| 摘要 |
PURPOSE:To minimize heat loss into the outside in the time of normal operation of a heating medium and highly efficiently utilize the heat of a heating medium by covering the outside of a heat transfer tube closed circuit, in which a cooling medium is sealed, by a heat tube and isolating the heat transfer tube closed circuit from the heating medium. CONSTITUTION:A heat transfer tube 4 is placed in a reactor vessel 1. The outside of the heat transfer tube 4 is enclosed by a heat tube 25a and the heat transfer tube 4 is isolated from Na 9 in the reactor vessel 1. Part of Na 9 in an upper plenum 16 flowed out from a reactor core 15 is flowed in a circular passage 19 at which the heat transfer tube 4 is arranged through an upper hole 12 provided in a wall 11, and, after it is lowered, flowed out from a lower hole 12. Na flowed out from the circular passage 19 is flowed in an intermediate heat exchanger 17 after Na is joined with Na 9 in the upper plenum 16. Since a heat tube 25 is arranged horizontally, the puddle of a working medium 21 can be made at all points in the heat tube, the inner surface of the heat tube 25 is dried and evaporation areas are not decreased. |
