Design and Fabrication of a 1-MW High-Temperature Superconductor DC Induction Heater

The high-temperature superconductor (HTS) dc induction heater shows great potential in the efficiency increase and heating quality improvement, which has been validated by previous prototypes. Now, Shanghai Jiao Tong University has been developing and fabricating an industrial scale 1-MW HTS dc induction heater in China. The heater is utilized to preheat aluminum billets 446 mm in diameter × 800-1500 mm in length. Two cryocoolers are applied for coil cooling with pluggable sleeve and providing an additional safety margin whose normal operating temperature is 30 K. The magnet consists of a double pancake coils wound by REBa2Cu3O7-δ-coated conductors, which are produced by Shanghai Superconductor Technology Company. More than 12-km HTS tapes are used and the inductance of coil with iron is 98 H. The HTS magnet's critical current is 213 A. The 0.5-T dc magnetic field is set up in the two air gaps of HTS magnet with an iron core. The adjustable iron yoke distribution along the axial direction of billets can meet the 100 °C adjustable temperature gradient design requirement. The results will be helpful to design for the commercialization of the HTS dc induction heater.