Spherical Tanks for Use in Thermal Energy Storage Systems

Abstract

Thermal energy storage (TES) is a vital component of concentrated solar power (CSP). TES makes up for intermittent solar radiation, bad weather, and peak power demand. Currently, a sensible heat storage system using two tanks containing molten salt is considered the most practical and economical TES. Yet further system development is needed in order to improve its performance and economics. In this study of molten salt storage tanks, spherical tanks were investigated as an alternative to cylindrical tanks. Structural and thermal aspects of cylindrical tanks with varying H/D ratios (0.25–5) and spherical tanks of the same volume were compared. Comparison showed that utilization of spherical instead of cylindrical tanks resulted in significant savings in shell building material (28–47%). Heat transfer from the spherical tank’s shell is at least 35% less than cylindrical tanks. Reduction in building material, foundation, and insulation cost can lead to significant cost savings.