Cryogenic system with the sub-cooled liquid nitrogen for cooling HTS power cable

A 10 m long, three-phase AC high-temperature superconducting (HTS) power cable had been fabricated and tested in China August 2003. The sub-cooled liquid nitrogen (LN2) was used to cool the HTS cable. The sub-cooled LN2 circulation was built by means of a centrifugal pump through a heat exchanger in the sub-cooler, the three-phase HTS cable cryostats and a LN2 gas-liquid separator. The LN2 was cooled down to 65 K by means of decompressing, and the maximum cooling capacity was about 3.3 kW and the amount of consumed LN2 was about 72 L/h at 1500 A. Cryogenic system design, test and some experimental results would be presented in this paper.