EP3769329A2

EP3769329A2 - Use of 1-chloro-2,3,3,3-tetrafluoropropene for isolating or extinguishing electric arcs

Info

Publication number: EP3769329A2
Application number: EP19742415.3A
Authority: EP
Inventors: Wissam Rached
Original assignee: Arkema France SA
Current assignee: Arkema France SA
Priority date: 2018-03-22
Filing date: 2019-03-14
Publication date: 2021-01-27
Also published as: FR3079359A1; FR3079359B1; US11133139B2; US20200365353A1; WO2019186017A3; WO2019186017A2

Abstract

The invention relates to the use of a gas as a medium for electrically isolating and/or extinguishing electric arcs, said gas comprising 1-chloro-2,3,3,3-tetrafluoropropene. The invention also relates to an electrical device comprising a sealed chamber containing electrical components and a gas for electrically isolating and/or extinguishing electric arcs, in which the gas comprises 1-chloro-2,3,3,3-tetrafluoropropene.

Description

USE OF 1-CHLORO-2.3.3.3-TETRAFLUOROPROPENE FOR THE INSULATION OR EXTINCTION OF ELECTRIC ARCS

FIELD OF THE INVENTION

The present invention relates to a gas used for the electrical insulation or extinguishing of electric arcs, as well as electrical appliances provided with an enclosure containing this gas. TECHNICAL BACKGROUND

In medium and high voltage electrical appliances, the electrical insulation and, where appropriate, the extinction of electric arcs are typically provided by a gas that is confined within an enclosure of these devices. Currently, the most commonly used gas is sulfur hexafluoride (SFe): this gas has a relatively high dielectric strength, good thermal conductivity and low dielectric losses. It is chemically inert and non-toxic to humans and animals and, after being dissociated by an electric arc, it recombines quickly and almost completely. In addition, it is nonflammable and its price is still moderate today.

However, SFe has the major disadvantage of having a global warming potential (GWP) of 22,800 (relative to CO2 over 100 years) and a residence time in the atmosphere of 3,200 years, which places it among the gases with strong greenhouse effect.

Industrialists are therefore looking for alternatives to SFe. Hybrid systems have been proposed which combine gas insulation with solid insulation (EP 1724802). This, however, increases the volume of electrical appliances compared to that allowed by SFe insulation; and the cut in the oil or vacuum requires a redesign of the equipment.

As an alternative to SFe, it is known to use so-called simple gases such as air or nitrogen, which have no negative impact on the environment. But these have a much lower dielectric strength than SFe; their use for electrical insulation and / or arc extinguishing in high-voltage / medium-voltage equipment involves drastically increasing the volume and / or filling pressure of these devices, which goes against the efforts that have been made in recent decades to develop compact electric, with more and more reduced space.

Perfluorocarbons generally have interesting dielectric strength properties, but their GWP is typically in a range of 5,000 to 10,000.

Other promising alternatives from a point of view of electrical and GWP characteristics, such as trifluoroiodomethane, are classified as carcinogenic, mutagenic and reprotoxic substances of category 3, which is unacceptable for use on an industrial scale.

Mixtures of SFe and other gases such as nitrogen or nitrogen dioxide are used to limit the impact of SFe on the environment: see, for example, WO 2009/049144. Nevertheless, because of the strong SFe GWP, the GWP of these mixtures remains very high. Thus, for example, a mixture of SFe and nitrogen in a volume ratio of 10/90 has a dielectric strength in alternating voltage (50 Hz) equal to 59% of that of SFe but its GWP is of the order of 8 000 to 8 650. Such mixtures can not therefore be used as a low environmental impact gas.

The document FR 2955970 proposes the use of fluoroketones in the gaseous state for electrical insulation. The fluoroketones can be combined with a carrier gas or dilution gas (for example nitrogen, air, nitrous oxide, carbon dioxide, oxygen, helium, etc.).

Document FR 2975818 proposes a mixture of octofluorobutan-2-one and carrier gas as isolation medium.

The document FR 2983341 proposes the use of polyfluorinated oxiranes as electric insulation gas and / or electric arc extinguishing.

Document FR 2986102 proposes the use of a combination of polyfluorinated oxirane and hydrofluoroolefin as electrical insulation gas. The hydrofluoroolefins mentioned are 1, 3,3,3-tetrafluoropropene (HFO-1234ze), 2,3,3,3-tetrafluoropropene (HFO-1234yf) and 1,2,3,3,3-pentafluoropropene (HFO -1225ye).

Document WO 2012/038443 proposes the use of a mixture of SFe and fluoroketone as electrical insulation gas.

WO 2012/160158 proposes the use of a mixture of decafluoro-2-methylbutan-3-one and a carrier gas as an electrical insulating gas. The document WO 2013/004796 proposes the use of a gas based on hydrofluoroolefin as an electrical insulation gas. The hydrofluoroolefins more particularly proposed are 1, 3,3,3-tetrafluoropropene

(HFO-1234ze) and 2,3,3,3-tetrafluoropropene (HFO-1234yf).

The document WO 2013/041695 proposes the use of a mixture of hydrofluoroolefin and of fluoroketone as electrical insulation gas. The hydrofluoroolefins more particularly proposed are the

1, 3,3,3-tetrafluoropropene (HFO-1234ze), 2,3,3,3-tetrafluoropropene

(HFO-1234yf) and 1,2,3,3,3-pentafluoropropene (HFO-1225ye).

The document WO 2013/136015 proposes the use of a mixture of hydrofluoroolefin and hydrofluorocarbon as electrical insulation gas. The hydrofluoroolefins more particularly proposed are the

1 .3.3.3-Tetrafluoropropene (HFO-1234ze), 2,3,3,3-tetrafluoropropene

(HFO-1234yf) and 1, 2, 3, 3, 3-pentafluoropropene (HFO-1225ye). Hydrofluorocarbons more particularly proposed are the

1 .1 .1 .2.3.3.3-heptafluoropropane (HFC-227ea), pentafluoroethane

(HFC-125) and 1,1,1,2-tetrafluoroethane (HFC-134a).

WO 2017/037360 proposes the use of hexafluorobutenes as gas for electrical insulation and / or extinction of electric arcs.

There is still a need to develop electrical isolation and / or arc extinguishing media with both low GWP and high dielectric strength.

SUMMARY OF THE INVENTION

The invention firstly relates to the use of a gas as an electrical insulation medium and / or electric arc extinguishing, wherein the gas comprises 1-chloro-2,3,3,3-tetrafluoropropene .

In embodiments, 1-chloro-2,3,3,3-tetrafluoropropene comprises more than 80 mol% 1-chloro-2,3,3,3-tetrafluoropropene in Z-form, preferably more than 90 mol% of 1-chloro-2,3,3,3-tetrafluoropropene in Z form, more preferably more than 95 mol% of 1-chloro-2,3,3,3-tetrafluoropropene in Z form and more preferably more than 99 mol% of 1-chloro-2,3,3,3-tetrafluoropropene in Z form.

In embodiments, the gas is used as an electrical isolation and / or arc extinguishing medium in a medium voltage substation electrical apparatus. In embodiments, the gas contains from 10 to 100 mol% of 1-chloro-2,3,3,3-tetrafluoropropene, preferably from 15 to 75 mol% and more particularly from 19 to 45 mol%. .

In embodiments, the gas also comprises a diluent, preferably selected from air, nitrogen, methane, oxygen, carbon dioxide or a mixture thereof; and preferably the gas is a binary mixture of 1-chloro-2,3,3,3-tetrafluoropropene and a diluent.

In embodiments, the gas further comprises a halogenated compound, preferably a fluorinated compound, further preferably selected from fluoroketones, hydrofluoroolefins, hydrochlorofluoroolefins and combinations thereof.

In embodiments, the gas is used in a temperature range whose lower limit is from -30 to 30 ° C, preferably from -20 to 25 ° C, more preferably from -15 to 20 ° C. preferably from -10 to 10 ° C.

In embodiments, the gas consists essentially, and preferably, of 1-chloro-2,3,3,3-tetrafluoropropene.

In embodiments, the gas is used in a temperature range whose lower bound is greater than or equal to 10 ° C, or 11 ° C, or 12 ° C, or 13 ° C, or 14 ° C. ° C, or at 15 ° C to 16 ° C, or at 18 ° C, or at 20 ° C.

The invention also relates to an electrical apparatus comprising a sealed enclosure in which there are electrical components as well as an electrical insulating gas and / or electric arc extinguishing, wherein the gas comprises 1-chloro-2, 3,3,3-tetrafluoropropene.

In embodiments, the gas further comprises a halogenated compound, preferably a fluorinated compound, preferably further selected among fluoroketones, hydrofluoroolefins, hydrochlorofluoroolefins and combinations thereof.

In embodiments, the electrical apparatus is a medium voltage electrical apparatus.

In embodiments, the electrical apparatus is a high voltage electrical apparatus.

In embodiments, the gas is at a pressure at 20 ° C of 0.1 to 1 MPa, preferably 0.1 to 0.5 MPa, and more preferably 0.12 to 0.15 MPa. .

In embodiments, the apparatus is selected from a gas-insulated electrical transformer, a gas-insulated line for the transmission or distribution of electricity, and an electrical connection / disconnection apparatus.

The present invention overcomes the disadvantages of the state of the art. More particularly, it provides electrical insulation and / or arc-extinguishing media having both low GWP and high dielectric strength.

This is accomplished by the discovery that 1-chloro-2,3,3,3-tetrafluoropropene-based media, commonly referred to as HCFO-1224yd, exhibit remarkable dielectric strength properties and that in admixture with inert compounds they provide effective electrical insulation even at relatively low temperatures.

DESCRIPTION OF EMBODIMENTS OF THE INVENTION

The invention is now described in more detail and without limitation in the description which follows.

The invention relates to a gas used as an electrical isolation medium and / or electric arc extinguishing.

The gas according to the invention comprises at least 1-chloro-2,3,3,3-tetrafluoropropene or HCFO-1224yd. HCFO-1224yd may be in E form, or Z form, or may be a mixture of both forms. Z form is preferred.

Preferably, the HCFO-1224yd comprises more than 50 mol% of the Z form, preferably more than 60 mol% of the Z form, preferably more than 70 mol% of the Z form, preferably more than 80 mol. % of the Z form, preferably more than 85 mole% of the Z form, preferably more than 90 mole%. of the Z form, preferably more than 95 mole% of the Z form, preferably more than 98 mole% of the Z form and more preferably more than 99 mole% of the Z form.

Preferably, HCFO-1224yd consists essentially or consists of H CFO-1224yd (Z).

HCFO 1224yd (Z) is non-flammable.

HCFO 1224yd (Z) has a very low level of toxicity.

HCFO 1224yd (Z) is thermally stable and compatible with elastomers and plastics.

The gas may also comprise additional compounds, in particular a diluent (or dilution gas, or buffer gas) and optionally one or more other halogenated compounds (especially fluorinated compounds).

In embodiments, the gas according to the invention consists essentially and preferably consists of HCFO-1224yd.

In embodiments, the gas of the invention comprises (or optionally consists essentially of, or optionally consists of) a binary mixture of HCFO-1224yd and a diluent.

In embodiments, the gas of the invention comprises (or optionally consists essentially of, or optionally consists of) a binary mixture of HCFO-1224yd and another halogenated compound.

In embodiments, the gas of the invention comprises (or optionally consists essentially of, or optionally consists of) a mixture of HCFO-1224yd, another halogenated compound and a diluent.

The diluent is an inert compound, which may be for example selected from air, nitrogen, methane, oxygen, nitrous oxide, helium and carbon dioxide. Mixtures of these are also possible.

As a halogenated compound that can be used in admixture with HCFO-1224yd, there may be mentioned in particular a chlorocarbon, a hydrochlorocarbon, a chlorofluorocarbon, a hydrochlorofluorocarbon, a chloroolefin, a hydrochloroolefin, a chlorofluoroolefin or a hydrochlorofluoroolefin, a hydrochlorofluorocetone, a fluoroketone, a hydrofluorocetone, a hydrochloroketone or a chloroketone. Preferably, the halogenated compound is a hydrochlorofluoroolefin, a hydrofluoroolefin or a fluoroketone.

In embodiments, the halogenated compound is a fluorinated compound, which is preferably selected from fluoroketones, fluoethers, fluoronitriles, fluorinated peroxides, fluoroamides and fluoroether oxides. Decafluoro-2-methylbutan-3-one is an example of a preferred halogenated compound. 2,3,3,3-Tetrafluoro-2- (trifluoromethyl) propanenitrile is an example of a preferred fluoronitrile compound. 1,1,1,4,4,4-Hexafluorobut-2-ene (E) is an example of a preferred hydrofluoroolefin compound.

It is preferably desired that the gas according to the invention does not undergo condensation for the entire range of projected use temperature. It is also desired to use this gas at a sufficiently high pressure, in principle greater than 10 ⁵ Pa. Under these conditions, the use of a diluent makes it possible to avoid reaching the saturation vapor pressure of HCFO-1224yd or other halogenated compounds that may be present throughout the range of the intended use temperature.

Thus, a diluent is generally a compound having a boiling point lower than that of HCFO-1224yd and also having a lower electrical rigidity (at a reference temperature of, for example, 20 ° C).

The absolute operating pressure of the gas according to the invention is preferably from 1 to 1.5 bar in medium voltage devices and from 4 to 7 bar in high voltage devices.

The terms "medium voltage" and "high voltage" are used herein in their usual acceptance that the term "medium voltage" refers to a voltage that is greater than 1000 volts AC and 1500 volts DC but that does not does not exceed 52000 volts AC and 75000 volts DC, while the term "high voltage" means a voltage that is strictly greater than 52000 volts AC and 75000 volts DC.

In order to maximize the amount of HCFO-1224yd and other possible halogenated compounds, the following formula can be used:

In this formula, Ptot represents the utilization pressure of the gas according to the invention, Pi represents the partial pressure of HCFO-1224yd and other halogenated compounds and PVSi represents the saturating vapor pressure of HCFO-1224yd and other halogenated compounds. The pressures are given at the filling temperature, in general about 20 ° C.

The molar percentage of each compound is then approximately given by Mi = (Pi / Ptot) × 100. It should be noted, however, that in some cases a small amount of liquid may be accepted at low temperatures, which may allow the use of HCFO-1224yd or other halogenated compounds in amounts slightly higher than those defined above.

In general, the gas according to the invention can be used in a temperature range whose lower limit is: -30 to -25 ° C; or from -25 to -20 ° C; or from -20 to -15 ° C; or from -15 to -C ° C; or from -10 to -5 ° C; or from -5 to 0 ° C; or from 0 to 5 ° C; or from 5 to 10 ° C; or d at 10 to 15 ° C; or 15 to 20 ° C; or from 20 to 25 ° C; or 25 to 30 ° C.

In some embodiments, the gas may be used in a temperature range whose lower limit is -30 to 30 ° C, preferably -20 to 25 ° C, more preferably -15 to 20 ° C, and still preferably from -10 to 10 ° C.

The gas according to the invention can be used in a temperature range whose upper limit is: 15 to 20 ° C; or from 20 to 25 ° C; or from 25 to 30 ° C; or from 30 to 35 ° C; or 35 to 40 ° C or 40 to 45 ° C; or 45 to 50 ° C.

In some embodiments, the gas may be used in a temperature range whose upper limit is 15 to 50 ° C, preferably 25 to 45 ° C, more preferably 20 to 40 ° C, and more preferably from 25 to 35 ° C.

The temperature of use of the gas corresponds to the actual temperature of the gas during its use; it may vary during use, but remains between the lower bound and the upper bound defined above. For example, when the gas is present in the enclosure of an electrical appliance, the temperature of use is the temperature of the gas in the enclosure, which may vary over time depending in particular on climatic or environmental conditions.

Embodiments in which a diluent gas is present, generally allow to work in a temperature range whose lower limit is lower than in embodiments in which no diluent gas is present.

Thus, when the gas consists essentially of, or consists of, an HCFO-1224yd (and preferably HCFO-1224yd (Z)), the lower limit of the temperature range is preferably greater than or equal to 10 ° C, or at 11 ° C, or at 12 ° C, or at 13 ° C, or at 14 ° C, or at 15 ° C to 16 ° C, or at 18 ° C, or at 20 ° C. Preferably, the gas according to the invention has a GWP of less than or equal to 20, more particularly less than or equal to 15 or to 10, or to 7, or to 5, or to 4, or to 3.

GWP is defined in relation to carbon dioxide and compared to a duration of 100 years, according to the method indicated in "The scientific assessment of ozone depletion, 2002, report of the World Meteorological Association's Global Ozone Research and Monitoring Project".

The (molar) proportion of HCFO-1224yd (and preferably HCFO-1224yd (Z)) in the gas may in some embodiments be 1 to 2%; or 2 to 3%; or 3-4%, or 4-5%; or from 5 to 6%; or 6-7%; or 7 to 8%; or from 8 to 9%; or from 9 to 10%; or from 10 to 12%; or from 12 to 14%; or from 14 to 16%; or from 16 to 18%; or 18 to 20%; or 20 to 22%; or 22 to 24%; or 24 to 26%; or from 26 to 28%; or from 28 to 30%; or from 30 to 35%; or 35 to 40%; or 40 to 45%; or 45 to 50%; or 50 to 55%; or 55 to 60%; or 60 to 70%; or 70 to 80%; or 80 to 90%; or 90 to 100%.

In some embodiments, the gas may contain from 10 to 100 mol. % of HCFO-1224yd, preferably from 15 to 75 mol% and more particularly from 19 to 45 mol%.

In some embodiments, the gas is used with a minimum temperature (lower limit of the temperature range of use) within the following ranges, in association with a proportion of HCFO-1224yd (and preferably HCFO-1224yd ( Z)) in the gas in the following ranges (in order to obtain maximum performance):

The partial pressure of HCFO-1224yd in the gas at 20 ° C may in some embodiments be 0.002 to 0.004 MPa; or from 0.004 to 0.006 MPa; or from 0.006 to 0.008 MPa; or from 0.008 to 0.01 MPa; or from 0.01 to 0.012 MPa; or from 0.012 to 0.014 MPa; or from 0.014 to 0.016 MPa; or from 0.016 to 0.018 MPa; or from 0.018 to 0.02 MPa; or from 0.02 to 0.022 MPa; or from 0.022 to 0.024 MPa; or from 0.024 to 0.026 MPa; or from 0.026 to 0.028 MPa; or from 0.028 to 0.03 MPa; or from 0.03 to 0.032 MPa; or from 0.032 to 0.034 MPa; or from 0.034 to 0.036 MPa; or from 0.036 to 0.038 MPa; or from 0.038 to 0.04 MPa; or from 0.04 to 0.045 MPa; or from 0.045 to 0.05 MPa; or from 0.05 to 0.055 MPa; or from 0.055 to 0.06 MPa; or from 0.06 to 0.07 MPa; or from 0.07 to 0.08 MPa; or from 0.08 to 0.09 MPa; or from 0.09 to 0.1 MPa; or from 0.1 to 0.1 1 MPa; or from 0.1 to 0.12 MPa; or from 0.12 to 0.13 MPa; or more than 0.13 MPa.

The gas may have a pressure at 20 ° C of 0.1 to 1 MF¾, preferably 0.1 to 0.5 MPa, and more preferably 0.12 to 0.15 MPa.

In some embodiments, the gas may have a pressure at 20 ° C of 0.1 to 0.15 MPa; or from 0.15 to 0.3 MPa; or 0.3 to 0.5 MPa; or from 0.5 to 0.7 MPa; or from 0.7 to 0.9 MPa; or from 0.9 to 1 MPa.

It is desirable that the electrical appliances contain a relatively high amount of HCFO-1224yd (and possibly other halogenated and especially fluorinated gases), so that the dielectric, thermal and gas-off characteristics are sufficient over the normative or desired temperature range.

To do this, it is advantageous to use a heating device in combination with an electrical appliance, said heating device being triggered according to the temperature of the gas mixture, its pressure or its density.

For example, a heating resistor ideally placed at the lowest point of the apparatus (point of convergence of the condensed liquids on the various parts inside the apparatus, by gravitation) can be used.

This ensures a gas pressure higher than the test pressure (gas pressure in the device during validation tests) defined normatively.

For the same reasons, it is advantageous to provide thermal insulation of the walls of the apparatus and / or thermal insulation of the installation or the premises containing it and / or heating this installation or these premises.

EXAMPLES

The following examples illustrate the invention without limiting it.

Example 1 - pure products

Dielectric strength measurements are made at 20 ° C. and at 1.3 bar in a homogeneous field, with a distance between electrodes of 12 mm. The results are as follows, expressed as a percentage of the dielectric strength of the SFe reference gas:

HCFO-1224yd (Z): 178%.

Given its condensation temperature, Fl CFO-1224yd (Z) can be used in a pure state at a minimum temperature of 17 ° C, at a pressure of 1.14 bar, without condensation. Its dielectric strength value (with a distance between electrodes of 12 mm) is then the following, always with respect to SFe:

HCFO-1224yd (Z) at 17 ° C: 159%.

EXAMPLE 2 - Mixtures with an Inert Compound

Using the ideal gas model, 1 m ³ of gas at 1, 3 bar and at 20 ° C contains 53.33 moles, regardless of the gas used. This same quantity of gas, in the same volume, gives a pressure of 1.144 bar at -15 ° C.

Always according to the theory of perfect gases, each gas is considered independent of other gases in the same volume. Thus, since the saturation pressure of HCFO-1224yd (Z) at -15 ° C is 0.29 bar, the maximum number of moles in 1 m ³ of gas is 13.5 moles, if one wishes to avoid any condensation at this temperature.

Since the total pressure is considered to be equal to the sum of the partial pressures, the remaining pressure is 0.85 bar and the number of moles of equivalent of inert compound to be added is 39.8. The HCFO-1224yd (Z) / inert mixture then comprises a molar composition of 25.3% of HCFO-1224yd (Z) and 74.7% of inert compound.

Since the dielectric strength of the air is 54% of that of SFe at -15 ° C. and at 1.14 bar, the dielectric strength of the above binary mixture can be calculated under the same conditions:

25.3 mol% HCFO-1224yd (Z) + 74.7 mol% air: 78%.

These results show that at -15 ° C a mixture of inert compound and HCFO-1224yd (Z) improves the dielectric performance of the inert compound. What is true for air is also true for CO2, whose dielectric strength is 51% of that of SFe at -15 ° C and 1.14 bar.

The contents of HCFO-1224yd (Z) indicated above were calculated according to the ideal gas theory.

However, in reality, the maximum content of HCFO-1224yd (Z) at vapor saturation at the temperature of -15 ° C and the pressure of 1.14 bar is greater than that predicted by the ideal gas theory. Thus, HCFO-1224yd (Z) / inert binary compositions of interest may have a content of H CFO-1224yd (Z) greater than the values indicated above. Correlatively, the dielectric strength obtained may be greater than that calculated above.

Claims

1. Use of a gas as an electrical isolation and / or arc extinguishing medium, wherein the gas comprises 1-chloro-2,3,3,3-tetrafluoropropene.

2. Use according to claim 1, wherein the

1-chloro-2,3,3,3-tetrafluoropropene comprises more than 80 mol% of 1-chloro-2,3,3,3-tetrafluoropropene in Z form, preferably more than 90 mol% of 1-chloro -2,3,3,3-tetrafluoropropene in Z form, more preferably more than 95 mol% of

1-chloro-2,3,3,3-tetrafluoropropene in Z form and more preferably more than 99 mol% of

1-chloro-2,3,3,3-tetrafluoropropene in Z form.

3. Use according to one of claims 1 to 2, as an electrical isolation medium and / or extinction of electric arc in a medium voltage substation electrical apparatus.

4. Use according to one of claims 1 to 3, wherein the gas contains from 10 to 100 mol% of 1-chloro-2,3,3,3-tetrafluoropropene, preferably from 15 to 75 mol% and more particularly from 19 to 45 mol%.

5. Use according to one of claims 1 to 4, wherein the gas also comprises a diluent, preferably selected from air, nitrogen, methane, oxygen, carbon dioxide or a mixture of those -this ; and preferably the gas is a binary mixture of 1-chloro-2,3,3,3-tetrafluoropropene and a diluent.

6. Use according to one of claims 1 to 5, wherein the gas further comprises a halogenated compound, preferably a fluorinated compound, further preferably selected from fluoroketones, hydrofluoroolefins, hydrochlorofluoroolefins and combinations thereof.

7. Use according to one of claims 1 to 6, in a temperature range whose lower limit is -30 to 30 ° C, preferably -20 to 25 ° C, more preferably -15 to 20 ° C and more preferably from -10 to 10 ° C.

8. Use according to one of claims 1 to 4, wherein the gas consists essentially, and preferably consists of

1-chloro-2,3,3,3-tetrafluoropropene.

9. Use according to claim 8, in a temperature range whose lower limit is greater than or equal to 10 ° C, or 1 1 ° C, or 12 ° C, or 13 ° C, or 14 ° C , or at 15 ° C, or at 16 ° C, or at 18 ° C, or at 20 ° C.

Electrical apparatus comprising a sealed enclosure in which there are electrical components as well as an electrical insulating gas and / or electric arc extinguishing, wherein the gas comprises 1-chloro-2,3,3, 3-tetrafluoropropene.

An electrical apparatus according to claim 10, wherein the 1-chloro-2,3,3,3-tetrafluoropropene comprises more than 80 mol% of 1-chloro-2,3,3,3-tetrafluoropropene in Z form, preferably more than 90 mol% of 1-chloro-2,3,3,3-tetrafluoropropene in Z form, more preferably more than 95 mol% of 1-chloro-2,3,3,3-tetrafluoropropene under Z form and more preferably more than 99 mol% of 1-chloro-2,3,3,3-tetrafluoropropene Z form.

12. Electrical apparatus according to one of claims 10 or 1 1, wherein the gas also comprises a diluent, preferably selected from air, nitrogen, methane, oxygen, carbon dioxide or a mixture of these; and preferably the gas is a binary mixture of 1-chloro-2,3,3,3-tetrafluoropropene and a diluent.

13. Apparatus according to one of claims 10 to 12, wherein the gas further comprises a halogenated compound, preferably a fluorinated compound, further preferably selected from fluoroketones, hydrofluoroolefins, hydrochlorofluoroolefins and combinations thereof .

14. Apparatus according to one of claims 10 or 1 1, wherein the gas consists essentially, and preferably consists of 1-chloro-2,3,3,3-tetrafluoropropene.

15. Apparatus according to one of claims 10 to 14, wherein the electrical apparatus is a medium voltage electrical apparatus.

Apparatus according to one of claims 10 to 14, wherein the electrical apparatus is a high voltage electrical apparatus.

17. Apparatus according to one of claims 10 to 16, wherein the gas is at a pressure at 20 ° C of 0.1 to 1 MPa, preferably 0.1 to 0.5 MPa, and still preferably from 0.12 to 0.15 MPa.

18. Electrical apparatus according to one of claims 10 to 17, which is selected from a gas-insulated electrical transformer, a gas-insulated line for the transport or distribution of electricity, and an electrical connection / disconnection apparatus.