Increasing ampacity of cables by an application of ventilated pipes

Abstract

We show that a substantial increase of cable ampacity can be achieved, if air-filled pipes are used, laying parallel to the cable cores or containing them, and if the ends of these pipes are lead up to the soil surface and therefore interacting with the ambient air. An additional advantage of using the metallic pipes is that they may lead to a substantial reduction of a magnetic field. We will examine this issue in This work as well. A numerical example involving a high voltage cable located in a cooling pipe is presented to show the effect of the natural and forced convection in the pipe on the ampacity of the cable circuit. In this practical example, the ampacity of the cable can be increased considerably, even for great cooling section lengths.