AC-2756 -- The Influence of Bottom and Side Wall Heat Loss on Solar Pond Performance ✓ Most Recent

Salt gradient nonconvective solar ponds have become recognized as effective devices for collect­ing and storing solar energy. One of the parameters affecting the thermal performance of finite solar ponds is the heat lost through the bottom and side walls of the pond. This study relates these heat losses to the thermal behavior of the pond for the following pond characteristics:

1. Different thermal properties for the earth adjacent to the bottom and side walls of the pond.
2. Various pond storage-zone thicknesses.
3. Various ratios of pond depth to half-width and radii for rectangular and axisymmetric shapes, respectively.

A finite-difference procedure is employed and the two-dimensional, unsteady conduction heat equation is solved numerically. The results reveal that the ratio of the temperature response of finite ponds to that of infinite ponds varies nonlinearly with the ratio of the pond depth to radius or pond depth to half-width for axisymmetric or rectangular ponds, respectively, contrary to previous suggestions. It is also demonstrated that this temperature ratio depends on the surrounding earth properties and on the pond storage-zone thickness.