Method and facility for filling a gas-insulated electrical apparatus comprising a mixture of (CF3)2CFCN and CO2
AssigneeGeneral Electric Technology GmbH
InventorsYannick Kieffel, François Biquez, Jacques Porte
Life of this patent
Estimating the term…
Abstract
A method and a facility for filling a high- or medium-voltage gas-insulated electrical apparatus in which the insulating gas comprises a mixture of heptafluoroisobutyronitrile ((CF3)2CFCN) and carbon dioxide. The method and the facility using a mixture of (CF3)2CFCN and CO2 in pressurised liquid form which is heated to a temperature no lower than the critical temperature of the mixture.
Claims10
A method of filling a closed casing containing at least one electrical component of equipment for a high-or medium-voltage electricity transmission line with a gas mixture comprising heptafluoroisobutyronitrile and carbon dioxide in predefined proportions, said method comprising:
- a) preparing, in a container, a pressurized liquid mixture comprising heptafluoroisobutyronitrile and carbon dioxide in predefined proportions;
- b) heating, in the container, the pressurized liquid mixture prepared in a) until it reaches a temperature that is higher than or equal to the critical temperature of the mixture whereby a gas mixture comprising heptafluoroisobutyronitrile and carbon dioxide in predefined proportions is obtained;
- and
- c) transferring said gas mixture obtained in b) from the container to the casing via a transfer circuit in which the gas mixture is decompressed and maintained at a temperature that is higher than the liquefaction temperature of heptafluoroisobutyronitrile at its partial pressure in the transfer circuit before it enters the casing to be filled.
An installation for filling a closed casing containing at least one electrical component of equipment for a high- or medium-voltage electricity transmission line with a gas mixture comprising heptafluoroisobutyronitrile and carbon dioxide in predefined proportions, the installation comprising:
- a container configured for containing a mixture comprising heptafluoroisobutyronitrile and carbon dioxide in predefined proportions;
- a heater member configured for heating the mixture comprising heptafluoroisobutyronitrile and carbon dioxide in predefined proportions present in the container in pressurized liquid form until it reaches a temperature that is higher than or equal to the critical temperature of the mixture whereby a gas mixture comprising heptafluoroisobutyronitrile and carbon dioxide in predefined proportions is obtained;
- and
- a transfer circuit configured for transferring the gas mixture comprising heptafluoroisobutyronitrile and carbon dioxide in predefined proportions from the container to the casing, the transfer circuit fluidly connecting said container with the casing and the transfer circuit having an expansion member configured for reducing the pressure of the gas mixture to a determined value to fill the casing for maintaining the gas mixture at a temperature that is higher than the liquefaction temperature of heptafluoroisobutyronitrile at its partial pressure in the transfer circuit, the filling installation comprising one or more temperature safety features.
Dependencies are inferred from the claim text.