scholarly journals Investigation of saturation temperature in solar pond for different sizes

2020 ◽  
Vol 24 (5 Part A) ◽  
pp. 2905-2914 ◽  
Author(s):  
Haci Sogukpinar ◽  
Ismail Bozkurt

This paper deals with the modelling of solar ponds for different sizes to calculate saturation time and temperature by using discrete ordinates method. The modeled solar pond is a subsoil type and aimed to minimize the heat losses by isolating side wall and ground with foam with the thickness of 10 cm in all cases. In the model, upper convective zone is 10 cm deep and non-convective zone consists of five layer and each layer is 10 cm deep and storage zone depth ranges from 40-400 cm. Therefore, the solar pond totally consists of seven layers. The saturation temperature was found to be about 322 K for 12 different solar pond. For a depth of 40 cm, the equilibrium temperature was reached in 1000 hours, 1300 hours for 60 cm, 1400 hours for 80 cm, 1500 hours for 100 cm, 1600 hours for 120 cm, 1750 hours for 1140 cm, 1800 hours for 180 cm, 2700 hours for 200 cm, 1800 hours for 250 cm, 3400 hours for 300 cm, and 6000 hours have passed for 400 cm. As the depth increases, time to reach to the equilibrium temperature increases but increment amount of water and time to reach equilibrium temperature shows a proportional increase. At the same time we calculated that, when we increase the width of the pond by keeping the depth constant, the saturation temperature and the time did not changed for the seven different cases.

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.


2017 ◽  
Vol 139 (4) ◽  
Author(s):  
A. A. Abdullah ◽  
K. A. Lindsay

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.


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.


2021 ◽  
Vol 39 (2) ◽  
pp. 486-492
Author(s):  
Periyasamy Rangaraju ◽  
Santhia Sivakumar

Varying salt density solar pond is a method that is best suited to absorb and store solar energy. This examination includes the test enhancement of the permeable and non-permeable sunlight-based ponds dependent on its exhibition in different conditions. This experiment was done in Salem, Tamil Nadu, India. This particular topographical area has a high level of solar radiation and is a tropical district. Readings for a period of 30 days were taken; the temperature circulation, a measure of heat energy stored and concentration of salt density was assessed. For examination, two comparable solar ponds of volume 0.02 m3 and a height of 0.32 m was built. Black granite pieces, broken glass pieces, and welding spatter were used as a permeable medium in the lower convective zone (LCZ) in one of the two solar ponds. The temperatures of the permeable solar pond and non-permeable solar pond reached the highest values of 42.3℃ and 40.6℃ respectively. The solar pond with a permeable medium demonstrated an increase of 4.18% in temperature. The difference in amounts of stored thermal energy is 4.54 kJ. From the obtained parameters, the optimization is done and the permeable medium solar pond is found to store more amount of heat energy than the non- permeable solar pond. For the optimization of the mixed medium, criterion parameter βelk has been acquired in the solar pond.


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.


2014 ◽  
Vol 1055 ◽  
pp. 188-192
Author(s):  
Hong Sheng Liu ◽  
Dan Wu ◽  
Wen Ce Sun

In this work, several methods are experimentally investigated with the aim of enhancing the thermal characters of solar pond. Which included putting porous medium to the bottom of the solar pond, combining a solar collector and building evaporation basin respectively .Two mini cylindrical solar ponds are built and the thermal performance of the solar pond is investigated by comparing the temperature distribution of the two solar ponds. The experimental results show that the utilization of the porous medium in the bottom layer might enhance the heat storage ability of the lower convective zone (LCZ); The introduction of the solar collector might advance the temperature of the LCZ greatly, which lessens the heat loss of the whole system. These methods play important roles in enhancing the thermal characters of the solar pond, which brings forward a new way for the improving of solar pond.


1995 ◽  
Vol 117 (2) ◽  
pp. 144-150 ◽  
Author(s):  
J. Estevadeordal ◽  
S. J. Kleis

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.


1983 ◽  
Vol 105 (4) ◽  
pp. 369-374 ◽  
Author(s):  
Z. Panahi ◽  
J. C. Batty ◽  
J. P. Riley

A one-dimensional mathematical model which simulates the dynamic performance of stratified solar brine ponds is described. The model simulates the upper convective zone, the middle nonconvective zone, and the lower convective zone. In addition to the energy flux, the model simulates the varying brine densities as a function of temperature and salt concentration, and thus is able to examine various pond stability criteria. On the basis of model operational studies, the following results are presented: (i) a study of overall pond efficiency in terms of the upper convective layer; (ii) an optimization study of the thickness of the nonconvective zone in terms of net energy transmission to the lower convective zone; (iii) an investigation of the heat storage efficiency and of the overall pond efficiency as a function of pond loading rate for a particular depth of storage zone.


1994 ◽  
Vol 4 (1) ◽  
pp. 47-51 ◽  
Author(s):  
Renyuan Zhang ◽  
C.E. Nielsen
Keyword(s):  

2018 ◽  
Vol 64 ◽  
pp. 02002
Author(s):  
Sogukpinar Haci ◽  
Bozkurt Ismail ◽  
Cag Serkan

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.


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