To provide a heat storage device capable of stabilizing operation pressure of a sealed tank into which a heated heating medium is introduced.
In the heat storage tank 11, water is fed into a heat storage tank 12 to be heated into superheated steam, the superheated steam is introduced into a steam tank 33 disposed outside of the heat storage tank 12. When the internal pressure in the steam tank 33 exceeds a specified operation pressure, the supply of the water to the heat storage tank 12 is stopped. A solenoid valve 42 is provided on a flow pipe 41 branched from and connected to a heating medium supply passage to the heat storage tank 12. In the case the internal pressure in the steam tank 33 rises even if supply of water to the heat storage tank 12 is stopped, the solenoid valve 42 is opened. IF the internal pressure in the steam tank 33 decreases to a specified operation pressure after the solenoid valve 42 is opened, the solenoid valve 42 is closed. Thus, the internal pressure in the steam tank 33 is kept constant.
OIKE HISANORI
SUZUKI KAZUHITO
