High-temperature direct-contact thermal energy storage using phase-change media

Claim 1

A high-temperature direct-contact thermal energy storage and retrieval system for storage of thermal energy at about 400° to about 3000° F. comprising: a plurality of high-temperature direct-contact thermal storage elements comprising about 10 to about 90 volume percent solid-liquid phase-change chemical having a phase-change temperature at about 400° to about 3000° F. and selected from the group consisting of alkali metal and alkaline earth carbonates, chlorides, nitrates, nitrites, fluorides, hydroxides and sulfates, metals, metallic alloys and mixtures thereof supported within the pores of sensible thermal energy storage-support materials selected from the group consisting of metallic carbides, nitrides, silicides, oxides, aluminates, titanates and zirconates having submicron particle size which do not substantially coarsen with thermal cycling at temperatures up to said phase change temperature and having a surface area greater than about 1 square meter per gram of storage-support material, said storage-support material comprising about 10 to about 90 volume percent of said thermal storage element; at least one containment vessel(s) for said thermal storage elements; a storage working fluid for thermal energy transfer from a thermal energy heat source to said storage elements by direct contact with said storage elements at a temperature higher than said phase-change temperature and means for passage of said storage working fluid from said heat source to contact with storage elements in a storage mode; and a retrieval working fluid for thermal energy transfer from said storage element by direct contact with said storage elements at a temperature lower than said phase-change temperature to a desired use and means for passage of said retrieval working fluid from contact with said storage elements to said desired use in a retrieval mode.