, ammonium etc.., these toxic substances are remove by using biofiltration method. In this research filter medium is constructed by extraction of Activated charcoal from coconut waste. . The main aim of our project is utilization of renewable resources that are already available in nature and turn back this energy into water. This project is design a device that can convert humid air directly into clean water.    


2020 ◽  
Vol 57 (1) ◽  
pp. 100-114 ◽  
Author(s):  
Arash Azizi ◽  
Guido Musso ◽  
Cristina Jommi

Soils used in earth construction projects are mostly unsaturated, and they undergo frequent drying–wetting cycles (repeated hydraulic loads) due to changes in climatic conditions or variations of the ground water level, particularly at shallow depths. After compaction, changes in water content can significantly influence the hydromechanical response of the construction material, which therefore must be assessed for repeated hydraulic loads. This research investigates the effect of such loads on the microstructure and hydraulic behaviour of a silty soil, typically used in the construction of embankments and dykes, with the aim of providing a better understanding of the consequences of drying–wetting cycles on the response of the material over time. Experimental tests were performed to study the impact of drying–wetting cycles on the water retention, hydraulic conductivity, and fabric of compacted specimens. Fabric changes are documented to take place even without significant volumetric strains, promoting an irreversible increase in the hydraulic conductivity and a reduction in the capacity to retain water compared to the as-compacted soil. The fabric changes are interpreted and quantified by means of a hydromechanical model, which accounts for the evolving pore-size distribution at different structural levels. The proposed model reproduces quite well the microstructural observations, together with the evolution of the water retention behaviour and hydraulic conductivity.


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