METHOD AND APPARATUS FOR MAINTAINING A SUPERCONDUCTING SYSTEM AT A PREDETERMINED TEMPERATURE DURING TRANSIT
A superconductor system cooling apparatus, the apparatus comprising a casing, a solid coolant and a cooling circuit; wherein the cooling circuit comprises a heat exchanger, and a connector to couple the heat exchanger to a pre-cool loop of the superconductor system; wherein the cooling circuit further comprises a heat exchange medium to transfer heat between the solid coolant and the superconducting system.
1 . A superconductor system cooling apparatus, comprising
a casing;
a solid coolant;
a cooling circuit comprising a heat exchanger and a pre-cooling loop of the superconductor system;
a connector that couples the heat exchanger to the pre-cooling loop; and
a heat exchange medium that transfers heat between the solid coolant and the superconducting system.
2 . An apparatus as claimed in claim 1 , wherein the coolant comprises solid nitrogen or solid water.
3 . An apparatus as claimed in claim 1 , wherein the heat exchanger comprises a plurality of tubes of high thermal conductivity embedded in the solid coolant.
4 . An apparatus as claimed in claim 3 , wherein the heat exchanger is provided with an impeller for pumping the heat exchange medium though the tubes.
5 . An apparatus as claimed in claim 3 , wherein convection flow is set up to transport the heat exchange medium through the tubes.
6 . An apparatus as claimed in claim 1 , wherein the heat exchange medium is a liquid or gaseous cryogen.
7 . An apparatus as claimed in claim 6 , wherein the cryogen comprises one of hydrogen or helium.
8 . An apparatus as claimed in claim 1 , wherein the cooling apparatus further comprises a store for storing a quantity of the heat exchange medium.
9 . An apparatus as claimed in claim 1 , wherein the high temperature superconductor system comprises one of a cryostat, an electric generator and an electric motor.
10 . An apparatus as claimed in claim 1 , wherein the cooling apparatus further comprises a vacuum pump to evacuate the cooling circuit.
11 . An apparatus as claimed in claim 1 , wherein the cooling circuit comprises a closed loop carrying a coolant medium through tubes of the heat exchanger, the pre-cool loop and the connector.
12 . An apparatus as claimed in claim 1 , wherein the cooling apparatus cools current leads of the cryostat during ramping up.
13 . A method for maintaining a superconducting system at a predetermined temperature during transit of the superconducting system, comprising the steps of:
cooling a cryostat of a superconducting system to a predetermined temperature;
installing a cooling apparatus at the superconducting system that includes a casing, a solid coolant, and a cooling circuit that includes a heat exchanger, a pre-cooling loop of the superconducting system and a connector that couples the heat exchanger to the pre-cooling loop, wherein the heat exchange medium transfers heat between the solid coolant and the superconducting system;
operating the cooling apparatus during transit of the superconducting system to maintain the superconducting system substantially at said predetermined temperature during said transit; and
replenishing a source of said coolant in the cooling apparatus as necessary until installation of the superconducting system at a destination.
14 . A method as claimed in claim 13 , wherein the cooling of the cryostat to a predetermined temperature uses a mechanical cooler.
15 . A method as claimed in claim 13 , the method further comprising, removing a refrigerator if installed.
16 . A method as claimed in claim 13 , wherein the installing comprises connecting the cooling apparatus to a pre-cooling loop of the cryostat.
17 . A method as claimed in claim 13 , wherein the method further comprises replenishing the solid coolant before cooling at the destination.
18 . A method as claimed in claim 17 , wherein the cooling comprises using the replenished cooling apparatus to pre-cool a magnet of the superconducting system to less than 40 K.
19 . A method as claimed in claim 13 , wherein the method further comprises, at the destination, replacing or installing the refrigerator and cooling to operating temperature.
20 . A method as claimed in claim 19 , wherein the method further comprises disconnecting the cooling apparatus before cooling to the operating temperature.
21 . A method as claimed in claim 13 , wherein the predetermined temperature is substantially 77K.
22 . A method as claimed in claim 13 , wherein the operating temperature is substantially 4K.