Cooling system for foam insulated bus

Abstract

Abstract In isolated phase bus systems comprising spaced substantially parallel aligned inner and outer tubular conductors, the interior space thereof being filled with a dielectric foam insulation made up of a predetermined percentage of open cells to enable free migration of vapors. A liquid dielectric having an appropriately selected and relatively low boiling point is inserted into the bus until it reaches a level whereby it substantially covers the inner conductor which is supported by the foam insulation. Conduction of current raises the bus temperature. If the magnitude of the current is such as to raise the temperature above a predetermined level, the liquid dielectric boils and vaporizes. The vaporized dielectric tends to move to a cooler zone within the structure and become condensed whereby the liquid dielectric continuously recirculates through the system to prevent the bus from exceeding a predetermined operating temperature. The controlled amount of the open cells provided in the foam and the positioning of the inner conductor below the longitudinal axis of the outer conductor substantially reduces the amount of liquid dielectric required with no reduction in dielectric withstand. The liquid dielectric may for example be taken from the group comprised of freons, ucons, or other liquids having predetermined relatively low boiling points and having the characteristics that they are non-reactive with the dielectric foam insulation.

Inventors

• 👤 David H Reighter

Bibliographic Details