Depth Sounding Diagnostic Measurements of Salt Gradient Solar Ponds

1985 ◽  
Vol 107 (2) ◽  
pp. 160-164 ◽  
Author(s):  
T. A. Newell ◽  
J. R. Hull
Keyword(s):  
National Laboratory ◽  
Argonne National Laboratory ◽  
Lower Boundary ◽  
Gradient Zone ◽  
Solar Ponds ◽  
Solar Pond ◽  
Side Walls ◽  
Salt Gradient ◽  
Depth Sounding

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.

Maintenance of Brine Transparency in Salinity Gradient Solar Ponds

1990 ◽  
Vol 112 (2) ◽  
pp. 65-69 ◽  
Author(s):  
J. R. Hull
Keyword(s):  
Aluminum Sulfate ◽  
Salinity Gradient ◽  
National Laboratory ◽  
Argonne National Laboratory ◽  
Algal Growth ◽  
Soluble Phosphate ◽  
Phosphate Content ◽  
Solar Ponds ◽  
Solar Pond ◽  
Good Transparency

Experience with maintenance of brine transparency during the more than eight years of operation of the 1000 m2 Research Salinity Gradient Solar Pond (RSGSP) at Argonne National Laboratory suggests that, in many sodium chloride brines, algal growth may be readily curtailed by minimizing the phosphate content of the brine. The addition of modest amounts of aluminum sulfate (<5 g m−2 yr−1) to precipitate soluble phosphate in the RSGSP has resulted in a reduction of the amount of chlorine used from 13 g m−2 yr−1 to 2.8 g m−2 yr−1, while still maintaining good transparency in the pond brine.

Study on the Thermal Effect of Adding Coal Cinder to the LCZ of Solar Pond

2010 ◽  
Vol 42 ◽  
pp. 294-298
Author(s):  
Hua Wang ◽  
Jun Li Liu ◽  
Jia Ning Zou
Keyword(s):  
Normal Modes ◽  
Temperature Evolution ◽  
Small Scale ◽  
Large Area ◽  
Solar Ponds ◽  
Average Temperature ◽  
Solar Pond ◽  
Salt Gradient ◽  
Increasing Temperature

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.

Operation of a Small-Scale Salt-Gradient Solar Pond: Experimental Results

1986 ◽  
Vol 108 (1) ◽  
pp. 55-59 ◽  
Author(s):  
M. A. Elhadidy ◽  
B. G. Nimmo ◽  
S. Zubair
Keyword(s):  
Small Scale ◽  
Chloride Salt ◽  
Temperature Profiles ◽  
Density Profiles ◽  
Gradient Zone ◽  
Solar Pond ◽  
Salt Gradient ◽  
Will Self ◽  
Bottom Zone ◽  
Convective Cells

A small-scale sodium chloride salt gradient solar pond was operated outdoors in Dhahran over a period of nine months. Vertical temperature profiles in the pond and in the ground underneath the pond, density profiles and temperatures at fixed locations in the pond were measured. Variation of the bottom zone temperature with time over the operating period is presented as well as representative vertical pond temperature profiles taken in the morning and afternoon. From these profiles and additional temperature data taken from fixed locations in the bottom zone, some insight was gained regarding onset of bottom convection and the midday total energy collection. Evidence is shown which suggests that weak convective cells in the gradient zone will “self-heal” even when on the order of 5 cm in thickness.

Comparative Productivity of Distillation and Reverse Osmosis Desalination Using Energy From Solar Ponds

1982 ◽  
Vol 104 (4) ◽  
pp. 299-304 ◽  
Author(s):  
B. W. Tleimat ◽  
E. D. Howe
Keyword(s):  
Reverse Osmosis ◽  
Electrical Power ◽  
Water System ◽  
Rankine Cycle ◽  
Pond Water ◽  
Generator System ◽  
Solar Ponds ◽  
Solar Pond ◽  
Salt Gradient ◽  
Hydrocarbon Vapor

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.

The Influence of Height of LCZ on the Salinity Diffusion of Solar Pond

2013 ◽  
Vol 448-453 ◽  
pp. 1521-1524
Author(s):  
Chun Juan Gao ◽  
Qi Zhang ◽  
Hai Hong Wu ◽  
Liang Wang ◽  
Xi Ping Huang
Keyword(s):  
Solar Energy ◽  
Fresh Water ◽  
Salt Water ◽  
Salinity Gradient ◽  
Good Method ◽  
Convective Zone ◽  
Solar Ponds ◽  
Solar Pond ◽  
Salt Gradient ◽  
And Diffusion

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.

Construction and Startup Performance of the Miamisburg Salt-Gradient Solar Pond

1981 ◽  
Vol 103 (1) ◽  
pp. 11-16 ◽  
Author(s):  
L. J. Wittenberg ◽  
M. J. Harris
Keyword(s):  
Storage Temperature ◽  
Water Clarity ◽  
Pond Water ◽  
Convective Zone ◽  
Fuel Oil ◽  
Gradient Zone ◽  
Solar Pond ◽  
Salt Gradient ◽  
Startup Performance ◽  
The Cost

The largest salt-gradient solar pond in the U. S. occupies an area of 2020 m2 and was installed for only $35/m2. The pond has a storage layer of 1.6 m consisting of 18 percent sodium chloride, a l-m gradient zone and a 0.4-m top convective zone. After 1.5 yr of operation, the storage temperature reached a maximum of 64°C in July and a minimum of 28°C in February. During July-September 1979, 143.5 GJ (136 million Btu) of heat was utilized. Under steady-state conditions, the pond is conservatively predicted to deliver over 1015 GJ/yr (962 million Btu) of heat to be used principally for heating an outdoor swimming pool in the summer and an adjacent recreation building from October to December each year. Based upon a 15-yr depreciation of the installation costs, the cost of this heat, $8.95/GJ ($9.45/million Btu) is already below the cost of heating with fuel oil. Maintenance of water clarity, corrosion of metallic components, and the assurance of the containment of the pond water have been the principal operational concerns and will require further study.

Experimental Study on Solar Ponds Combination with Solar Collector

2011 ◽  
Vol 347-353 ◽  
pp. 174-177 ◽  
Author(s):  
Dan Wu ◽  
Hong Sheng Liu ◽  
Wen Ce Sun
Keyword(s):  
Experimental Study ◽  
Solar Radiation ◽  
Solar Collector ◽  
Experimental Period ◽  
Convective Zone ◽  
Ambient Conditions ◽  
Solar Ponds ◽  
Ambient Temperatures ◽  
Solar Pond ◽  
Salt Gradient

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.

scholarly journals Performance comparison of aboveground and underground solar ponds

2018 ◽  
Vol 22 (2) ◽  
pp. 953-961 ◽  
Author(s):  
Haci Sogukpinar ◽  
Ismail Bozkurt ◽  
Mehmet Karakilcik
Keyword(s):  
Performance Evaluation ◽  
Density Distribution ◽  
Structural Parameters ◽  
Performance Comparison ◽  
Underground Construction ◽  
Gradient Zone ◽  
Solar Ponds ◽  
Convective Heat Loss ◽  
Solar Pond ◽  
Temperature Distributions

This paper deals with the modeling of two different solar ponds which has some different structural parameters such as aboveground and underground, and its performance evaluation. The solar pond system generally consists of three zones, and the densities of these zones decrease from the bottom of the pond to the surface. The most significant decrease in the density distribution of the salt between bottom and up of the pond is the gradient zone. The convective heat loss in the solar pond is prevented with this zone. In this study, aboveground and underground solar ponds were modeled at the same dimensions, but different structural parameters in the same conditions. In this model, the temperature distributions of the solar pond were obtained during a year. The thermal performances of the solar pond were calculated and the results were compared with an experiment. This study shows that the efficiency of the aboveground solar pond is observed to be a maximum of 25.93% in July, a minimum of 4.53% in January. Furthermore, the efficiency of the underground solar pond is observed to be a maximum of 21.49% in July, a minimum of 6.55% in January. This study indicates that the underground construction of solar ponds, designed to be insulated using appropriate insulation materials, is found to be more efficient with respect to the aboveground pond.

Parametric Study of Salt Gradient Solar Ponds

1986 ◽  
Vol 108 (1) ◽  
pp. 75-77 ◽  
Author(s):  
R. S. Beniwal ◽  
N. S. Saxena ◽  
R. C. Bhandari
Keyword(s):  
Thermal Conductivity ◽  
Mathematical Model ◽  
Thermal Resistance ◽  
Effective Thermal Conductivity ◽  
Parametric Study ◽  
Heat Losses ◽  
Insulating Materials ◽  
Solar Ponds ◽  
Solar Pond ◽  
Salt Gradient

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.

Gradient-Zone Erosion by Extraction in Solar Ponds

1995 ◽  
Vol 117 (2) ◽  
pp. 144-150 ◽  
Author(s):  
J. Estevadeordal ◽  
S. J. Kleis
Keyword(s):  
Steady State ◽  
Salinity Gradient ◽  
Operating Conditions ◽  
Density Difference ◽  
Finite Density ◽  
Gradient Zone ◽  
Solar Ponds ◽  
Solar Pond ◽  
Flow Parameters ◽  
Storage Zone

The erosion the dynamically stable gradient zone of a salinity-gradient solar pond, due to the extraction of fluid from the storage zone, is numerically investigated. The effects of fluid withdrawal rate, density stratification level, pond and diffuser geometries, and diffuser placement are considered. It is found, for a typical salinity-gradient solar pond with uniform salinity in the storage zone and a continuous salinity gradient above that a finite amount of fluid entrainment from the gradient zone is inevitable. That is, a finite density difference across the interface is always required for a finite extraction rate under steady-state conditions. The magnitude of the density difference is predicted as function of the geometric and flow parameters. From the results, it is possible to predict the total amount of fluid entrained from the gradient zone as the pond reaches steady-state for prescribed operating conditions.

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