Experimental Investigations on Salt Gradient Solar Pond with Additional Non-Convective Zone for Improved Thermal Performance and Stability

2021 ◽  
Vol 43 ◽  
pp. 59-71
Author(s):  
Devendra B. Sadaphale ◽  
S.P. Shekhawat ◽  
Vijay R. Diware
Keyword(s):  
Heat Storage ◽  
Salinity Gradient ◽  
Convective Zone ◽  
Salt Flux ◽  
Maximum Temperature ◽  
Experimental Investigations ◽  
Thickness Variation ◽  
Salty Water ◽  
Solar Pond ◽  
Salt Gradient

Salt gradient solar ponds are to be designed for thermal efficiency and salinity profile stability. As the salt flux moves upward in the pond, the gradient gets destabilized. This is counteracted by intrusion of salt at different levels as and when required. The density of salt is highest at the bottom and minimum at the top. Hence the destabilization effect is more at top that is at the interface of upper convective zone and non-convective zone (NCZ). In order to keep the interface stable, it is desirable to provide a higher slope of salt gradient near it. However, throughout the non-convective zone, it is not feasible to provide higher slope due to solubility limitations. Hence Husain et al (2012) to divide the NCZ into two parts. The top few centimeters may be given a higher slope and the rest of the zone may be given mild slope as usual. Husain et al (2012) have given analysis for the same and found it to be feasible. However, the experimental feasibility of the same needs to be verified. The present work has done an attempt for the same. In this study, an insulated solar pond with a surface area of 1.40 m2and a depth of 1.14 m is built at the SSBT’s College of Engineering and Technology, Jalgaon in the Maharashtra State (India). The three salty water zones (upper convective, non-convective and heat storage) were formed by filling the pond with salty water of various densities. 6 Thermocouples (type Pt100A) (C+0.2%) were used to measure the temperature profile within the pond. A maximum temperature of 47°C was recorded in the heat storage zone in time span considered for study. The results obtained from experimentation is verified with the concept suggested by Hussain et al (2012) it has been found that they are in a good agreement. The influence of varying the thicknesses of the zones present in a salinity gradient solar pond on the temperatures of the upper convective zone (UCZ) and the lower convective zone (LCZ) is investigated. Also, it is found that by adding the additional non convective zone of 50 mm thickness above the UCZ the heat collection capacity of the LCZ is increased noticeably. The study finds that thickness variation of the zones within the pond is a practical feasibility. The system worked for the entire experimental duration effectively without failure.

Study of Establishment and Operation of Salt-Gradient Solar Pond

2014 ◽  
Vol 472 ◽  
pp. 409-412
Author(s):  
Chun Juan Gao ◽  
Qi Zhang ◽  
Ze Liang Dong ◽  
Shu Yuan Guo ◽  
Xi Ping Huang
Keyword(s):  
Experimental Investigation ◽  
Solar Energy ◽  
Convective Zone ◽  
Saline Injection ◽  
Salty Water ◽  
Long Period ◽  
Gradient Layer ◽  
Solar Pond ◽  
Injection Parameters ◽  
Salt Gradient

In this paper, it was presented that the establishment and experimental investigation of a salt-gradient solar pond. The solar pond was filled with salty water to form three zones (e.g., upper convective zone, non-convective zone and lower convective zone) accordingly with different methods of saline injection. Parameters like salinity and temperature were measured and recorded daily at various locations in the salt-gradient solar pond. The results showed that solar pond collected and stored solar energy for a long period of time can be possible by controlling the thickness and salinity of salt gradient layer 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 Impact of Non-convective Zone and Lower Convective Zone Thickness on the Performance Characteristics of Salinity Gradient Solar Pond

2021 ◽  
Vol 1206 (1) ◽  
pp. 012003
Author(s):  
S G Chakrabarty ◽  
U S Wankhede ◽  
R S Shelke
Keyword(s):  
Solar Radiation ◽  
Numerical Investigation ◽  
Heat Loss ◽  
Salinity Gradient ◽  
Convective Zone ◽  
Performance Characteristics ◽  
Maximum Temperature ◽  
Maturation Period ◽  
Solar Pond ◽  
The Impact

Abstract A solar pond technology employs a layer of salinity gradient to prevent heat loss due to convection from the lower convective zone. Thus, the energy received from solar radiation is stored in a lower convective zone. The thickness of various zones significantly affects the behaviour of solar pond temperature. In this present study, a transient numerical investigation is conducted to evaluate the impact of depths of different zones on the performance characteristics of solar pond. The variation in maximum temperature and maturation period under the influence of non-convective zone and lower convective zone thickness is discussed. The energy obtained from a solar pond significantly depends on various losses associated with the zones. Thus, an assessment of conduction and ground heat loss is presented for the variation in thickness of zones. An attempt is also made to study the effect of thickness of zones on the temperature of the lower convective zone. It is found that the configuration of a smaller thickness of LCZ and a higher thickness of NCZ yields maximum LCZ temperature.

scholarly journals A Prototype of Salt Gradient Solar Pond as Alternative Energy Source for Coastal Communities in Bengkulu

2019 ◽  
Vol 2 (2) ◽  
pp. 25-27
Author(s):  
Afdhal Kuniawan Mainil
Keyword(s):  
Alternative Energy ◽  
Saline Solution ◽  
Salt Water ◽  
Salinity Gradient ◽  
Maximum Temperature ◽  
Average Temperature ◽  
Solar Pond ◽  
Storage Zone ◽  
Salt Gradient ◽  
Further Development

One of the developing technologies of renewable energy is the Salt Gradient Solar Pond (SGSP). SGSP utilize solar energy by storing its thermal energy in a pond of saline solution. Bengkulu Province has a high intensity of sunlight and a long coastline with an abundance of salt water. Therefore, it is a very suitable location for further development of SGSP technology. The design of SGSP prototype had been carried out by using a 1 m3 cylinder as the saline solution pond. The density and temperature of the solution were measured at 11 points from the bottom to the top of the cylinder. The results show that the keeper of the pond, the more density of the solution, in which the highest solution density was at the bottom of the pond, i.e., 1.206 gr/cm3. The average temperature of the solution was 44.2°C. The maximum temperature, which was 48.7 °C, was observed around the storage zone, about 0.3 m from the pond‘s bottom. The results of the measurements of salinity gradient and temperatures show that this prototype of SGSP is appropriate to be used for storing heat around the storage zone.

scholarly journals A Technical Note on Fabrication and Thermal Performance Studies of a Solar Pond Model

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Abhishek Saxena ◽  
Varun Goel
Keyword(s):  
Thermal Performance ◽  
Performance Studies ◽  
Heat Storage ◽  
Uttar Pradesh ◽  
Climatic Conditions ◽  
Technical Note ◽  
Rigid Surface ◽  
Salty Water ◽  
Solar Pond ◽  
Salt Gradient

A solar pond has been fabricated to analyze the thermal behavior of it, in the climatic conditions of Moradabad, Uttar Pradesh. Sodium chloride (NaCl) has been used to form a salt gradient for better performance, and a dark-colored (blackened) rigid surface bottom with 1 mm irregularities has been considered for trapping the heat in a good amount. A solar pond with a surface area of 2.56 m2and a depth of 1 m has been filled with salty water of various densities to form three salty water zones (upper convective, nonconvective, and heat storage). A few investigations have been carried out to evaluate the thermal efficiencies of three different zones of the solar pond. An attempt is also made to improve the thermal performance of the salt gradient solar pond.

scholarly journals Evaluation of Solar Ponds and Aplication Area

2018 ◽  
Vol 64 ◽  
pp. 02002
Author(s):  
Sogukpinar Haci ◽  
Bozkurt Ismail ◽  
Cag Serkan
Keyword(s):  
Solar Energy ◽  
Electricity Generation ◽  
Storage Capacity ◽  
Heat Storage ◽  
Storage Systems ◽  
Hot Water ◽  
Temperature Variations ◽  
Solar Ponds ◽  
Salty Water ◽  
Solar Pond

Solar ponds are heat storage systems where solar energy is collected and stored thermally. Solar ponds were discovered during the temperature variations in the lower regions of existing saltwater pond in the area is found to be higher than their surface. Later, it was constructed artificially and started to be used. These systems have heat storage capacity at moderate temperatures. Solar pons are used in many areas such as electricity generation, heating the environment, meeting the need of hot water, drying food and obtaining fresh water from salty water. In this study, the studies about solar ponds were summarized, the construction of solar pond was explained, and the application areas were examined.

Assessing the Maximum Stability of the Nonconvective Zone in a Salinity-Gradient Solar Pond

2017 ◽  
Vol 139 (4) ◽  
Author(s):  
A. A. Abdullah ◽  
K. A. Lindsay
Keyword(s):  
Salinity Gradient ◽  
Fluid Velocity ◽  
Weather Conditions ◽  
Convective Zone ◽  
Heat Extraction ◽  
Solar Pond ◽  
Maximum Stability ◽  
Storage Zone ◽  
The Stability

The quality of the stability of the nonconvective zone of a salinity-gradient solar pond (SGSP) is investigated for an operating protocol in which the flushing procedure exactly compensates for evaporation losses from the solar pond and its associated evaporation pond. The mathematical model of the pond uses simplified, but accurate, constitutive expressions for the physical properties of aqueous sodium chloride. Also, realistic boundary conditions are used for the behaviors of the upper and lower convective zones (LCZs). The performance of a salinity-gradient solar pond is investigated in the context of the weather conditions at Makkah, Saudi Arabia, for several thickness of upper convective zone (UCZ) and operating temperature of the storage zone. Spectral collocation based on Chebyshev polynomials is used to assess the quality of the stability of the pond throughout the year in terms of the time scale for the restoration of disturbances in temperature, salinity, and fluid velocity underlying the critical eigenstate. The critical eigenvalue is found to be real and negative at all times of year indicating that the steady-state configuration of the pond is always stable, and suggesting that stationary instability would be the anticipated mechanism of instability. Annual profiles of surface temperature, salinity, and heat extraction are constructed for various combinations for the thickness of the upper convective zone and storage zone temperature.

El Paso Solar Pond

2001 ◽  
Vol 123 (3) ◽  
pp. 178-178 ◽  
Author(s):  
Huanmin Lu and ◽  
Andrew H. P. Swift
Keyword(s):  
Systems Approach ◽  
Salinity Gradient ◽  
El Paso ◽  
Industrial Process ◽  
The United States ◽  
Convective Zone ◽  
Bureau Of Reclamation ◽  
University Of Texas ◽  
Solar Pond ◽  
Brine Management

The El Paso Solar Pond, a research, development, and demonstration project operated by the University of Texas at El Paso, is a salinity-gradient solar pond with a surface area of 3,000 m2 and a depth of 3.2 m. The pond utilizes an aqueous solution of predominantly sodium chloride (NaCl). The surface convective zone, main gradient zone, and bottom convective zone are approximately 0.6 m, 1.4 m, and 1.2 m, respectively. The project, located on the property of Bruce Foods, Inc., was initiated in 1983 in cooperation with the U.S. Bureau of Reclamation. Since then, the El Paso Solar Pond has successfully developed a series of technologies for solar pond operation and maintenance, as well as demonstrated several different applications. In 1985, the El Paso Solar Pond became the first in the world to deliver industrial process heat to a commercial manufacturer; in 1986 became the first solar pond electric power generating facility in the United States; and in 1987 became the nation’s first experimental solar pond powered water desalting facility. Currently, the major research at El Paso Solar Pond is focused on desalination and brine management technologies. The long-term goal of this research is to develop a systems approach for desalination/brine management via a multiple process desalination coupled with solar ponds. This systems approach will reuse the brine concentrate rejected from desalting plants thereby negating the need for disposal (zero discharge), and provide additional pollution-free renewable energy for the desalting process.

Thermal Heat Storage Gain of Salinity Gradient Solar Pond Using Evacuated Tube Solar Collectors

2015 ◽  
Vol 1113 ◽  
pp. 800-805 ◽  
Author(s):  
Baljit Singh ◽  
Muhammad Fairuz Remeli ◽  
Alex Pedemont ◽  
Amandeep Oberoi ◽  
Abhijit Date ◽  
...  
Keyword(s):  
Large Scale ◽  
Heat Storage ◽  
Salinity Gradient ◽  
Heat Energy ◽  
Working Fluid ◽  
The Sun ◽  
Solar Ponds ◽  
Solar Pond ◽  
Evacuated Tube Collectors ◽  
Evacuated Tube

This paper investigates the capability of running a system which uses hot fluid from solar evacuated tube collectors to boost the temperature and overall heat storage of the solar pond. The system is circulated by a solar powered pump, producing heat energy entirely from the incoming solar radiation from the sun. Solar evacuated tube collectors use a renewable source of power directly from the sun to heat the working fluid to very high temperatures. Solar ponds are emerging on the renewable energy scene with the capacity to provide a simple and inexpensive thermal storage for the production of heat on a large scale. The results of the performance of the system show a significant heat energy increase into the solar ponds lower convective region, increasing the overall performance of the solar pond.

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