| 摘要 |
PURPOSE:To prevent local overheating and internal pressure rise and improve safty and simplify the structure of a coil by a method wherein a valve provided to a coolant by-pass is opened when a superconductor is turned into a normal conductive condition to stop transfer of the coolant into the superconductive coil. CONSTITUTION:A coolant by-pass 15 is connected between both ends of a superconductive coil 5 and a valve 16 controlled by an electrical control circuit 14 is provided to the coolant by-pass. The coolant by-pass 15 is composed of a low flow resistance pipe with a large pipe diameter and a short pipe length. The valve 16 is opened when a superconductor 4 is turned into a normal conductive condition to make a coolant path short-circuited. Supply of the coolant to the superconductive coil 5 is stopped and only the coolant filling the superconductive coil 5 is vaporized. Therefore, quantity of vaporized coolant is small and and internal pressure rise of a conduit is reduced. Along with the progress of the vaporization of the coolant, the normal conductivity area is expanded to the whole coil and electrical energy consumption becomes distributed to the whole coil. Therefore, melting down caused by rocal overheating of the superconductor 4 is avoided. |
