JPS6138995B

PURPOSE:To improve an efficiency of the heat reserve system using a discharged heat from a subway by a method wherein a plurality of heat storage tanks are connected to a center through a heating medium feeding pipe of one circuit and then the medium is fed out of the heat storage tanks heated up to an available temperature. CONSTITUTION:Assuming that, for example, a temperature of a temperature detector 20 for a main heating medium feeding pipe 16 is 50 deg.C, a temperature of the temperature detector 19 for the heat storage tank is 60 deg.C and the required temperature of a heat utilization apparatus 3 and a center 18 is 55 deg.C, the heating medium in the main heating medium feeding pipe 16 may not be utilized and a heat storage tank 1 can be discharged of its heat. Therefore, a pump 21 is operated, a valve 23 and a surface control valve 27 are opened, the heating medium in the heat storage tank 1 is fed to the center 18 and then returned back to the heat storage tank 1 through the heating medium feeding pipe 17. With this arrargement, the heat storage tank selected from a dispersed group of heat storage tanks is utilized so as to improve the utilization efficiency of the system.