A Numerical Model to Describe the Layer Behavior in Salt-Gradient Solar Ponds

1983 ◽  
Vol 105 (4) ◽  
pp. 341-347 ◽  
Author(s):  
K. A. Meyer
Keyword(s):  
Numerical Model ◽  
Operating Conditions ◽  
Temperature Profiles ◽  
Empirical Correlations ◽  
Simulation Experiments ◽  
Solar Ponds ◽  
Solar Pond ◽  
Dependent Behavior ◽  
Salt Gradient ◽  
Layer Behavior

A numerical model has been developed to describe the time-dependent behavior of the interfaces between the convecting and nonconvecting regions of a salt-gradient solar pond. Salinity and temperature profiles, as a function of time, are also determined by the model. The model utilizes empirical correlations from the oceanographic literature that describe the heat and salt fluxes across the interfaces. The model also contains a treatment of entrainment caused by wind-generated turbulence. We find agreement of the calculated behavior with observations made on laboratory-scale solar pond simulation experiments. The model is used to determine pond performance under various operating conditions.

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.

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.

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.

Numerical model for the behaviour of a salt-gradient solar-pond greenhouse-heating system

1997 ◽  
Vol 58 (1) ◽  
pp. 57-72 ◽  
Author(s):  
A.A. Badran ◽  
B.A. Jubran ◽  
E.M. Qasem ◽  
M.A. Hamdan
Keyword(s):  
Numerical Model ◽  
Heating System ◽  
Solar Pond ◽  
Salt Gradient

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.

Effects of Friction and Extraction on the Stability of Solar Ponds

1983 ◽  
Vol 105 (4) ◽  
pp. 356-362 ◽  
Author(s):  
Y. S. Cha ◽  
W. T. Sha ◽  
S. L. Soo
Keyword(s):  
Experimental Results ◽  
Stability Criteria ◽  
Solar Ponds ◽  
Solar Pond ◽  
Salt Gradient ◽  
The Stability ◽  
Cellular Motion

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.

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