Cooling Superconducting DC Power Cables

DC superconducting power cables typically operate at temperatures lower than the freezing point of liquid nitrogen. Therefore, these cables are cooled using a flow of cooled helium gas in the range of 20 to 50 K.

Stirling Cryogenics Closed Loop Cooling

Stirling Cryogenics provides such cryogenic cooling power with its two-stage Stirling Cryogenerator, which will deliver closed loop cooling using a cold helium gas flow down to 20 K. For this purpose, the cryocooler has an integrated heat exchanger in the cold head used for helium cooling working in conjunction with a Stirling Cryogenics CryoFan to circulate the cold gas.

The helium gas is cooled in the Stirling cryocooler heat exchanger and fed to the cable conduit surrounding the superconductive tape. As the helium flows along the length of the superconducting cable, it warms up, removing heat from the tape and extracting heat inleak coming through the cable insulation. This heat inleak will be the main source of heat. Consequently, the return flow of helium is often routed through an annular space surrounding the central conduit to intercept heat before it reaches the superconductive tape. The return conduit is connected to the Stirling cryocooler inlet, where the heat will be removed, and the helium gas will be cooled to the required inlet temperature for the cable.

Set up of DC cable cooled by an SPC-1T, courtesy of Advanced Conductor, Boulder, Colorado, US

Customized Stirling Cryocooler

Stirling can design and offer a customized system for your specific project.

Specifications SPC-1T
Specifications SPC-4T
Stirling CryoFans
HTS leaflet Stirling Cryogenics

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