Department of Mechanical Engineering, Nehru Institute of Technology, Kaliyapuram, Coimbatore 6411 05, Tamilnadu, India
Solar ponds combine solar energy collection with long-term storage and can provide reliable thermal energy at temperature ranges from 50 to 90 0C. A solar pond consists of three main zones. The first zone, which is located at the top of the pond and contains the less dense saltwater mixture, is the absorption and transmission region, also known as the upper convective zone (UCZ). The second zone is the gradient zone or non-convective zone (NCZ) which contains a variation of saltwater densities increasing with depth. The last zone is the storage zone or lower convective zone (LCZ),where density is uniform and near saturation. The stability of a solar pond prototype was experimentally performed in a mild steel tank of height 1.2m, width and length of 1m with black coating on the inner sides and the exteriors were insulated with 0.2m of polystyrene sheets at the sides and bottom. The effects of the solar-pond's depth and its water's salinity on the store's temperature distributions were determined experimentally and compared with theoretical predictions.