scholarly journals A Thermal Model for Predicting the Performance of a Solar Still with Fresnel Lens

Water ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1860 ◽  
Author(s):  
Ana Johnson ◽  
Lei Mu ◽  
Young Ho Park ◽  
Delia J. Valles ◽  
Huiyao Wang ◽  
...  
Keyword(s):  
New Mexico ◽  
Theoretical Model ◽  
Numerical Model ◽  
Water Depth ◽  
Thermal Model ◽  
Fresnel Lens ◽  
Significant Rise ◽  
Solar Still ◽  
Overall Efficiency ◽  
Water Depths

This study presents a theoretical model to simulate the temperatures and productivity of a single-slope, single-basin solar still when an external solar enhancement is used. Experiments were performed in the New Mexico region (32.3199° N, 106.7637° W) to validate the numerical model. A point focusing Fresnel lens was used in the experiments to enhance the solar input. It was found that a significant rise in the productivity of the still was achieved with the Fresnel lens. Parametric study by varying the water depth showed the Fresnel lens was more effective for larger water depths. In addition, the Fresnel lens can aid in improving the overall efficiency of the solar still.

Effect of Inclination of Condensing Cover and Water Depth in Solar Still for Maximum Yield: In Winter Climatic Condition

2005 ◽  
Author(s):  
Anil Kr Tiwari ◽  
G. N. Tiwari
Keyword(s):  
Mass Transfer ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Water Depth ◽  
Climatic Condition ◽  
Maximum Yield ◽  
Effective Area ◽  
Solar Still ◽  
Passive Solar Still ◽  
Water Depths

In this communication, an effect of inclination of condensing cover and water depth in still, on convective mass transfer coefficient in passive solar still has been studied. Three solar stills with effective basin area of 1 m2 for three inclinations of condensing cover namely 15°, 30° and 45° have been considered. Another still with same effective area but fixed cover inclination of 30° is considered to see the effect of water depths on still performance for water depths 0.04m, 0.08m, 0.12m, 0.16m and 0.18m. Outdoor experiments have been conducted for Delhi climatic condition. Hourly variations of water, vapor, and cover temperatures along with yield have been measured. Regression analysis is used to determine the convective heat and mass transfer coefficient for outdoor condition. The 45° condensing cover is found giving maximum yield and lower water depth responded for higher yield in winter climatic condition.

Performance enhancement of a single slope solar still with single basin using Fresnel lens

2021 ◽  
Vol 15 (1) ◽  
pp. 7781-7791
Author(s):  
Parimal Sharad Bhambare ◽  
Dinesh Keloth Kaithari ◽  
Said Abdullah Rashid AI Hosni
Keyword(s):  
Experimental Study ◽  
Performance Enhancement ◽  
Fresnel Lens ◽  
International Standards ◽  
Solar Still ◽  
Distillate Yield ◽  
Overall Efficiency ◽  
Production Output

This paper presents an experimental study using Fresnel lens to increase the overall efficiency of the conventional Single Slope Solar Still (SSSS) with single basin. The work aims to increase the performance of single basin conventional SSSS while maintaining the simplicity and usability of the system. Especially in the rural parts of Oman, the device is very simple to use. For the present unit, the conventional single basin SSSS has been fitted with an adjustable Fresnel lens. The adjustment enables the carrying out the experiments with and without the Fresnel lens at our Institute. The equipment was constructed from simple available materials and was placed north-south during the experimentation. The Fresnel lens fitted frame once adjusted in the morning was kept at same position for the entire day without tracking. The depth of water in the basin was maintained constant at 0.02 m during the study. The distillate yield for single basin SSSS fitted with Fresnel lens is observed 3 to 3.5 times higher than the conventional. The overall efficiency of the system has also increased almost 32.19 percent over the conventional. The quality of the distillate was assessed, which was estimated to be within limits in compliance with international standards. In conclusion, Fresnel lens has significantly improved the distillate production output and overall efficiency of conventional single basin SSSS.

scholarly journals Microplastic contamination of the drilling bivalve Hiatella arctica in Arctic rhodolith beds

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sebastian Teichert ◽  
Martin G. J. Löder ◽  
Ines Pyko ◽  
Marlene Mordek ◽  
Christian Schulbert ◽  
...  
Keyword(s):  
Polyethylene Terephthalate ◽  
Water Depth ◽  
The Arctic ◽  
Polymer Composition ◽  
Bivalve Species ◽  
Filter Feeder ◽  
Hiatella Arctica ◽  
Long Term Consequences ◽  
Water Depths

AbstractThere is an increasing number of studies reporting microplastic (MP) contamination in the Arctic environment. We analysed MP abundance in samples from a marine Arctic ecosystem that has not been investigated in this context and that features a high biodiversity: hollow rhodoliths gouged by the bivalve Hiatella arctica. This bivalve is a filter feeder that potentially accumulates MPs and may therefore reflect MP contamination of the rhodolith ecosystem at northern Svalbard. Our analyses revealed that 100% of the examined specimens were contaminated with MP, ranging between one and 184 MP particles per bivalve in samples from two water depths. Polymer composition and abundance differed strongly between both water depths: samples from 40 m water depth showed a generally higher concentration of MPs and were clearly dominated by polystyrene, samples from 27 m water depth were more balanced in composition, mainly consisting of polyethylene, polyethylene terephthalate, and polypropylene. Long-term consequences of MP contamination in the investigated bivalve species and for the rhodolith bed ecosystem are yet unclear. However, the uptake of MPs may potentially impact H. arctica and consequently its functioning as ecosystem engineers in Arctic rhodolith beds.

Performance enhancement using TiO2 nano particles in solar still at variable water depth

2021 ◽  
pp. 1-8
Author(s):  
Ruchir Parikh ◽  
Umang Patdiwala ◽  
Shaival Parikh ◽  
Hitesh Panchal ◽  
Kishor Kumar Sadasivuni
Keyword(s):  
Water Depth ◽  
Performance Enhancement ◽  
Nano Particles ◽  
Solar Still ◽  
Variable Water

scholarly journals Production and water yield of cauliflower under irrigation depths and nitrogen doses

2019 ◽  
Vol 23 (8) ◽  
pp. 561-565
Author(s):  
Reginaldo M. de Oliveira ◽  
Rubens A. de Oliveira ◽  
Sanzio M. Vidigal ◽  
Ednaldo M. de Oliveira ◽  
Lorença B. Guimarães ◽  
...  
Keyword(s):  
Water Depth ◽  
Irrigation Water ◽  
Water Yield ◽  
Crop Evapotranspiration ◽  
Fresh Weight ◽  
Randomized Design ◽  
Mean Diameter ◽  
Irrigation Depth ◽  
Completely Randomized Design ◽  
Water Depths

ABSTRACT Cauliflower is a brassica produced and consumed in Brazil, whose cultivation depends on the adequate supply of water and nutrients. The objective of this study was to evaluate the effect of irrigation depths and nitrogen doses on the production components and water yield of cauliflower hybrid Barcelona CMS. The treatments consisted of five irrigation water depths (0, 75, 100, 125 and 150% of the crop evapotranspiration) combined with five nitrogen doses (0, 75, 150, 300 and 450 kg ha-1). The experiment was conducted in a completely randomized design with a split-plot arrangement. The effects of these factors were evaluated using the response surface methodology. The water yield of the crop decreases with increasing irrigation water depth; therefore, the yield is higher when water replenishment is lower than the recommended. The highest estimated total inflorescence yield is 24,547.80 kg ha-1, with a inflorescence mean diameter of 19.60 cm, a inflorescence mean height of 12.25 cm, and an inflorescence fresh weight of 858.90 g plant-1, obtained with an irrigation water depth equivalent to 132.09% of the crop evapotranspiration (ETc) and a nitrogen dose of 450 kg ha-1. The highest inflorescence diameter and height are obtained with an irrigation depth equivalent to 128.70 and 108.20% of ETc, respectively, and a nitrogen dose of 450 kg ha-1. Therefore, the best productivity response of the Barcelona CMS cauliflower hybrid can be obtained using an irrigation depth greater than the crop evapotranspiration, regardless of the nitrogen doses.

Mechanical Qualification of Dynamic Deep Water Power Cable

2011 ◽  
Author(s):  
Roger Slora ◽  
Stian Karlsen ◽  
Per Arne Osborg
Keyword(s):  
Water Depth ◽  
Deep Water ◽  
Failure Modes ◽  
Electrical Power ◽  
Oil And Gas Industry ◽  
Electrical Heating ◽  
Power Cable ◽  
Water Power ◽  
System Integrity ◽  
Water Depths

There is an increasing demand for subsea electrical power transmission in the oil- and gas industry. Electrical power is mainly required for subsea pumps, compressors and for direct electrical heating of pipelines. The majority of subsea processing equipment is installed at water depths less than 1000 meters. However, projects located offshore Africa, Brazil and in the Gulf of Mexico are reported to be in water depths down to 3000 meters. Hence, Nexans initiated a development programme to qualify a dynamic deep water power cable. The qualification programme was based on DNV-RP-A203. An overall project plan, consisting of feasibility study, concept selection and pre-engineering was outlined as defined in DNV-OSS-401. An armoured three-phase power cable concept assumed suspended from a semi-submersible vessel at 3000 m water depth was selected as qualification basis. As proven cable technology was selected, the overall qualification scope is classified as class 2 according to DNV-RP-A203. Presumed high conductor stress at 3000 m water depth made basis for the identified failure modes. An optimised prototype cable, with the aim of reducing the failure mode risks, was designed based on extensive testing and analyses of various test cables. Analyses confirmed that the prototype cable will withstand the extreme loads and fatigue damage during a service life of 30 years with good margins. The system integrity, consisting of prototype cable and end terminations, was verified by means of tension tests. The electrical integrity was intact after tensioning to 2040 kN, which corresponds to 13 000 m static water depth. A full scale flex test of the prototype cable verified the extreme and fatigue analyses. Hence, the prototype cable is qualified for 3000 m water depth.

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

2021 ◽  
Vol 10 (4) ◽  
pp. 789-802
Author(s):  
Tri Hieu Le ◽  
Minh Tuan Pham ◽  
H Hadiyanto ◽  
Van Viet Pham ◽  
Anh Tuan Hoang
Keyword(s):  
Water Depth ◽  
Thermal Efficiency ◽  
Tracking System ◽  
Design Parameters ◽  
Cylindrical Shape ◽  
Solar Still ◽  
Practical Utilization ◽  
Passive Solar Still ◽  
Passive Solar ◽  
The Impact

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 depth, insulators, basin liner absorptivity, reflectors, sun tracking system, etc). The inclined angle of the top cover is suggested to equal the latitude of the experimental place. Moreover, the decrease of water depth was obtained as a good operational parameter, however, the shallow water depth is required additional feed water for ensuring no dry spot existence. Reflectors and sun-tracking systems help solar still absorb as much solar intensity as possible. The internal reflector can enhance daily yield and efficiency of stepped solar still up to 75% and 56% respectively, whereas, passive solar still with the support of a sun-tracking system improved daily yield up to 22%. Despite large efforts to investigate the impact of the different parameters on passive solar distillation, the effect of the basin liner (including appropriate shapes and type of material), needs to be analyzed for improvement in practical utilization. The present work has reviewed the investigation of the solar still performance with various types of basin liner. The review of solar stills has been conducted critically with rectangular basin, fins basin, corrugated basin, wick type, steps shape, and cylindrical shape basin with variety of top cover shapes. The findings from this work conclude that the basin liner with a cylindrical shape had better performance in comparison with other metal types and provides higher freshwater output. Stepped type, inclined, fin absorber, and corrugated shapes had the efficient performance.  Further exploration revealed that copper is the best-used material for the productivity of passive solar still.

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