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.

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.

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.

scholarly journals Comparative Study of Shallow Solar Ponds with Different Depths

2017 ◽  
Vol 13 (1) ◽  
pp. 13-28
Author(s):  
K Shanmugasundaram B Janarthanan
Keyword(s):  
Energy Balance ◽  
Comparative Study ◽  
Pond Water ◽  
Maximum Temperature ◽  
Balance Equations ◽  
Solar Ponds ◽  
Glass Cover ◽  
Solar Pond ◽  
Different Depths

In this paper, an attempt has been made to design and construct the shallow solar ponds with different depths such as 0.06 m and 0.15 m at Coimbatore (11 ͦ - latitude and 77 ͦ - longitudes), Tamilnadu, and India. The experiments have been carried out during the period from January-March 2012. The energy balance equations have been written for different elements of the two shallow solar ponds such as upper glass cover, lower glass cover and pond water and solved analytically. The performance of the two shallow solar ponds has been compared and found that the maximum temperature of the pond water in different depths (0.06 m and 0.15 m) of shallow solar pond is found to be 57  C and 42  C.

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.

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.

Selection of a Working Fluid for an Organic Rankine Cycle Coupled to a Salt-Gradient Solar Pond by Direct-Contact Heat Exchange

1982 ◽  
Vol 104 (4) ◽  
pp. 286-292 ◽  
Author(s):  
J. D. Wright
Keyword(s):  
Heat Exchange ◽  
Direct Contact ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Working Fluid ◽  
Contact Heat ◽  
Solar Pond ◽  
Contact Heat Exchange ◽  
Salt Gradient ◽  
Fluid Losses

An analysis was conducted of power production by an organic Rankine cycle engine coupled to a solar pond with direct-contact heat exchange. Use of a direct-contact boiler reduced the projected plant cost by 25 percent. The choice of a working fluid affects plant efficiency, turbine size, and working fluid losses. Pentane was shown to be the working fluid best suited to this application.

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.

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.

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
Keyword(s):  
Saline Water ◽  
Evaporation Surface ◽  
Solar Ponds ◽  
Evaporation Ponds ◽  
Solar Pond ◽  
Salt Brine ◽  
Salt Gradient ◽  
Dry Climates ◽  
High Precipitation ◽  
Salt Diffusion

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.

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