Entropy generation in a high temperature superconducting current lead

Abstract

The minimization of entropy generation has been used as a convenient thermal design tool in predicting the optimal temperature distribution in a cryogenic current lead. A vapour-cooled lead with non-ideal cooling has been modelled by a set of non-linear differential equations with corresponding boundary conditions. Highly non-linear temperature dependent thermophysical properties, typical for a high temperature superconducting YBCO compound, have been incorporated in a current lead model. Numerically obtained current lead temperature profiles have been used to calculate entropy generation within the lead as a function of the relevant physical and operational parameters. It has been shown that with respect to thermodynamic irreversibility as an objective function, in both resistive and superconducting modes of operation, there is an optimal thermal design. © 1992.