GB1375466A - - Google Patents

Abstract

1375466 Cooling cables SUMITOMO ELECTRIC INDUSTRIES Ltd 26 May 1972 [28 May 1971 11 June 1971] 25110/72 Heading F4U An evaporative cooling system using either an halogenated hydrocarbon (freon) or sulphur hexafluoride for cooling an electric power transmission assembly, includes means for supplying liquid phase coolant along a cooling path within or in cooling relationship with a conductor of a cable of the assembly, to return to the supply means as liquid and vapour along separate incoming paths or as a liquid/vapour mixture along one or more incoming paths; and a valve device provided to control the flow in the incoming path or paths in response to the amount of one of the coolant phases in the cooling path and/or in said incoming paths. In Fig. 7, the cables 1 having cooling paths 5, are disposed in a steel pipe 6 which forms an incoming path Ra for vapour phase coolant. A return pipe RT forms an incoming path Rb for liquid phase coolant. A float valve SP is provided to separate the liquid and vapour phases. The embodiment shown in Fig. 9, differs in that the float valve enables the vapour phase to return in pipe RT, and the liquid phase in Rb. Both the above embodiments have cooling paths S within the cable, the vapour formed through the cooling of the cable passing through the insulation 3. In the embodiment shown in Fig. 11, the insulation is impervious to the vapour and a control valve FC is provided to regulate the amount of circulating coolant flow in proportion to the amount of vapour phase coolant.