Heat rejection and energy extraction within solar ponds

A study of the heat transfer and fluid flow processes governing heat rejection to the surface layer and energy extraction from the storage zone has been carried out. The literature available on this and other related problems was studied in detail to determine the nature of the recirculating flows that arise and the effect they might have on the stability of the gradient layer. Simplified analytical models were considered to determine the governing parameters and their effect on the performance and efficiency of the solar pond. Estimates of the surface temperature rise and the increase in evaporation caused by heat rejection were made. Two flow configurations, end-to-end and top-to-bottom, were considered for every extraction and the spread of the flow in the storage zone was studied. It was found that the limited penetration of the top-to-bottom configuration restricts its satisfactory operation to small ponds. The experimental modeling of the flows under study was considered in terms of the governing parameters and it was found that the top-to-bottom configuration cannot be uniquely modeled. The choice of these parameters for a full-size pond is also discussed.