Heat-storage material pref. based on hydrated salts - contg. nucleating agent, is suspended in colloidal suspension of thixotropic material

摘要

A medium for storage of heat is based on a compsn. that changes from the liq. to the solid state subject to undesirable sedimentation of a solid, particular fraction when the compsn. is at least at the temp. of change of state. The compsn. includes a nucleating agent and the medium is obtd. by suspending the compsn. in a colloidal suspension of a thixotropic material. The colloidal suspension is pref. stabilised by a peptising agent, pref. CMC with addn. of a wetting agent. The medium is used as a method of accumulating heat in an isothermal manner over the temp. range -30 degrees C to 180 degrees C esp. for storage of solar heat. The medium resists the degradation by sepn. into two phases that is a disadvantage of the use of polyhydrated salts for heat storage. This permits the medium to undergo several hundred storage- "destorage" cycles with only small loss of efficiency. The addn., the use of new nucleating agents increases the range of polyhydrated salts and hence widens the range of temps. of change of state that can be used.