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 ◽  
...  

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.

2021 ◽  
pp. 185-185
Author(s):  
Ismail Bozkurt

Solar ponds are systems that store solar energy in salt water as heat energy. In order to store heat energy for a long time in solar pond, the heat insulation should be done well. In this study, the effect of phase change materials (PCMs) was investigated to improve the insulation of the pond and to store the heat energy for a longer time. The melting temperature is a key parameter in the selection of PCMs. The temperature distribution of the solar pond was examined and PCMs with melting temperatures in the range of the pond average temperature ? 10?C were selected.Three different phase change materials were used in the walls of the solar pond for insulation. The temperature and enthalpy changes of the system were calculated numerically for a year. The heat storage ratio of the solar pond was determined by using the obtained enthalpy and solar radiation data. Consequently, the heat storage ratio of the pond with glass-wool is maximum 20.95% in July and minimum 7.92% in January. The heat storage ratio of the solar pond which Paraffin C18, Capric acid and Paraffin 44 are used as PCMs is maximum 32.22%, 34.85% and 47.81% in December, respectively. It is observed that the appropriate selection of PCMs is provided a longer storage time for solar ponds.


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.


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 ◽  
Author(s):  
Hannah Weger ◽  
Jenn McArthur

Photovoltaic thermal and/or evacuated tube collectors on building roofs can be effectively used to reduce fossil fuel use for heating and reliance on the electrical grid. To evaluate the potential of this reduction, a set of models were created for rooftop photovoltaic thermal and evacuated tube collector energy production, both thermal and electricity, and tested using a series of potential layouts. Five collector area ratios, two layout options, and three working fluid flowrates were investigated using five reference buildings as case studies. From these case studies it was determined that in Toronto’s climate, the exclusive use of photovoltaic thermal collectors produces the most total energy, while using only evacuated tube collectors maximally offsets greenhouse gasses. The results suggest that district heating would be highly effective to reduce the carbon footprint of city cores like the Toronto 2030 District.


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.


2021 ◽  
Vol 43 ◽  
pp. 59-71
Author(s):  
Devendra B. Sadaphale ◽  
S.P. Shekhawat ◽  
Vijay R. Diware

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.


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.


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.


Entropy ◽  
2020 ◽  
Vol 22 (10) ◽  
pp. 1165
Author(s):  
Adil Al-Falahi ◽  
Falah Alobaid ◽  
Bernd Epple

The main objective of this paper is to simulate solar absorption cooling systems that use ammonia mixture as a working fluid to produce cooling. In this study, we have considered different configurations based on the ammonia–water (NH3–H2O) cooling cycle depending on the solar thermal technology: Evacuated tube collectors (ETC) and parabolic trough (PTC) solar collectors. To compare the configurations we have performed the energy, exergy, and economic analysis. The effect of heat source temperature on the critical parameters such as coefficient of performance (COP) and exegetic efficiency has been investigated for each configuration. Furthermore, the required optimum area and associated cost for each collector type have been determined. The methodology is applied in a specific case study for a sports arena with a 700~800 kW total cooling load. Results reveal that (PTC/NH3-H2O)configuration gives lower design aspects and minimum rates of hourly costs (USD 11.3/h) while (ETC/NH3-H2O) configuration (USD 12.16/h). (ETC/NH3-H2O) gives lower thermo-economic product cost (USD 0.14/GJ). The cycle coefficient of performance (COP) (of 0.5).


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