Effect of domain subdivisions on alloy solidification

摘要

The sensible heat portion of thermal energy storage (TES) for concentrated solar power (CSP) can be achieved using off-eutectic materials. These materials have the advantage of storing in latent as well as sensible heat through a given temperature range. On the other hand, off-eutectic materials have the disadvantage of possibly experiencing segregation effects, most likely impairing their solidification. During solidification, macrosegregation can occur due to a number of possible causes such as density differences in the solid and liquid portions of the mixture/alloy, flows due to capillary forces, flows due to electromagnetic fields or forced stirring, etc. In some cases, macrosegregation can severely affect solidification. One possible means to limit this segregation is with porous media. In this study, the segregation of an off-eutectic material in a porous medium is studied. Pore sizes and porous medium thermal conductivity are varied, revealing the importance of various mechanisms affecting solidification. Smaller pore sizes and higher porous medium thermal conductivities are shown to improve segregation and solidification.