HEAT ACCUMULATOR, METHOD FOR THE PRODUCTION THEREOF AND ENERGY SYSTEM PROVIDED WITH SUCH A HEAT ACCUMULATOR
The invention provides a heat accumulator for the storage and/or release of heat, consisting of a vessel having a wall which is at least partially heat-conducting, which vessel contains a crystalline material which exothermally absorbs and endothermally desorbs a heat-transporting substance. The crystalline material, in particular sodium sulphide, adheres to the wall of the vessel and remains adhering during use and has essentially the same structure in a state in which more heat-transporting substance is absorbed and in a state in which less heat-transporting substance is absorbed. In a process for the production of such a heat accumulator, the crystalline material is applied in the molten or highly hydrated state to the inner wall of a closeable vessel and is made to adhere to the wall by cooling and/or evaporation. An energy system, comprising such a heat accumulator, and a vaporiser and condenser, connected via a closeable vapour line to the heat accumulator, is also provided.