A perfluorohexanone synergistic fire extinguishing unit based on solid strontium-based aerosols

Abstract

This invention discloses a perfluorohexanone (PFH) synergistic fire extinguishing unit based on solid strontium-based aerosols. The solid strontium-based heat generator is encapsulated in a first polymer shell. A perfluorohexanone encapsulation body, in contact with the solid strontium-based heat generator, comprises a second polymer shell and multiple microcapsules uniformly filled within the second polymer shell. Each microcapsule encapsulates liquid perfluorohexanone. This system enables autonomous triggering by a fire source, rapid and uniform distribution, and in-situ suppression of deep-seated fires.

Description

Technical Field

[0001] This application relates to the field of fire extinguishing technology, specifically to a perfluorohexanone synergistic fire extinguishing unit based on solid strontium-based aerosol. Background Technology

[0002] In small, enclosed spaces containing numerous electrical units, a fire can spread initially to the surface of combustible materials (such as insulation materials and cable sheaths). Due to limited oxygen, incomplete combustion occurs, producing large amounts of dense smoke and toxic gases like hydrogen chloride. The continuous accumulation of heat causes a rapid temperature rise, making the fire both concealed and sudden, with a short response time. Opening the enclosed space allows fresh air to rush in, potentially triggering a flashover or deflagration, instantly filling the entire space with flames. Even after the combustibles in the enclosed space have burned out, they can easily smolder and reignite upon regaining oxygen, posing risks of electrical contamination, toxicity, and explosion.

[0003] Currently, the main fire extinguishing media for confined spaces are gaseous fire extinguishing agents and aerosol fire extinguishing agents. Although they can quickly extinguish open flames, perfluorohexanone depends on the temperature of the fire scene for decomposition. Its chemical inhibition efficiency is not high in the early stage of a fire or in low-temperature environments, and its uniform distribution efficiency is low. Aerosols have weak cooling capacity and can only suppress open flames, making it difficult to extinguish deep smoldering fires.

[0004] CN110141815B discloses a novel cooling fire extinguishing bomb, which uses microcapsule perfluorohexanone and S-type aerosol fire extinguishing agent placed in different cavities, separated by a thermally conductive partition, and triggered by an electric igniter. This design requires an external power source or electrical signal for triggering, and cannot be activated in a power-free environment; furthermore, the electric igniter itself has reliability risks. The thermally conductive partition conducts heat unidirectionally from the aerosol side to the microcapsule side, relying on the thermal conductivity of the partition; and it does not suppress deep-seated smoldering.

[0005] Therefore, this application is submitted. Summary of the Invention

[0006] The purpose of this invention is to provide a perfluorohexanone synergistic fire extinguishing unit based on solid strontium-based aerosol, which realizes a synergistic fire extinguishing unit that is autonomously triggered by the fire source and suppresses deep fires in situ, thus solving the problems existing in the background technology.

[0007] To solve the above-mentioned technical problems, the present invention adopts the following solution: A perfluorohexanone synergistic fire extinguishing unit based on solid strontium-based aerosols includes: A solid strontium-based heat generator, which is covered with a first polymer shell; The perfluorohexanone encapsulation, in contact with the solid strontium-based heat generator, comprises a second polymer shell and a plurality of microcapsules uniformly filled inside the second polymer shell, wherein the microcapsules encapsulate liquid perfluorohexanone. When the first polymer shell comes into contact with a fire source, it ruptures or melts, exposing the solid strontium-based heat generator to the fire source and initiating an exothermic reaction. The released heat acts on the perfluorohexanone encapsulation in contact with it through thermal conduction, causing multiple microcapsules to rupture, liquid perfluorohexanone to vaporize and decompose to extinguish the fire.

[0008] Furthermore, the solid strontium-based heat generator is one or more of strontium carbonate, strontium nitrate, strontium nitrite, and strontium hydroxide that are compressed into a block shape.

[0009] Furthermore, the melting point of the first polymer shell is higher than the ambient storage temperature and lower than the initial exothermic reaction temperature of the solid strontium-based heat generator; the melting point of the second polymer shell is lower than the temperature that the exothermic reaction of the solid strontium-based heat generator can reach, and higher than the melting point of the first polymer shell.

[0010] Furthermore, the solid strontium-based heat generator and the perfluorohexanone inclusion body form a vertically stacked structure without physical isolation, allowing heat to be transferred directionally along the vertical direction.

[0011] Furthermore, the shell thickness of the microcapsule is less than the wall thickness of the second polymer shell.

[0012] Furthermore, the wall thickness of the second polymer shell is 10 to 100 times the thickness of the microcapsule shell.

[0013] Furthermore, the multiple microcapsules are arranged in a single-layer or multi-layer array within the second polymer shell, with uniform gaps between adjacent microcapsules. These gaps constitute heat conduction medium channels and release channels after perfluorohexanone vaporization.

[0014] Furthermore, the average particle size of the microcapsules is 200~1500μm.

[0015] Furthermore, the amount of liquid perfluorohexanone filling the microcapsule is 70-80% of the internal volume of the microcapsule.

[0016] Furthermore, the effective mass ratio of the strontium-based active component in the solid strontium-based heat generator to the liquid perfluorohexanone in the perfluorohexanone inclusion is 10:1~2.

[0017] The beneficial effects of this invention are as follows: This invention uses a solid strontium-based heat generator encased in a first polymer shell and a perfluorohexanone encapsulated in a second polymer shell, with the two shells in contact with each other. This synergistic fire extinguishing unit is placed in a sealed space. When a fire source in the sealed space comes into contact with the first polymer shell, it causes the shell to rupture or melt, exposing the solid strontium-based heat generator inside to the fire source. The fire source initiates a combustion reaction and releases heat. The heat generated during the heat release process is conducted to the second polymer shell, which is in contact with the first polymer shell, causing it to rupture or melt. This heat continues to be transferred to the microcapsule, causing it to rupture as well. At this point, the heat in the sealed space vaporizes and forcibly decomposes the perfluorohexanone inside the microcapsule, resulting in rapid and uniform distribution of the perfluorohexanone, effectively extinguishing deep-seated smoldering fires within 20 seconds and inhibiting reignition. This achieves autonomous triggering by the fire source, in-situ suppression of deep-seated fires, and optimal heat utilization efficiency and perfluorohexanone decomposition rate. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the inactivation unit of the present invention.

[0019] Reference numerals: 1-Solid strontium-based thermogenerator, 10-First polymer shell, 2-Perfluorohexanone inclusion, 20-Second polymer shell, 21-Microcapsule. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0021] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of the invention.

[0022] At the same time, it should be understood that, for ease of description, the dimensions of the various parts shown in the accompanying drawings are not drawn according to actual scale.

[0023] Furthermore, for clarity and brevity, descriptions of well-known structures, functions, and configurations may have been omitted. Those skilled in the art will recognize that various changes and modifications can be made to the examples described herein without departing from the spirit and scope of this disclosure.

[0024] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0025] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0026] Example 1 A perfluorohexanone synergistic fire extinguishing unit based on solid strontium-based aerosol includes: a solid strontium-based heat generator 1, which is externally covered by a first polymer shell 10; a perfluorohexanone encapsulation 2, which is in contact with the solid strontium-based heat generator 1, and includes a second polymer shell and a plurality of microcapsules 21 uniformly filled inside the second polymer shell 20, wherein the microcapsules 21 encapsulate liquid perfluorohexanone; when the first polymer shell 10 comes into contact with a fire source, it ruptures or melts, exposing the solid strontium-based heat generator 1 to the fire source and initiating an exothermic reaction. The released heat acts on the perfluorohexanone encapsulation 2 in contact with it through thermal conduction, causing the plurality of microcapsules 21 to rupture, the liquid perfluorohexanone to vaporize and decompose to extinguish the fire.

[0027] Reference Figure 1 The technical concept of this invention is a solid strontium-based heat generator 1 encased in a first polymer shell 10 and a perfluorohexanone encapsulation 2 encased in a second polymer shell. The two shells are in contact with each other. This synergistic fire extinguishing unit is placed in a sealed space. When the fire source in the sealed space comes into contact with the first polymer shell 10, it causes the shell to rupture or melt, exposing the solid strontium-based heat generator 1 inside the shell to the fire source. The fire source heats up and initiates a combustion reaction, releasing heat. The heat generated during the heat release process is conducted to the second polymer shell in contact with the first polymer shell 10, causing the second polymer shell to rupture or melt. This heat continues to be transferred to the microcapsule 21 and causes it to rupture. At this time, the heat in the sealed space can vaporize and forcibly decompose the perfluorohexanone inside the microcapsule 21. The perfluorohexanone is then rapidly and evenly distributed, effectively extinguishing deep-seated smoldering fires or flames within 20 seconds and inhibiting reignition.

[0028] Solid strontium-based thermal decomposition generates strontium oxide (SrO) and oxygen free radicals (·O). SrO undergoes an electron transfer reaction with carbon free radicals (·C) on the surface of combustibles, deactivating them. At the same time, it reacts with hydrogen fluoride (HF) produced by the cracking of perfluorohexanone to form strontium fluoride (SrF2), forming a dense glassy coating layer on the surface of combustibles, physically isolating oxygen.

[0029] Perfluorohexanone decomposes under the localized high temperature generated by the exothermic reaction of solid strontium, generating trifluoromethyl radicals (·CF3), difluorocarbene (:CF2), and fluorine radicals (·F). These fluorine radicals capture hydrogen radicals (H·) and hydroxyl radicals (OH·) in the combustion chain reaction, interrupting the gas-phase combustion reaction.

[0030] Gas-phase suppression rapidly extinguishes open flames, while solid-phase suppression provides long-term inhibition of smoldering. These two technologies complement each other in time and space, achieving highly efficient fire extinguishing at low agent concentrations. This reduces the concentration of liquid perfluorohexanone to only 1 / 3 to 1 / 2 of the conventional method. In some preferred embodiments, the solid strontium-based heat generator 1 is one or more of strontium carbonate, strontium nitrate, strontium nitrite, and strontium hydroxide that are pressed into a block shape.

[0031] It also includes binders and reducing agents. During the pressing process, the binder (such as polyvinyl alcohol (PVA), carboxymethyl cellulose (CMC), polyethylene glycol (PEG), etc.) binds the discrete strontium-based powder together. The binder can decompose at high temperatures, leaving micropores that serve as channels for heat transfer, allowing heat to be uniformly transferred from the interior of the block to the perfluorohexanone inclusion 2. By adjusting the amount of binder, the time delay from ignition to perfluorohexanone cracking can be precisely controlled. The reducing agent (aluminum, magnesium, phenolic resin, etc.) reacts exothermically with the strontium-based oxidant, providing the heat required to drive the cracking of perfluorohexanone.

[0032] In some preferred embodiments, the melting point of the first polymer shell 10 is higher than the ambient storage temperature and lower than the initial exothermic reaction temperature of the solid strontium-based heat generator 1; the melting point of the second polymer shell 20 is lower than the temperature that the exothermic reaction of the solid strontium-based heat generator 1 can reach and higher than the melting point of the first polymer shell 10.

[0033] The reasons for this design are as follows: 1) To prevent the solid strontium-based heat generator 1 from being exposed to air before encountering an ignition source, thus avoiding moisture absorption, deterioration, or premature slow reactions, and ensuring the stability of the extinguishing unit's performance during storage. 2) To ensure that the ignition source burns the first polymer shell 10 first, exposing and igniting the strontium group, which is a prerequisite for activating the extinguishing process. 3) To ensure that the second polymer shell does not rupture before the first polymer shell 10 when the ignition source first contacts the extinguishing unit. That is, before the ignition source burns the first polymer shell 10 and the strontium group activates and releases heat, the second polymer shell must remain intact to prevent the perfluorohexanone microcapsule 21 from being exposed to the ignition source too early, thus preventing the perfluorohexanone from being lost or ineffectively decomposed before the strontium group is activated.

[0034] The melting point of the second polymer shell is higher than that of the first polymer shell 10, ensuring that the strontium group is activated first and the perfluorohexanone is released later; the melting point of the second polymer shell is lower than the maximum exothermic temperature of the strontium group, ensuring that the perfluorohexanone can be effectively driven.

[0035] In some preferred embodiments, the solid strontium-based heat generator 1 and the perfluorohexanone encapsulation 2 form a vertically stacked structure without physical separation, allowing heat to be transferred directionally in the vertical direction. That is, the outer shells of the two are in contact with each other, so that the heat released by the solid strontium-based heat generator 1 is sequentially transferred to the second polymer shell and the shell of the microcapsule 21, ultimately triggering the liquid perfluorohexanone to rupture upon heating, vaporizing and pyrolyzing to extinguish the fire.

[0036] In some preferred embodiments, the shell thickness of the microcapsule 21 is less than the wall thickness of the second polymer shell 20. The wall thickness of the second polymer shell 20 is 10 to 100 times the shell thickness of the microcapsule 21. The first polymer shell 10 (1 to 5 mm) is made of polyethylene and polyurethane; the second polymer shell (100 to 300 μm) can be made of polypropylene and high-density polyethylene; the shell of the microcapsule 21 (1 to 30 μm) can be made of melamine-formaldehyde resin, so that the rupture temperature of its shell is lower than that of the second polymer shell, ensuring that the microcapsule 21 releases liquid perfluorohexanone immediately after the second shell ruptures.

[0037] The first polymer shell 10 is the thickest, providing mechanical strength to support the overall shape; the second polymer shell, with a thickness in between, supports the uniform arrangement of the internal microsphere array; conducts heat from the strontium groups above; and ruptures upon heating to release microcapsules 21. The wall thickness should not be too large to avoid hindering heat conduction, nor too small to avoid insufficient mechanical strength leading to microsphere displacement. Microcapsules 21 have the smallest wall thickness, effectively preventing the volatilization of perfluorohexanone during storage, and can rapidly rupture and release it under the exothermic effect of the strontium groups.

[0038] In some preferred embodiments, the plurality of microcapsules 21 are arranged in a single-layer or multi-layer array within the second polymer shell 20, and there are uniform gaps between adjacent microcapsules 21. These gaps constitute heat conduction medium channels and release channels after perfluorohexanone vaporization.

[0039] The uniform gaps allow for rapid horizontal heat diffusion within the array, ensuring that all microcapsules 21 are heated and ruptured simultaneously, resulting in the concentrated release of perfluorohexanone. Simultaneously, after the microcapsules 21 rupture, perfluorohexanone preferentially flows downwards along the gaps, forming a directional jet that directly acts on the deep-seated ignition source below, improving cooling and pyrolysis efficiency.

[0040] In the multilayer array, the perfluorohexanone released by the upper microcapsule 21 is further heated by the lower region as it flows downward, achieving relay-type pyrolysis and improving the free radical yield.

[0041] In some preferred embodiments, the average particle size of the microcapsule 21 is 200~1500 μm. The amount of liquid perfluorohexanone filling the microcapsule 21 is 70~80% of the internal volume of the microcapsule 21. The effective mass ratio of the strontium-based active component in the solid strontium-based heat generator 1 to the liquid perfluorohexanone in the perfluorohexanone inclusion 2 is 10:1~2.

[0042] This particle size range, combined with the wall thickness of microcapsules 21, allows the microcapsules 21 to rupture synchronously within 1-5 seconds after the solid strontium-based material is exothermized, while maintaining their integrity during compression molding, transportation, and storage. This filling amount enables controlled brittle fracture upon heating, rather than slow infiltration or outer shell melting. Furthermore, it prevents rupture due to pressure changes within the microcapsules 21 caused by fluctuations in ambient temperature.

[0043] Example 2 This embodiment is basically the same as Embodiment 1, except that the particle size and filling amount of the microcapsules 21 are adjusted.

[0044] Sample 2-1: Microcapsules 21 have an average particle size of 200 μm, a wall thickness of 5 μm, and a filling amount of 70%.

[0045] Sample 2-2: Microcapsules 21 have an average particle size of 1500 μm, a wall thickness of 30 μm, and a filling amount of 80%.

[0046] Example 3 This embodiment is basically the same as Embodiment 1, except that the microcapsules 21 are arranged in the second polymer shell.

[0047] Sample 3: Microcapsules 21 are arranged in a multi-layer array (3 layers), with a uniform gap between adjacent microcapsules 21.

[0048] Comparative Example 1 An electric igniter was used as the triggering device. Solid strontium-based aerosol and perfluorohexanone microcapsules 21 were placed in different cavities, and a thermally conductive partition (aluminum plate with a thickness of 2 mm) was set between them. The rest was the same as in Example 1.

[0049] Comparative Example 2 This embodiment is basically the same as Embodiment 1, except that the particle size of the microcapsule 21 exceeds the range.

[0050] Sample 2-1: Microcapsules 21 with an average particle size of 100 μm (less than the range), a wall thickness of 3 μm, and a filling amount of 75%.

[0051] Sample 2-2: Microcapsules 21 with an average particle size of 2000 μm (greater than the range), a wall thickness of 40 μm, and a filling amount of 75%.

[0052] Comparative Example 3 This embodiment is basically the same as Embodiment 1, except that the microcapsules 21 are arranged in a close-packed manner (without uniform gaps) inside the second polymer shell, and are directly filled inside the second polymer shell.

[0053] Performance testing results are shown in Table 1: Table 1 shows the test results of the fire extinguishing performance of each sample. As shown in Table 1, the present invention uses a solid strontium-based heat generator in contact with the perfluorohexanone inclusion body. After the ignition source is generated, no electric igniter is required to trigger it. The start-up time is shorter than that of comparative examples 2 and 3, and the inactivation time is short. There is no reignition within 24 hours. The heat utilization efficiency and perfluorohexanone cracking rate are both optimal.

[0054] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A perfluorohexanone synergistic fire extinguishing unit based on solid strontium-based aerosol, characterized in that, include: A solid strontium-based heat generator (1) is covered with a first polymer shell (10). The perfluorohexanone encapsulation (2) is in contact with the solid strontium-based heat generator (1), and includes a second polymer shell and a plurality of microcapsules (21) uniformly filled inside the second polymer shell (20), wherein the microcapsules (21) encapsulate liquid perfluorohexanone; When the first polymer shell (10) comes into contact with the fire source, it breaks or melts, exposing the solid strontium-based heat generator (1) to the fire source and initiating an exothermic reaction. The released heat acts on the perfluorohexanone encapsulation (2) in contact with it through thermal conduction, causing multiple microcapsules (21) to break, liquid perfluorohexanone to vaporize and decompose to extinguish the fire.

2. The perfluorohexanone synergistic fire extinguishing unit based on solid strontium-based aerosol according to claim 1, characterized in that, The solid strontium-based heat generator (1) is a block formed by pressing one or more of strontium carbonate, strontium nitrate, strontium nitrite, and strontium hydroxide.

3. The perfluorohexanone synergistic fire extinguishing unit based on solid strontium-based aerosol according to claim 1, characterized in that, The melting point of the first polymer shell (10) is higher than the ambient storage temperature and lower than the initial exothermic reaction temperature of the solid strontium-based heat generator (1); the melting point of the second polymer shell (20) is lower than the temperature that the exothermic reaction of the solid strontium-based heat generator (1) can reach and higher than the melting point of the first polymer shell (10).

4. The perfluorohexanone synergistic fire extinguishing unit based on solid strontium-based aerosol according to claim 1, characterized in that, The solid strontium-based heat generator (1) and the perfluorohexanone inclusion (2) form a vertical stacked structure without physical isolation, so that heat is transferred in a directional manner along the vertical direction.

5. The perfluorohexanone synergistic fire extinguishing unit based on solid strontium-based aerosol according to claim 1, characterized in that, The shell thickness of the microcapsule (21) is less than the wall thickness of the second polymer shell (20).

6. The perfluorohexanone synergistic fire extinguishing unit based on solid strontium-based aerosol according to claim 1, characterized in that, The wall thickness of the second polymer shell (20) is 10 to 100 times that of the shell thickness of the microcapsule (21).

7. The perfluorohexanone synergistic fire extinguishing unit based on solid strontium-based aerosol according to claim 1, characterized in that, The plurality of microcapsules (21) are arranged in a single layer or multiple layers in the second polymer shell (20), and there is a uniform gap between adjacent microcapsules (21). The gap constitutes a heat conduction medium channel and a release channel after perfluorohexanone vaporization.

8. The perfluorohexanone synergistic fire extinguishing unit based on solid strontium-based aerosol according to claim 1, characterized in that, The average particle size of the microcapsules (21) is 200~1500μm.

9. The perfluorohexanone synergistic fire extinguishing unit based on solid strontium-based aerosol according to claim 1, characterized in that, The amount of liquid perfluorohexanone in the microcapsule (21) is 70-80% of the internal volume of the microcapsule (21).

10. The perfluorohexanone synergistic fire extinguishing unit based on solid strontium-based aerosol according to claim 1, characterized in that, The effective mass ratio of the strontium-based active component in the solid strontium-based heat generator (1) to the liquid perfluorohexanone in the perfluorohexanone inclusion (2) is 10:1~2.

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