THERMAL SCIENCE

International Scientific Journal

Najam-Ul-Hassan Shah

,

Adeel Arshad

,

Azhar Abbas Khosa

,

Hafiz Muhammad Ali

,

Muzaffar Ali

THERMAL ANALYSIS OF A MINI SOLAR POND OF SMALL SURFACE AREA WHILE EXTRACTING HEAT FROM LOWER CONVECTIVE LAYER

ABSTRACT
Solar energy is major renewable energy resource which can potentially fulfill 100% energy demand of the world while releasing no polluting agents to the atmosphere in contrast to the conventional fossil fuels. However, due to its intermittent nature, solar energy requires effective storage of energy for utilizing during the night and cloudy weather. A solar pond is a promising solution because it has its own energy storage which is suitable for low-temperature application like building heating and cooling. This paper presents a thermal analysis of a salt gradient solar pond while extracting heat from the lower convective zone. A mathematical model of 2m2 surface area is developed. Efficiency analysis is performed numerically using a MATLAB code for steady temperature difference of 30°C as well as 20°C across the gradient layer for three different pond sizes of depths 1,5m, 1,0m and 0.5m. The thermal efficiency of first pond of 1.5m depth varies from around 21% in summer to 11% in winter. Thermal efficiency of solar pond drops significantly by reducing its size and non-convective zone thickness: Annual average efficiencies are 21% 19% and 9.5% for the three ponds of 1,5m, 1,0m and 0.5m depths respectively. So it is recommended to prefer a pond 1.5m of over others. However, the efficiency of smaller the pond can be significantly improved by compromising on quality the of thermal energy, efficiency of 0.5m pond rises to 17% when operating at temperature just 20°C above ambient, compared with 9.5% for 30°C above ambient. Solar pond therefore proves to be suitable for effectively utilizing solar energy and can present an effective solution for low temperature energy needs like space heating.
KEYWORDS
mini solar pond, salt gradient, solar energy, energy storage and utilization, thermal performance, sensible heat based storage
PAPER SUBMITTED: 2017-01-29
PAPER REVISED: 2017-05-26
PAPER ACCEPTED: 2017-07-04
PUBLISHED ONLINE: 2017-08-05
DOI REFERENCE: https://doi.org/10.2298/TSCI170129166S
CITATION EXPORT: view in browser or download as text file
THERMAL SCIENCE YEAR 2019, VOLUME 23, ISSUE Issue 2, PAGES [763 - 776]
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Thermal analysis of a mini solar pond of small surface area while extracting heat from lower convective layer

© 2024 Society of Thermal Engineers of Serbia. Published by the Vinča Institute of Nuclear Sciences, National Institute of the Republic of Serbia, Belgrade, Serbia. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International licence