Numerical analysis of thermal stability of an immersion-cooled, pancake type superconducting coil

Abstract

A numerical analysis of the thermal stability of an immersion-cooled, single pancake type superconducting coil has been carried out, taking into account transient boiling heat transfer and the temperature dependence of the physical properties of the superconducting composite. The unsteady heat conduction equation, with source terms allowing for heat conduction through an electric insulation film, thermal disturbance, heat transfer and Joule heat generation, has been solved by a control volume finite method. The stability limit of the variable property solution (VPS) is compared with that of the constant property solution (CPS). The result shows that the VPS is 1.5 times as large as the CPS. Also, the effects of the transport current density and the magnetic flux density on the stability of the superconducting coil are clarified.