Numerical Study of Hydrodynamic, Heat Transfer and Stability in a Salt Gradient Solar Pond

The problem of hydrodynamic, heat transfer and stability in a salt gradient solar pond has been numerically studied by means of computational fluid dynamics in transient regime in the present study. The body of the simulated pond is an enclosure of height H and length L wherein an artificial salinity gradient is created in order to suppress convective motions induced by solar radiation absorption and to stabilize the solar pond during the period of operation. The distribution of temperature and salt concentration fields during energy collection and storage in a solar pond filled with water and consisting of three different salinity zones has been shown. The bottom of the pond is blackened and the free-surface is subjected to heat losses by convection, evaporation and radiation while the vertical walls are adiabatic and impermeable. The governing equations of continuity, momentum, thermal energy and mass transfer are discretized by finite–volume method in transient regime. This study shows the importance of buoyancy ratio in the decrease of temperature in the UCZ and in the preservation of high temperature in the LCZ. It shows also the importance of the thickness of Non-Convective Zone (NCZ) in the reduction of the upward heat losses.