Distribution of a dielectric gaseous mixture to a high-voltage apparatus

Patent metadata

Field	Value
Publication number	US-11005241-B2
Application number	US-201716317061-A
Country	US
Kind code	B2
Filing date	Jul 7, 2017
Priority date	Jul 13, 2016
Publication date	May 11, 2021
Grant date	May 11, 2021

Abstract

A method of distributing an electrically insulating liquefied gas mixture to high-voltage electrical equipment from a storage means containing an insulating gas mixture, including: heating the insulating gas mixture to a temperature such that the contents of the storage means are a homogeneous fluid; and withdrawing the insulating mixture resulting from step a) to fill high-voltage electrical equipment by raising the temperature of the mixture resulting from step a), wherein, during step b), a set value for regulation is applied at variable pressure, calculated in real time based on weighing the storage means, when the change in the set value of pressure is less than 0.2 bar per 1 kg/m3 of change in density, and then a set value for regulation is applied at constant temperature until the storage means is emptied of its content.

First claim

The invention claimed is:

1. A method of distributing an electrically insulating liquefied gas mixture to high-voltage electrical equipment from a storage means containing an electrically insulating liquefied gas mixture, the method comprising the following steps:
Step a): heating the electrically insulating liquefied gas mixture to a temperature such that the contents of the storage means are a homogeneous fluid;
Step b): withdrawing the electrically insulating liquefied gas mixture resulting from step a) to fill high-voltage electrical equipment by raising the temperature of the electrically insulating liquefied gas mixture resulting from step a);

wherein, during step b), a set value for regulation is applied at variable pressure, calculated in real time based on weighing the storage means, when the change in the set value of pressure is less than 0.2 bar per 1 kg/m 3 of change in density, and then a set value for regulation is applied at constant temperature until the storage means is emptied of its content.

2. The method of claim 1 , wherein step a) comprises heating the electrically insulating liquefied gas mixture to a temperature greater than or equal to a critical temperature in order to obtain a homogeneous supercritical fluid inside the storage means.

3. The method of claim 1 , wherein, during step b), the electrically insulating liquefied gas mixture undergoes expansion to a pressure between 0 bar and 12 bar relative.

4. The method of claim 3 , wherein the temperature of the electrically insulating liquefied gas mixture resulting from step a) is raised to a temperature between 65° C. and 90° C. during withdrawal in step b).

5. The method of claim 1 , wherein the pressure inside the storage means between step a) and step b) is between 15 bar and 90 bar relative.

6. The method of claim 1 , wherein the temperature of the electrically insulating liquefied gas mixture inside the storage means between step a) and step b) is between 40° C. and 65° C.

7. The method of claim 1 , wherein said storage means comprises heating means consisting of electromagnetic induction means capable of heating the electrically insulating liquefied gas mixture inside the storage means.

8. The method of claim 1 , wherein the electrically insulating liquefied gas mixture comprises at least 80 mol % of CO 2 in the case of a two-component mixture and comprises at least 50 mol % in the case of mixtures comprising at least three components.

9. The method of claim 8 , wherein that the electrically insulating liquefied gas mixture comprises at least one component selected from the fluoronitriles having at least four carbon atoms.

10. The method of claim 9 , wherein the electrically insulating liquefied gas mixture comprises between 2 and 20 mol % of said component selected from the fluoronitriles having at least four carbon atoms.

11. The method of claim 1 , wherein said storage means has a capacity for storage of the electrically insulating liquefied gas mixture between 30 L and 700 L.

12. The method of claim 1 , wherein, in step b), the rate of withdrawal of the electrically insulating liquefied gas mixture resulting from step a) is between 10 Nm 3 /h and 50 Nm 3 /h.

Assignees

• Air Liquide

Inventors

• Loray Frédéric
• DULPHY HERVé
• Satin Ariel

Classifications

• H01H33/22

  Selection of fluids for arc-extinguishing · CPC title

• F17C2223/0115

  dense or supercritical, i.e. at high pressure and high density · CPC title

• H01H33/562

  Means for avoiding liquefaction or for disposing of liquefaction products · CPC title

• H01H2033/566

  Avoiding the use of SF6 · CPC title

• F17C5/06 Primary

  for filling with compressed gases · CPC title