Engineering Design of Forced-Flow Cooling HTS Cable for SMES System With High Current Capacity

Accelerator Complex such as NICA built in JINR has superconducting magnets operating at 10 kA level, the stable operation of which needs high performance SMES system to achieve energy compensation. The SMES needs to be operated with several kA-level current carrying and kA/s current ramping rate. The AC loss heat deposition resulting from fast current ramping makes immersion cooling and conduction cooling method inapplicable. The forced flowing cooling high temperature superconducting (HTS) CORC cable used for the SMES system with high current capacity is introduced in this paper. For achieving better bending performance and control the ohmic loss in the mandrel of the CORC cable, we choose flexible metal conduit as the mandrel and casing externally. It can form an internal cooling channel and outer channel at the same time, which can realize satisfactory cooling effect. The bending performance of the CORC with new type mandrel is also studied in this paper and related testing experiments are conducted at liquid nitrogen temperature zone. The results show that the CORC cable with flexible metal conduit as mandrel has satisfied bending performance and there is nearly no critical current degradation after bending and straighten. The pressure drop of the forced flow cooling based on this kind of CORC cable is also analyzed. The pressure drop meets the operation requirements of forced flow cooling. The SMES system based on this kind of CORC cable is being developed and will be finished in 2024.