Abstract: The present invention provides a circulation cooling system of a cryogenic cable in which a reserver unit can be made smaller and a conventional adjustment mechanism or adjustment task of the amount of a refrigerant within a reserver unit is not necessary. The circulation cooling system of a cryogenic cable according to the present invention has a reserver unit storing a refrigerant and a cable cooling portion cooling down a cable by the refrigerant sent from the reserver unit and the refrigerant sent from the cable cooling portion is returned to the reserver unit again for circulation. The system is characterized in that it has a refrigerant temperature adjustment mechanism to keep constant the amount of the refrigerant within the reserver unit.

Abstract: To provide a cooling method of a superconducting cable line wherein moistures contained in the cable in the superconducting cable line after laid is removed before cooling, so that solidification of the moistures can be prevented from clogging of piping including a coolant flow channel and a return pipe. There is provided an inert gas generating vessel so that before the coolant is flown into the superconducting cable line 15, the inert gas is blown into the cable line from an inflow pipe 23 connected with a supply pipe 19? and is discharged from a discharge pipe 22 together with the gas. The inert gas is preheated by a heater 3 before feeding it into the cable line. The discharge pipe 22 connected with a discharge side B of the return pipe 19 is provided with a moisture measuring instrument 20 to measure a moisture content of the discharged gas.

Abstract: The present invention provides a circulation cooling system of a cryogenic cable in which a reserver unit can be made smaller and a conventional adjustment mechanism or adjustment task of the amount of a refrigerant within a reserver unit is not necessary. The circulation cooling system of a cryogenic cable according to the present invention has a reserver unit storing a refrigerant and a cable cooling portion cooling down a cable by the refrigerant sent from the reserver unit and the refrigerant sent from the cable cooling portion is returned to the reserver unit again for circulation. The system is characterized in that it has a refrigerant temperature adjustment mechanism to keep constant the amount of the refrigerant within the reserver unit.

Abstract: To provide a cooling method of a superconducting cable line wherein moistures contained in the cable in the superconducting cable line after laid is removed before cooling, so that solidification of the moistures can be prevented from clogging of piping including a coolant flow channel and a return pipe. There is provided an inert gas generating vessel so that before the coolant is flown into the superconducting cable line 15, the inert gas is blown into the cable line from an inflow pipe 23 connected with a supply pipe 19? and is discharged from a discharge pipe 22 together with the gas. The inert gas is preheated by a heater 3 before feeding it into the cable line. The discharge pipe 22 connected with a discharge side B of the return pipe 19 is provided with a moisture measuring instrument 20 to measure a moisture content of the discharged gas.

Abstract: A current-carrying lead that may be connected between a source of current and a superconducting device and which comprises a ceramic superconductor and a support made of an insulator, a nonmagnetic metal or a good electrical conductor. The lead may be contructed to conduct currents having a single or dual polarities.