№3 (2018)

Hismatullin A.S., Konys E.M.  

Article is devoted to a problem relevant today – to increase in efficiency of cooling systems of power oil transformers at considerable long and short-term overloads. Increase in efficiency of cooling of power oil transformers allows to increase their resource, to increase profitability and safety of operation. Statistical data on causes of failures of transformers of various classes of tension and with various terms of operation are provided. On the basis of studying of statistical data it is established that one of the main reasons for failure of transformers is the inefficiency of systems of oil cooling during the summer period of operation and at considerable long and short-term overloads. For increase in system effectiveness of cooling of power oil transformers the barbotirovaniye of the cooling oil circulating elegazy and the subsequent cooling of an elegaz with the thermoelectric refrigerator is offered. The system of circulation and cooling of an elegaz joins automatically at considerable long and short-term overloads. The design and operation of the offered cooling system of oil transformers are considered. A series of laboratory experiments of cooling of transformer oil in a tank of the power transformer without compressor and with existence of the compressor is conducted. Schedules of dependences of temperature from time at natural cooling are provided and when using a barbotirovaniye. Coefficients of thermal diffusivity and a thermolysis of transformer oil at various distances of an otnagrevatelny element are experimentally defined. The mathematical problem of distribution of a thermal stream in a rectangular parallelepiped is considered, the solution of the equation of heat conductivity is provided in a tank of the power transformer which represents a rectangular parallelepiped. The design of laboratory installation is in detail described. Brands of the used thermocouples, brand of the compressor and analog digitizer are given.
Keywords: technical condition of the transformer, power supply, control, repair, элегаз, efficiency, barbotirovaniye.