Sodium hydroxide-based heat storage material

摘要

Heat storage material comprises a latent heat storage agent (I) consisting of a caustic soda liquor with a concn. of 60-80 wt.% NaOH and 40-20 wt.% H2O, and 0.01-5 (pref. 0.05-1) wt. parts (per 100 wt. parts I) of seed crystals or nucleating agent (II), enclosed in liquid-tight manner in a casing, capsule, flexible tube, sphere or similar container or package which is in (in-)direct heat transfer contact with a liq. heat-transfer medium of density lower than that of (I). The novelty is that (I) exhibits an eutectic at 62.3 deg.C (corresponding to a 74.3 wt.% caustic soda liquor) and (II) are aluminates of formula M Al(OH)4 (where M=alkali metal) or non-toxic aluminium salts or aluminium hydroxide (in anhydrous or hydrated form) which react with NaOH to form sodium aluminate, and/or CaCO3 (in anhydrous or hydrated form).