Fireproof and explosion-proof integrated coating for substation / converter station plugging and preparation method thereof

Abstract

The application discloses a fireproof and explosion-proof integrated coating for plugging of a transformer substation / conversion station and a preparation method thereof, and relates to the field of coatings.The coating paint comprises the following components in parts by weight: polyurea resin: 5-8 parts; graphene tube: 0.5-3 parts; nano tin antimony oxide: 0.5-5 parts; nano silicon dioxide: 20-30 parts; vermiculite powder: 30-50 parts; water glass: 20-40 parts.The application solves the problems that current organic coatings are not fireproof and inorganic coatings are prone to cracking and not explosion-proof, adopts an organic-inorganic two-component curing system to improve the fireproof and explosion-proof functions, the nano-level particles can reduce the heat conduction of the material, improve the fireproof grade, the vermiculite powder has a cavity structure, the solid heat conduction is relatively weak, and the vermiculite powder has an energy absorption and explosion prevention effect, and the coating is used for the plugging system of the conversion station, so that the problems of great construction and maintenance difficulty and long cycle of the conversion station can be effectively solved.

Description

Technical Field

[0001] This invention relates to the field of coatings, and more particularly to an integrated fireproof and explosion-proof coating for sealing substations / converter stations and its preparation method. Background Technology

[0002] Converter stations are the core of ultra-high voltage direct current (UHVDC) projects, enabling AC-DC conversion. Their operational reliability directly impacts personnel and equipment safety, as well as the stable operation of the power grid. The insulating oil in the converter transformer tank can exceed 100 tons. If a fault arc causes a fire or even an explosion, it can damage the valve hall's fireproof sealing system, allowing the fire to spread inside the valve hall and causing incalculable economic losses and social impact. Substations are locations in power systems that transform voltage and current, receiving and distributing electrical energy. Substations within power plants are step-up substations, responsible for boosting the voltage of electricity generated by generators before feeding it into the high-voltage power grid. They are the hub of the entire transmission and transformation system, playing a crucial role in connecting upstream and downstream systems. Because substations often operate under high voltage and high current, they have a high fire risk and require fire prevention measures.

[0003] Following the Tianshan fire in 2018, the State Grid Corporation of China initiated a fire protection upgrade plan, dismantling the existing converter station sealing system and installing explosion-proof doors with a dynamic load of no less than 80 kPa. This improved the safety margin of the converter transformers to some extent, but also significantly increased the construction period and maintenance difficulty. Furthermore, the separation of fire protection and explosion-proof design made construction and replacement complex, leading to extended maintenance cycles. Taking a ±800kV / 8GW UHV converter station as an example, the separation of fire protection and explosion-proof design can extend the maintenance cycle by 3-4 days. Preliminary estimates suggest that if a ±800kV / 8GW UHV converter station operates at half power, a one-day power outage would result in an economic loss of up to 9.6 million yuan.

[0004] Meanwhile, fire prevention measures in substations mainly include the installation of fire doors. These doors serve to block fires, provide escape routes, and act as smoke barriers. However, current substation fire doors focus on improving fire resistance, but their explosion-proof capabilities are limited and cannot simultaneously meet the integrated fire-resistant and explosion-proof performance requirements for substation sealing.

[0005] Therefore, there is an urgent need to develop an integrated fireproof and explosion-proof coating for power line sealing, which can not only improve the fire protection of substations / converter stations, but also avoid the material waste caused by dismantling the sealing, and at the same time significantly reduce the economic losses caused by power outages. Summary of the Invention

[0006] This invention provides an integrated fireproof and explosion-proof coating for substation / converter station sealing and its preparation method. To reduce the cost of converter station renovation and improve the fire resistance and explosion-proof function of the protective doors of the substation / converter station sealing system, an organic-inorganic two-component curing system is adopted to achieve excellent fire resistance and explosion-proof capabilities of the coating. Fire resistance and explosion-proof design are implemented simultaneously, improving construction efficiency.

[0007] To address the aforementioned technical problems, one objective of this invention is to provide an integrated fireproof and explosion-proof coating for sealing substations / converter stations, comprising the following components by weight:

[0008] Polyurea resin: 5-8 parts;

[0009] Graphene tubes: 0.5-3 parts;

[0010] Nano-sized antimony tin oxide: 0.5-5 parts;

[0011] Nano silica: 20-30 parts;

[0012] Vermiculite powder: 30-50 parts;

[0013] Water glass: 20-40 parts.

[0014] Through numerous experiments and studies, the inventors of this application discovered that by simultaneously adding polyurea resin as an organic component, water glass as an inorganic curing agent and crosslinking agent, and nano-silica as an inorganic thickener, an organic-inorganic two-component curing system solves the current problems of organic coatings being unfire-resistant and inorganic coatings being prone to cracking and not explosion-proof. Simultaneously, nano-level silica reduces the material's heat transfer, lowers the thermal conductivity, and improves the fire resistance rating. High-refractive-index nano-tin antimony oxide can effectively block infrared radiation, enhancing the coating's fire resistance. Furthermore, the antireflective mechanism of nano-tin antimony oxide promotes particle uniformity in the coating, improving its impact resistance. In addition, vermiculite powder, with its structure containing vermiculite flakes and hollow particles, has a small contact area between solids and relatively weak solid-state thermal conductivity. This allows it to store heat and reduce the material's thermal conductivity. Utilizing graphene tubes to enhance the strength of vermiculite powder and promote impact energy absorption, when applied to fireproofing and explosion-proofing for substation / converter station sealing, it combines fire resistance and impact resistance, exhibiting excellent explosion-proof performance.

[0015] As a preferred embodiment, the polyurea resin is an aqueous aspartic polyurea resin.

[0016] As a preferred embodiment, the viscosity of the polyurea resin is 400-1500 mPas. The polyurea resin can be used as a dispersant for inorganic components, as a carrier for nanomaterials, to improve bonding strength, prevent coating cracking, and improve impact resistance.

[0017] As a preferred embodiment, the viscosity of the polyurea resin is any one or any two of the following: 400 mPas, 500 mPas, 600 mPas, 700 mPas, 800 mPas, 900 mPas, 1000 mPas, 1100 mPas, 1200 mPas, 1300 mPas, 1400 mPas, and 1500 mPas.

[0018] As a preferred embodiment, the viscosity of the polyurea resin is 1000-1300 mPas. Within this viscosity range, the bonding strength of the organic-inorganic curing system can be satisfied, maximizing the impact resistance and crack resistance of the coating. At the same time, the required amount of added organic components is small, which can avoid the organic components affecting the fire resistance rating of the coating, thus achieving a balance.

[0019] As a preferred embodiment, the nano-silica has a particle size of 10-100 nm and a purity of ≥93%.

[0020] Nano silica is mainly used as an inorganic thickener. Compared with organic thickeners, it can significantly improve the fire resistance of the coating. Moreover, nano silica is a nanoparticle, which can reduce the heat conduction of the material and reduce the thermal conductivity. Nano silica accounts for a relatively high proportion in the coating. By controlling the particle size of nano silica within the above range, it is possible to avoid the particle size being too large and having a high thermal conductivity, while avoiding the particle size being too small and causing agglomeration, which would increase the thermal conductivity.

[0021] As a preferred embodiment, the particle size of the nano-silica is any one or a combination of 10nm, 15nm, 20nm, 25nm, 30nm, 35nm, 40nm, 45nm, 50nm, 55nm, 60nm, 65nm, 75nm, 80nm, 85nm, and 90nm.

[0022] As a preferred embodiment, the particle size of the nano-silica is 40-80 nm, and the purity is preferably ≥95.5%.

[0023] As a preferred embodiment, the nano-tin antimony oxide has a particle size of 20-80 nm and a purity of ≥99%. The nano-tin antimony oxide has high transmittance in the visible light region and high blocking rate in the infrared light region, which can increase the transparency of the coating and block infrared light at high temperatures, thereby improving the aesthetics and fire resistance of the coating.

[0024] As a preferred embodiment, the particle size of the nano-tin antimony oxide is any one or any two of the following: 20nm, 25nm, 30nm, 35nm, 40nm, 45nm, 50nm, 55nm, 60nm, 65nm, 70nm, 75nm, and 80nm.

[0025] As a preferred embodiment, the particle size of the nano-tin antimony oxide is 50-70 nm, and the purity is preferably ≥99.5%.

[0026] As a preferred embodiment, the graphene tube has a specific surface area of ​​1000-1500 m². 2 / g, graphene tubes typically consist of a two-dimensional honeycomb crystal structure composed of single or multiple layers of graphene, primarily serving to enhance the strength of vermiculite powder and absorb impact energy. Graphene tubes are micro / nanomaterials; if the specific surface area is too high, strong adsorption between particles can lead to agglomeration, affecting the mechanical strength of the coating. Conversely, if the specific surface area is too small, the increased contact area between particles and other materials increases thermal conductivity, negatively impacting the material's refractory properties. Controlling the specific surface area within the aforementioned range improves the dispersion of graphene tubes while simultaneously reducing thermal conductivity and improving the refractory rating.

[0027] As a preferred embodiment, the graphene tube has a specific surface area of ​​1000 m². 2 / g, 1050m 2 / g、1100m 2 / g、1150m 2 / g、1200m 2 / g、1250m 2 / g、1300m 2 / g, 1350m 2 / g, 1400m 2 / g, 1450m 2 / g, 1500m 2 The range of one or both of the values ​​in / g.

[0028] As a preferred embodiment, the graphene tube has a specific surface area of ​​1100-1300 m². 2 / g.

[0029] As a preferred embodiment, the vermiculite powder is obtained by thermally expanding and grinding vermiculite flakes at 400-600 ℃.

[0030] As a preferred embodiment, the vermiculite powder has a particle size of 0.1-1 mm and a loose bulk density of 200-250 kg / m³. 3 .

[0031] As a preferred embodiment, the particle size of the vermiculite powder is any one or any two of the following: 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, and 1mm.

[0032] As a preferred embodiment, the vermiculite powder has a particle size of 0.4-0.6 mm and a loose bulk density of 220-240 kg / m³.3 .

[0033] As a preferred embodiment, the mass ratio of the nano-silica, vermiculite powder and water glass is 30:(35-75):(25-30).

[0034] In this application, water glass is used as an inorganic curing agent and crosslinking agent, which plays an important role in the stability of the entire component system. Nano-silica is used to provide thickening and reduce thermal conductivity, while vermiculite powder provides strength and reduces thermal conductivity. By controlling the ratio range of the three, the flame retardant and fire-resistant properties of the coating can be effectively improved, while also improving the strength of the coating. The structure is tightly bonded and has excellent explosion-proof properties.

[0035] As a preferred embodiment, the mass ratio of the nano-silica, vermiculite powder, and water glass is 5:9:5.

[0036] As a preferred embodiment, the modulus of the water glass is 1.5-3.5.

[0037] As a preferred embodiment, the modulus of the water glass is any one or any two of the following: 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3, 3.1, 3.2, 3.3, 3.4, and 3.5.

[0038] As a preferred embodiment, the modulus of the water glass is 3.2-3.4.

[0039] As a preferred embodiment, the coating material comprises the following components in parts by weight:

[0040] Polyurea resin: 5-7 parts;

[0041] Graphene tubes: 1-3 parts;

[0042] Nano-sized antimony tin oxide: 1-3 parts;

[0043] Inorganic thickener: 22-28 parts;

[0044] Vermiculite powder: 42-48 parts;

[0045] Water glass: 22-28 parts.

[0046] To address the aforementioned technical problems, a second objective of this invention is to provide a method for preparing an integrated fireproof and explosion-proof coating for substation / converter station sealing, comprising the following steps:

[0047] S1. Stir and mix the graphene tube and nano-tin antimony oxide evenly to obtain a mixed filler;

[0048] S2. Mix the mixed filler with polyurea resin evenly, react and freeze dry to obtain polyurea resin modified aerogel;

[0049] S3. Mix vermiculite powder and nano-silica evenly, then dissolve them in water glass and stir to form a stable suspension;

[0050] S4. Stir and mix the aerogel and suspension evenly to obtain the coating material.

[0051] As a preferred embodiment, in S1, the stirring rate is 300-1000 rpm and the stirring time is 2-4 min.

[0052] As a preferred option, in S2, the reaction temperature is 40-100 ℃ and the reaction time is 6-18 h.

[0053] As a preferred option, in S4, the stirring rate is 200-500 rpm and the stirring time is 12-48 h.

[0054] To solve the above-mentioned technical problems, the third objective of this invention is to provide a fireproof and explosion-proof door for sealing substations / converter stations, comprising a plate and an integrated fireproof and explosion-proof coating on the surface of the plate, wherein the integrated fireproof and explosion-proof coating is prepared using the aforementioned integrated fireproof and explosion-proof coating material for sealing substations / converter stations.

[0055] As a preferred embodiment, the thickness of the fireproof and explosion-proof integrated coating is 15-20mm, and the thickness of the plate is 20-30mm.

[0056] Compared with the prior art, the present invention has the following beneficial effects:

[0057] 1. This application solves the current problems of organic coatings being unfire-resistant and inorganic coatings being prone to cracking and not explosion-proof by simultaneously adding polyurea resin as an organic component, water glass as an inorganic curing agent and crosslinking agent, and nano-silica as an inorganic thickener. The organic-inorganic two-component curing system improves both fire resistance and impact resistance. At the same time, the nano-level silica reduces the heat conduction of the material and lowers the thermal conductivity. The added vermiculite powder has a structure containing vermiculite flakes and hollow particles, which has relatively weak solid heat conduction, further improving the fire resistance rating.

[0058] 2. The addition of high-refractive-index nano-tin antimony oxide to the coating material of this application can effectively block infrared radiation and improve the fire resistance of the coating. Furthermore, the antireflective mechanism of nano-tin antimony oxide can promote the uniformity of particles in the coating and improve the impact resistance of the coating.

[0059] 3. The vermiculite powder added in this application has a hollow particle structure, which has the functions of energy absorption and reducing thermal conductivity. The graphene tube is used to enhance the strength of the vermiculite powder and promote its impact energy absorption, which can improve both fire resistance and impact resistance.

[0060] 4. The preparation method of the present invention is simple and quick to operate. The composite protective coating material obtained therefrom can be used in the sealing system of substations / converter stations, which can effectively solve the problems of high construction and maintenance difficulty and long cycle. Detailed Implementation

[0061] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0062] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any stated value or intermediate value within a stated range, as well as each smaller range between any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0063] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0064] As used in this article:

[0065] "Prepared from" is synonymous with "comprising". The terms "comprising", "including", "having", "containing", or any other variations thereof as used herein are intended to cover non-exclusive inclusion. For example, a composition, step, method, article, or apparatus that includes the listed elements is not necessarily limited to those elements, but may include other elements not expressly listed or elements inherent to such composition, step, method, article, or apparatus.

[0066] The conjunction "composed of..." excludes any unspecified elements, steps, or components. If used in a claim, this phrase makes the claim closed, excluding materials other than those described, except for associated conventional impurities. When the phrase "composed of..." appears in a clause of the body of a claim rather than immediately following it, it limits only the elements described in that clause; other elements are not excluded from the claim as a whole.

[0067] In these embodiments, unless otherwise specified, the portions and percentages are all by weight.

[0068] "Parts by mass" refers to the basic unit of measurement that expresses the proportional relationship of the mass of multiple components. One part can represent any unit mass. It is important to understand that, unlike the number of parts by mass, the sum of the parts by mass of all components is not limited to 100 parts.

[0069] "And / or" is used to indicate that one or both of the described situations may occur, for example, A and / or B includes (A and B) and (A or B).

[0070] In the description of this invention, it should be understood that the terms "upper", "lower", "left", "right", "top", "bottom", etc., indicating orientation or positional relationship are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0071] To further illustrate the present invention, the following detailed description is provided in conjunction with embodiments, but these should not be construed as limiting the scope of protection of the present invention. Table 1 below shows the source information of the raw materials used in the embodiments and comparative examples of this application. Unless otherwise specified, all raw materials used are commercially available, and the same raw materials were used in parallel experiments.

[0072] Table 1 - Source information of raw materials used in the embodiments and comparative examples of this application

[0073]

[0074] Example 1

[0075] A fireproof and explosion-proof integrated coating for sealing substations / converter stations comprises 2 kg of graphene tube, 6 kg of waterborne aspartic polyurea resin, 2 kg of nano-tin antimony oxide, 25 kg of nano-silica, 45 kg of vermiculite flakes, and 25 kg of water glass, wherein the graphene tube has a specific surface area of ​​1250 m². 2The nano-silica has a particle size of 75 nm and a purity of 97%, the water-based aspartic polyurea has a viscosity of 1100 mPas, the nano-tin antimony oxide has a particle size of 60 nm and a purity ≥99%, and the water glass has a modulus of 3.3. The preparation method includes the following steps:

[0076] S1. Mix the graphene tube and nano-tin antimony oxide evenly, and stir for 3 minutes using a high-speed mixer at a stirring speed of 500 rpm to obtain the mixed filler.

[0077] S2. Mix the mixed filler with the aqueous aspartic polyurea resin solution evenly, react at 60 °C for 12 h, and freeze-dry to obtain polyurea resin modified aerogel.

[0078] S3. Vermiculite flakes are thermally expanded at 500 ℃ and then ground to obtain vermiculite powder with a particle size of 0.5 mm and a bulk density of 220 kg / m³. 3 The powder is mixed evenly with nano-silica, dissolved in water glass, and stirred to form a stable suspension.

[0079] S4. Place the aerogel and suspension in a magnetic stirrer and mix them. Stir at 300 r / min for 24 h to ensure they are fully dissolved and homogeneous, thus obtaining the coating material.

[0080] Example 2

[0081] A fireproof and explosion-proof integrated coating for sealing substations / converter stations is prepared using the same reagents, equipment, and process parameters as in Example 1. The difference lies in that the coating comprises 1 kg of graphene tube, 5 kg of waterborne aspartic polyurea resin, 1 kg of nano-tin antimony oxide, 20 kg of nano-silica, 30 kg of vermiculite flakes, and 20 kg of water glass. The graphene tube has a specific surface area of ​​1250 m². 2 / g, nano-silica with a particle size of 75 nm and a purity of ≥95.5%, waterborne aspartic polyurea with a viscosity of 1100 mPas, nano-tin antimony oxide with a particle size of 60 nm and a purity of ≥99%, and water glass with a modulus of 3.3.

[0082] Example 3

[0083] A fireproof and explosion-proof integrated coating for sealing substations / converter stations is prepared using the same reagents, equipment, and process parameters as in Example 1. The difference lies in that the coating comprises 3 kg of graphene tube, 8 kg of waterborne aspartic polyurea resin, 4 kg of nano-tin antimony oxide, 30 kg of nano-silica, 50 kg of vermiculite flakes, and 40 kg of water glass. The graphene tube has a specific surface area of ​​1250 m². 2 / g, nano-silica with a particle size of 75 nm and a purity of ≥95.5%, waterborne aspartic polyurea with a viscosity of 1100 mPas, nano-tin antimony oxide with a particle size of 60 nm and a purity of ≥99%, and water glass with a modulus of 3.3.

[0084] Example 4

[0085] A fireproof and explosion-proof integrated coating for sealing substations / converter stations is prepared using the same reagents, equipment, and process parameters as in Example 1, except that the graphene tube has a specific surface area of ​​1500 m². 2 / g.

[0086] Example 5

[0087] A fireproof and explosion-proof integrated coating for sealing substations / converter stations is prepared using the same reagents, equipment, and process parameters as in Example 1, except that the particle size of the nano-silica is 100 nm.

[0088] Example 6

[0089] A fireproof and explosion-proof integrated coating for sealing substations / converter stations is prepared using the same reagents, equipment, and process parameters as in Example 1. The difference is that the coating contains 30 kg of nano-silica, 35 kg of vermiculite flakes, and 25 kg of water glass.

[0090] Example 7

[0091] A fireproof and explosion-proof integrated coating for sealing substations / converter stations is prepared using the same reagents, equipment, and process parameters as in Example 1. The difference is that the coating contains 20 kg of nano-silica, 50 kg of vermiculite flakes, and 20 kg of water glass.

[0092] Comparative Example 1

[0093] A fireproof and explosion-proof integrated coating for sealing substations / converter stations is prepared using the same reagents, equipment, and process parameters as in Example 1, except that the amount of graphene tube added is 0.

[0094] Comparative Example 2

[0095] A fireproof and explosion-proof integrated coating for sealing substations / converter stations is prepared using the same reagents, equipment, and process parameters as in Example 1. The difference is that the amount of nano-tin antimony oxide added to the coating is 0.

[0096] Comparative Example 3

[0097] A fireproof and explosion-proof integrated coating for sealing substations / converter stations is prepared using the same reagents, equipment, and process parameters as in Example 1. The difference is that the coating contains 30 kg of nano-silica, 25 kg of vermiculite flakes, and 35 kg of water glass.

[0098] Comparative Example 4

[0099] A fireproof and explosion-proof integrated coating for sealing substations / converter stations is prepared using the same reagents, equipment, and process parameters as in Example 1. The difference is that the coating contains 40 kg of nano-silica, 25 kg of vermiculite flakes, and 25 kg of water glass.

[0100] Comparative Example 5

[0101] A fireproof and explosion-proof integrated coating for sealing substations / converter stations is prepared using the same reagents, equipment, and process parameters as in Example 1. The difference is that the vermiculite powder in S3 is replaced by an equal amount of mica with a particle size of 0.5 mm.

[0102] Comparative Example 6

[0103] A fireproof and explosion-proof integrated coating for sealing substations / converter stations is prepared using the same reagents, equipment, and process parameters as in Example 1. The difference is that vermiculite powder in S3 is replaced by an equal amount of nano-silica.

[0104] Comparative Example 7

[0105] A fireproof and explosion-proof integrated coating for sealing substations / converter stations is prepared using the same reagents, equipment, and process parameters as in Example 1. The difference is that the water-based aspartic polyurea resin in the coating is replaced by an equal amount of acrylic resin.

[0106] Comparative Example 8

[0107] A fireproof and explosion-proof integrated coating for sealing substations / converter stations is prepared using the same reagents, equipment, and process parameters as in Example 1. The difference is that the amount of waterborne aspartic polyurea resin added to the coating is 0.

[0108] Comparative Example 9

[0109] A fireproof and explosion-proof integrated coating for sealing substations / converter stations is prepared using the same reagents, equipment, and process parameters as in Example 1. The difference is that the graphene tube is replaced by an equal amount of nano-tin antimony oxide.

[0110] Comparative Example 10

[0111] A fireproof and explosion-proof integrated coating for sealing substations / converter stations is prepared using the same reagents, equipment, and process parameters as in Example 1. The difference is that nano-tin antimony oxide is replaced by an equal amount of graphene tube.

[0112] Performance testing

[0113] 1. Fire resistance performance: The coatings prepared in the above examples and comparative examples were applied to the surface of a 25mm thick board using a brush method, with the coating thickness controlled at 15mm. The board was then left in the air for 48 hours to ensure complete drying. Meanwhile, boards coated with the same thickness as commercially available sample 1 and sample 2 were used as control groups. The fire resistance limit of the board was tested according to the method described in GB 23864-2023 "Fireproof Sealing Materials". The test results are shown in Table 2 below.

[0114] 2. Explosion resistance: The impact strength of the above-mentioned coated panels with the examples and comparative examples was tested according to Q / IEM 3003.39-2011 "Test method for explosion resistance and venting performance of doors and windows". The test results are shown in Table 2 below.

[0115] Table 2 - Performance test results of the substrates containing the coatings of the embodiments and comparative examples of this application.

[0116]

[0117] As shown in Table 2, the graphene tubes with a two-dimensional honeycomb crystal structure added in Example 1 of this application can enhance the strength of vermiculite powder and improve its impact energy absorption, thereby increasing the impact resistance of the coating and exhibiting excellent explosion-proof performance. In contrast, Comparative Example 1 did not add graphene tubes, resulting in a 33% decrease in the impact resistance of the coating and poor explosion-proof capability. Comparative Example 9 used nano-tin antimony oxide instead of graphene tubes, leading to a decrease in the impact resistance of the coating and insufficient explosion-proof capability.

[0118] As shown in Table 2, in Example 1 of this application, nano-tin antimony oxide was added. Nano-tin antimony oxide has high transmittance in the visible light region and high blocking rate in the infrared light region, thus increasing the coating's transparency and providing infrared blocking at high temperatures, thereby improving the coating's fire resistance. In contrast, the coating in Comparative Example 2 did not contain nano-tin antimony oxide, resulting in a reduced fire resistance limit and decreased fire resistance. In Comparative Example 10, nano-tin antimony oxide was replaced with graphene tubes, and the coating could not effectively block infrared light under high-temperature conditions, significantly reducing its fire resistance.

[0119] As shown in Table 2, in Examples 1 and 6-7 of this application, the ratio of nano-silica, vermiculite powder, and water glass in the suspension is controlled to be 30:(35-75):(25-30). Water glass provides curing and cross-linking effects, nano-silica reduces thermal conductivity while providing thickening effect, ensuring uniform particle size in the system, and vermiculite powder further reduces thermal conductivity and has energy absorption and strength enhancement effects. By controlling the ratio of the three components within the above range, the fire resistance and impact resistance properties can be balanced. However, in Comparative Example 3, the proportion of vermiculite flakes is too low, resulting in a decrease in the fire resistance rating of the coating. In Comparative Example 4, the proportion of nano-silica is too high while the proportion of vermiculite powder is too low, resulting in a decrease in both the fire resistance and impact resistance of the coating.

[0120] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. In particular, it should be noted that any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention for those skilled in the art.

Claims

1. A fireproof and explosion-proof door for sealing off substations / converter stations, characterized in that, The product includes a sheet material and an integrated fire-resistant and explosion-proof coating on the surface of the sheet material. The integrated fire-resistant and explosion-proof coating is prepared using a fire-resistant and explosion-proof integrated coating material for substation / converter station sealing, and the thickness of the integrated fire-resistant and explosion-proof coating is 15-20 mm. The fire-resistant and explosion-proof integrated coating material for substation / converter station sealing comprises the following components in parts by weight: Polyurea resin: 5-8 parts; Graphene tubes: 0.5-3 parts; Nano-sized antimony tin oxide: 0.5-5 parts; Nano silica: 20-30 parts; Vermiculite powder: 30-50 parts; Water glass: 20-40 parts; The polyurea resin is a water-based aspartic polyurea resin with a viscosity of 400-1500 mPa·s; the vermiculite powder is obtained by thermally expanding and grinding vermiculite flakes at 500℃, with a particle size of 0.1-1 mm and a bulk density of 200-250 kg / m³. 3 The mass ratio of the nano-silica, vermiculite powder, and water glass is 30:54:30; the specific surface area of ​​the graphene tube is 1000-1250 m². 2 / g; The nano-tin antimony oxide has a particle size of 20-80 nm and a purity of ≥99%. The nano-silica has a particle size of 10-100 nm and a purity of ≥93%. The modulus of the water glass is 1.5-3.

5.

2. A method for preparing an integrated fireproof and explosion-proof coating for substation / converter station sealing as described in claim 1, characterized in that, Includes the following steps: S1. Stir and mix the graphene tube and nano-tin antimony oxide evenly to obtain a mixed filler; S2. Mix the mixed filler with polyurea resin evenly, react and freeze dry to obtain polyurea resin modified aerogel; S3. Mix vermiculite powder and nano-silica evenly, then dissolve them in water glass and stir to form a stable suspension; S4. Stir and mix the aerogel and suspension evenly to obtain the coating material.

3. The preparation method of the fireproof and explosion-proof integrated coating for substation / converter station sealing as described in claim 2, characterized in that, In S1, the stirring speed is 300-1000 rpm and the stirring time is 2-4 min; And / or, in S2, the reaction temperature is 40-100℃ and the reaction time is 6-18h; And / or, in S4, the stirring rate is 200-500 rpm and the stirring time is 12-48 h.

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