Turbulent natural convection and thermal behaviour of cylindrical gas-insulated transmission lines (GIL)

This paper presents a numerical study of the natural convection of gases in a horizontal annulus of gas-insulated transmission lines (GIL). It consist of thermal analysis of high voltage power gas insulated transmission lines. In different case studies, the inner cylinder is heated at a constant heat or kept at a constant temperature, whilst the outer cylinder is maintained at constant temperature. The cylinders are long and the flow is assumed to have axially independent properties. The two dimensional analyses of the heat transfer and fluid motion are performed for Rayleigh number ranging from 10/sup 5/ to 10/sup 10/, the radius ratio is at 2,5. Comparisons are made with experimental test set up and measurements.