Computational analysis of solar pond for energy storage and desalination

Abstract

Desalination of sea water with a help of solar pond is one of the most promising and developing technology. Salinity gradient solar ponds are essentially low cost solar energy collectors with integrated energy storage system, and hence are potential, cheaper alternatives to flat plate collectors system in certain locations. Solar ponds combine solar energy collection with long-term storage and can provide reliable thermal energy. The salt water has natural tendency to form a salt gradient in a water body with higher density salt water at the bottom and low density water at the top. In a solar pond the solar energy is transmits through the water and created heated water region at the bottom and tend to create a natural convection due to negative temperature gradient which is in opposition to positive salt gradient. In a solar pond this double-diffusive transport system controls the formation of three layer water body: Upper Convective Zone (UCZ), Middle non-convective zone, and Lower Convective Zone (LCZ). A stronger negative temperature gradient in opposition to the favorable positive salt gradient is detrimental to the stable run and collection of energy at the bottom. The objective of this study is to analyze the double-diffusive transport phenomena in a solar pond, the formation of the stable tri-layer and energy storage using a multi-physics computation fluid dynamics model. Sensitivity analysis will be performed to determine the stable conditions for the system to operate and ensure solar energy storage.