DE2345743A1 - Oil power cable with water cooling - uses axial grooves in layer above sheathing for high pressure water - Google Patents

Abstract

The oil cable consists of a tubular sectionalised conductor as cooling oil passage surrounded by an oil impregnated insulating layer connected to an oil channel and covered by a screening foil, sheathing and protective sheathing. Between sheathing and protective sheathing are cooling channels to convey water under high pressure. Between sheathing the protective sheathing and the cooling channels containing layer a pressure protection is provided by glass fibres wound in short-lay turns around the cable. The cooling channels can be realised by forcing onto the sheathing an intermediate layer of synthetic material such as PVC with continuous grooves in cable axis direction and near the sheathing. The protective sheathing may be designed weaker due to the provided pressure protection layer. The cable may be loaded to full capacity without emersion into a water cooling tube.

Description

• 7 QCP SIEMENS AKTIENGESELLSCHAFT Erlangen, "/ · ^ ¹ - ¹ ·

Berlin and Munich Werner-von-Siemens-Str. 50

Our reference: VPA 73/473 * Ba / Wk

Oil cable with water cooling

The invention relates to an oil cable with a conductor, an overlying, oil-soaked one in connection with an oil channel standing insulating layer, which is surrounded by a shielding film, a jacket and a protective jacket.

The power that can be transmitted with a cable depends essentially on the dissipation of the power loss, i.e. on the cooling. You therefore already have the oil of an oil cable, which is primarily used for insulation, via a heat exchanger and a separate one Return pipe circulated to increase the power that can be transmitted with a certain type of cable. Because of the compared However, the cooling effect that can be achieved is relatively low compared to water, which is lower in the specific heat of oil; aside from that the additional effort for the return of the oil interferes with this.

Better cooling results can be achieved with the help of circulated and recooled water; for this you have oil cables with you Conventional structure laid in cooling pipes of larger diameter, through which the cooling water is then pumped. Here, too, must a relatively large effort for laying the cooling pipe, pulling the cable into the cooling pipe and for the Reflux tube are accepted.

The invention is based on the object of more effective cooling to achieve an oil cable without having to arrange it in a separate cooling tube. The solution according to the invention this task is characterized in that cooling channels are arranged between the jacket and the protective jacket of the oil cable are. These cooling channels are preferably as groove-shaped

509812/0598 - ^? - -

VPA 73Λ73 ² *

Recesses in a pressed onto the metal jacket of the oil cable Interlayer formed. An embodiment of this form is explained using the figure:

The waveguide i with the oil duct 11 and transverse ducts 12 between the sub-conductors, with the oil-soaked paper insulation 2 and the core shield 3, has a conventional structure. The metal jacket 4 lying over the core shielding 3 can, however, be dimensioned to be weaker in comparison to the conventional design with regard to the layers explained below. An intermediate layer 5 made of PVC, PE or a similar plastic, in which grooves as cooling channels 51 run parallel to the axis of the cable, is namely pressed onto this metal jacket k. The cross section of these cooling channels is relatively small; this results in a high flow resistance, so that the cooling water must be put under high pressure for effective cooling. For this reason, the intermediate layer 5 is provided with a pressure protection 6, which here consists of glass fibers that are wound with a short blow. This glass fiber pressure protection can be designed for 50 bar, for example. A conventional protective jacket 7, for example made of PVC, is sprayed onto the pressure protection 6.

The aforementioned weaker dimensioning of the metal jacket h in comparison to conventional designs has the prerequisite that the pressure of the cooling water does not fall below the internal pressure of the oil even at the end of the oil cable; under this condition, the mechanical function of the metal jacket is partly taken over by the pressure protection 6.

A closed pipe can be used to return the cooling water made of insulating material are used, which has a smaller diameter than the oil channel 11 of the conductor 1 and inside this oil channel runs.

5 claims 509812/0 598

1 figure - 3 -

Claims (5)

VPA 73/4734 Expectations Oil cable with a conductor, an overlying, oil-soaked insulating layer which is connected to an oil duct and is surrounded by a shielding film, a jacket and a protective jacket, characterized in that between jacket (h) and
Protective jacket (7) cooling channels (51) are arranged. 2. Oil cable according to claim 1, characterized in that between Protective jacket (7) and cooling channels (51) a pressure protection (6) lies. 3. Oil cable according to claim 2, characterized in that the pressure protection (6) consists of glass fibers with a short
Blow are wound. k. Oil cable according to one of Claims i to 3, characterized in that the cooling channels (5i) are designed as groove-shaped recesses in an intermediate layer (5) pressed onto the jacket (h) » 5. Oil cable according to one of claims 1 to h, characterized in that the jacket (k) with regard to the pressure protection (6) is dimensioned weaker than in known oil cables with the same oil pressurex 509812/0 5 98 Blank page