High-expansion, difficult-to-deform, fire-resistant and heat-insulating composite fireproof structure and distribution box

Abstract

The invention provides a high-expansion, non-deformable, fireproof and heat-insulating composite fireproof structure and a distribution box. The high-expansion, difficult-to-deform, fireproof and heat-insulating composite fireproof structure comprises a high-expansion fireproof coating, a metal plate and an inorganic high-temperature-resistant fireproof plate which are sequentially stacked from outside to inside, and the high-expansion fireproof coating comprises the following components by mass: 30-35 parts of water-based alkyd resin; 1-10 parts of an inorganic modified filler; wherein the inorganic filler comprises at least one hammer-milled glass fiber; 15 to 30 parts of a high-expansion flame retardant; 5-10 parts of an inorganic flame retardant; 5 to 15 parts of a nano SiO2-Al2O3 porous composite heat insulation agent; and 1 to 10 parts of a nano Fe2O3-ZnO mixture. The composite fireproof structure still has corrosion resistance and water resistance under the conditions that a waterproof coating is not used, a preservative is not added and a large number of hydrophilic groups are introduced, and normal operation of the distribution box is ensured within 0.5-1.5 hours of flame combustion at 1000 DEG C; the distribution box is especially suitable for being applied to a fire extinguishing system, wherein the distribution box has a large number of electrical elements and has temperature-sensitive electrical elements in a narrow outdoor space.

Description

Technical Field

[0001] The present invention relates to the technical field of fire protection of distribution boxes, and in particular to a composite fire protection structure and a distribution box which are highly expandable, not easily deformed, fire-resistant and heat-insulating. Background Art

[0002] The distribution box is divided into power distribution box, lighting distribution box and metering box. It is the final equipment of the power distribution system. They distribute the power of a circuit of the upper-level distribution equipment to the nearest load. This level of equipment should provide protection, monitoring and control for the load.

[0003] At present, most distribution boxes mainly achieve their fireproof performance by adding fire extinguishing agents, fire extinguishing devices, fireproof composite panels, etc. For example, Chinese document CN 104734026 A discloses a fireproof AC low-voltage distribution cabinet, which adopts a control module and a fire extinguishing material storage tank at the rear end of the cabinet frame to achieve the effect of fireproofing and heat insulation. However, the volume of the fire extinguishing material storage tank generally added is relatively large, resulting in a low space utilization rate in the distribution box. For this reason, some scholars believe that by adding a fireproof composite panel, the space utilization rate in the distribution box can be maximized, just as the fireproof material and preparation process for the manufacture of a low-voltage distribution cabinet disclosed in Chinese document CN115819971 B directly uses a polycarbonate system fireproof composite panel to replace the metal distribution cabinet, which improves the safety performance of the low-voltage distribution cabinet while also improving the space utilization rate of the distribution cabinet.

[0004] In actual applications, polycarbonate system fireproof composite panels are directly used to replace metal distribution cabinets. Since the melting point of the polycarbonate system is 200-300°C, when encountering open flames, the temperature of the open flame is usually 1000°C, causing the polycarbonate system fireproof composite panels to soften and collapse in just a few minutes.

[0005] Therefore, a new type of fire retardant coating has appeared in the market. For example, CN 110343457 A discloses a self-cleaning, fire-proof multifunctional coating for steel structure, and specifically discloses that it includes component A and component B, component B includes a curing agent, and component A is prepared by including the following components by mass: 30-40 parts of organic silicon modified waterborne polyurethane resin; 3-8 parts of modified nano titanium dioxide; 5-10 parts of hydroxide inorganic flame retardant; 25-40 parts of intumescent flame retardant. High intumescent fire retardant coating is usually applied to the body of the distribution box to effectively improve the fire-resistant and heat-insulating performance of the distribution box under open flame combustion.

[0006] However, although the above-mentioned self-cleaning and fire-proof multifunctional coating for steel structure can improve its fire-resistant and heat-insulating properties under 1000°C flame combustion to a certain extent, the added silicone-modified water-based polyurethane resin introduces more polyurethane prepolymers containing hydrophilic groups, resulting in a lower surface energy of the self-cleaning and fire-proof multifunctional coating for steel structure, resulting in a weaker connection strength between the self-cleaning and fire-proof multifunctional coating layer for steel structure and the steel plate, resulting in the above-mentioned self-cleaning and fire-proof multifunctional coating for steel structure falling off within 10 to 20 minutes of 1000°C flame combustion, causing the temperature of the back panel inside the distribution box to exceed 100°C, causing the electrical components in the distribution box to fail to work normally. Summary of the invention

[0007] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a composite fireproof structure that has anti-corrosion and waterproof properties without using a waterproof coating, adding a preservative, or introducing a large amount of hydrophilic groups, and also ensures that the high-expansion, non-deformable, fire-resistant and heat-insulating composite fireproof structure can maintain the normal operation of the distribution box within 0.5-1.5 hours of flame combustion at 1000°C; it also improves the connection strength between the high-expansion fireproof coating and the metal plate, and is particularly suitable for outdoor narrow spaces, distribution boxes with a large number of electrical components and temperature-sensitive electrical components. The composite fireproof structure and distribution box with high expansion, non-deformation, fire-resistant and heat-insulating properties are used in fire protection systems.

[0008] The purpose of this disclosure is achieved through the following technical solutions:

[0009] A composite fireproof structure with high expansion, non-deformation resistance and heat insulation, which includes a high expansion fireproof coating, a metal plate and an inorganic high temperature resistant fireproof plate stacked in sequence from the outside to the inside.

[0010] The high expansion fire retardant coating comprises the following mass components:

[0011]

[0012]

[0013] In one embodiment, the inorganic high temperature resistant fireproof board is at least one of a magnesium sulfate fireproof board and a silicate fireproof board.

[0014] In one embodiment, the diameter of the hammer-milled glass fiber is 10um to 20um, and the length is 0.01 to 1.0mm; and / or;

[0015] The hammer-milled glass fiber is used in an amount of 0.5-3 parts by weight.

[0016] In one embodiment, the inorganic modified filler is also selected from at least one of titanium dioxide, kaolin and attapulgite.

[0017] In one embodiment, the high expansion flame retardant includes at least one of ammonium polyphosphate (type II), pentaerythritol and melamine phosphate; and / or;

[0018] The inorganic flame retardant includes at least one of hydrotalcite, aluminum sulfate, magnesium hydroxide and aluminum hydroxide; and / or,

[0019] The expansion rate of the high expansion fireproof coating is 40 to 50 times.

[0020] In one embodiment, the thickness of the high expansion fire retardant coating is 800um to 2000um.

[0021] In one of the embodiments, the nano-SiO2-Al2O3 porous composite thermal insulation agent is a mixture of SiO2 and SiO2-Al2O3.

[0022] In one embodiment, the high expansion fire retardant coating further comprises 1-5 parts of an auxiliary agent and 1-5 parts of a smoke suppressant.

[0023] In one of the embodiments, the inorganic high temperature resistant fireproof board is connected to the metal plate by welding nails.

[0024] A distribution box comprises the high expansion, non-deformable, fire-resistant and heat-insulating composite fireproof structure described in any of the above embodiments.

[0025] Compared with the prior art, the present invention has at least the following advantages:

[0026] 1) Since the high expansion fire retardant coating has an expansion rate of 40 to 50 times, which is higher than the expansion rate of the traditional expansion fire retardant coating of about 20 times, the high expansion fire retardant coating is easy to undergo rapid carbonization and expansion under 1000°C flame combustion, thereby forming a high expansion and dense carbonized layer on the metal plate. If only traditional general fillers such as titanium dioxide, kaolin, attapulgite, etc. are used, the high expansion and dense carbonized layer is prone to combustion collapse under 1000°C flame combustion, which affects the fire resistant and heat insulating properties of the high expansion and dense carbonized layer. Therefore, the hammer-milled glass fiber added in the present invention can enhance the structural strength of the high-expansion dense carbonized layer, especially when used in conjunction with the nano-SiO2-Al2O3 porous composite thermal insulation agent and the nano-Fe2O3-ZnO mixture, so that the porous structure of the nano-SiO2-Al2O3 porous composite thermal insulation agent can effectively absorb the heat in the flame, thereby ensuring that the high-expansion fire-retardant coating has a better structural morphology during the rapid expansion process, and the nano-Fe2O3-ZnO mixture can further enhance the structural strength of the high-expansion dense carbonized layer, and better ensure that the high-expansion fire-retardant coating is not prone to combustion collapse during 1000°C flame combustion, that is, ensure that the high-expansion fire-retardant coating is not easy to deform during flame combustion and has good fire resistance and heat insulation, thereby ensuring that the high-expansion fire-retardant coating is burned at 1000°C for 0.5h to 1.5h, and the internal back panel temperature of the distribution box is still maintained below 85°C, which better ensures the normal operation of the distribution box.

[0027] 2) In actual applications, the external ignition source of the distribution box is usually higher than the internal ignition source of the distribution box, which makes the distribution box susceptible to fire caused by the flame of the external ignition source. Therefore, in the present disclosure, by setting the high-expansion fire-retardant coating on the outermost layer and the inorganic high-temperature resistant fire-proof board on the inside, the high-expansion fire-retardant coating can expand rapidly under 1000°C flame combustion to play a better fire-resistant and heat-insulating role, while the internal inorganic high-temperature resistant fire-retardant board will not carbonize and expand, thereby ensuring that the inorganic high-temperature resistant fire-retardant board can still maintain a good structural form during a long combustion process, and thus can well resist external flames, and effectively avoid the high-expansion fire-retardant coating being set inside to cause the high-expansion fire-retardant coating to squeeze the electrical components in the distribution box and affect the normal operation of the distribution box. It is worth mentioning that the added inorganic high-temperature resistant fireproof board can better block the entry of external heat to ensure that the high-expansion, non-deformable, fire-resistant and heat-insulating composite fireproof structure is burned at 1000℃ for 0.5-1.5 hours. The internal back panel temperature of the distribution box does not exceed 85℃, thereby ensuring that all electrical components in the distribution box can still work normally. It is especially suitable for the application of distribution boxes in fire protection systems in some small outdoor spaces, with a large number of electrical components and temperature-sensitive electrical components.

[0028] 3) Since Al2O3 absorbs heat faster than SiO2, Al2O3 can absorb heat from the flame more quickly, thereby improving the thermal stability of SiO2, thereby better ensuring the fire-resistant and heat-insulating properties and non-deformation of the high expansion fire-retardant coating.

[0029] 4) Since the hammer-milled glass fiber also helps the high-expansion fire-retardant coating to form a "Grade A" polished surface on the metal plate, the high-expansion fire-retardant coating is not easy to adhere to dirt and grease, and is convenient for cleaning and maintenance; and because the ZnO in the nano-Fe2O3-ZnO mixture can react with the hole electrons excited in the water molecules under the condition of light to generate superoxide anions and hydroxyl radicals, so as to promote the affinity between ZnO and alkyd resin, thereby forming a super-hydrophobic coating with high connection strength, further improving the waterproof and anti-fouling properties of the high-expansion fire-retardant coating, that is, the "Grade A" polished surface formed by the hammer-milled glass fiber and the use of ZnO effectively avoids the setting of the waterproof coating and the introduction of a large number of hydrophilic groups, thereby improving the connection strength between the high-expansion fire-retardant coating and the metal plate, thereby ensuring that the high-expansion composite fire-retardant structure that is not easy to deform and fire-resistant and heat-insulating can still maintain normal operation in the distribution box within 0.5h to 1.5h of 1000°C flame combustion, and improve its waterproof and anti-fouling properties, especially suitable for some outdoor open-air distribution boxes in fire protection systems.

[0030] 5) The "Class A" polished surface and super hydrophobic coating formed by hammer-milled glass fiber will affect the adhesion of the high expansion fire retardant coating to the metal plate. Therefore, in the present disclosure, the Fe2O3-ZnO mixture added 3+ The interaction between the high expansion fire retardant coating and the alkyd resin surface is enhanced, and the presence of oxygen in Fe2O3 improves the adhesion between the high expansion fire retardant coating and the metal plate, thereby ensuring the connection strength between the high expansion fire retardant coating and the metal plate; and Fe2O3 can inhibit the diffusion of corrosive ions to the interface of the metal plate, thereby ensuring that the high expansion fire retardant coating can achieve the anti-corrosion performance of the high expansion fire retardant coating without the need for additional preservatives. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present disclosure and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0032] Figure 1 A schematic diagram of the structure of a distribution box in one direction according to an embodiment of the present invention;

[0033] Figure 2This is a schematic diagram of the structure of a main cabinet door in one direction according to an embodiment of the present invention;

[0034] Figure 3 A cross-sectional view of a main cabinet door in one direction according to another embodiment of the present invention;

[0035] Figure 4 for Figure 3 The enlarged view of point A shown in FIG.

[0036] Figure numerals: 10, distribution box; 100, box body; 200, main cabinet door; 21, composite fireproof structure that is not easily deformed and is fire-resistant and heat-insulating; 210, high-expansion fireproof coating; 220, metal plate; 230, inorganic high-temperature resistant fireproof board; 231, through hole; 2311, limiting cavity; 240, welding nail; 250, fireproof sealant layer; 260, magnetic expansion fireproof sealing strip; 270, low-expansion sealing fireproof cap; 271, cap body; 272, cap crown; 273, deformation limiting part; 274, expansion accommodating cavity. DETAILED DESCRIPTION

[0037] In order to facilitate the understanding of the present disclosure, the present disclosure will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present disclosure are given in the drawings. However, the present disclosure can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present disclosure more thoroughly and comprehensively understood.

[0038] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only and do not represent the only implementation method.

[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present disclosure. The terms used herein in the specification of the present disclosure are only for the purpose of describing specific embodiments and are not intended to limit the present disclosure. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0040] In order to better understand the technical solutions and beneficial effects of the present invention, the present invention is further described in detail below in conjunction with specific embodiments:

[0041] See also Figure 3 and Figure 4A high-expansion, non-deformable, fire-resistant and heat-insulating composite fireproof structure 21 of an embodiment includes, from the outside to the inside, a high-expansion fireproof coating 210, a metal plate 220 and an inorganic high-temperature resistant fireproof board 230 stacked in sequence, and the high-expansion fireproof coating 210 includes the following mass components: 30-35 parts of water-based alkyd resin; 1-10 parts of inorganic modified filler; wherein the inorganic filler includes at least one hammer-milled glass fiber; 15-30 parts of high-expansion flame retardant; 5-10 parts of inorganic flame retardant; 5-15 parts of nano-SiO2-Al2O3 porous composite thermal insulation agent; 1-10 parts of nano-Fe2O3-ZnO mixture.

[0042] It can be understood that since the high expansion fire retardant coating 210 has an expansion rate of 40 to 50 times, which is higher than the expansion rate of the traditional expansion fire retardant coating of about 20 times; the high expansion fire retardant coating 210 is prone to rapid carbonization and expansion under 1000°C flame combustion, thereby forming a high expansion and dense carbonized layer on the metal plate 220. If only traditional general fillers such as titanium dioxide, kaolin, and attapulgite are used, the high expansion and dense carbonized layer is prone to combustion collapse under 1000°C flame combustion, which affects the fire resistant and heat insulating properties of the high expansion and dense carbonized layer.

[0043] Therefore, the hammer-milled glass fiber added in the present invention can enhance the structural strength of the high-expansion dense carbonized layer, especially when used in conjunction with the nano-SiO2-Al2O3 porous composite thermal insulation agent and the nano-Fe2O3-ZnO mixture, so that the porous structure of the nano-SiO2-Al2O3 porous composite thermal insulation agent can effectively absorb the heat in the flame, thereby ensuring that the high-expansion fire-retardant coating 210 has a better structural morphology during the rapid expansion process, and the nano-Fe2O3-ZnO mixture can further enhance the structural strength of the high-expansion dense carbonized layer, and better ensure that the high-expansion fire-retardant coating 210 is not prone to combustion collapse during 1000°C flame combustion, that is, to ensure that the high-expansion fire-retardant coating 210 is not easily deformed during flame combustion and has good fire resistance and heat insulation, thereby ensuring that the high-expansion fire-retardant coating 210 is burned at 1000°C for 0.5h to 1.5h. The internal back panel temperature of the distribution box 10 is still maintained below 85°C, thereby better ensuring the normal operation of the distribution box 10.

[0044] It can also be understood that in actual applications, the external ignition source of the distribution box 10 is usually higher than the internal ignition source of the distribution box 10, which makes the distribution box 10 susceptible to the flame of the external ignition source and causes a fire. Therefore, in order to resist the external flame well. In the present disclosure, by setting the high expansion fire retardant coating 210 in the outermost layer and the inorganic high temperature resistant fireproof board 230 in the interior, the high expansion fireproof coating 210 can expand rapidly under the flame combustion of 1000°C to play a better fire-resistant and heat-insulating role, while the internal inorganic high temperature resistant fireproof board 230 will not carbonize and expand, thereby ensuring that the inorganic high temperature resistant fireproof board 230 can still maintain a good structural form during a long combustion process, and thus can resist the external flame well, and effectively avoid the high expansion fireproof coating 210 being set in the interior to cause the high expansion fireproof coating 210 to squeeze the electrical components in the distribution box 10 and affect the normal operation of the distribution box 10. It is worth mentioning that the added inorganic high-temperature resistant fireproof board 230 can better block the entry of external heat to ensure that the high-expansion, non-deformable, fire-resistant and heat-insulating composite fireproof structure 21 is burned at 1000°C for 0.5-1.5 hours. The internal back panel temperature of the distribution box 10 still does not exceed 85°C, thereby ensuring that all electrical components in the distribution box 10 can still work normally. It is especially suitable for use in fire protection systems in some small outdoor spaces, with a large number of electrical components and temperature-sensitive electrical components.

[0045] It can also be understood that since Al2O3 absorbs heat faster than SiO2, Al2O3 can absorb heat from the flame more quickly, thereby improving the thermal stability of SiO2, thereby better ensuring the fire-resistant and heat-insulating properties and non-deformation of the high expansion fire-retardant coating 210.

[0046] It can also be understood that, since the hammer-milled glass fiber also helps the high expansion fire retardant coating 210 to form an "A-grade" polished surface on the metal plate 220, the high expansion fire retardant coating 210 is not easy to adhere to dirt and grease, and is convenient for cleaning and maintenance; and because the ZnO in the nano-Fe2O3-ZnO mixture can react with the hole electrons excited in the water molecules under the condition of light to generate superoxide anions and hydroxyl radicals, so as to promote the affinity between ZnO and alkyd resin, thereby forming a super hydrophobic coating with high connection strength, further improving the high The waterproof and anti-fouling properties of the intumescent fire-retardant coating 210, that is, the combination of the "Grade A" polished surface formed by hammer-ground glass fiber and ZnO, effectively avoids the setting of the waterproof coating and the introduction of a large number of hydrophilic groups, thereby improving the connection strength between the high-expansion fire-retardant coating 210 and the metal plate 220, thereby ensuring that the high-expansion, non-deformable, fire-resistant and heat-insulating composite fire-proof structure 21 can still maintain normal operation when the distribution box is burned by a flame at 1000°C for 0.5h to 1.5h, and improves its waterproof and anti-fouling properties, which is particularly suitable for the application of some outdoor open-air distribution boxes 10.

[0047] It can also be understood that the "A-grade" polished surface formed by hammer-milled glass fiber and the super-hydrophobic coating formed will affect the adhesion between the high expansion fire retardant coating 210 and the metal plate 220, and the general practice is to modify the resin, such as introducing some hydrophilic groups, as disclosed in Chinese patent document No. CN 110343457A, first prepare a polyurethane prepolymer containing a hydrophilic group, then react with trimethylolpropane, then add a silane coupling agent for coupling, and finally react with a diamine to obtain an organosilicon-modified waterborne polyurethane resin, which has the problem of complicated preparation. Therefore, in the present disclosure, there is no need to introduce a hydrophilic group, which can reduce costs on the one hand, and help improve the connection strength between the high expansion fire retardant coating and the metal plate on the other hand; on the other hand, the Fe in the added nano-Fe2O3-ZnO mixture 3+ The interaction between the high expansion fire retardant coating 210 and the alkyd resin surface is enhanced, and the presence of oxygen in Fe2O3 improves the adhesion between the high expansion fire retardant coating 210 and the metal plate 220, thereby ensuring the connection strength between the high expansion fire retardant coating 210 and the metal plate 220, and reducing the problem of complicated preparation of the high expansion fire retardant coating 210 due to the need to introduce hydrophilic groups; and Fe2O3 can inhibit the diffusion of corrosive ions to the interface of the metal plate 220, thereby ensuring that the high expansion fire retardant coating 210 can achieve the anti-corrosion performance of the high expansion fire retardant coating 210 without the need to add additional preservatives.

[0048] In one embodiment, the inorganic high temperature resistant fireproof board 230 is at least one of a magnesium sulfate fireproof board and a silicate fireproof board. Since the magnesium sulfate fireproof board and the silicate fireproof board have high fireproof and heat resistant properties, they can effectively block the heat transferred by the metal plate 220, so as to ensure that the high expansion, non-deformable and fire-resistant and heat-insulating composite fireproof structure 21 is burned by a flame of 1000°C for 0.5-1.5 hours, and the temperature of the back plate inside the distribution box 10 still does not exceed 85°C, thereby ensuring that all electrical components in the distribution box 10 can still work normally.

[0049] In one of the embodiments, the diameter of the hammer-milled glass fiber is 10um to 20um, and the length is 0.01 to 1.0mm. It is understandable that if the diameter of the hammer-milled glass fiber is greater than 20um or the length is greater than 1.0mm, it will affect the surface smoothness of the high expansion fire retardant coating 210, thereby failing to ensure that the high expansion fire retardant coating 210 can form a "Grade A" polished surface; if the diameter of the hammer-milled glass fiber is less than 10um or the length is less than 0.01mm, it will fail to enhance the structural strength of the high expansion dense carbonized layer, resulting in the high expansion fire retardant coating 210 being prone to collapse during 1000°C flame combustion. Therefore, in the present disclosure, by controlling the diameter of the hammer-milled glass fiber to 10um to 20um and the length to 0.01 to 1.0mm, while ensuring that the hammer-milled glass fiber can enhance the structural strength of the high expansion dense carbonized layer, it will not affect the surface smoothness of the high expansion fire retardant coating 210, thereby ensuring that the high expansion fire retardant coating 210 can form a "Grade A" polished surface.

[0050] It can be understood that if the amount of hammer-milled glass fiber used is too much, it will affect the expansion multiple of the high expansion fire-retardant coating 210 and the surface smoothness of the high expansion fire-retardant coating 210, so that it is impossible to ensure that the high expansion fire-retardant coating 210 with a high expansion rate and a "Grade A" polished surface is obtained; if the amount of hammer-milled glass fiber used is too little, it is impossible to enhance the structural strength of the high expansion dense carbonized layer, resulting in the high expansion fire-retardant coating 210 being prone to collapse during flame combustion at 1000°C. Therefore, in one of the embodiments, the mass fraction of hammer-milled glass fiber used is 0.5-3 parts to ensure that the amount of hammer-milled glass fiber used is more appropriate. On the premise of ensuring that the high expansion fire-retardant coating 210 has a high expansion multiple and good surface smoothness, it can also enhance the structural strength of the high expansion dense carbonized layer, thereby ensuring that a high expansion composite fireproof structure 21 that is not easily deformed and fire-resistant and heat-insulating is obtained.

[0051] In one embodiment, the preparation method of hammer-milled glass fiber includes: firstly, hammer-milling long glass fibers to obtain powdered short fiber filler, and then sieving the powdered short fiber filler with a sieve to obtain hammer-milled glass fibers with the particle size and length required for production.

[0052] It is understood that if only hammer-milled glass fiber is used as filler, the hammer-milled glass fiber is prone to fiber breakage, which may cause the high expansion fire retardant coating 210 to collapse during flame combustion at 1000° C. Therefore, in one embodiment, the inorganic modified filler is also selected from at least one of titanium dioxide, kaolin and attapulgite, so that the added titanium dioxide, kaolin and attapulgite can play a better reinforcing effect with the hammer-milled glass fiber, so as to ensure that the high expansion fire retardant coating 210 is not easily deformed during flame combustion at 1000° C. for 0.5-1.5 hours.

[0053] In one embodiment, the inorganic modified filler is a mixture of titanium dioxide and hammer-milled glass fiber, so that the titanium dioxide and hammer-milled glass fiber can play a good synergistic role, thereby ensuring that the high expansion fire retardant coating 210 is not easily deformed within 0.5-1.5 hours of flame combustion at 1000°C.

[0054] In a preferred embodiment, the titanium dioxide is a rutile titanium dioxide with uniform particle size distribution. It can be understood that, due to the slender and compact crystal structure of the rutile titanium dioxide, it can be mixed with hammer-milled glass fiber to form an interlaced mesh structure, so that the high expansion fire retardant coating 210 is not easy to deform during 0.5-1.5 hours of flame combustion at 1000°C, which ensures that the rutile titanium dioxide and the hammer-milled glass fiber can play a good synergistic role; and the rutile titanium dioxide with uniform particle size distribution is also conducive to the high expansion fire retardant coating 210 forming an "A-grade" polished surface, thereby improving the waterproof and antifouling properties of the high expansion fire retardant coating 210.

[0055] In one embodiment, the high expansion flame retardant includes at least one of ammonium polyphosphate (type II), pentaerythritol and melamine phosphate to ensure that a high expansion fire retardant coating 210 of 40 to 50 times is prepared.

[0056] In one embodiment, the inorganic flame retardant includes at least one of hydrotalcite, aluminum sulfate, magnesium hydroxide and aluminum hydroxide to ensure that a high expansion fire retardant coating 210 of 40 to 50 times is prepared. It can be understood that if a high expansion flame retardant is used alone, there is a problem that the high expansion fire retardant coating 210 will deform and collapse within a few minutes of burning at 1000°C; if an inorganic flame retardant is used alone, a large amount of usage needs to be added to cause the high expansion, non-deformable and fire-resistant and heat-insulating composite fireproof structure 21 to have a high brittleness and affect its fire-resistant and heat-insulating properties. Therefore, in the present disclosure, by compounding the inorganic flame retardant with the high expansion flame retardant, the high expansion fire retardant coating 210 has a higher expansion multiple, and it is also ensured that the high expansion fire retardant coating 210 is not prone to deformation and collapse within 0.5-1.5 hours of burning at 1000°C.

[0057] In a preferred embodiment, the inorganic flame retardant is a mixture of hydrotalcite, magnesium hydroxide and aluminum hydroxide. It is understood that hydrotalcite has a long-lasting flame retardant effect, and when mixed with magnesium hydroxide and aluminum hydroxide, it can play a better synergistic role, thereby ensuring that the high expansion fire retardant coating 210 is not prone to deformation and collapse within 0.5-1.5 hours of 1000°C flame combustion.

[0058] In a more preferred embodiment, the inorganic flame retardant is a mixture of non-ferromagnetic hydrotalcite, magnesium hydroxide and aluminum hydroxide. It can be understood that since the layered structure of non-ferromagnetic hydrotalcite has a large specific surface area and a rich pore structure, it can not only provide a better long-lasting flame retardant effect, but also enable the non-ferromagnetic hydrotalcite to adsorb and fix microorganisms such as bacteria, and the non-ferromagnetic hydrotalcite contains metal ions with antibacterial activity such as Cu2+ and Zn2+, which better inhibit the growth of bacteria, especially when used in combination with Fe2O3, the high expansion fire retardant coating 210 can achieve the antibacterial and anticorrosive effect of the high expansion fire retardant coating 210 without the need to add additional preservatives.

[0059] It can be understood that if the thickness of the high expansion fire retardant coating 210 is less than 800um, the normal operation of the electrical components in the distribution box 10 cannot be ensured within 0.5-1.5 hours when the flame burns at 1000°C; if the thickness of the high expansion fire retardant coating 210 is greater than 2000um, the high expansion fire retardant coating 210 will be too thick within 0.5-1.5 hours when the flame burns at 1000°C, resulting in the problem of weak connection strength between the high expansion fire retardant coating 210 and the metal plate 220. Therefore, in one of the embodiments, the thickness of the high expansion fire retardant coating 210 is 800um to 2000um, so that the thickness of the high expansion fire retardant coating 210 is more appropriate. On the premise of ensuring that the connection strength between the high expansion fire retardant coating 210 and the metal plate 220 is good when the distribution box 10 burns in a flame of 1000°C for 0.5-1.5 hours, it is also ensured that the high expansion fire retardant coating 210 has the properties of not being easy to deform and being fire-resistant and heat-insulating, thereby ensuring the normal operation of the electrical components in the distribution box 10.

[0060] In one embodiment, the nano-SiO2-Al2O3 porous composite heat insulating agent is a mixture of SiO2 and SiO2-Al2O3. It can be understood that since Al2O3 absorbs heat faster than SiO2, Al2O3 can absorb heat in the flame more quickly, thereby improving the thermal stability of SiO2, thereby better ensuring the fire-resistant heat insulation performance of the high expansion fire-retardant coating 210 and preventing deformation and collapse.

[0061] In one of the embodiments, since the ratio of the mixture of SiO2 and nano-SiO2-Al2O3 is 2:1, the combination of SiO2 and nano-SiO2-Al2O3 can better ensure the fire-resistant and heat-insulating performance of the high expansion fire-retardant coating 210 and prevent deformation and collapse.

[0062] In one embodiment, the high expansion fire retardant coating 210 also includes 1-5 parts of an additive and 1-5 parts of a smoke suppressant. The addition of the additive is beneficial to the dispersion of the various components in the high expansion fire retardant coating 210, and helps to form a uniform high expansion fire retardant coating 210 on the surface of the metal plate 220; the added smoke suppressant can effectively suppress the high expansion fire retardant coating 210 from producing a large amount of smoke when burning in a flame at 1000°C.

[0063] Specifically, in one embodiment, the auxiliary agent includes a film-forming auxiliary agent, a wetting and dispersing agent, an antifreeze agent, a defoaming agent, and a thickener. In one embodiment, the smoke suppressant includes at least one of zinc borate and phosphomolybdate.

[0064] It can be understood that if only adhesive is used to fix the inorganic high-temperature resistant fireproof board 230 and the metal plate 220, the traditional adhesive is prone to failure under high temperature conditions, resulting in the high-expansion, non-deformable, fire-resistant and heat-insulating composite fireproof structure 21 being prone to the inorganic high-temperature resistant fireproof board 230 and the metal plate 220 falling off when the flame burns at 1000°C for 0.5-1.5 hours. Therefore, in one of the embodiments, the inorganic high temperature resistant fireproof board 230 is connected to the metal plate 220 by means of welding nails 240, so that the added welding nails 240 can achieve better connection and fixation of the inorganic high temperature resistant fireproof board 230 and the metal plate 220, and effectively avoid the inorganic high temperature resistant fireproof board 230 from falling off within 0.5-1.5 hours of burning with a flame at 1000°C, thereby ensuring that the high expansion, non-deformable, fire-resistant and heat-insulating composite fireproof structure 21 has good fire-resistant and heat-insulating properties inside and outside, and effectively avoids the problem of falling off between layers of the high expansion, non-deformable, fire-resistant and heat-insulating composite fireproof structure 21 within 0.5-1.5 hours of burning with a flame at 1000°C.

[0065] In one of the embodiments, the welding nail 240 is welded and fixed to the metal plate 220 to achieve a better connection and fixation between the welding nail 240 and the metal plate 220. The inorganic high temperature resistant fireproof board 230 is provided with a through hole 231, and the welding nail 240 is clamped in the through hole 231 so that the welding nail 240 can clamp and fix the inorganic high temperature resistant fireproof board 230 on the metal plate 220.

[0066] It is understood that the welding nail 240 is usually made of metal, and the metal plate 220 is also made of metal, which causes the heat of the high expansion fire retardant coating 210 to be easily transferred to the welding nail 240 through the metal plate 220, and then transferred to the inside of the distribution box 10 by the welding nail 240, thereby affecting the normal operation of the electrical components in the distribution box 10. Therefore, please refer to Figure 3 and Figure 4 In one of the embodiments, the high-expansion, non-deformable, fire-resistant and heat-insulating composite fireproof structure 21 also includes a low-expansion sealed fire-resistant cap 270, which is filled in the gap between the through hole 231 and the screw, so that the added low-expansion sealed fire-resistant cap 270 can, on the one hand, enhance the connection strength between the metal plate 220 and the inorganic high-temperature resistant fireproof board 230, and effectively avoid the problem that the metal plate 220 and the inorganic high-temperature resistant fireproof board 230 are easily detached when the high-expansion, non-deformable, fire-resistant and heat-insulating composite fireproof structure 21 burns at 1000°C for 0.5-1.5 hours. On the other hand, the low-expansion sealed fire-resistant cap 270 can also effectively block the path for the heat of the welding nail 240 to be transferred to the inside of the distribution box 10, thereby ensuring the normal operation of the electrical components in the distribution box 10.

[0067] It can be understood that if the expansion multiple of the low expansion sealed fire-resistant cap 270 is less than 1.5 times or higher than 5 times, the gap between the welding pin 240 and the through hole 231 of the inorganic high temperature resistant fireproof board 230 cannot be properly expanded due to heat, resulting in the metal plate 220 and the inorganic high temperature resistant fireproof board 230 easily falling off when burning at 1000°C flame within 0.5-1.5 hours. Therefore, in one embodiment, the expansion multiple of the low expansion sealing fire-resistant cap 270 is 1.5 to 5 times, so as to ensure that the low expansion sealing fire-resistant cap 270 can be better sealed and filled in the gap between the welding nail 240 and the through hole 231 of the inorganic high temperature resistant fireproof board 230, thereby ensuring that the inorganic high temperature resistant fireproof board 230 is not easy to fall off within 0.5-1.5 hours of burning with a 1000°C flame, so that the low expansion sealing fire-resistant cap 270 can slowly expand and seal in the gap between the welding nail 240 and the through hole 231 of the inorganic high temperature resistant fireproof board 230 as the 1000°C flame continues to burn, thereby ensuring the connection strength between the inorganic high temperature resistant fireproof board 230 and the welding nail 240 and the metal plate 220 within 0.5-1.5 hours of burning with a 1000°C flame.

[0068] It is worth mentioning that since the low expansion sealing fire-resistant cap 270 is located in the gap between the welding nail 240 and the through hole 231, the expansion space of the low expansion sealing fire-resistant cap 270 is limited. If a low expansion sealing fire-resistant cap 270 with a thickness higher than 5 times is used, the low expansion sealing fire-resistant cap 270 connected to the inner wall of the through hole 231 will be broken first when heated at high temperature. As the burning time continues to increase, the broken low expansion sealing fire-resistant cap 270 will slowly be carbonized, and in severe cases, it will fall off, causing the welding nail 240 to be exposed and the gap between the welding nail 240 and the inorganic high temperature resistant fireproof board 230 to become larger, causing the heat of the metal plate 220 to be quickly transferred to the inside of the distribution box 10 and affecting the normal operation of the distribution box 10. Therefore, when the expansion multiple of the low expansion sealing fire-resistant cap 270 is controlled between 1.5 and 5 times, it can be ensured that the expansion rate of the low expansion sealing fire-resistant cap 270 is more suitable when the flame continues to burn at 1000°C, and it can effectively avoid the low expansion sealing fire-resistant cap 270 and the inner wall of the through hole 231 from breaking due to high temperature expansion, which affects the sealing and heat insulation effect of the low expansion sealing fire-resistant cap 270, thereby ensuring that the low expansion sealing fire-resistant cap 270 still has good sealing and heat insulation performance when the flame continues to burn at 1000°C for 0.5-1.5 hours.

[0069] In addition, if the expansion rate of the low expansion sealed fire-resistant cap 270 is significantly different from that of the inorganic high temperature resistant fireproof board 230, the low expansion sealed fire-resistant cap 270 will easily expand and lift up the inorganic high temperature resistant fireproof board 230 when the flame continues to burn at 1000°C for 0.5-1.5 hours, causing the inorganic high temperature resistant fireproof board 230 to be misaligned and the inorganic high temperature resistant fireproof board 230 to separate from the metal plate 220 to form a heat transfer channel; the heat of the metal plate 220 will quickly enter the distribution box 10 from the heat transfer channel and affect the normal operation of the distribution box 10. Therefore, in the present disclosure, by setting the expansion multiple of the low expansion sealing fire-resistant cap 270 to 1.5 times to 5 times, the difference in expansion rate between the low expansion sealing fire-resistant cap 270 and the inorganic high temperature resistant fireproof board 230 is made more appropriate, so as to ensure that when the low expansion sealing fire-resistant cap 270 continues to burn at 1000°C for 0.5-1.5 hours, the expansion rate of the low expansion sealing fire-resistant cap 270 can be more appropriate to the expansion rate of the inorganic high temperature resistant fireproof board 230, and the problem of the low expansion sealing fire-resistant cap 270 expanding to lift up the inorganic high temperature resistant fireproof board 230 and detach from it to form a heat transfer channel will not be caused.

[0070] In one embodiment, the low expansion sealing fireproof cap 270 is extruded from an organic silicon low expansion sealing fireproof coating. Specifically, the organic silicon low expansion sealing fireproof coating can be compounded by a person skilled in the art according to the expansion multiple actually used, or can be adjusted according to the formula of the high expansion fireproof coating 210 disclosed in the present invention to obtain a suitable expansion multiple.

[0071] See also Figure 3 and Figure 4 In one embodiment, the low expansion sealing fire-resistant cap 270 includes a cap body 271, a cap crown 272 and a deformation limiting portion 273. The cap crown 272 is connected to the cap body 271. The cap body 271 forms a accommodating cavity. The welding nail 240 is located in the accommodating cavity. The deformation limiting portion 273 is arranged on the outer peripheral wall of the cap body 271. The inner wall of the through hole 231 forms a limiting cavity 2311. The deformation limiting portion 273 is clamped in the limiting cavity 2311 to realize the connection and fixation between the low expansion sealing fire-resistant cap 270 and the inorganic high temperature resistant fireproof board 230.

[0072] In order to achieve the firm connection between the low expansion sealed fire-resistant cap 270 and the inorganic high temperature resistant fireproof board 230, in one embodiment, the two ends of the welding nail 240 are respectively protruded and set in the through hole 231, and the two ends of the cap body 271 are respectively protruded and set in the through hole 231, and the cap body 271 is close to the metal plate 220. The end is formed with an expansion accommodating cavity 274, so that the protruding welding nail 240 improves the connection strength between the metal plate 220 and the inorganic high temperature resistant fireproof board 230, and the welding nail 240 can provide better support for the low expansion sealed fire-resistant cap 270, so as to ensure that the low expansion sealed fire-resistant cap 270 can fully fill the sealing welding nail 240 and the through hole. 231; and because an expansion accommodating cavity 274 is formed at one end of the cap body 271 close to the metal plate 220, the expansion accommodating cavity 274 can provide expansion space for the low-expansion sealed fire-resistant cap 270, effectively avoiding the problem that the low-expansion sealed fire-resistant cap 270 expands and lifts up the inorganic high-temperature resistant fireproof board 230 during continuous burning of a 1000°C flame for 0.5-1.5 hours, thereby causing the inorganic high-temperature resistant fireproof board 230 to separate from the metal plate 220 to form a heat transfer channel, thereby better ensuring the firmness of the connection between the inorganic high-temperature resistant fireproof board 230 and the metal plate 220, and also ensuring the sealing and fireproofing effect of the low-expansion sealed fire-resistant cap 270.

[0073] It can be understood that if the welding nail 240 and the cap body 271 are both protruding from the through hole 231, the protruding welding nail 240 and the cap body 271 will occupy the space inside the inner distribution box 10, causing the problem of low space utilization inside the distribution box 10. Therefore, in the present disclosure, a fixed cavity is formed on the side of the inorganic high temperature resistant fireproof board 230 away from the metal plate 220, and the cap crown 272 is stuck in the fixed cavity, and the cap crown 272 is flush with the inorganic high temperature resistant fireproof board 230, so that the additional fixed cavity can further improve the connection strength between the low expansion sealing fireproof cap 270 and the inorganic high temperature resistant fireproof board 230, and the cap crown 272 is flush with the inorganic high temperature resistant fireproof board 230, effectively avoiding the problem of the cap crown 272 protruding outward to cause low space utilization inside the distribution box 10.

[0074] In one embodiment, there are multiple welding pins 240 and multiple low expansion sealing fire-resistant caps 270, and each welding pin 240 is arranged in one-to-one correspondence with each low expansion sealing fire-resistant cap 270. In this way, the additional multiple welding pins 240 can better improve the connection strength between the inorganic high temperature resistant fireproof board 230 and the metal plate 220.

[0075] It can be understood that although the additional multiple welding nails 240 and multiple low expansion sealing fireproof caps 270 can improve the connection strength between the inorganic high temperature resistant fireproof board 230 and the metal plate 220, it is necessary to install multiple low expansion sealing fireproof caps 270 one by one during installation, which leads to low installation efficiency, and the number of through holes 231 of the inorganic high temperature resistant fireproof board 230 corresponding to the multiple welding nails 240 also increases. If the low expansion sealing fireproof caps 270 are improperly installed, it will cause heat to easily enter the distribution box 10 from the through holes 231, that is, the probability of heat transfer from the through holes 231 is increased. Therefore, in the present disclosure, the number of welding nails 240 and low expansion sealing fireproof caps 270 is 4 to 9, so as to ensure that the number of welding nails 240 and low expansion sealing fireproof caps 270 is relatively appropriate. In this way, while satisfying the firmness of the connection between the metal plate 220 and the inorganic high temperature resistant fireproof board 230, it is also convenient for users to install, and the installation efficiency is improved, and the probability of heat transfer from the through holes 231 is reduced.

[0076] In one of the embodiments, the number of welding pins 240 and low expansion sealing fire-resistant caps 270 is 4, and the 4 welding pins 240 are respectively distributed at the four corners of the inorganic high temperature resistant fireproof board 230, and at the same time, the use of the fireproof sealant layer 250 is better guaranteed to better ensure the firmness of the connection between the inorganic high temperature resistant fireproof board 230 and the inorganic high temperature resistant fireproof board 230, and the installation efficiency is improved, and the probability of heat transfer from the through hole 231 is reduced.

[0077] In one of the embodiments, the number of welding pins 240 and low expansion sealing fireproof caps 270 is 5, and 4 welding pins 240 are respectively distributed at the four corners of the inorganic high temperature resistant fireproof board 230, and the 5th welding pin 240 is distributed in the middle of the inorganic high temperature resistant fireproof board 230, and at the same time cooperates with the use of the fireproof sealant layer 250, so that the 5 welding pins 240 can be evenly distributed on the inorganic high temperature resistant fireproof board 230, thereby better ensuring the firmness of the connection between the inorganic high temperature resistant fireproof board 230 and the inorganic high temperature resistant fireproof board 230, and improving the installation efficiency, and reducing the probability of heat transfer from the through hole 231.

[0078] In one of the embodiments, the number of welding nails 240 and low expansion sealing fireproof caps 270 is 9, and the 9 are divided into a corner fixing group and a center fixing group. The corner fixing group includes the first welding nail 240, the second welding nail 240, the third welding nail 240 and the fourth welding nail 240, and the first welding nail 240, the second welding nail 240, the third welding nail 240 and the fourth welding nail 240 are respectively distributed at the four corners of the inorganic high temperature resistant fireproof board 230; the center fixing group includes the fifth welding nail 240, the sixth welding nail 240, the seventh welding nail 240, the eighth welding nail 240 and the ninth welding nail 240, and the fifth welding nail 240 is set between the first welding nail 240 and the first welding nail 240. The sixth weld nail 240 is set at the center position of the second weld nail 240 and the third weld nail 240, the seventh weld nail 240 is set at the center position of the third weld nail 240 and the fourth weld nail 240, the eighth weld nail 240 is set at the center position of the fourth weld nail 240 and the first weld nail 240, and the ninth weld nail 240 is set at the center position of the inorganic high temperature resistant fireproof board 230, and at the same time cooperates with the use of the fireproof sealant layer 250, so that the firmness of the connection between the inorganic high temperature resistant fireproof board 230 and the inorganic high temperature resistant fireproof board 230 is better guaranteed, the installation efficiency is improved, and the probability of heat transfer from the through hole 231 is reduced.

[0079] It is understandable that although the addition of the low expansion sealing fireproof cap 270 can effectively reduce the probability of the inorganic high temperature fireproof board 230 and the metal plate 220 separating and forming a heat transfer channel within 0.5-1.5 hours of 1000°C flame burning, as the 1000°C flame continues to burn for a longer time, the various properties of the low expansion sealing fireproof cap 270, the inorganic high temperature fireproof board 230, and the metal plate 220 will change significantly, resulting in the low expansion sealing fireproof cap 270, the inorganic high temperature fireproof board 230, and the metal plate 220 still having the probability of separation. Therefore, please refer to Figure 3 and Figure 4 In one embodiment, the high expansion, non-deformable, fire-resistant and heat-insulating composite fireproof structure 21 also includes a fireproof sealant layer 250, which is arranged along the outer peripheral wall of the inorganic high-temperature resistant fireproof board 230, and the magnetic expansion fireproof sealing strip 260 is connected to the metal plate 220. The fireproof sealant layer 250 is used to seal the connection between the inorganic high-temperature resistant fireproof board 230 and the metal plate 220, so that the added fireproof sealant layer 250 can improve the connection strength of the inorganic high-temperature resistant fireproof board 230 and the metal plate 220, ensuring that the high expansion, non-deformable, fire-resistant and heat-insulating composite fireproof structure 21 can still maintain a relatively stable connection structure within 0.5-1.5 hours of 1000°C flame burning, reducing the probability of separation between the inorganic high-temperature resistant fireproof board 230 and the metal plate 220 during a longer flame burning time.

[0080] See also Figure 3 and Figure 4In one of the embodiments, the cross-section of the fireproof sealant layer 250 is triangular. Since the triangular fireproof sealant layer 250 has a better structural stability and is a non-expanded fireproof sealant layer 250, it can ensure that the fireproof sealant layer 250 can maintain a better structural form during 0.5-1.5 hours of flame burning at 1000°C, so that the fireproof sealant layer 250 can provide a more reliable connection between the inorganic high-temperature resistant fireproof board 230 and the metal plate 220, and effectively reduce the probability of separation between the inorganic high-temperature resistant fireproof board 230 and the metal plate 220 during a longer flame burning time.

[0081] In one embodiment, the first end of the fireproof sealant layer 250 is connected to the metal plate 220, and the second end of the fireproof sealant layer 250 is connected to the outer peripheral wall of the inorganic high temperature resistant fireproof board 230 to achieve a reliable connection among the fireproof sealant layer 250, the metal plate 220 and the fireproof sealant layer 250.

[0082] See also Figure 1 and Figure 2 The present disclosure further provides a distribution box 10, comprising a high expansion, non-deformable, fire-resistant and heat-insulating composite fireproof structure 21 of any of the above-mentioned embodiments. It can be understood that the high expansion, non-deformable, fire-resistant and heat-insulating composite fireproof structure 21 of the present disclosure is applied to the distribution box 10, so that the temperature of the back plate inside the distribution box 10 does not exceed 85°C when the distribution box 10 is burned by a flame at 1000°C for 0.5-1.5 hours, thereby ensuring that all electrical components in the distribution box 10 can still work normally, and is particularly suitable for the application of distribution boxes in fire protection systems in some small outdoor spaces, with a large number of electrical components and temperature-sensitive electrical components.

[0083] See also Figures 2 to 4 In one embodiment, the distribution box 10 also includes a box body 100 and a main cabinet door 200. A accommodating cavity is formed in the box body 100, and the accommodating cavity has an opening. Each electrical component is arranged in the accommodating cavity. The main cabinet door 200 is rotatably arranged in the box body 100, and the main cabinet door 200 is used to close the opening of the accommodating cavity. The main cabinet door 200 and the box body 100 both adopt the high-expansion, non-deformable, fire-resistant and heat-insulating composite fireproof structure 21 disclosed in the present invention, thereby better ensuring the fireproof and heat-insulating performance of the distribution box 10, effectively avoiding the spread of flames and reducing the rapid transfer of heat.

[0084] It should be noted that, for example, Chinese document CN 114583567 B discloses a low-voltage power distribution cabinet with a fireproof function, in which a sealing ball and an isolation membrane are arranged in a metal cabinet door, and the isolation membrane is filled with carbon dioxide gas and high-temperature sealant, a release hole is drilled at the right end of the sealing ball, and an arc plate is arranged on the left side of the sealing ball. In this way, when the high temperature generated by the open flame causes the memory telescopic rod to deform and push the arc plate to squeeze the sealing ball, the high temperature is evenly transferred to the sealing ball through the metal anti-slip ball, and the extrusion of the arc plate and the expansion of the carbon dioxide gas simultaneously squeeze the high-temperature sealant in the sealing ball to break the plastic paper to the outside of the sealing strip, thereby sealing the cabinet, reducing the fire source from entering the interior of the cabinet through the gap between a pair of metal cabinet doors, and effectively reducing the damage inside the cabinet. However, since it takes a certain amount of time for the arc plate to deform, heat still enters the interior of the power distribution cabinet when the arc plate is not deformed, especially for some electronic components with high temperature sensitivity, there is still a probability of failure of the electronic components. In addition, the above-mentioned low-voltage distribution cabinet requires the use of sealing balls, isolation membranes filled with carbon dioxide gas, high-temperature sealants, and curved plates to block heat and flames, which has a complex structure.

[0085] Therefore, please refer to Figure 3 and Figure 4 In one embodiment, the main cabinet door 200 also includes a magnetic expansion fireproof sealing strip 260, which is spaced apart on one side of the fireproof sealant layer 250. The magnetic expansion fireproof sealing strip 260 is used to seal the opening of the accommodating cavity, so that the added magnetic expansion fireproof sealing strip 260 can expand within 0.5-1.5 hours of burning at 1000°C flame, and tightly adhere to the side wall of the opening, effectively preventing flame or heat from entering. It not only has a simple structure and good sealing effect, but also can effectively isolate heat from entering the metal cabinet without waiting for the arc plate to deform, thereby reducing the probability of failure of electronic components with high temperature sensitivity. The added fireproof sealant layer 250 improves the connection strength between the inorganic high-temperature resistant fireproof board 230 and the metal plate 220, ensuring that the highly expansive, non-deformable, fire-resistant and heat-insulating composite fireproof structure 21 can still maintain a relatively stable connection structure within 0.5-1.5 hours of 1000°C flame burning, further reducing the probability of the inorganic high-temperature resistant fireproof board 230 and the metal plate 220 separating and forming a heat transfer channel within 0.5-1.5 hours of 1000°C flame burning.

[0086] In one embodiment, the magnetic expansion fireproof sealing strip 260 includes a magnetic component and an expansion fireproof sealing ring. The magnetic component is arranged on the side of the metal door frame facing the metal cabinet, and the expansion fireproof sealing ring is arranged on the side of the magnetic component facing the metal cabinet to ensure that the magnetic expansion fireproof sealing strip 260 has the effects of magnetic attraction and fireproofing and heat insulation, thereby realizing the magnetic sealing between the magnetic expansion fireproof sealing strip 260 and the side wall of the opening.

[0087] In one of the embodiments, the expansion fireproof sealing ring is coated on the outer peripheral wall of the magnetic suction component, which increases the distribution area of ​​the expansion fireproof sealing ring on the outer peripheral wall of the magnetic suction component, thereby improving the sealing effect between the expansion fireproof sealing ring and the side wall of the opening.

[0088] In one embodiment, the distribution box 10 of the present disclosure is applied in a fire protection system. It is understandable that the distribution box 10 is generally used in a fire protection system, mainly to control the operation of fire protection equipment. The fire protection system usually needs to be activated when a fire occurs. Therefore, the fire protection performance requirements of the distribution box 10 of the fire protection system are higher than those of other application scenarios. However, the fireproof composite board of the traditional distribution box on the market will soften and collapse in just a few minutes, resulting in the paralysis of the fire protection equipment in the fire protection system, and it is impossible to effectively control the fire. The present disclosure applies a high expansion fireproof coating 210, a metal plate 220, an inorganic high temperature resistant fireproof board 230, a fireproof sealant layer 250, a magnetic expansion fireproof sealing strip 260 and a low expansion sealing fireproof cap 270 to the distribution box 10, which greatly improves the fire resistance and heat insulation performance of the distribution box 10, so that the distribution box 10 can effectively prevent the transmission of flames, smoke and high temperature, thereby reducing the probability of failure of electronic components with high temperature sensitivity, and effectively avoiding the paralysis of fire protection equipment in the fire protection system.

[0089] Some specific examples are given below, and if % is mentioned, it means percentage by weight. It should be noted that the following examples do not exhaust all possible situations, and the materials used in the following examples can be obtained from commercial sources unless otherwise specified.

[0090] It should be noted that water-based alkyd resin (provided by Guangdong Heiwei Fire Protection Technology Co., Ltd.), hammer-milled glass fiber (model: EMG10-35, manufacturer: Tai'an Zhongshuo Glass Fiber Products Co., Ltd., diameter 10μm, length 35μm), titanium dioxide (rutile type) (model: R218, manufacturer: Shanghai Yuejiang Titanium Dioxide Chemical Products Co., Ltd.), ammonium polyphosphate (type II) (model: n>1000, manufacturer: Klein Chemical), pentaerythritol (model: PM10, manufacturer: Tianjin Aolochi Chemical Technology Co., Ltd.), melamine phosphate (model: EPFR-400A, manufacturer: Pusei Fufos Chemical Co., Ltd.), hydrotalcite (model: superior product, manufacturer: Jiahe Chaoyang (Shandong) New Material Technology Co., Ltd.), magnesium hydroxide (model: 13G1, manufacturer: Jiangsu Zehui Magnesium-based New Material Technology Co., Ltd.), aluminum hydroxide (model: JLH-WF8, manufacturer: Shenzhen Jinhaohui Industrial Development Co., Ltd. Company), SiO2 (Model: A-110, Manufacturer: Guangdong Ailisheng Technology Co., Ltd.), SiO2-Al2O3 (Model: A-110S, Manufacturer: Guangdong Ailisheng Technology Co., Ltd.), Fe2O3 (Model: C130-1, Manufacturer: Hebei Canri Chemical Co., Ltd.), ZnO (Model: Superior, Manufacturer: Shanghai Yuanjiang Chemical Co., Ltd.), Film-forming Aid (Model: HY-12C, Manufacturer: Beijing Mail Chemical Technology Co., Ltd.), Wetting Dispersant (Model: HY-1608A, Manufacturer: Beijing Mail Chemical Technology Co., Ltd.), Defoamer (Model: HY-2253, Manufacturer: Beijing Mail Chemical Technology Co., Ltd.), Thickener (Model: HY-304, Manufacturer: Beijing Mail Chemical Technology Co., Ltd.), Antifreeze (Model: Ethylene Glycol, Manufacturer: Shandong Shengrun Chemical Co., Ltd.), Zinc Borate (Model: Superior, Manufacturer: Jiangyin Changjing Tonghe Chemical Co., Ltd.).

[0091] Table 1 Recipe

[0092]

[0093]

[0094] The formulations of Examples 1 to 3 and Comparative Examples 1 to 7 in Table 1 were prepared according to the following steps:

[0095] First, water-based alkyd resin, hammer-milled glass fiber, titanium dioxide (rutile type), ammonium polyphosphate (type II), pentaerythritol, melamine phosphate, hydrotalcite, magnesium hydroxide, aluminum hydroxide, SiO2, SiO2-Al2O3, Fe2O3, ZnO, film-forming aid, wetting dispersant, defoamer, thickener, antifreeze agent, and zinc borate are mixed to obtain a high-expansion fire-retardant coating; then, the high-expansion fire-retardant coating is applied to the outer surfaces of the box body and the main cabinet door of the distribution box respectively, and then a plurality of welding nails are welded to the three sides of the box body (9 on each side), and then the magnesium sulfate fireproof board is installed on the inner surface of the box body and the main cabinet door. The side is plugged and fixed with multiple low-expansion sealed fire-resistant caps, wherein the expansion multiple of the low-expansion sealed fire-resistant cap is 2, and the low-expansion sealed fire-resistant cap includes a cap body, a cap crown and a deformation limiting portion; and an expansion accommodating cavity is formed at one end of the cap body close to the metal plate; and the cap crown is flush with the inorganic high-temperature resistant fireproof board; then fireproof sealant is applied along the outer peripheral wall of the magnesium sulfate fireproof board to form a fireproof sealant layer; and the main cabinet door also includes a magnetic expansion fireproof sealing strip, which is spaced apart on one side of the fireproof sealant layer, and the magnetic expansion fireproof sealing strip is connected to the metal plate, and the magnetic expansion fireproof sealing strip is used to seal the opening of the closed accommodating cavity.

[0096] Comparative Example 8

[0097] The difference between Comparative Example 8 and Example 1 is that Comparative Example 8 is not provided with a fireproof sealant layer, and the rest remains unchanged.

[0098] Comparative Example 9

[0099] The difference between Comparative Example 9 and Example 1 is that Comparative Example 9 is not provided with a magnetic expansion fireproof sealing strip, and the rest remains unchanged.

[0100] The distribution boxes prepared in the above-mentioned Examples 1 to 3 and Comparative Examples 1 to 9 were tested for expansion multiple, fire resistance, waterproof performance, antibacterial and anticorrosive performance to obtain the experimental data in Table 2 below.

[0101] Expansion multiple test method: Inject the high expansion fire retardant coating into three steel containers with an inner diameter of 50mm in the middle and 50mm in the height. The injection height of the high expansion fire retardant coating is 3mm±1mm. Then, put the steel container into an electric heating blast drying oven at a temperature of 60C±5℃ and dry it for more than 48 hours. According to the use requirements of the product, it can also be dried in layers. The thickness of the test piece after drying is 3mm±1mm.

[0102] Use a steel ruler to measure the height of the sample before expansion. Then, place the steel container containing the sample in a resistance furnace at a temperature of 540℃±10℃ and take it out after keeping the temperature constant for 30 minutes. After sufficient cooling, measure the height of the sample after expansion (if the surface of the sample after expansion is uneven, test multiple points and take the average value). The ratio of the height of the sample after expansion to the height before expansion is the expansion multiple of the material. The expansion performance is expressed as the arithmetic mean of the expansion multiples of the three samples, accurate to the first decimal place.

[0103] Fireproof and thermal insulation performance testing method: refer to GB / T 9978-1 General requirements for fire resistance of building structures and "Standard For Safety Fire Tests of Penetration Firestops" UL1479-2021.

[0104] Testing method for waterproof performance: Test according to GB / T31815-2015.

[0105] Antibacterial and anticorrosive performance test method: According to GB / T 21866 Antibacterial coating (paint film) antibacterial property determination method and antibacterial effect regulation method.

[0106] Testing method for the connection strength between metal plate and high expansion fire retardant coating: Conduct according to the test method specified in GB / T 5210 pull-off adhesion test.

[0107] Table 2

[0108]

[0109]

[0110]

[0111]

[0112]

[0113] From the comparison between Examples 1 to 3 and Comparative Examples 1 to 7, it can be seen that since Examples 1 to 3 simultaneously use hammer-milled glass fiber, titanium dioxide (rutile type), hydrotalcite, magnesium hydroxide, aluminum hydroxide, SiO 2、 SiO2-Al2O 3、 Fe2O 3、The compound use of ZnO can play a good synergistic effect, thereby ensuring that Examples 1 to 3 still have good anti-corrosion and waterproof properties without using a waterproof coating, adding a preservative, and introducing a large number of hydrophilic groups; and ensuring that the distribution box can still maintain normal operation within 0.5-1.5 hours of flame combustion at 1000°C, so that the comprehensive indicators of Examples 1 to 3 are better than those of Comparative Examples 1 to 7, among which the comprehensive indicators of Example 1 are the best.

[0114] From the comparison between Example 1 and Comparative Example 8, it can be seen that since Comparative Example 8 does not use a fireproof sealant layer, the comprehensive indicators of Comparative Example 8 are worse than those of Example 1.

[0115] From the comparison between Example 1 and Comparative Example 9, it can be seen that since Comparative Example 9 does not use the magnetic expansion fireproof sealing strip, the comprehensive indicators of Comparative Example 9 are worse than those of Example 1.

[0116] The above embodiments only express several implementation methods of the present disclosure, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the disclosed patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present disclosure, and these all belong to the protection scope of the present disclosure. Therefore, the protection scope of the disclosed patent shall be subject to the attached claims.

Claims

1. A high expansion, non-deformable, fire-resistant and heat-insulating composite fireproof structure, comprising a high expansion fireproof coating, a metal plate and an inorganic high temperature resistant fireproof plate stacked in sequence from the outside to the inside, characterized in that: The high expansion fire retardant coating comprises the following mass components:

2. The high expansion, non-deformable, fire-resistant and heat-insulating composite fireproof structure according to claim 1, characterized in that: The inorganic high temperature resistant fireproof board is at least one of a magnesium sulfate fireproof board and a silicate fireproof board.

3. The high expansion, non-deformable, fire-resistant and heat-insulating composite fireproof structure according to claim 1, characterized in that: The hammer-milled glass fiber has a diameter of 10um to 20um and a length of 0.01 to 1.0mm; and / or; The hammer-milled glass fiber is used in an amount of 0.5-3 parts by weight.

4. The high expansion, non-deformable, fire-resistant and heat-insulating composite fireproof structure according to claim 1, characterized in that: The inorganic modified filler is also selected from at least one of titanium dioxide, kaolin and attapulgite.

5. The high expansion, non-deformable, fire-resistant and heat-insulating composite fireproof structure according to claim 1, characterized in that: The high expansion flame retardant comprises at least one of ammonium polyphosphate (type II), pentaerythritol and melamine phosphate; and / or; The inorganic flame retardant includes at least one of hydrotalcite, aluminum sulfate, magnesium hydroxide and aluminum hydroxide; and / or, The expansion rate of the high expansion fireproof coating is 40 to 50 times.

6. The high expansion, non-deformable, fire-resistant and heat-insulating composite fireproof structure according to claim 1, characterized in that: The thickness of the high expansion fireproof coating is 800um to 2000um.

7. The high expansion, non-deformable, fire-resistant and heat-insulating composite fireproof structure according to claim 1, characterized in that: The nano-SiO2-Al2O3 porous composite heat insulating agent is a mixture of SiO2 and SiO2-Al2O3.

8. The high expansion, non-deformable, fire-resistant and heat-insulating composite fireproof structure according to claim 1, characterized in that: The high expansion fireproof coating also includes 1-5 parts of auxiliary agent and 1-5 parts of smoke suppressant.

9. The high expansion, non-deformable, fire-resistant and heat-insulating composite fireproof structure according to claim 1, characterized in that: The inorganic high temperature resistant fireproof board is connected to the metal plate through welding nails.

10. A distribution box, characterized in that: A composite fireproof structure comprising the high expansion, non-deformable, fire-resistant and heat-insulating structure according to any one of claims 1 to 9.

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