Abstract
Long-length high temperature superconducting (HTS) cable projects, over 1 km, are
being designed that are cooled by flowing liquid nitrogen. The compact counter-flow
cooling arrangement which has the supply and return stream in a single cryostat offers
several advantages including smallest space requirement, least heat load, and reduced cost
since a return cryostat is not required. One issue in long length HTS cable systems is the
magnitude of the heat transfer radially through the cable. It is extremely difficult to
instrument an HTS cable in service on the grid with the needed thermometry because of the
issues associated with installing thermometers on high voltage components. A 5-meter
long test system has been built that simulates a counter-flow cooled, HTS cable using a
heated tube to simulate the cable. Measurements of the temperatures in the flow stream and
on the tube wall are presented and compared to analysis. These data can be used to
benchmark different HTS cable heat transfer and fluid flow analysis approaches.
