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.

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 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.

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.

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.

Experimental investigation on a novel composite salt-gradient solar pond with East-West side reflector

2021 ◽  
pp. 1-31
Author(s):  
Dhandapani Sathish ◽  
Selvaraj Jegadheeswaran
Keyword(s):  
Thermal Energy ◽  
Salinity Gradient ◽  
The Novel ◽  
Solar Pond ◽  
Triple Layer ◽  
Solar Radiation Intensity ◽  
Salt Gradient ◽  
Cost Efficient ◽  
East West ◽  
Diurnal Period

Abstract A salt gradient solar pond acts as an eco-friendly and cost-efficient device for storing thermal energy storage. It is crucial to enrich the efficiency of the salt gradient solar pond to boost its thermal energy storage.This current study investigates the hexagonal composite salinity gradient solar pond (HCSGSP) augmented with a dual inclined reflector and triple-layer transparent cover. A micro solar pond having a hexagonal cross-section was fabricated and experimented at Coimbatore, India having a datum and surface area of 1 m and 0.679 m2 respectively. The novel usage of composite salt (Sodium chloride 30%, Magnesium chloride 10%, and Potassium chloride 60%) led to the enhancement of the daily average ponds' temperature. The pond's upper portion was packed with a triple layer glazed cover which shows an uplift of thermal energy and the pond is provided with inclined reflectors made of plywood fixed with mirrors on the east west direction. The purpose of the mirrors is to increase the solar radiation intensity during the diurnal period and also it acts as an insulator which minimizes the heat losses during the nocturnal period.The maximum thermal efficiencies of the top convective, middle non-convective, and bottom convective layers of reformed solar pond were measured to be 23.44%, 30.68%, and 35.63% respectively whereas they were 1.32%, 12.32%, and 23.44% respectively in case of conventional pond.

Effect of Water Distribution Ways on the Operation of Solar Pond

2013 ◽  
Vol 805-806 ◽  
pp. 74-77
Author(s):  
Chun Juan Gao ◽  
Qi Zhang ◽  
Liang Wang ◽  
Ying Wang ◽  
Xi Ping Huang
Keyword(s):  
Water Distribution ◽  
Salinity Gradient ◽  
Convective Zone ◽  
The Body ◽  
Solar Ponds ◽  
Solar Pond ◽  
Storage Zone ◽  
Small Model ◽  
Laboratory Tank ◽  
Salt Diffusion

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.

scholarly journals Kajian Performansi Kompor Surya dengan Erythrytol Sebagai Pcm untuk Memasak Langsung dan Tidak Langsung

2018 ◽  
Vol 1 (1) ◽  
pp. 067-074
Author(s):  
Safri Gunawan ◽  
Farel Hasiholan Napitupulu ◽  
Himsar Ambarita
Keyword(s):  
Solar Energy ◽  
Solar Collector ◽  
Alternative Energy ◽  
Mineral Resources ◽  
Heat Energy ◽  
Maximum Temperature ◽  
Measurement Point ◽  
Average Temperature ◽  
Cooking Process ◽  
Bottom Side

Menipisnya persediaan energi yang berasal dari fosil seperti minyak bumi, batu bara dan gas alam mengharuskan masyarakat beralih menggunakan energi alternatif. Dalam hal ini, Kementrian ESDM menghimbau untuk mencari dan mengembangkan energi alternatif sebagai pengganti energi konvensional. Salah satu energi alternatif yang harus dikembangkan adalah energi surya. Salah satu penggunaan energi surya dapat diaplikasikan dalam proses memasak. Tujuan penelitian ini adalah untuk mengetahui perubahantemperatur tiap titik pengukuran pada box kolektor surya dan vessel saat proses charging dan discharging, mengetahui perbandingan temperatur vessel yang menggunakan lug dan tidak menggunakan lug pada proses charging dan discharging, serta untuk mengetahui efesiensi termal box kolektor surya pada proses charging dan silinder isolator pada proses discharging dalam menjaga temperatur nasi. Pengujian pada proses charging dilakukan dengan menggunakan box kolektor berukuran 120 × 120 (cm) dan pada proses discharging menggunakan silinder isolator berukuran 30 × 45 (cm). Pada proses charging dilakukan pada pukul 10:00-16:00 WIB dan proses discharging pukul 16:00-09:00 WIB. Temperatur rata-rata proses charging untuk vessel menggunakan lug adalah 78,81 oC dan tidak menggunakan lug adalah 73,10 oC. Hal ini terjadi karena pada vessel yang menggunakan lug dapat menyerap energi panas dari sisi bawah vessel. Sedangkan efesiensi yang diperoleh box kolektor surya tertinggi adalah pada proses charging 41,54 % namun belum mampu meleburkan PCM yang memiliki temperatur lebur 120 oC karena temperatur maksimal yang mampu ditangkap box kolektor adalah 99,52 oC.   The depletion of energy supplies derived from fossils such as oil, coal and natural gas requires people to switch to use alternative energy. In this case, the Ministry of Energy and Mineral Resources calls for seeking and developing alternative energy as a replacement for conventional energy. One of alternative energy which must be developed is solar energy. Solar energy can be applied in cooking process. The purposes of this study were to determine the change in temperature of each measurement point in solar collector box and vessel during the charging and discharging process; to compare the temperature vessel using lug and not using lug on the charging and discharging process; and to determine thermal efficiency of solar collector box during the charging process and cylinder insulator in discharging process for maintaining the temperature of rice. Testing on the charging process was conducted by using collector box of 120 × 120 (cm) and in discharging process by using an insulator cylinder of 30 × 45 (cm). The charging process was done at 10:00 - 16:00 WIB and discharging process from 16:00 to 09:00 WIB. The average temperature of the charging process for vessels using lug was 78.81oC and not using lug was 73.10oC. This happens because the vessel using lug could absorb heat energy from the bottom side of the vessel. While the highest efficiency obtained by the solar collector box was on the charging process, i.e. 41.54% but had not been able to melt PCM which has melting temperature of 120oC because the maximum temperature that could be captured by the collector box was 99.52oC.

scholarly journals Numerical and experimental study of effect of paraffin phase change heat storage capsules on the thermal performance of the solar pond

2020 ◽  
pp. 014459872097416
Author(s):  
Hua Wang ◽  
Ma Xiaomeng ◽  
Zhang Liugang ◽  
Xinmin Zhang ◽  
Yanyang Mei ◽  
...  
Keyword(s):  
Phase Change ◽  
Thermal Performance ◽  
Heat Storage ◽  
Transition Process ◽  
Suppression Effect ◽  
Solar Pond ◽  
Phase Transition Process ◽  
Storage Zone ◽  
Salt Gradient ◽  
Change Material

In this paper, the effect of adding the composite PCM (Phase Change Material) heat storage capsules to the heat storage layer of the salt gradient solar pond on the thermal performance of the solar pond was studied numerically and experimentally. Based on the program-controlled temperature simulation of the solar pond experimental platform, the effect of adding the composite PCM (48–50°C and 58–60°C melting point paraffin) heat storage capsules on the solar pond temperature and stability was studied, and a numerical simulation model was established to be compared by the experimental results. The results showed that the experimental temperature was consistent with the simulation results; the solar pond with PCM capsules had a smaller temperature change range than the conventional solar pond during the phase change process, but it did not have such effect in the non-phase transition process; in terms of flow, the addition of the PCM phase change units could reduce the flow rate of the heat storage zone, and the PCM with a larger latent heat had a more obvious suppression effect on the flow. Therefore, within a certain temperature range, adding PCM units to the solar pond had a positive effect on maintaining the stable temperature and stability of solar pond.

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