Parametric study of thermal behavior of the salt gradient solar pond under Urmia climate conditions

Solar pond technology is the easiest and the most economical system for converting and storing the solar heat energy. In this study, the effect of various parameters such as thickness of various layers, heat loss from the pond’s surface, the wall-shading effect and the pond size on the temperature of the storage zone were numerically investigated. The validity of the model is tested against experimental data for a small square pond constructed and tested in Urmia university under Urmia climate conditions, and a good agreement between theoretical and experimental data for the temperature in the storage zone has been obtained. According to the results it was observed that the thickness of the surface layer should be as thin as possible and that the gradient layer thickness plays a primary role in storing the heat in the pond and its thickness should be selected appropriately. In addition, the results indicated that the heat loss from the pond’s surface occurs mostly by evaporation rather than radiation and convection. It was indicated through case studies that the wall-shading effect is very high in small ponds but in larger ponds the shading effect does not exert a high influence on the storing layer temperature.