Fireproof and antiknock sandwich panel for transformer substation and preparation method of fireproof and antiknock sandwich panel

Abstract

The invention belongs to the field of building materials, and particularly relates to a fireproof anti-explosion sandwich panel for a transformer substation and a preparation method of the fireproof anti-explosion sandwich panel. According to the technical scheme, the fireproof and antiknock sandwich panel for the transformer substation comprises a concave hexagonal honeycomb structure steel plate and hydrated magnesium silicate cement concrete panels, the concave hexagonal honeycomb structure steel plate serves as a sandwich layer, and the hydrated magnesium silicate cement concrete panels are fixedly arranged on the two sides of the concave hexagonal honeycomb structure steel plate to form the sandwich panel. According to the fireproof and antiknock sandwich panel for the transformer substation and the preparation method of the fireproof and antiknock sandwich panel, the fireproof performance, the antiknock performance, the electromagnetic interference shielding performance and the overall performance after explosion impact of the sandwich panel can be improved, the bonding strength of a steel core and a concrete interface is enhanced, it is ensured that complex holes of a honeycomb structure are evenly filled with concrete, the integrity of the sandwich panel is improved, and the service life of the sandwich panel is prolonged. And the engineering requirements of transformer substations with relatively high fireproof and anti-explosion levels are met.

Description

Technical Field

[0001] This invention belongs to the field of building materials, specifically relating to a fireproof and explosion-proof sandwich panel for substations and its preparation method. Background Technology

[0002] In the field of substation construction, ordinary concrete and metal sheets, as widely used enclosure structural materials, have provided crucial support for the safe and stable operation of power facilities for many years, thanks to their mature application technology system accumulated through long-term practice and their stable guarantee of basic performance such as structural strength and durability. For a long time, these materials have played an irreplaceable role in key parts of substations such as walls and partitions, effectively meeting the structural protection requirements under normal operating conditions.

[0003] However, as the core hub of the power system, the substation has a significant characteristic of high safety requirements in its operating environment. It not only needs to resist fire, but also needs to cope with the impact of explosions and interference from complex electromagnetic environments. This puts forward multiple stringent requirements on the building envelope materials, such as excellent fire resistance, strong explosion resistance, and high electromagnetic shielding effectiveness.

[0004] Existing fireproof and explosion-proof panels mostly use concrete and metal sandwich panels as their main base materials. Specifically, traditional concrete panels are prone to cracking under high-temperature environments due to the rapid evaporation of internal moisture, and their fire resistance limit is usually difficult to reach 2 hours, which is insufficient to meet the long-term protection requirements of substations in the event of a fire. At the same time, under the action of explosive impact loads, the concrete layer and the core layer are prone to surface peeling due to insufficient bonding strength, leading to the overall failure of the component and failing to effectively resist impact damage. In addition, the electromagnetic shielding effectiveness of existing explosion-proof panels is mostly below 45dB, which is insufficient to block the radiation and interference of strong electromagnetic fields in substations and fails to meet their specific electromagnetic protection requirements. Summary of the Invention

[0005] This invention provides a fireproof and explosion-proof sandwich panel for substations and its preparation method, which can improve the fire resistance, explosion resistance, electromagnetic interference shielding performance, and overall performance after explosion impact of the sandwich panel, enhance the bonding strength between the steel core and the concrete interface, ensure that the concrete uniformly fills the complex pores of the honeycomb structure, improve the integrity of the sandwich panel, and meet the needs of substation projects with higher fire and explosion resistance levels.

[0006] The technical solution of the present invention is as follows:

[0007] A fireproof and explosion-proof sandwich panel for substations includes a concave hexagonal honeycomb structure steel plate and a hydrated magnesium silicate cement concrete panel. The concave hexagonal honeycomb structure steel plate serves as the core layer, and the hydrated magnesium silicate cement concrete panel is fixedly installed on both sides of the concave hexagonal honeycomb structure steel plate to form a sandwich panel.

[0008] Furthermore, the fireproof and explosion-proof sandwich panel for substations is composed of concave hexagonal honeycomb steel plates made up of cells. Each cell is a strip-shaped hollow structure with a concave hexagonal cross-section. Each cell includes two end faces and four inclined faces, with an angle of 45° between the end faces and the inclined faces. The two end faces and the four inclined faces form a concave hexagon. Multiple cells are joined together through their respective end faces to form a cell column, and the cell columns are joined together through their respective inclined faces to extend laterally to form a concave hexagonal honeycomb steel plate.

[0009] Furthermore, in the fireproof and explosion-proof sandwich panel for substations, the cell has a wall thickness of 0.8-3mm, a height of 10-30mm, and a width of 15-35mm.

[0010] Furthermore, in the fireproof and explosion-proof sandwich panel for substations, the nodes between the end face and the inclined surface are rounded with a radius of 0.5-2mm.

[0011] Furthermore, the fireproof and explosion-proof sandwich panel for substations is made of hot-dip galvanized low-carbon steel sheet using a stamping process.

[0012] Furthermore, the fireproof and explosion-proof sandwich panel for substations, the hydrated magnesium silicate cement concrete panel comprises: 100-120 parts of lightly calcined active magnesium oxide powder, 150-180 parts of silica fume, 225 parts of quartz sand, 125-150 parts of water, 15-25 parts of polyethylene fiber, 5-10 parts of sodium hexametaphosphate, and 0.8-1.2 parts of polymer superplasticizer.

[0013] The preparation method of the above-mentioned fireproof and explosion-proof sandwich panel for substations includes the following steps:

[0014] 1) Spray silane coupling agent onto the surface of the concave hexagonal honeycomb structure steel plate, and form a bonding transition layer of 0.1-0.3mm thickness by electrostatic spraying;

[0015] 2) Place the sprayed concave hexagonal honeycomb structure steel plate into the mold, and inject hydrated magnesium silicate cement concrete using a double-sided synchronous high-pressure pouring method, while applying a vacuum pressure of -0.08 to -0.1 MPa and maintaining it for 15-20 minutes.

[0016] 3) Curing at 50-60℃ for 24 hours.

[0017] Furthermore, in the preparation method of the fireproof and explosion-proof sandwich panel for substations, in step 1), the silane coupling agent is γ-aminopropyltriethoxysilane, which is prepared by hydrolysis in an aqueous ethanol solution with a concentration of 1%-1.5%, the hydrolysis temperature is 55-65℃, the hydrolysis time is 30-50 minutes, and the pH value is adjusted to 4-5.

[0018] Furthermore, in the method for preparing the fireproof and explosion-proof sandwich panel for substations, in step 2), the high-pressure pouring pressure is 3-6 MPa, the concrete pouring speed is 6-12 L / min, and auxiliary vibration with a vibration frequency of 20-30 Hz is used during the pouring process.

[0019] Furthermore, in the preparation method of the fireproof and explosion-proof sandwich panel for substations, in step 2), the preparation process of hydrated magnesium silicate cement concrete is as follows: lightly calcined active magnesium oxide powder is calcined at 820℃ for 2.5 hours, and then processed to a particle size ≤5μm by an air jet mill; quartz sand is magnetically separated to remove iron, screened to obtain 100-mesh particles, and then soaked in 5% hydrochloric acid solution for 2 hours, and rinsed with distilled water until neutral; the surface of polyethylene fiber is plasma treated for 45 seconds to introduce hydroxyl functional groups, and the fiber aspect ratio is 900; nano-silica is modified with silane coupling agent KH-550, and the amount of modifier is 4% of the mass of nano-silica.

[0020] The beneficial effects of this invention are as follows:

[0021] 1. The fire resistance limit of hydrated magnesium silicate cement concrete panels is ≥4 hours, far exceeding that of traditional materials.

[0022] 2. The honeycomb steel core structure of the concave hexagonal honeycomb structure steel plate can effectively dissipate explosion energy. Combined with high-strength concrete, the blast resistance pressure is increased by more than 50%.

[0023] 3. The metal honeycomb structure of the concave hexagonal honeycomb steel plate forms a composite electromagnetic shielding layer with concrete, and the electromagnetic shielding effectiveness is ≥75dB in the 30MHz-18GHz frequency band.

[0024] 4. Vacuum pressure casting and silane coupling agent transition layer increase the bonding strength between the concave hexagonal honeycomb structure steel plate and concrete interface by 30%. The concave hexagonal honeycomb structure combined with the steel plate can increase the mechanical interlocking force between the concrete and the steel plate, and the plate will not delaminate after an explosion. Attached Figure Description

[0025] Figure 1 A schematic diagram of the cross-section of a fireproof and explosion-proof sandwich panel for substations;

[0026] Figure 2 Schematic diagram of a concave hexagonal honeycomb structure steel plate;

[0027] Figure 3 This is a schematic diagram of a cell cross-section;

[0028] Figure 4 This is a schematic diagram illustrating the connection methods between cell columns. Detailed Implementation

[0029] like Figure 1-4As shown, a fireproof and explosion-proof sandwich panel for substations includes a concave hexagonal honeycomb structure steel plate 2 and a hydrated magnesium silicate cement concrete panel 1. The concave hexagonal honeycomb structure steel plate 2 serves as the core layer, and the hydrated magnesium silicate cement concrete panel 1 is fixedly installed on both sides of the concave hexagonal honeycomb structure steel plate 2 to form a sandwich panel.

[0030] The concave hexagonal honeycomb structure steel plate 2 is composed of cells 3, each cell 3 being a strip-shaped hollow structure with a concave hexagonal cross-section. Each cell 3 includes two end faces 4 and four inclined faces 5, with an angle of 45° between the end faces 4 and the inclined faces 5, forming a concave hexagon. Three cells 3 are joined together through their respective end faces to form a group A cell column 7, and two cells 3 are joined together through their respective end faces to form a group B cell column 8. A group B cell column 8 is placed between two groups A cell columns 7, and the cell columns are joined together through their respective inclined faces 5, extending laterally to form the concave hexagonal honeycomb structure steel plate 2. The cell 3 has a wall thickness of 1.5 mm, a height of 30 mm, and a width of 35 mm. The nodes 6 between the end faces 4 and the inclined faces 5 are rounded with a radius of 1 mm. The concave hexagonal honeycomb structure steel plate 2 is manufactured by stamping hot-dip galvanized low-carbon steel plate.

[0031] The hydrated magnesium silicate cement concrete panel 1 is composed of: 110 parts of lightly calcined active magnesium oxide powder, 165 parts of silica fume, 225 parts of quartz sand, 135 parts of water, 20 parts of polyethylene fiber, 7 parts of sodium hexametaphosphate, and 1 part of polymer superplasticizer.

[0032] The preparation method of the above-mentioned fireproof and explosion-proof sandwich panel for substations includes the following steps:

[0033] 1) Spray a silane coupling agent onto the surface of the concave hexagonal honeycomb structure steel plate 2. The silane coupling agent is γ-aminopropyltriethoxysilane, which is prepared by hydrolysis in a 2% ethanol aqueous solution at a hydrolysis temperature of 55-65℃ for 30-50 minutes and a pH value adjusted to 4-5. A 0.2mm thick bonding transition layer is formed by electrostatic spraying. After drying at room temperature for 30 minutes, it is cured in an 80℃ oven for 1 hour.

[0034] 2) Place the sprayed concave hexagonal honeycomb structure steel plate 2 into the mold, and inject hydrated magnesium silicate cement concrete using a double-sided synchronous high-pressure pouring method, while applying a vacuum pressure of -0.09MPa and maintaining it for 17 minutes; the high-pressure pouring pressure is 5MPa, the concrete pouring speed is 8L / min, the double-sided pouring speed error is ≤5%, and auxiliary vibration with a vibration frequency of 25Hz is used during the pouring process;

[0035] The preparation process of hydrated magnesium silicate cement concrete is as follows: Lightly calcined active magnesium oxide powder is calcined at 820℃ for 2.5 hours, then processed to a particle size ≤5μm using an air jet mill; quartz sand is magnetically separated to remove iron, screened to obtain 100-mesh particles, then soaked in 5% hydrochloric acid solution for 2 hours, and rinsed with distilled water until neutral; the surface of polyethylene fiber is plasma-treated for 45 seconds to introduce hydroxyl functional groups, resulting in a fiber aspect ratio of 900; nano-silica is modified with silane coupling agent KH-550, with the modifier dosage being 4% of the nano-silica mass; 110 parts of lightly calcined active magnesium oxide powder, 165 parts of silica fume, and 225 parts of quartz sand are added and dry-mixed for 4 minutes; 81 parts of water (60% of the formula amount) are added and stirred for 2 minutes, then 7 parts of sodium hexametaphosphate and 1 part of polymer superplasticizer are added and stirred for 3 minutes; 20 parts of polyethylene fiber, 4 parts of nano-silica, and the remaining 54 parts of water are added, and the mixture is stirred at high speed for 6 minutes to form a concrete slurry with a fluidity of 190mm;

[0036] 3) Curing at 50-60℃ for 24 hours; initial curing at 55℃ and humidity ≥90% for 12 hours; secondary curing at 80℃ and humidity 80% for 8 hours; final curing at room temperature naturally for 4 hours (spraying water to keep moist every 2 hours); temperature (±2℃) and humidity (±5%) controlled by an intelligent system.

[0037] The prepared hydrated magnesium silicate cement concrete slab 1 has a compressive strength ≥55MPa, a flexural strength ≥15MPa, and a bulk density ≤1750kg / m³. 3 The resulting sandwich panel has fire resistance that meets the Class A non-combustible standard in GB 8624, with a fire resistance limit of ≥3.5h; its explosion resistance is unbroken under 150kPa explosion pressure, with a maximum back deflection of ≤12mm; and its electromagnetic shielding effectiveness is ≥75dB in the 30MHz-18GHz frequency band.

[0038] The expression for the total energy dissipation E of a sandwich panel under explosive impact is:

[0039] E = k·k d ·σ ys ·ρ * ·A·δ·f(θ)

[0040] In the formula: k—an empirical coefficient, usually taken as 0.6-0.8 (related to cell regularity and boundary conditions); k d —Dynamic strengthening coefficient, typically taken as 1.2-2.0; σ ys — Yield strength of the matrix material (Pa); ρ — Relative density of the honeycomb structure, for a concave hexagon ρ≈A cell 6atsin(π-θ / 2)(A cell A—Area of ​​a single cell; A—Total cross-sectional area of ​​the steel plate (m²) 2 ); δ—maximum plastic deformation under explosive impact (m); f(θ)—concave angle correction function.

Claims

1. A fireproof and explosion-proof sandwich panel for substations, characterized in that, It includes a concave hexagonal honeycomb structure steel plate and a hydrated magnesium silicate cement concrete panel. The concave hexagonal honeycomb structure steel plate serves as the core layer, and the hydrated magnesium silicate cement concrete panel is fixedly installed on both sides of the concave hexagonal honeycomb structure steel plate to form a sandwich panel.

2. The fireproof and explosion-proof sandwich panel for substations according to claim 1, characterized in that, The concave hexagonal honeycomb structure steel plate is composed of cells, which are strip-shaped hollow structures with a concave hexagonal cross-section. Each cell includes two end faces and four inclined faces, with an angle of 45° between the end faces and the inclined faces. The two end faces and the four inclined faces form a concave hexagon. Multiple cells are joined together by their respective end faces to form a cell column, and the cell columns are joined together by their respective inclined faces to extend laterally to form the concave hexagonal honeycomb structure steel plate.

3. The fireproof and explosion-proof sandwich panel for substations according to claim 2, characterized in that, The cell has a wall thickness of 0.8-3 mm, a height of 10-30 mm, and a width of 15-35 mm.

4. The fireproof and explosion-proof sandwich panel for substations according to claim 2, characterized in that, The node between the end face and the inclined surface is rounded with a radius of 0.5-2mm.

5. The fireproof and explosion-proof sandwich panel for substations according to claim 1, characterized in that, The concave hexagonal honeycomb structure steel plate is prepared by stamping hot-dip galvanized low-carbon steel plate.

6. The fireproof and explosion-proof sandwich panel for substations according to claim 1, characterized in that, The components of hydrated magnesium silicate cement concrete for the panel are: 100-120 parts lightly calcined active magnesium oxide powder, 150-180 parts silica fume, 225 parts quartz sand, 125-150 parts water, 15-25 parts polyethylene fiber, 5-10 parts sodium hexametaphosphate, and 0.8-1.2 parts polymer superplasticizer.

7. The method for preparing fireproof and explosion-proof sandwich panels for substations as described in any one of claims 1-6, characterized in that, Includes the following steps: 1) Spray silane coupling agent onto the surface of the concave hexagonal honeycomb structure steel plate, and form a bonding transition layer of 0.1-0.3mm thickness by electrostatic spraying; 2) Place the sprayed concave hexagonal honeycomb structure steel plate into the mold, and inject hydrated magnesium silicate cement concrete using a double-sided synchronous high-pressure pouring method, while applying a vacuum pressure of -0.08 to -0.1 MPa and maintaining it for 15-20 minutes. 3) Curing at 50-60℃ for 24 hours.

8. The method for preparing fireproof and explosion-proof sandwich panels for substations according to claim 7, characterized in that, In step 1), the silane coupling agent is γ-aminopropyltriethoxysilane, which is prepared by hydrolysis in an aqueous ethanol solution with a concentration of 1%-1.5%, at a hydrolysis temperature of 55-65°C, a hydrolysis time of 30-50 minutes, and a pH value adjusted to 4-5.

9. The method for preparing fireproof and explosion-proof sandwich panels for substations according to claim 7, characterized in that, In step 2), the high-pressure pouring pressure is 3-6 MPa, the concrete pouring speed is 6-12 L / min, and auxiliary vibration with a vibration frequency of 20-30 Hz is used during the pouring process.

10. The method for preparing fireproof and explosion-proof sandwich panels for substations according to claim 7, characterized in that, In step 2), the preparation process of hydrated magnesium silicate cement concrete is as follows: lightly calcined active magnesium oxide powder is calcined at 820℃ for 2.5 hours and then processed to a particle size ≤5μm by an air jet mill; after magnetic separation to remove iron, quartz sand is screened to obtain 100-mesh particles, then soaked in 5% hydrochloric acid solution for 2 hours and rinsed with distilled water until neutral. The surface of the polyethylene fiber is treated with plasma for 45 seconds to introduce hydroxyl functional groups, and the fiber aspect ratio is 900; the nano-silica is modified with silane coupling agent KH-550, and the amount of modifier is 4% of the mass of nano-silica.

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