scholarly journals A Comparison between Evaporation Ponds and Evaporation Surfaces as a Source of the Concentrated Salt Brine for Salt Gradient Maintenance at Tajoura’s Solar Pond

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Abdulghani M Ramadan ◽  
Khairy R Agha ◽  
Saleh M Abughres

One of the main problems that negatively affect the operation of salt gradient solar ponds and influence its thermal stability is the maintenance of salt gradient profile. Evaporation pond (EP) is designed to generate the salt which is lost by upward salt diffusion from the lower convective zone (LCZ) of the solar pond. Another attractive method is the Evaporation Surface facility (ES). Regions with moderate to high precipitation favor Evaporation Surfaces over Evaporation Ponds. Dry climates will generally favor Evaporation Ponds for the brine re-concentration. This paper investigates the differences between (EP) and (ES) both as a source for salt brine generation by evaporation. The effect of (EP) depth on the area ratio and daily variations of salt concentrations for three years of operation is shown. Results show that evaporation can be a reasonable method for salt brine generation. Reducing the depth of (EP) improves the capability of (EP) for brine re-concentration. It also increases the (EP) surface area for the same quantity of saline water used. Therefore, ESs are more powerful than Eps in salt re-concentration.

2010 ◽  
Vol 42 ◽  
pp. 294-298
Author(s):  
Hua Wang ◽  
Jun Li Liu ◽  
Jia Ning Zou

In this study, adding coal cinder to bottom of solar pond as a means of increasing temperature of the solar pond is presented. A series of small-scale tests are conducted in the simple mini solar ponds. These small-scale tests include the temperature evolution comparisons of this mode with other normal modes; the comparisons of the material added to LCZ and the comparisons of the different soaking times for coal cinder. In addition, a numerical calculation on predicting temperature evolution in large area of salt gradient solar pond is also given. Both of the experimental and numerical results suggest that adding porous media with low thermal diffusivity (e.g. coal cinder) could significantly increase the temperature in the vicinity of the bottom of the pond. From the view of long-term, this effect is supposed to enhance the average temperature of the solar pond.


1994 ◽  
Vol 116 (2) ◽  
pp. 69-73 ◽  
Author(s):  
T. A. Newell ◽  
M. K. Smith ◽  
R. G. Cowie ◽  
J. M. Upper ◽  
C. L. Cler

An active brine reconcentration system has been incorporated into the design of the University of Illinois half-acre salt gradient solar pond facility. An important feature of the system is its ability to keep precipitation from diluting the brine. Experimental data presented is in good agreement with a numerical simulation model of the evaporation process. The “film”-type evaporation process used in the system efficiently collects solar energy for evaporating water from brine. Parasitic electrical energy requirements for the evaporation system are 1.2 watts per square meter of evaporation surface area.


1982 ◽  
Vol 104 (4) ◽  
pp. 299-304 ◽  
Author(s):  
B. W. Tleimat ◽  
E. D. Howe

This paper presents comparative analyses of two methods for producing desalted water using the heat collected by a solar pond—the first by distillation, and the second by reverse osmosis. The distillation scheme uses a multiple-effect distiller supplied with steam generated in a flash boiler using heat from a solar pond. Solar pond water passes through a heat exchanger in the water system ahead of the flash boiler. The second scheme uses a similar arrangement to generate hydrocarbon vapor which drives a Rankine cycle engine. This engine produces mechanical/electrical power for the RO plant. The analyses use two pond water temperatures—82.2°C (180°F) and 71.1°C (160°F)—which seem to cover the range expected from salt-gradient ponds. In each case, the pond water temperature drops by 5.56°C (10°F) while passing through the vapor generator system. Results of these analyses show that, based on the assumptions made, desalted water could be produced by distillation at productivity rates much greater than those estimated for the RO plant.


2013 ◽  
Vol 448-453 ◽  
pp. 1521-1524
Author(s):  
Chun Juan Gao ◽  
Qi Zhang ◽  
Hai Hong Wu ◽  
Liang Wang ◽  
Xi Ping Huang

The solar ponds with a surface of 0.3m2were filled with different concentration salt water and fresh water. The three layer’s structure of solar ponds was formed in the laboratory ponds by using the salinity redistribution. The performance and diffusion of salinity were xperimentally in the solar pond. The measurements were taken and recorded daily at various locations in the salt-gradient solar pond during a period of 30 days of experimentation. The experimental results showed that the salinity gradient layer can sustain a longer time when the lower convective zone is thicker, which is benefit to store solar energy. Therefore, properly increasing the height of LCZ is a good method to enhance the solar pond performance.


2011 ◽  
Vol 347-353 ◽  
pp. 174-177 ◽  
Author(s):  
Dan Wu ◽  
Hong Sheng Liu ◽  
Wen Ce Sun

The performance of Salt-gradient solar ponds (SGSP) with and without the solar collector are investigated experimentally in this paper. Two mini solar ponds with same structure are built, and one the them is appended with an exceptive solar collector for compared study. The salinity, temperature and turbidity of solar pond are studied contrastively for the two solar ponds under the same ambient conditions. The ambient temperatures,humidity and solar radiation are investigated during the experimental period. It was found that the temperature of the lower convective zone in the solar pond coupled with a solar collector increases by about 20% due to the introduce of solar collector.


A salt gradient is imposed on a black-bottomed pond about 1 m deep; this creates a density gradient (positive measured downwards) which suppresses convection when the pond is heated from the bottom by absorbed solar radiation. Between 15 and 25 % of the incident radiation, depending upon pond cleanliness, reaches the bottom and can be decanted by stratified hydrodynamic flow of the bottom layer. Temperatures approaching the boiling point have been recorded. At 32° latitude and under Israel sunshine conditions, estimated annual thermal output from a pond of 1 km 2 is equivalent to 43000 t of fuel oil. A method of avoiding salt diffusion, which would slowly destroy the gradient, is described. Practical problems include suppression of surface mixing by wind and the possible effects of heating large areas of ground.


2013 ◽  
Vol 805-806 ◽  
pp. 74-77
Author(s):  
Chun Juan Gao ◽  
Qi Zhang ◽  
Liang Wang ◽  
Ying Wang ◽  
Xi Ping Huang

An experimental study on the evolution of the salinity profiles in the salinity gradient solar ponds was executed using a small model pond. The body of the simulated pond is a cylindrical plastic tank, with 50 cm height and 45 cm diameter. The salinity gradient was established in the laboratory tank by using the salinity redistribution technique. The measurements were taken during a period of 20 days of experimentation. This period of time allowed the existence of salt diffusion from the storage zone to the surface. Results obtained from this study show that when the ratio of brine/water is 1/1, the salinity gradient layer can sustain a longer time and the lower convective zone is thicker, which is benefit to store solar energy.


1986 ◽  
Vol 108 (1) ◽  
pp. 75-77 ◽  
Author(s):  
R. S. Beniwal ◽  
N. S. Saxena ◽  
R. C. Bhandari

A mathematical model for efficiency of a salt gradient solar pond is described. Heat losses from the bottom of the pond have been calculated, and the results for the effective thermal conductivity with the thicknesses of various insulating materials have been presented. The effect of the ground thermal resistance on the efficiency of the pond for different values of ΔT/So have also been shown.


1983 ◽  
Vol 105 (4) ◽  
pp. 356-362 ◽  
Author(s):  
Y. S. Cha ◽  
W. T. Sha ◽  
S. L. Soo

Experimental results were compared to theoretical stability criteria of a salt gradient solar pond. Cellular motion in the nonconvective layer may be caused by instablity. Extension of stability criteria suggests use of stabilizing barriers via friction. Stability of longitudinal extraction assures optimum availability of energy from a solar pond.


1985 ◽  
Vol 107 (2) ◽  
pp. 160-164 ◽  
Author(s):  
T. A. Newell ◽  
J. R. Hull

A recording depth sounding instrument has provided several different diagnostic measurements in the 1000 m2 Research Salt Gradient Solar Pond at Argonne National Laboratory. The sounder has been used to locate gradient zone boundaries and layers of debris within the pond. The instrument has also helped to verify that the presence of salt piles in the bottom of the pond has been responsible for automatically maintaining the constant position of the gradient zone lower boundary during the last three years. Subsurface waves have been observed at the bottom of the gradient zone near the pond side walls. The sounding instrument has also proved capable of identifying density driven plumes and turbulent disturbances within the pond.


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