Vacuum-Adiabatic Characteristic of High Temperature Super-Conducting Cable (Part 4)

The hot temperature super conducting cable (HTS cable) cooled by the liquid nitrogen has many merits, for example, large power capacity, compact size, low loss and no leakage of magnetic field. First HTS cable in Japan is constructed now in a substation of Tokyo Electric Power Company. As the liquid nitrogen of which temperature is 77 [K] is used as the coolant, the thermal heat load transferred between the environment and the cable must be interrupted. The thermal insulating space, that is, cryostat is installed at outer part of the cable. The space is kept in high vacuum condition and Super Insulation (SI) is wound on the surface of the inner pipe in which three cable cores and liquid nitorogen are installed. We studied heat transfer characteristic of the cryostat in follwing the article part 1(1), Part 2(2) and Part 3(3)