| Abstract: |
A salinity gradient solar pond (SGSP), termed in this study ”solar pond”, is a simple and effective way of capturing and storing solar energy. This study presents the results of temperature developed in the inner zones of a salinity gradient solar pond model (SGSPM) under Egyptian solar radiation climate conditions during 2010. An insulated SGSPM with a surface area of 1.5 m × 1.5 m and a depth of 1.44 m was constructed in Faculty of Agriculture, Zagazig University, Sharkia Governorate, Egypt (Latitude 30o 35/ N, Longitude 31o 31/ E).The objectives of this study are to:1. Study the density and temperature profiles for the solar pond.2. Study the temperature variations of the solar pond zones under Egyptian climate conditions.3. Evaluate the thermal pond performance.4. Study the effect of both upper and lower convective zones thickness on the thermal pond performance.SGSPM filled with prepared different concentrations of sodium chloride salt in water of densities to form salty water zones (upper convective zone, UCZ, the non-convective zone, NCZ, and the lower convective zone, LCZ, with thickness of 0.1, 0.6 and 0.74 m, respectively). The salinity difference between UCZ and LCZ was 6 % for 1st experiment, 10 % for 2nd experiment and 15 % for 3rd experiment. Twelve temperature sensors (thermocouples type ”T”) distributed vertically at different locations along the centered inner zones of the pond to measure temperature variations during day times. Temperature difference was an important indicator for forced heat transfer. The highest stored temperature was obtained from 3rd experiment as follow: 38.3, 49.9 and 53.5 oC for UCZ, NCZ and LCZ, respectively during April; 39.1, 52.6 and 58.8 oC in June; 24.7, 31.8 and 37.9 oC in December. The highest thermal efficiency was obtained in December as 43.7, 48.5 and 55.5 % for 1st, 2nd and 3rd experiments, respectively.
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