Numerical Calculation of Advection Heat Transfer and Fluid Flow Dynamics of $\mbox{LN}_{2}$ Flowing HTS Cable

Abstract

For long-distance operation of high-temperature superconducting (HTS) cables, evaluations of heat transfer and fluid flow dynamics of liquid nitrogen (LN <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ) flowing in the HTS cable is important. However, the LN <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> flow is complicated when the cable core is positioned at an eccentric position to the center of the cryostat pipe. A computer simulation analysis is effective in evaluating these characteristics with the complicated LN <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> flow. In the computer simulation analysis, design of an appropriate simulation model, which is considering the cable configuration and LN <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> flow conditions, is necessary. In this paper, at first, the accuracy of the computer simulation model was evaluated by comparison of the theoretical arithmetic analysis model for a simplified cable configuration, which is assumed that the cable core is positioned at the center. As a result, the value of computer simulation analysis showed a good agreement with that of the theoretical analysis. Then, using this computer simulation model, the effects of the eccentric arrangement on the pressure drops and the temperature rise of the flowing LN <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> were simulated. As a result, the pressure drop of the eccentric configuration became to about two-third as compared with that of the central core configuration, and no significant temperature difference of the HTS conductor of each configuration was confirmed.