JPS63710B

PURPOSE:To facilitate connection of a high temperature vessel and a storage vessel to heat exchange chambers by a method wherein heat pipes inserted into another pipes having fins fixed therearound are used for the heat exchange between a heat accumulating material consisting of a metal hydride, and a heat medium. CONSTITUTION:The heat accumulating vessel 1 filled with the metal hydride 3 and the storage vessel 2 have insert pipes 25 therein, respectively, which are attached with the heat exchanging fins 24 on the outer circumferences thereof and the heat pipes 7 and 8 are inserted into these pipes 25, respectively. Further, the opposite ends of the pipes 7 and 8 extending outside the vessels 1 and 2 are inserted into another insert pipes 27 which are attached with fins 28 and which are inserted into the heat exchange chambers 9 and 10, respectively. The heat exchange chambers 9 and 10 are divided into two subchambers, respectively, by means of partition plates 11 and 12 and a high temperature heat medium or a low temperature heat medium is circulated through these subchambers separately. The subchambers are connected to a solar heat collecting system of the apparatus so that the heat transfer from the solar heat collecting system to the heat pipes 7 and 8 is made possible.