Tools for Cryogenic Design of Superconducting Induction Heater

Abstract

The design of cryogenic systems requires knowledge about many material parameters to accurately simulate the system before the construction. This thesis presents the cryogenic design of a superconducting induction heater in an Aluheat project and important tools and simulation models needed whilst designing this system. These tools and models provide better understanding about the material properties as well as about the characterization of short samples and coils to improve existing simulation models. First, I present the physical background of concepts used in the thesis. To evaluate the coil stability, and to simulate quench, the transverse thermal conductivity of a MgB2 coil was measured and simulated. Furthermore, the viability of several solders for small scale HTS current lead construction was shown and their performance compared against commercial current lead designs. Next, I studied the short sample and coil characterization and stability by means of voltage (V) current (I) characteristics. A method to improve the V(I) characteristics of the conduction cooled short samples was presented and tested for two superconducting tapes. Simulations of charging characteristics of the coil were also studied. Finally, the design of a superconducting induction heater with improved efficiency is shown, and some issues faced during the project explained.