GB622648A - Improvements in and relating to cooling systems for electrical apparatus - Google Patents

Abstract

622,648. Closed liquid circulating systems for cooling engines. BRITISH THOMSONHOUSTON CO., Ltd. March 28, 1946, No. 9670. Convention date, April 2, 1945. [Class 64(iii)] A cooling system for cooling electrical apparatus, e.g. power transformers, comprises a casing containing the apparatus to be cooled immersed in a dielectric liquid, e.g. mineral oil, mixed with a refrigerating liquid which boils below the operating temperature of the dielectric liquid, a compressor for drawing off the vapours of the refrigerant evolved during the cooling and discharging vapours into a condenser, and a return connection for discharging condensate from the condenser back to the dielectric liquid. Automatic control means are provided for maintaining the dielectric below a certain value. A tank 1 enclosing a power transformer 6 has an exterior cooling unit 4 and contains the dielectric liquid mixed with the refrigerating liquid. A compressor 11 removes refrigerant vapour through a conduit 10 and passes it through coils of an air-cooled radiator 3 from which the condensate is recirculated under pressure to the tank 1 through nozzles 16. Baffles 18, 19 are provided to prevent vapour bubbles from contacting the transformer case. A thermal relay 20 with temperature responsive bulbs 21 may be employed to control the system automatically.