| 摘要 |
PURPOSE:To enable axial expansion and contraction of the heat conducton tube of a heat exchanger by attracting said heat conduction tube by electromagnetic force to the support for preventing the lateral vibration and the fretting caused thereby. CONSTITUTION:A steam generator comprising an upper shell 1, a lower shell 2, an upper head plate 3, and a lower head plate 4, and having an inner shroud 5 and heat conduction tubes 7, 8, 9, has a magnet 16 provided in a hole of a support ring 15 and fixed by a screw 17 thereto. The thermal stress corresponding to the thermal expasion and contraction of the down comer heat conduction tube 7 during the steam generating operation is rlieved by the axial sliding movement of the tube 7 along the surface of the magnet 16 resisting its magnetic force. The radial vibration of the tube caused by the flow of sodium and the like can be prevented by the attraction force of the magnet 16 which attracts the tube 7 to the support ring 15. |
