The Bottom Heat Loss of a Solar Pond in the Presence of Moving Ground Water

Abstract

The bottom heat loss from a solar pond in the presence of moving ground water was determined under steady state conditions. A simplified pond model was used which restricts the results to long, narrow, shallow ponds. The analysis was based on the steady two-dimensional energy equation utilizing an effective thermal conductivity. The ground was modeled as a porous soil consisting of two distinct regions; one above the water table and one below where the ground water was assumed to flow in the horizontal direction. Solutions were obtained by the finite-difference direct method utilizing matrix concepts. The bottom heat loss is represented by a conductance coefficient whose values are plotted as a function of Peclet number, water table level, and the thermal conductivity ratio of the two distinct soil regions. The results indicate that the heat loss rate significantly increases as the water table level moves closer to the pond bottom. At water table levels close to the pond bottom, the heat loss rate increases significantly with increasing Peclet number.