EP4277713A1

EP4277713A1 - Fire extinguishing device

Info

Publication number: EP4277713A1
Application number: EP22702512.9A
Authority: EP
Inventors: Frédéric MARLIN; Gilles GONTHIER
Original assignee: ArianeGroup SAS
Current assignee: ArianeGroup SAS
Priority date: 2021-01-15
Filing date: 2022-01-13
Publication date: 2023-11-22
Also published as: FR3118885A1; WO2022153011A1

Abstract

The invention relates to a fire extinguishing device (1) comprising: - a body (2) defining a storage chamber (4) containing an extinguishing composition, and - a distribution system (20) configured to distribute the extinguishing composition outside the body through an outlet port (10), characterised in that the extinguishing composition has, at an operating temperature and at 1 bar, a saturated vapour concentration greater than or equal to its extinguishing concentration as determined according to the standard ISO 14520 for a heptane fire at 1 bar, the operating temperature being less than or equal to -10°C, and the extinguishing composition comprising at least one perfluoroketone and/or at least one perfluoronitrile.

Description

Title of the invention: Device for extinguishing a fire

Technical area

The invention falls within the field of extinguishing fires, and more particularly of extinguishing fires at low temperature.

Prior technique

The extinction of fires in a low temperature environment, that is to say at a temperature lower than or equal to -10°C, is a problem encountered in particular in the aeronautical field, for example when it is sought to put out a fire at the nacelle of an aircraft.

Extinguishing fires at these temperatures currently uses Halons (particularly Halon 1301 - CBrFs) as the extinguishing agent. Halons are brominated halogenated chemical compounds. Halons have the advantage of having a high vapor pressure even when cold, making it possible, even under low temperature conditions, to have a gaseous concentration higher than the extinguishing concentration. For each extinguishing agent, the extinguishing concentration constitutes a quantity indicated by the supplier of this agent. It indicates the minimum concentration by volume of extinguishing agent to be delivered into the atmosphere in order to extinguish a fire linked to the combustion of a given material. The quench concentration is commonly evaluated according to ISO 14520, 3rd edition, published in December 2015 by cup-burner test.

Halons, on the other hand, are polluting products, sources of the depletion of the ozone layer, the use of which is subject to increasingly strict regulatory prohibitions. It is also expected that Halons will no longer be available in the course of the 2030s. The use of a Halon as an extinguishing agent therefore constitutes an interim solution that is not environmentally satisfactory and which it is desirable to replace. As such, various extinguishing agents that do not have the harmful effects of Halons have been developed. Such extinguishing agents have a low saturation vapor pressure and are more environmentally friendly than Halons. An example of an existing low saturation vapor pressure extinguishing agent is FK-5-1-12. It also bears the trade name of Novec™ 1230. This extinguishing agent effectively allows extinction at low temperature but requires for this to be used in the form of a gas/droplet mixture. In such devices, it is therefore necessary to avoid condensation of the extinguishing composition and to take care that the composition reaches the fire in the form of a gas/droplet mixture, otherwise the extinction will not is not assured. The mixture can be obtained using misting nozzles as described for example in application WO2019162603A1. It is desirable to further simplify the design of extinguishing devices, while continuing to use extinguishing means devoid of the disadvantages resulting from the use of Halons.

Disclosure of Invention

The invention relates, according to a first of its aspects, to a fire extinguishing device comprising:

- a body (2) defining a storage chamber (4) containing an extinguishing composition, and

- a delivery system (20) configured to deliver the extinguishing composition to the outside of the body through an outlet orifice (10), characterized in that the extinguishing composition has, at an operating temperature and at 1 bar, a saturation vapor concentration greater than or equal to its extinguishing concentration determined according to the ISO 14520 standard for a heptane fire at 1 bar, said operating temperature being less than or equal to -10°C, and said extinguishing composition comprising at least one perfluoroketone and/or at least one perfluoronitrile.

The saturation vapor pressure of a composition is understood as the partial pressure of this composition at liquid/gas equilibrium under given conditions. In other words, the saturation vapor pressure characterizes the ability of a composition to remain in gaseous form rather than to condense. For a given temperature and out of thermodynamic equilibrium, if the gaseous concentration of a composition is greater than the saturated vapor concentration, the gaseous part of the composition will tend to condense rather than remain in gaseous form.

By definition, the “saturation vapor concentration of the extinguishing composition” is equal to the following ratio: [saturation vapor pressure of the extinguishing composition]/[1 bar].

In one embodiment, the extinguishing composition includes a plurality of compounds. In this case, the saturation vapor pressure of the extinguishing composition is defined as the sum of the saturation vapor pressures of the compounds constituting it.

In one embodiment, the extinguishing composition comprises at least one perfluoroketone, or alternatively at least one perfluoronitrile, having, at an operating temperature and at 1 bar, a saturation vapor concentration greater than or equal to its determined extinguishing concentration according to ISO 14520 for a heptane fire at 1 bar. This is for example the case of the compounds Novec™ 5110, Novec™ 4710 and C4K mentioned below. This embodiment allows easier preparation of the extinguishing composition because it may contain only the perfluoroketone or the perfluoronitrile.

Within the meaning of the invention, an organic compound will be said to be “perfluorinated” when the whole of the carbon chain is devoid of hydrogen atoms except in the presence of an alcohol function and when the latter are replaced by fluorine atoms.

Moreover, the perfluorinated compound may not comprise a halogen atom distinct from fluorine. Preferably, the perfluorinated compound does not include bromine. It is indeed desirable to avoid the presence of bromine, present in Halons, to reduce the environmental impact of the compounds of the extinguishing composition.

The extinguishing composition of the invention makes it possible to achieve a concentration in the gas phase which is higher than the extinguishing concentration, avoiding the condensation of the composition, while being less harmful to the environment than compositions based on Halons.

In fact, the perfluoroketone(s) or perfluoronitrile(s) used can have extinguishing concentrations at the operating temperature of at least 4%.

These concentrations can be achieved in the gas phase using an extinguishing composition of the invention. In addition, perfluoroketones or perfluoronitriles are less harmful to the environment than the Halons usually used in such extinguishing compositions.

The extinguishing concentration is understood as the concentration of extinguishing composition necessary in the gas phase to allow the extinction of a fire at the operating temperature. The extinguishing concentration is commonly evaluated according to ISO 14520, 3rd edition, published in December 2015, by cup-burner test, for a heptane fire at 1 bar.

In addition, the saturated vapor concentration characteristics, and the presence of perfluoroketone and/or perfluoronitrile ensure that a composition of the invention allows the extinction of a fire at low temperature with the extinguishing composition in the form gaseous only, which facilitates the design of the extinguisher by in particular making superfluous the use of a misting nozzle to generate a liquid/gas mixture as in the prior art.

Such a composition also has the advantage of being able to be dispensed from a point relatively far from the fire to be extinguished. Like Halon compositions, quenching is enabled by a gas phase comprising a gas phase concentration greater than the quenching concentration. Thus, the distribution paths of the extinguishing composition between its storage point and the point of the fire can be analogous to the distribution paths currently considered for the distribution of compositions using Halon.

For example, in the case of use in a turbomachine nacelle, the distribution of the extinguishing composition can take place at points of the nacelle identical to the distribution points currently selected for the distribution of extinguishing compositions using Halon.

For example, the operating temperature can be less than or equal to -10°C, or even less than or equal to -40°C.

In one embodiment, the extinguishing composition comprises at least one perfluoroketone and/or at least one perfluoronitrile whose molecular weight is less than or equal to 267 g. mol ¹ .

It is generally observed that the lower the molar mass of a compound, the more volatile the compound. Thus, a perfluoroketone and/or a perfluoronitrile with a molar mass of less than 267 g. mol ¹ makes it easier to satisfy the saturation vapor concentration condition desired for the extinguishing composition.

For example, the perfluoroketone can have a molecular mass between 216 g. mol ¹ and 267 g. mol ¹ .

In one embodiment, the perfluoroketone comprises only one ketone function.

For example, perfluoronitrile can have a molecular mass between 195 g. mol ¹ and 267 g. mol ¹ .

In one embodiment, the extinguishing composition may comprise 1,1,1,3,4,4,4-heptafluoro-3-(trifluoromethyl)-2-butanone.

This compound is also available under the trade name Novec™ 5110 and will be referred to as such hereafter. The inventors have observed that this compound makes it possible to obtain, alone or in combination with one or more other compounds, an extinguishing composition with satisfactory properties.

In one embodiment, the extinguishing composition does not include an extinguishing agent other than 1,1,1,3,4,4,4-heptafluoro-3-(trifluoromethyl)-2-butanone.

In one embodiment, the extinguishing composition may be composed of greater than 80% by volume of 1,1,1,3,4,4,4-heptafluoro-3-(trifluoromethyl)-2-butanone, or even may consist of 1,1,1,3,4,4,4-heptafluoro-3-(trifluoromethyl)-2-butanone at 100%.

In one embodiment, the extinguishing composition may comprise 2,3,3,3-tetrafluoro-2-(trifluoromethyl)-propanenitrile.

This perfluoronitrile compound is commercially available under the name Novec™ 4710 and will be so called hereafter. This compound has good extinguishing properties and also has a higher concentration of saturation vapor at low temperature than Novec™ 1230. It makes it possible to produce an extinguishing composition having the desired properties.

In one embodiment, the extinguishing composition does not include an extinguishing agent other than 2,3,3,3-tetrafluoro-2-(trifluoromethyl)-propanenitrile.

In one embodiment, the extinguishing composition may be composed of more than 80% by volume of 2,3,3,3-tetrafluoro-2-(trifluoromethyl)-propanenitrile, or even may be composed of 2,3,3 100% ,3-tetrafluoro-2-(trifluoromethyl)-propanenitrile.

In one embodiment, the extinguishing composition may comprise 1,1,1,2,2,4,4,4-octafluoro-3-butanone. This product is commercially available under the name C4K and will be referred to as such hereafter.

The inventors have found that an extinguishing composition comprising C4K makes it possible to ensure good extinguishing because the C4K has a saturation vapor concentration at a temperature less than or equal to -10°C greater than or equal to the extinguishing concentration .

In one embodiment, the extinguishing composition does not include an extinguishing agent other than 1,1,1,2,2,4,4,4-octafluoro-3-butanone.

In one embodiment, the extinguishing composition may be composed of more than 80% by volume of 1,1,1,2,2,4,4,4-octafluoro-3-butanone, or even may consist of ,1,1,2,2,4,4,4-octafluoro-3-butanone 100%. In one embodiment, the quenching composition may comprise in combination with another perfluoroketone and/or with a perfluoronitrile 1,1,1,2,2,4,5,5,5-nonafluoro-4-( trifluoromethyl)-3-pentanone.

This compound is commercially available under the name Novec™ 1230 and will be so called hereafter.

Such a composition is particularly advantageous for extinguishing a fire in an environment at a temperature below or equal to -40°C, in particular between -40°C and -55°C. Although Novec™ 1230 does not have, alone and in the gaseous phase alone, the required extinguishing capacity, its presence in the extinguishing composition makes it possible to improve the extinguishing properties, even at low temperature. Indeed, Novec™ 1230 can, within the limit of its saturated vapor concentration, be present in the gaseous phase, and thus contribute in part to extinction.

Moreover, this compound is commercially available at lower cost, its properties are more widely documented and the chemical proximity to the Novec™ 5110 compound ensures a good mixture of these two compounds. Finally, Novec™ 1230 is a compound of low toxicity which makes it possible to ensure, when it is present, a lower toxicity of the composition as a whole. This low toxicity is particularly important to avoid any intoxication of a user in the event of a leak, for example during the packaging of the composition.

In one embodiment, the extinguishing composition does not include an extinguishing agent other than 1,1,1,3,4,4,4-heptafluoro-3-(trifluoromethyl)-2-butanone and 1,1,1,2,2,4,5,5,5-nonafluoro-4-(trifluoromethyl)-3-pentanone.

In one embodiment, the extinguishing composition has an extinguishing concentration of at least 4% at operating temperature.

In one embodiment, the extinguishing composition may comprise one or more of the compounds chosen from 1,1,1,3,4,4,4-heptafluoro-3-(trifluoromethyl)-2-butanone, 1, 1,1,2,2,4,4,4-octafluoro-3-butanone and/or 2,3,3,3-tetrafluoro-2-(trifluoromethyl)-propanenitrile. In such a mode of embodiment, the composition may comprise at least 80% by volume of the compound(s).

In one embodiment, the extinguishing composition may include the following combinations of extinguishing agents:

- 1,1,1,2,2,4,4,4-octafluoro-3-butanone and 1,1,1,3,4,4,4-heptafluoro-3-(trifluoromethyl)-2 -butanone;

- 1,1,1,2,2,4,4,4-octafluoro-3-butanone and 1,1,1,2,2,4,5,5,5-nonafluoro-4- ( trifluoromethyl)-3-pentanone;

- 1,1,1,2,2,4,4,4-octafluoro-3-butanone and 2,3,3,3-tetrafluoro-2-(trifluoromethyl)-propanenitrile;

- 2,3,3,3-tetrafluoro-2-(trifluoromethyl)-propanenitrile and 1,1,1,3,4,4,4-heptafluoro-3-(trifluoromethyl)-2-butanone;

- 2,3,3,3-tetrafluoro-2-(trifluoromethyl)-propanenitrile and 1, 1,1, 2, 2, 4, 5,5,5-nonafluoro-4-(trifluoromethyl)-3- pentanone;

- 1,1,1,2,2,4,5,5,5-nonafluoro-4-(trifluoromethyl)-3-pentanone and 1,1,1,3,4,4,4-heptafluoro -3-(trifluoromethyl)-2-butanone;

- 1,1,1,2,2,4,4,4-octafluoro-3-butanone, hence 1,1,1,3,4,4,4-heptafluoro-3-

(trifluoromethyl)-2-butanone and 1,1,1,2,2,4,5,5,5-nonafluoro-4-(trifluoromethyl)-3-pentanone;

- 1,1,1,2,2,4,4,4-octafluoro-3-butanone, hence 1,1,1,3,4,4,4-heptafluoro-3-(trifluoromethyl)-2 -butanone and 2,3,3,3-tetrafluoro-2-(trifluoromethyl)-propanenitrile;

- 1,1,1,2,2,4,4,4-octafluoro-3-butanone, 1,1,1,2,2,4,5,5,5-nonafluoro-4- ( trifluoromethyl)-3-pentanone and 2,3,3,3-tetrafluoro-2-(trifluoromethyl)-propanenitrile;

- 2,3,3,3-tetrafluoro-2-(trifluoromethyl)-propanenitrile, hence 1, 1,1, 3, 4,4,4-heptafluoro-3-(trifluoromethyl)-2-butanone and 1,1,1,2,2,4,5,5,5-nonafluoro-4-(trifluoromethyl)-3-pentanone; or,

- 1,1,1,2,2,4,4,4-octafluoro-3-butanone, 1,1,1,3,4,4,4-heptafluoro-3-(trifluoromethyl)-2 -butanone, 1,1,1,2,2,4,5,5,5-nonafluoro-4-(trifluoromethyl)-3-pentanone and 2,3,3,3-tetrafluoro-2-(trifluoromethyl )-propanenitrile. In one embodiment, the extinguishing composition of the invention can be stored in a liquid state.

In one embodiment, the device can be configured to distribute the extinguishing composition through the outlet orifice with a flow rate greater than or equal to 1 Ls ⁻¹ .

According to another of its aspects, the invention also relates to a process for extinguishing a fire in an environment at a temperature lower than or equal to -10° C. by distributing on the fire an extinguishing composition having, at this temperature and at 1 bar, a saturated vapor concentration greater than or equal to its extinguishing concentration determined according to the ISO 14520 standard for a heptane fire at 1 bar, said extinguishing composition comprising at least one perfluoroketone and/or at least one perfluoronitrile.

Such a method makes it possible to ensure the extinction of a fire, by overcoming the disadvantages of the methods of the prior art, in particular because the presence of the perfluoroketone or the perfluoronitrile makes it possible to ensure that the extinguishing concentration is low, and also, thanks to the saturation vapor concentration value, to ensure that the extinguishing composition in the gaseous state is sufficient to extinguish the fire. Since the gaseous phase of the composition alone is sufficient to exceed the quenching concentration, the distribution of the composition becomes easier.

In one embodiment, the extinguishing method can be used on a fire in an environment at a temperature of -40°C or less.

In one embodiment, the extinguishing composition can be distributed over the fire with an extinguishing composition flow rate greater than or equal to 1 Ls ¹ .

Such a flow makes it possible to reach the extinction concentration, even in an environment subjected to a high air flow, as is the case for example in a turbomachine nacelle.

Indeed, and even in such an environment, a flow rate as indicated makes it possible to reach for at least a few seconds a concentration of extinction composition in the gas phase greater than or equal to the extinction concentration. In one embodiment, the quenching concentration may be stored in a liquid state. Even stored in a liquid state, upon dispensing, the quenching composition will come into equilibrium with a gas phase, in which the quenching concentration is reached.

For example, the method of extinguishing a fire can comprise the distribution on the fire of an extinguishing composition using a device as described above.

According to a third of its aspects, the invention relates to an aircraft equipped with a fire extinguishing device as described above, the fire extinguishing device being for example present at the level of the nacelle of this aircraft.

Brief description of the drawings

[Fig. 1] Figure 1 is a schematic representation of a device in one embodiment.

[Fig. 2] Figure 2 is a schematic representation of a device in an extinguishing composition dispensing mode.

Description of embodiments

The invention is now described by means of figures representing embodiments of the invention, which should not, however, be interpreted in a limiting manner.

Figure 1 describes an extinguishing device according to one embodiment.

Device 1 comprises a body 2 extending along a longitudinal axis X and defining a storage chamber 4 in which an extinguishing composition (not shown) is present. The extinguishing composition can be contained in a solid or liquid state.

Preferably, the extinguishing composition is contained in the storage chamber 4 in the liquid state. For example, the storage chamber can contain a volume of extinguishing composition greater than or equal to 1 liter, or even greater than or equal to 3 liters. The extinguishing device further includes an extinguishing composition delivery system. In the non-limiting example shown in Figure 1, the distribution system is a pyrotechnic gas generator 20. The gas generator 20 includes an initiator 26 for initiating the combustion of the relay charge I which will trigger the combustion of the charge pyrotechnic 23 in order to generate the pressurizing gas.

However, in variants not shown, the distribution system can be a pressurized gas cartridge also called a “sparklet”.

In general, the distribution of the extinguishing composition to the exterior of the body 2 can be actuated by pressurizing the extinguishing composition with a gas. Said gas can be generated by a pyrotechnic gas generator or be distributed by a pressurized gas cartridge.

The pressurizing chamber 5 is separated from the storage chamber 4 by a movable wall 7 in the example shown. The body 2 has, in the example shown, a symmetrical shape of revolution, here cylindrical. Of course, the invention is not limited to such shapes for the body 2. The body 2 comprises a side wall 2a extending along the longitudinal axis X of the body 2 and surrounding the storage chamber 4. The side wall 2a of the body 2 further surrounds the pressurizing chamber 5. The body 2 further comprises a first bottom wall 2b and a second bottom wall 2c. The first and second bottom walls 2b and 2c longitudinally delimit the body 2. The first bottom wall 2b delimits the storage chamber 4. The first bottom wall 2b has at least one outlet orifice 10 configured to deliver the composition of extinction outside the body 2 when the gas generator 20 is actuated. The second bottom wall 2c delimits the pressurization chamber 5. The pressurization chamber 5 is located between the movable wall 7 and the second bottom wall 2c. The storage chamber 4 is located between the first bottom wall 2b and the movable wall 7, the latter delimiting the storage chamber 4.

The movable wall 7 can be formed from a metallic material, for example aluminum. Advantageously, the movable wall 7 is made of a single material and this in order to further simplify the method of manufacturing the device 1. The wall mobile 7 is configured to separate the storage chamber 4 from the pressurizing chamber 5 in a sealed manner. The mobile wall 7 is configured to communicate to the extinguishing composition present in the storage chamber 4 the pressure imposed by the gas generated in the pressurizing chamber 5. The direction in which the pressure is applied by the movable wall 7 to the extinguishing composition to be dispensed is substantially parallel to the longitudinal axis X of the body 2. As illustrated, the movable wall 7 extends transversely, for example perpendicularly, with respect to the longitudinal axis X of the body 2. The movable wall 7 extends over the entire internal diameter D _s of the storage chamber 4. The movable wall 7 is configured not to be ruptured under the effect of the pressure imposed by the gas generated in the pressurizing chamber 5.

The device 1 may further comprise a shutter 15 sealing off the outlet orifice 10 and configured to allow the exit of the extinguishing composition outside the body 2 when the pressure in the storage chamber 4 exceeds a predefined value. In other words, the shutter 15 is configured to prevent, when it is in a first configuration, the exit of the extinguishing composition outside the body 2, the shutter 15 is furthermore configured to pass in a second configuration when the pressure in the storage chamber 4 exceeds a predefined value, this second configuration of the shutter 15 allowing the exit of the extinguishing composition outside the body 2. The shutter 15 can, for example, being in the form of a membrane configured to yield when the pressure in the storage chamber 4 exceeds a predefined value. In this case, the shutter 15 can, for example, be an aluminum membrane or an alloy of the Inconel® type.

Figure 2 illustrates the device in a situation of dispensing the extinguishing composition by the example device shown in Figure 1.

The gas generator 20 is first of all actuated in order to pressurize the chamber 5. This overpressure created in the chamber 5 is transmitted by the movable wall 7 to the extinguishing composition present in the storage chamber 4. Once a predefined value reached for the pressure in the storage chamber 4, the shutter 15 passes into a second configuration allowing the exit of the extinguishing composition outside the body 2 through the exit orifice 10.

The movable wall 7 is set in motion towards the first bottom wall 2b in order to cause the distribution of the extinguishing composition. The movable wall 7 is set in motion along the longitudinal axis X.

The extinguishing composition is distributed outside the extinguisher through the opening and makes it possible to obtain the distribution 19 of the extinguishing composition.

Claims

[Claim 1] Fire extinguishing device (1) comprising:

[Claim 2] An extinguishing device (1) according to claim 1, wherein the molecular weight of the perfluororoketone and/or the perfluoronitrile is less than or equal to 267 g. mol ¹ .

[Claim 3] An extinguishing device (1) according to claim 2, wherein the extinguishing composition comprises 1,1,1,3,4,4,4-heptafluoro-3-(trifluoromethyl)-2-butanone .

[Claim 4] Extinguishing device (1) according to one of Claims 2 to 3, in which the extinguishing composition comprises 1,1, 1,2, 2,4,4, 4-octafluoro-3- butanone.

[Claim 5] Extinguishing device (1) according to one of Claims 2 to 4, in which the extinguishing composition comprises 2,3,3,3-tetrafluoro-2-(trifluoromethyl)-propanenitrile.

[Claim 6] Extinguishing device (1) according to one of Claims 2 to 5, in which the extinguishing composition further comprises 1, 1,1, 2, 2, 4, 5,5,5 - nonafluoro-4-(trifluoromethyl)-3-pentanone.

[Claim 7] An extinguishing device (1) according to any one of claims 1 to 6, wherein the extinguishing composition is stored in a liquid state.

[Claim 8] Extinguishing device (1) according to any one of claims 1 to 7, in which the device is configured to distribute the extinguishing composition through the outlet orifice with a flow rate greater than or equal to 1 Ls ^-1 .

[Claim 9] Process for extinguishing a fire in an environment at a temperature lower than or equal to -10°C by distributing on said fire an extinguishing composition having, at this temperature and at 1 bar, a concentration saturated vapor greater than or equal to its extinguishing concentration determined according to the ISO 14520 standard for a heptane fire at 1 bar, said extinguishing composition comprising at least one perfluoroketone and/or at least one perfluoronitrile.

[Claim 10] A method of extinguishing a fire according to claim 9, wherein the fire is in an environment at a temperature of -40°C or less.

[Claim 11] A method of extinguishing a fire according to claim 9 or 10, in which the extinguishing composition is dispensed with a flow rate greater than or equal to 1 L.s' ¹ .

[Claim 12] A method of extinguishing a fire according to any one of claims 9 to 11, comprising the distribution on the fire of the extinguishing composition using a device according to one of claims 1 at 8.

[Claim 13] Aircraft equipped with a fire extinguishing device according to one of claims 1 to 8.