Thermal Performance of TF Coils Case in HT-7U in the Case of Plasma Disruption
BINGJIA XIAO
Institute of Plasma Physics, Chinese Academy of Sciences
P. O. Box 1126, Hefei, Anhui, 230031, P. R. China
Email: bjxiao@mail.ipp.ac.cn
Abstract: One of the most severe events in HT-7U TF coils is the plasma disruption event. After the plasma disruption, the case will be heated by the eddy current, which is caused by the magnetic field change. Consequently certain amount of the deposited heat will be conducted to the coil bundles. In this paper, the center plasma disruption is modeled and the eddy current heating is calculated by ANSYS software. The generated heat is thus directly coupled to the transient thermal analysis with the same software. It was found when the plasma current in normal condition is 1.5 MA and the disruption time constant is 3 ms, the eddy current will heat the case up to a temperature increase of about 16 K in the middle of the inner straight leg. The heat transferred to the cable can warm up the helium in the CIC bundle to a temperature increase of about 0.4 0.5 K if the case coolant inlet temperature is 4 K and the mass flow rate for a single case is 15 g/s. An optimized cooling scheme for the TF coil is also made
1 INTRODUCTION
HT-7U tokamak is a fusion experiment device with a major radius of 1.7 m and a minor radius of 0.4 m. The magnets of the tokamak consist of 16 D-shaped coils for the toroidal field (TF), 6 coils for the...