Development of Encapsulated Lithium Hydride Thermal Energy Storage

摘要

A packaged bed thermal storage unit using encapsulated LiH spheres has been proposed as a means of reducing the mass and size of space-based heat rejection systems in applications with pulsed power needs. The initial value analysis indicated that the thermal energy storage (TES) system could be beneficial. Preliminary assessment of the concept identified several feasibility issues and indicated that the encapsulating shell must be relatively thin (0.127 mm) for the concept to be attractive. The major area of technical uncertainty is associated with shell stresses during heating when the expanding material (LiH density changes by about 27% between the solid and liquid state) at the shell surface is trapped between the encapsulating shell and the solid LiH core. Preliminary experimental results indicated that shell rupture does not occur because cracks formed in the LiH during cooling allow the liquid to communicate with a central void volume. This paper presents an overview of the recent analytical and experimental work performed to demonstrate the feasibility of the encapsulated LiH concept. 7 refs., 8 figs.