Heat Rejection to the Surface Layer of a Solar Pond

Abstract

An analytical and numerical study of the thermal and fluid flow effects of heat rejection to the surface layer of a salt-gradient solar pond, by means of a recirculating thermal discharge, is carried out. The use of solar ponds for power generation involves heat rejection, for which the surface zone may be employed. However, it is very important to determine the effect of the discharge of hot fluid on the temperature field in the surface zone and on the stability of the non-convective zone, which lies between the surface and storage zones. Of particular interest is the dependence of this flow on the inflow conditions, on heat loss at the surface and on the inflow-outflow configuration. The downward penetration of the flow is strongly governed by the buoyancy effects, and the study considers both the transient and the steady-state circumstances. The effect of the surface energy loss and of the conductive heat gained from below the surface zone is also studied. The flow is found to be strongly dependent on the inflow and outflow conditions and on the surface heat loss. The disturbance to the nonconvective zone is also studied. The basic physical processes involved are considered in detail, and the relevance of the results obtained in the design of the corresponding recirculating flow is outlined.