Noise-reduction fireproof acoustic shield suitable for converter transformer

Abstract

The invention discloses a noise-reduction fireproof acoustic enclosure suitable for a converter transformer, which comprises a firewall, and the firewall comprises a concrete frame structure, a middle skeleton and a fireproof sound-absorbing wallboard, wherein the concrete frame structure is internally provided with a middle framework and a fire-resistant sound-absorbing wallboard; a plurality of middle frameworks are arranged in the middle position between two adjacent concrete frame structures in a straight line mode, the straight line formed by the multiple middle frameworks serves as a center line, and fireproof sound absorption wallboards are arranged on the two side faces of the multiple middle frameworks in a mirror image mode. And closed spaces formed between the gaps among the plurality of middle frameworks and the fire-resistant sound-absorbing wallboards are filled with aluminum silicate wool. By means of the noise-reduction fireproof acoustic enclosure suitable for the converter transformer, the acoustic enclosure can meet the requirements of fireproof partition, sound absorption and noise reduction at the same time.

Description

Technical Field

[0001] The invention relates to the technical field of fire prevention and control of ultra-high voltage large oil-filled equipment, and in particular to a noise reduction, fireproof and soundproof enclosure suitable for a converter transformer. Background Art

[0002] As the core equipment of the converter station, the safe and stable operation of the converter transformer is the basis for the normal operation of the entire converter station. Each converter transformer contains hundreds of tons of flammable insulating oil. When a fire occurs in the equipment, the high-temperature hot oil fire generated will rise rapidly and reach more than 1100°C within 1 minute, which is extremely dangerous. In order to prevent the fire of the burning equipment from spreading and igniting other adjacent converter transformers and valve hall equipment, firewalls are set between the converter transformers and between the converter transformers and the valve hall equipment in the project, thus forming a layout in which firewalls are set on the left, right and rear ends of the converter transformers. The firewalls on the left and right sides mainly separate the converter transformers, and the firewall at the rear end separates the converter transformers from the valve hall. Therefore, the side firewall is shared by two converter transformers, and the firewall at the rear end is shared by the converter transformer and the valve hall wall. The firewall adopts a fully cast-in-place reinforced concrete structure, or a reinforced concrete frame structure and an internal brick wall, with a thickness of generally 300mm to 400mm.

[0003] When designing the converter transformer soundproof enclosure, noise reduction plates are generally only set on the top and front of the converter transformer, and form a closed whole with the left, right and rear sides of the converter transformer to form a closed soundproof enclosure. At the same time, in order to reduce the reverberation sound inside the soundproof enclosure and improve the noise reduction effect of the soundproof enclosure, wall sound absorbers will be installed on the firewall inside the soundproof enclosure. The wall sound absorbers, front wall noise reduction plates and top cover noise reduction plates of the converter transformer soundproof enclosure are all metal noise reduction plates with a thickness of 100mm to 150mm. The structure consists of: a back plate made of 1mm to 2mm thick galvanized sheet, a frame made of 1.5mm thick galvanized sheet, glass wool filling, about 0.5mm thick glass fiber cloth, and a 1mm thick steel perforated panel.

[0004] In the past, it was necessary to construct a firewall and maintain the concrete first. Only when the strength of the firewall meets the requirements can other structural parts be installed on it, and then the converter transformer equipment can be put in place. If a frame-structured firewall is used, the concrete columns and beams must be maintained before the interior can be filled with bricks and the walls can be plastered, and then the subsequent structural parts can be installed and the converter transformer equipment can be put in place. This makes the construction period of the project longer. If the construction is carried out in winter or in cold areas, the maintenance of the concrete also requires additional heating and insulation measures, which further extends the construction period and increases the construction cost. At the same time, if a large amount of civil construction is carried out in ecologically fragile areas such as the Qinghai-Tibet Plateau and Xinjiang, it is also very easy to cause damage to the surrounding water, plants and other ecological environments, making it difficult for the ecological environment to recover for many years.

[0005] After the construction of the firewall is completed, in order to enable the sound insulation cover to take root, a large number of holes need to be drilled in the firewall to install anchor bolts and expansion bolts for installing steel columns, steel beams and wall sound absorbers. That is, the existing converter transformer firewall needs to install a sound absorption and insulation structure on the wall to achieve the sound absorption function, and install a sound absorption and insulation structure with sound absorption cotton to achieve sound absorption and insulation. The traditional sound absorption and insulation structure usually weighs 200 kg / m 2 , which is relatively heavy and needs to be fixed by fastening bolts, which is not conducive to installation and has a long construction period. At the same time, setting the sound absorber on the firewall also occupies the space inside the sound insulation cover, indirectly increasing the land use area. In order to ensure the stable installation of the sound absorber, the specifications of the installed expansion bolts are relatively large and the firewall is made of high-strength reinforced concrete, resulting in extremely difficult drilling and low construction efficiency, and even causing problems such as personnel injuries due to excessive strength. At the same time, due to the large weight of the sound absorber, a crane is also required on site to ensure installation, which not only increases the construction difficulty, but also increases the on-site construction safety risk due to the lifting operation.

[0006] After the project is put into use, the previous sound insulation cover cannot be opened when the converter transformer catches fire, which hinders external fire fighting and rescue, and the fire cannot be extinguished in time, threatening the safety of adjacent converter transformers and adjacent valve hall equipment. At the same time, with the increase of the service life, the glass wool filled in the wall sound absorber and the noise reduction board of the sound insulation cover will also be dusted, and the generated dust is extremely easy to be adsorbed by the UHV DC live body in the converter station, causing tip discharge and energy loss.

[0007] In the prior art, the utility model patent with the patent publication number CN209817602 discloses a three-dimensional prefabricated sound-absorbing and sound-insulating firewall module enclosure structure, which includes columns and sound-absorbing and fireproof panels fixedly arranged in a grid shape between adjacent columns through mounting brackets. The sound-absorbing and fireproof panels include a sound-insulating panel, sound-absorbing layers arranged on both sides of the sound-insulating panel, and facing hole panels arranged outside the two sound-absorbing layers. It also includes a frame skeleton arranged around the sound-absorbing and fireproof panels and used to fix the sound-absorbing and fireproof panels into a shape, so that the firewall enclosure structure has both sound-absorbing and sound-insulating properties and fireproof properties. The focus of this patent is on the enclosure structure of the firewall, effectively solving the problem of noise disturbing residents caused by building a substation near or directly in a residential area. Similar devices in real life, such as noise reduction panels installed on viaducts near residential buildings. However, it is not the same volume concept as the firewall of a converter station. Specifically, in this patent, neither the columns nor the steel frames are coated with fire-resistant materials or heat-insulating materials, which is equivalent to being exposed to high-temperature flue gas or flames. Coupled with the fact that the columns can use H-shaped steel and the brackets are made of steel, which has a very high heat conduction coefficient, so it does not have good heat insulation. At the same time, when facing the high temperature generated by the fire of large oil-filled electrical equipment, the strength of the steel will drop sharply. In this case, the firewall in the comparative document is extremely easy to collapse at high temperatures. And in this patent, the fire-facing surface is an open-hole steel plate, gypsum board or cement board. Among the three, only the refractoriness of gypsum can reach 1200°C to 1400°C, and the refractoriness of the other two materials is lower than 800°C. As described above, in a converter station, when a fire occurs in the equipment, the high-temperature hot oil fire temperature rises rapidly and can reach above 1100°C within 1 minute. Summary of the Invention

[0008] The technical problem to be solved by the present invention is: to provide a noise reduction and fire prevention integrated sound insulation cover applicable to a converter station, which can meet the requirements of fire prevention partition and sound absorption and noise reduction at the same time, and combine the sound absorption and fire prevention functions into one firewall.

[0009] To solve the above technical problems, the present invention provides the following technical solutions:

[0010] A noise reduction and fire prevention sound insulation cover applicable to a converter transformer includes a firewall, and the firewall includes a concrete frame structure 110, an intermediate skeleton 120 and a fire-resistant and sound-absorbing wall panel;

[0011] Among them, an intermediate skeleton 120 and a fire-resistant and sound-absorbing wall panel are arranged in the concrete frame structure 110; a plurality of intermediate skeletons 120 are arranged in a straight line at the middle position between two adjacent concrete frame structures 110, and with the straight line formed by the plurality of intermediate skeletons 120 as the center line, the fire-resistant and sound-absorbing wall panels are mirror-image arranged on both sides of the plurality of intermediate skeletons 120; and, the space formed by the gaps between the plurality of intermediate skeletons 120 and the fire-resistant and sound-absorbing wall panels is filled with aluminosilicate cotton 140.

[0012] In an embodiment of the present invention, the refractory sound-absorbing wall panel includes a cenosphere refractory board 131, a microporous board 132, and a fiber-reinforced silicate board 133 which are sequentially connected and arranged;

[0013] Wherein, a first filling interval is formed between the cenosphere refractory board 131 and the microporous board 132, and a second filling interval is formed between the microporous board 132 and the fiber-reinforced silicate board 133; and, aluminosilicate cotton 140 is filled in the first filling interval and the second filling interval; and, the cenosphere refractory board 131 is the outermost side of the firewall.

[0014] In an embodiment of the present invention, a channel steel skeleton 134 is further arranged in the refractory sound-absorbing wall panel, and the channel steel skeleton 134 fixes the cenosphere refractory board 131, the microporous board 132, and the fiber-reinforced silicate board 133.

[0015] In an embodiment of the present invention, the concrete frame structure 110 includes precast concrete frame columns 111 and frame beams 112; and reinforcing bars 101 and through sleeves 102 are reserved at the connection parts of the concrete frame columns 111 and the frame beams 112. During use, concrete is injected through the grouting holes 103 connecting the through sleeves 102 to realize the assembly of the two;

[0016] In addition, when the concrete frame columns 111 and the frame beams 112 are precast in the factory, connection fittings are embedded according to the sound insulation cover design drawing.

[0017] In an embodiment of the present invention, the intermediate skeleton 120 is fixedly connected to the concrete frame structure 110 through embedded connection fittings, and the fiber-reinforced silicate board 133 is fixedly connected to the intermediate skeleton 120.

[0018] In an embodiment of the present invention, pores that communicate with each other and penetrate through the cenosphere refractory board 131 are formed between the cenosphere particles in the cenosphere refractory board 131; when sound enters the inside of the cenosphere refractory board 131, part of the sound is absorbed by mutual friction between the pores and the cenosphere particles, and the other part of the sound penetrates through the cenosphere refractory board 131 and is dissipated by the microporous board 132 and the aluminosilicate cotton 140 after reflecting back and forth between the cenosphere refractory board 131 and the fiber-reinforced silicate board 133.

[0019] In an embodiment of the present invention, the sound insulation cover includes a wall steel structure 200, a roof steel structure 500, and a top cover. Among them, the wall steel structure 200 is fixedly connected to the firewall, the top of the roof steel structure 500 is fixedly connected to the wall steel structure 200, and the top cover is fixedly connected to the roof steel structure 500.

[0020] In an embodiment of the present invention, the shedding scheme of the top cover includes: applying a detachable noise reduction board 630; fixing the detachable noise reduction board 630 on the roof steel structure 500;

[0021] When the converter transformer is operating normally, the detachable noise reduction plate 630 serves as a component of the top cover;

[0022] When a fire occurs in the converter transformer, the adhesive inside the detachable noise reduction plate 630 undergoes molecular chain breakage under the action of high temperature, causing the detachable noise reduction plate 630 to disintegrate or fuse itself, and then it falls downward under the action of gravity, and the top cover opens.

[0023] In an embodiment of the present invention, the detachable noise reduction plate 630 includes: a grid plate 631, a frame 632, a substrate 633, a plastic film 634, an outer surface coating 635, and an inner surface coating 636;

[0024] The frame 632 is a groove structure framework, and the grid plate 631 is connected to the frame 632;

[0025] The substrate 633 is partially embedded in the grid plate 631 and partially protrudes from the grid plate 631; and an outer surface coating 635 is provided on the substrate 633 that protrudes from the grid plate 631;

[0026] The plastic film 634 wraps the frame 632, so as to form a closed cavity 637 with the grid plate 631 embedded in the substrate 633; and, the inner surface coating 636 is adhered to the plastic film 634, facing the sound source directly, and is adhesively sealed with the outer surface coating 635, so as to form a closed air layer inside the detachable noise reduction plate 630;

[0027] When the inner surface coating 636 encounters sound, it forms a resonance system with the air layer, playing a role of thin film resonance sound absorption.

[0028] In an embodiment of the present invention, the substrate 633 includes a first sand plate 6331 and a second sand plate 6332; the first sand plate 6331 is embedded in the grid plate 631, and the second sand plate 6332 protrudes from the grid plate 631; wherein, the first sand plate 6331 is made of coarse sand components, and the second sand plate 6332 is made of fine sand components.

[0029] In an embodiment of the present invention, the frame 632 includes a first groove and a second groove, the grid plate 631 is fixedly located in the first groove, and the second groove and the first sand plate 6331 serve as the framework of the cavity 637, and together with the plastic film 634, form a closed cavity 637.

[0030] In an embodiment of the present invention, during use, when sound waves are incident on the inner surface coating 636, the inner surface coating 636 vibrates under the excitation of the sound wave pressure. The plastic film 634 and the inner surface coating 636 undergo bending deformation, and frictional losses occur inside them, consuming sound energy. At the same time, the resonance system dissipates the resonant sound waves. In addition, after the sound waves outside the remaining resonant frequencies enter its cavity 637, the pores in the first layer of sand plate 6331 generate friction to dissipate sound energy.

[0031] In an embodiment of the present invention, the top cover includes fixed noise reduction plates 700. A plurality of fixed noise reduction plates 700 are respectively located at the top and the front end of the wall steel structure 200. Among them, each fixed noise reduction plate 700 includes a perforated panel 710 and a steel back plate 720. The steel back plate 720 has an opening in a rectangular shape, and the perforated panel 710 is fixedly connected to the steel back plate 720 at the opening to form a noise reduction cavity 730. And inside the noise reduction cavity 730, an aluminum fiber layer 740 is provided on the perforated panel 710.

[0032] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0033] In the present invention, the firewall and the sound absorber are combined into one, meeting the requirements of fire prevention partition and sound absorption and noise reduction at the same time. In the past, in order to achieve the functions of fire prevention and sound absorption and noise reduction simultaneously for the converter transformer firewall, it was necessary to first construct the firewall, and then install sound absorbers on both sides of the firewall. The thickness of the sound absorber is generally 100 mm thick. Installing sound absorbers on both sides increases the thickness of each firewall by 200 mm, thus increasing the space occupation and land use. Compared with the past practice, the intermediate framework and the fire-resistant sound-absorbing wall panel of the present invention are located inside the concrete frame structure, reducing the space occupation and indirectly saving the land use. At the same time, the integration of the firewall and the sound absorber also reduces the on-site construction procedures. In addition, the modular installation of the firewall plays a positive role in controlling the installation accuracy on site and simplifying the construction process.

[0034] The fire-resistant sound-absorbing wall panel of the present invention dissipates sound energy from two aspects. One is that when sound waves enter the pores between the cenospheres, a part of the sound energy will be dissipated due to the principle of porous sound absorption. The second is that after a part of the sound waves pass through the cenosphere board, a part of the sound energy will be dissipated by the aluminosilicate cotton board behind. This part of sound absorption is mainly due to the porous sound absorption characteristics of the aluminosilicate cotton. The third is that the sound waves passing through the cenosphere board will also reflect back and forth between the cenosphere board and the fiber-reinforced silicate board behind, achieving the effect of dissipating sound energy and having the characteristics of resonance sound absorption.

[0035] There is also a 20-mm-thick cenosphere fire-resistant board on the outer layer of the aluminosilicate cotton board in the fire-resistant sound-absorbing wall panel. The gap between the cenosphere particles is smaller than the dust particle size, and the thickness of the cenosphere fire-resistant board reaches 20 mm, avoiding the escape of the fiber material after pulverization.

[0036] All the main structures of the present invention are precast reinforced concrete, and the secondary structures such as the channel steel skeleton are wrapped inside with refractory and heat-insulating materials such as cenosphere refractory plates and aluminum silicate wool, and are not directly affected by flames and high-temperature flue gases, so as to ensure excellent mechanical properties and support functions during a fire.

[0037] The present invention adopts a design without fireproof coating. The fire-facing surface (which is also the sound source-facing surface) uses cenosphere refractory plates. There are a large number of irregular and connected pores between the surface of the cenosphere plates and the cenosphere particles inside. When external sound waves can enter its interior, it can play the role of sound absorption. If a fireproof coating is used, the pores on the surface of the cenosphere plates will be completely blocked, hindering the sound waves from entering its interior.

[0038] The present invention adopts a design combining a sound-absorbing layer and a sound-insulating layer, thus playing the roles of sound absorption and sound insulation. In the present invention, the cenosphere refractory plates and aluminum silicate wool are porous materials and have good sound-absorbing effects; the fiber-reinforced silicate plates in the present invention are dense materials and have good sound-insulating effects. By adopting the composite sound-absorbing and sound-insulating structure design of the present invention, it plays the roles of sound absorption and sound insulation at the same time, thus having a good noise reduction effect.

[0039] The present invention adopts a design combining a refractory and sound-absorbing wall panel and a channel steel skeleton. Thus, the refractory and sound-absorbing wall panel has excellent fireproof and heat-insulating properties, and the channel steel skeleton plays a supporting role. In the face of a fire, the refractory and sound-absorbing wall panel protects the channel steel skeleton from the influence of flames and high-temperature flue gases, and the channel steel skeleton plays a supporting role for the refractory and sound-absorbing wall panel. Therefore, the present invention is applicable to large-area fireproof structure projects.

[0040] The firewall of the present invention is mainly used between adjacent converter station equipment, and in scenarios where the converter station equipment needs to be provided with a sound-insulating cover. As a component of the sound-insulating cover, it can serve as both a shared wall between adjacent sound-insulating covers and a wall of a single sound-insulating cover, and at the same time play the roles of fireproof partition and noise reduction.

[0041] The present invention significantly reduces the cumbersome process flows of civil construction and brick wall masonry in the construction of the firewall. Compared with the previous civil construction that required work such as cement mortar mixing, on-site formwork support, pouring, and later curing, the present invention significantly reduces on-site operations, avoids dust pollution to the air during transportation and mixing, and also avoids the problem of a large amount of water resources required for mortar mixing. The present invention simplifies the process, shortens the construction period, and reduces costs through prefabricated production and assembled installation. In addition, for ecologically fragile areas such as the Qinghai-Tibet Plateau and the Gobi Desert in Xinjiang, the conventional on-site concrete construction method also pollutes water resources, damages the ecological environment, and causes the ecological environment to be difficult to recover for a long time. At the same time, for alpine regions, the concrete curing period is very long, and even artificial heating or heat preservation methods are required, which also increases the construction period. Therefore, the present invention reduces on-site civil construction, shortens the construction period, and also plays a role in protecting the ecological environment and saving on-site construction costs.

[0042] The present invention uses a fixed noise reduction board arranged based on the principle of a perforated panel sound absorption structure, reducing the use of glass wool to avoid problems such as tip discharge and increased fitting noise caused by the dusting of glass wool during long-term use. To achieve the purpose of sound absorption, in the past, the sound absorbers of converter transformer sound insulation enclosures and metal sound insulation and absorption boards were filled with glass wool as the sound absorption layer. Many round holes need to be opened on the panel of the sound absorber and the metal sound insulation and absorption board facing the sound source to ensure that sound waves can enter the internal sound absorption layer. This causes the glass wool to easily leak out through these small holes. Although generally a layer of fiberglass cloth is added between the glass wool and the hole plate, as the service life extends, the glass wool becomes dusted due to aging and is also likely to diffuse into the air through the fiberglass cloth. In addition, the imperfect wrapping of the fiberglass cloth and the aging of the fiberglass cloth itself will also exacerbate the exposure of glass wool dust into the air. Eventually, under the action of extra-high voltage direct current, it is adsorbed onto the charged body, forming tip discharge and the problem of increased fitting noise.

[0043] Combined with the actual situation of the extra-high voltage direct current transmission site, the present invention does not require glass wool that is polluting and prone to powdering and causing pollution. In the fireproof sound absorption wall panel, aluminosilicate wool is also placed inside a 20-mm-thick cenosphere board. These measures avoid the problems of tip discharge and increased fitting noise caused by the adsorption of high-voltage direct current after the dusting of these materials.

[0044] The sound insulation enclosure of the present invention also has the ability to open by fire melting and explosion relief, which plays an important role in fire control and reducing economic losses.

[0045] The present invention also creatively combines thin-film resonance sound absorption and porous sound absorption, enabling the detachable noise reduction board to have sound absorption performance. In the past, in order to ensure the basic noise reduction ability of the sound insulation enclosure, the detachable fuseable noise reduction board only had sound insulation performance. Although there was sound absorption by the sound absorber inside the sound insulation enclosure, due to the small sound absorption area inside the sound insulation enclosure, the reverberant sound inside the sound insulation enclosure was relatively large. On the one hand, it deteriorated the acoustic environment for personnel to work inside the sound insulation enclosure. At the same time, the increase in the reverberant sound inside the sound insulation enclosure offset the sound insulation ability of the sound insulation enclosure to a certain extent, resulting in a decline in the overall noise reduction ability of the sound insulation enclosure. The present invention makes full use of the elastic characteristics of the polyurea coating film and the porous sound absorption characteristics of particulate materials, enabling the detachable fuseable noise reduction board to have excellent sound absorption performance, reducing the reverberant sound inside the sound insulation enclosure, and thus improving the overall noise reduction ability of the sound insulation enclosure.

[0046] The flip explosion relief module of the present invention uses a spring catch limiter with adjustable opening difficulty, which can prevent it from being overturned by strong winds, ensuring the stability of the overall structure, and can also ensure rapid opening during an explosion shock, preventing false triggering caused by too low pressure relief and achieving the purpose of pressure relief under an explosion shock. Description of the Drawings

[0047] Figure 1 Schematic diagram of a noise reduction, fire prevention and sound insulation cover applicable to a converter transformer according to an embodiment of the present invention.

[0048] Figure 2 Schematic diagram of a concrete frame structure according to an embodiment of the present invention.

[0049] Figure 3 Schematic diagram of an embedded connection fitting according to an embodiment of the present invention.

[0050] Figure 4 Schematic diagram of a concrete frame structure and an intermediate skeleton according to an embodiment of the present invention.

[0051] Figure 5 Plan view of a sound insulation cover according to an embodiment of the present invention.

[0052] Figure 6 Three-dimensional view of a sound insulation cover according to an embodiment of the present invention.

[0053] Figure 7 Schematic diagram of the first shedding scheme according to an embodiment of the present invention.

[0054] Figure 8 Schematic diagram of the second shedding scheme according to an embodiment of the present invention.

[0055] Figure 9 Schematic diagram of a detachable noise reduction board according to an embodiment of the present invention.

[0056] Figure 10 Schematic diagram of a grid board according to an embodiment of the present invention.

[0057] Figure 11 Schematic diagram of a grid board and a substrate according to an embodiment of the present invention.

[0058] Figure 12 Schematic diagram of a rectangular mold according to an embodiment of the present invention.

[0059] Figure 13 Schematic diagram of a drum mold according to an embodiment of the present invention.

[0060] Figure 14 Schematic diagram of a pit according to an embodiment of the present invention.

[0061] Figure 15 Schematic diagram of alignment between a rectangular mold and a grid board according to an embodiment of the present invention.

[0062] Figure 16 Schematic diagram of a rolling mold according to an embodiment of the present invention.

[0063] Figure 17 Schematic diagram of the use of a rolling mold according to an embodiment of the present invention.

[0064] Figure 18 Schematic diagram of the third shedding solution according to an embodiment of the present invention.

[0065] Figure 19 Schematic diagram of the fixed noise reduction plate according to an embodiment of the present invention.

[0066] Figure 20 Schematic diagram of the flip explosion venting module according to an embodiment of the present invention.

[0067] Figure 21 Schematic diagram of the spring catch limiter according to an embodiment of the present invention.

[0068] Figure 22 Schematic diagram of the flip cover being flipped up according to an embodiment of the present invention.

[0069] Figure 23 Schematic diagram showing that the distance between the fixed catch assembly and the movable catch assembly is adjustable according to an embodiment of the present invention.

[0070] Figure 24 Absorption curve of a single fixed noise reduction plate according to an embodiment of the present invention.

[0071] Figure 25 Sound insulation curve of a single fixed noise reduction plate according to an embodiment of the present invention.

[0072] Figure 26 Absorption curve of the fire-resistant sound-absorbing wall panel according to an embodiment of the present invention. Detailed implementation manners

[0073] To facilitate those skilled in the art to understand the technical solution of the present invention, the technical solution of the present invention will be further described below in conjunction with the accompanying drawings of the specification.

[0074] The terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present application, "a plurality" means two or more unless otherwise specifically defined.

[0075] Embodiment 1

[0076] Please refer to Figure 1As shown in the figure, the present invention provides a noise reduction, fire prevention and sound insulation cover applicable to a converter transformer, including a firewall, and the firewall includes: a concrete frame structure 110, an intermediate skeleton 120 and a fireproof and sound-absorbing wall panel. Among them, the intermediate skeleton 120 and the fireproof and sound-absorbing wall panel are arranged inside the concrete frame structure 110. A plurality of intermediate skeletons 120 are arranged in a straight line at the middle position between two adjacent concrete frame structures 110, and taking the straight line formed by the plurality of intermediate skeletons 120 as the center line, the fireproof and sound-absorbing wall panels are mirror-symmetrically arranged on both sides of the plurality of intermediate skeletons 120. And, aluminum silicate cotton 140 is filled in the closed space formed between the intervals of the plurality of intermediate skeletons 120 and the fireproof and sound-absorbing wall panels.

[0077] Please refer to Figures 1 to 3 As shown in the figure, in an embodiment of the present invention, the concrete frame structure 110 includes concrete frame columns 111 and frame beams 112, both of which are prefabricated in the factory and assembled on site. The strength grade of the concrete is not less than C30. The cross-section specification of the concrete column formed by the concrete frame structure 110 is 300mm×400mm, and the cross-section specification of the concrete beam formed by the frame beam 112 is 300mm×300mm. At the same time, on the inner side of the frame formed by the concrete frame columns 111, the outer edges of the concrete columns and the concrete beams both protrude to form a concrete step 105 to prevent the flow of flue gas. Reinforcing bars 101 and through sleeves 102 are reserved at the connection part of the concrete frame columns 111 and the frame beams 112. During use, concrete is injected through the grouting holes 103 of the through sleeves 102 to realize the assembly of the two. During construction, only high-strength cement-based grouting material is grouted at the connection part, and local concrete curing is required. And, when the concrete frame columns 111 and the frame beams 112 are prefabricated in the factory, connection fittings 104 are embedded according to the sound insulation cover design drawing for fixing the steel structure of the sound insulation cover and other components to be installed. Among them, the connection fittings are, for example, anchor bolts.

[0078] In the embodiment, by changing the concrete construction of the firewall to the assembled structure of the present invention, it is possible to greatly save water and energy consumption at the construction site, reduce processes such as mixing and pouring, shorten the construction period, reduce costs, and also have a good environmental protection effect.

[0079] Please refer to Figure 1 、 Figure 4As shown, in an embodiment of the present invention, the intermediate skeleton 120 is made of galvanized square tubes with a size of 120×(6 - 8) mm and a Q235B material. It is fixed within the frame formed by the concrete frame columns 111 and frame beams 112, located at the middle position in the thickness direction of the firewall, and fixed by the anchor bolts embedded in the concrete frame columns 111 and frame beams 112. Connection plates are reserved on the intermediate skeleton 120 for the mutual fixation between the intermediate skeletons 120. Each connection point between the intermediate skeletons 120 is fixed with no less than two connection bolts, and the bolts are M12 bolts of grade 8.8. The main function of the intermediate skeleton 120 is to install each module of the fire-resistant sound-absorbing wallboard and support the fire-resistant sound-absorbing wallboard. The layout size on the intermediate skeleton 120 does not exceed 600 mm×1000 mm, which can ensure that the firewall foundation formed by the concrete frame structure 110 and the intermediate skeleton 120 of the present invention can withstand the explosion impact of 600 kPa generated during the explosion of the converter transformer bushing.

[0080] Please refer to Figure 1 As shown, in an embodiment of the present invention, the space formed between the intervals of multiple intermediate skeletons 120 and the fire-resistant sound-absorbing wallboard is filled with aluminum silicate wool 140 to play a role in heat insulation and strengthening, reducing the heat transferred from one side of the firewall to the other side. In this embodiment, it is purchased on the market according to technical parameters. The thickness of the aluminum silicate wool 140 is consistent with the cross-sectional side length dimension of the intermediate skeleton 120, and the bulk density is 100 - 120 kg / m 3 , and the thermal conductivity does not exceed 0.045 W / m·K.

[0081] Please refer to Figure 1 As shown, in an embodiment of the present invention, the fire-resistant sound-absorbing wallboard is assembled by multiple modular wallboards, fabricated in the factory and assembled on site. During on-site assembly, the mirror-image fire-resistant sound-absorbing wallboards are respectively installed in the concrete frame columns 111 and frame beams 112. The thickness of the fire-resistant sound-absorbing wallboard on each side of the intermediate skeleton 120 is 80 - 90 mm, including the cenosphere refractory board 131, microporous board 132, and fiber-reinforced silicate board 133 connected in sequence from the outside to the inside. Among them, a first filling interval is formed between the cenosphere refractory board 131 and the microporous board 132, and a second filling interval is formed between the microporous board 132 and the fiber-reinforced silicate board 133. And, the first filling interval and the second filling interval are filled with aluminum silicate wool. That is, the cenosphere refractory board 131 is the outermost side of the firewall. Among them, a channel steel skeleton 134 is also provided inside the fire-resistant sound-absorbing wallboard, and the channel steel skeleton 134 fixes the cenosphere refractory board 131, microporous board 132, and fiber-reinforced silicate board 133. And, the ends of the cenosphere refractory board 131 and the fiber-reinforced silicate board 133 match the concrete step 105 to prevent the penetration of smoke during a fire.

[0082] In this embodiment, the cenosphere refractory board 131 is made of cenosphere particles, inorganic adhesives, and curing agents. In this embodiment, the mass ratio of the cenosphere particles is about 70%, and the mass ratio of the inorganic adhesives and curing agents is about 30%. Pores that communicate with each other and penetrate through the cenosphere refractory board 131 are formed between the cenosphere particles in the cenosphere refractory board 131. When sound enters the interior of the cenosphere refractory board 131, a part of the sound is absorbed by the mutual friction between the pores and the cenosphere particles, showing the characteristics of porous sound absorption. Another part of the sound penetrates through the cenosphere refractory board 131 and is reflected back and forth between the cenosphere refractory board 131 and the fiber-reinforced silicate board 133, and is dissipated by the micro-perforated board 132 and the aluminosilicate cotton 140, showing the sound absorption characteristics of the micro-perforated board 132. In addition, the aluminosilicate cotton also has good sound absorption performance, which can effectively reduce the reverberant sound in the sound insulation enclosure and improve the noise reduction effect of the sound insulation enclosure.

[0083] In this embodiment, during production and processing, the cenosphere refractory boards 131 with different thicknesses and different particle gradation ratios show different fire resistance and sound absorption performances, as shown in Table 1.

[0084] Table 1 Performance of Cenosphere Refractory Boards with Different Thicknesses and Different Formulations

[0085]

[0086] Among them, the bulk density of the cenosphere particles of the cenosphere refractory boards 131 of the above different numbered samples is 600 - 700 kg / m 3 , and the refractoriness is ≥1600 °C.

[0087] The manufacturing processes of the above different samples are the same, specifically: First, fully stir two kinds of cenospheres with different mesh numbers evenly, then add inorganic adhesives and curing agents and continue to stir until it becomes a uniform mortar-like state. Then pour the stirred mortar into a mold for pre-forming, compact it, scrape it flat, let it stand for about 5 minutes, and then continue to add a small amount of stirred mortar to fill the depressions that appear on the surface. Then bake it in a baking furnace. When baking, heat it at a heating rate of no more than 30 °C every 3 minutes until it reaches about 300 °C, keep it warm for about 150 minutes, and finally take it out of the furnace to form.

[0088] According to the performance data in Table 1 and considering the cost of the product, the 4# sample is preferably used for engineering. In this structure, the cenosphere refractory board 131 is set on the surface. On the one hand, it is for sound absorption and sound transmission. On the other hand, when the cenosphere refractory board 131 encounters fire, its strength will become higher under high-temperature action, further improving the fire resistance support and fire integrity of the fire-resistant sound-absorbing wall panel. At the same time, the 20-mm-thick cenosphere refractory board 131 used as the panel can also solve the problem of the escape of dust generated by the aging of the internal aluminosilicate cotton and avoid the problem of dust being adsorbed by high-voltage direct current.

[0089] In an embodiment of the present invention, the fire-resistant sound-absorbing wallboard is fixed by self-tapping screws. The self-tapping screws are made of 304 stainless steel and come in two specifications. Among them, the st6.3×70mm specification is used to fix the cenosphere fire-resistant board 131 and the channel steel skeleton 134 together. The st6.3×120mm specification penetrates the fire-resistant sound-absorbing wallboard and drills into the intermediate skeleton 120 to fix the cenosphere fire-resistant board 131 on the intermediate skeleton 120. Since the self-tapping screws will directly face the high-temperature flame during a fire, 304 stainless steel with better high-temperature resistance is selected for the self-tapping screws this time.

[0090] In this embodiment, the aluminosilicate cotton 140 filled in the first filling interval and the second filling interval has a thickness of 50 - 60 mm and a bulk density of 100 - 120 kg / m 3 , and its thermal conductivity does not exceed 0.045 W / m·K, playing a role in heat insulation strengthening and sound absorption. On the one hand, heat insulation strengthening reduces the heat transfer from the cenosphere fire-resistant board 131 to the fiber-reinforced silicate board 133, and on the other hand, it reduces the heat transfer to the intermediate skeleton 120. The sound absorption effect is reflected in that the sound passing through the cenosphere fire-resistant board 131 into the fiber-reinforced silicate board 133 will be dissipated in the tiny pores inside it.

[0091] In this embodiment, the micro-perforated plate 132 is made of galvanized steel sheet with a thickness of 0.8 - 1 mm, the hole diameter is 1.8 - 2 mm, and the hole opening rate is 1.9 - 2%. It is arranged in the aluminosilicate cotton and is 30 - 40 mm away from the fiber-reinforced silicate board 133. The micro-perforated plate 132 itself can play a role in resonance sound absorption, improving the low-frequency sound absorption performance. Cooperating with the sound absorption of the cenosphere fire-resistant board 131 and the sound absorption of the fiber-reinforced silicate board 133, the fire-resistant sound-absorbing wallboard can have a wider frequency band of sound absorption performance.

[0092] In this embodiment, the fiber-reinforced silicate board 133 is purchased on the market according to technical parameters, with a thickness of 9 - 10 mm and a bulk density of 1100 kg / m 3 , the thermal conductivity ≤ 0.2 W / m·K, the combustion performance is A1 level, the flexural strength ≥ 8 MPa, it does not contain asbestos, and has no smoke toxicity.

[0093] In this embodiment, the channel steel skeleton 134 is folded from 304 stainless steel plate with a thickness of 1.5 - 2 mm and processed into a channel shape of 25 mm × 60 mm × 25 mm. It is fixed to the cenosphere fire-resistant board 131 by self-tapping screws. Since the channel steel skeleton 134 is closer to the high-temperature surface than the intermediate skeleton 120, 304 stainless steel with better high-temperature resistance is selected for the channel steel skeleton 134 in the present invention.

[0094] Please refer to Figures 1 to 4As shown, in the present invention, through material selection, structural design, and determination of the processing technology of the perlite refractory board, the heat insulation, fire resistance integrity, and fire resistance support performance of the refractory sound-absorbing wallboard simultaneously pass the 4-hour high-temperature oil fire combustion test.

[0095] Please refer to Figures 1 to 23 As shown, the sound insulation enclosure further includes a wall steel structure 200, a roof steel structure 500, and a top cover. Among them, the wall steel structure 200 is fixedly connected to the firewall, the top of the roof steel structure 500 is fixedly connected to the wall steel structure 200, and the top cover is fixedly connected to the roof steel structure 500. Among them, on both sides and the rear wall of the sound insulation enclosure, the firewall described in Embodiment 1 is provided, and the firewall plays the roles of noise reduction and fire prevention for the sound insulation enclosure at the same time.

[0096] In an embodiment of the present invention, the detachable area 600 of the top cover can be melted and broken under the high-temperature conditions generated by the converter transformer fire, and fall off downward under the action of gravity, so that the top cover of the sound insulation enclosure can be opened, thereby providing a window for external fire fighting. Among them, there are three detachable solutions for the top cover:

[0097] Detachable solution one: a heat-melt support plate 610 combined with a metal sound-absorbing and sound-insulating module 620 without glass wool material.

[0098] Detachable solution two: applying a detachable noise reduction board 630.

[0099] Detachable solution three: a heat-melt support plate 610 combined with a detachable noise reduction board 630.

[0100] Specifically, when in use, select the detachable solution according to the actual situation.

[0101] Please refer to Figure 7 As shown, in an embodiment of the present invention, in the detachable noise reduction board solution formed by combining the heat-melt support plate 610 with the metal sound-absorbing and sound-insulating module 620 without glass wool material, it further includes a plugging block 640 without glass wool material.

[0102] The heat-melt support plate 610 is fixed on the roof steel structure 500, the metal sound-absorbing and sound-insulating module 620 is fixed at the end of the heat-melt support plate 610, and the fixed plugging block 640 is fixed in the middle of the heat-melt support plate 610.

[0103] In this embodiment, when the converter transformer is operating normally, the heat-melt support plate 610 serves as the load-bearing member for the metal sound-absorbing and sound-insulating module 620 and the plugging block 640, and the metal sound-absorbing and sound-insulating module 620 and the plugging block 640 serve as components of the top cover.

[0104] When a fire occurs in the converter transformer, the heat-melt support plate 610 undergoes thermal deformation or melting, losing the support for the metal sound-absorbing and sound-insulating module 620, and the metal sound-absorbing and sound-insulating module 620 falls off downward under the action of gravity, and the top cover opens.

[0105] In this embodiment, both ends of the metal sound absorption and insulation module 620 are placed on the hot-melt support plate 610, and the hot-melt support plate 610 is used to cantilever it. The horizontal distance between both ends and the roof steel structure 500 is 20 - 30 mm. In this embodiment, the horizontal distance is 25 mm. This method can ensure that when the hot-melt support plate 610 melts, the metal sound absorption and insulation module 620 falls and is not blocked by the roof steel structure 500.

[0106] In this embodiment, the thickness of the hot-melt support plate 610 is 10 mm - 15 mm, and the width is 100 - 150 mm. It is made of nylon material and is purchased on the market according to technical parameters. Its performance parameters are: the flexural strength ≥ 75 MPa to ensure its load-bearing performance. The heat distortion temperature of the hot-melt support plate 610 ≥ 180 °C, and the melting peak value is 200 °C - 300 °C. The combustion performance is B1 level and above. The range of the heat distortion temperature and the melting peak value is mainly determined according to the flash point of the insulating oil in the converter transformer. The flash point of the insulating oil is generally 135 °C, and the normal operating temperature is about 90 °C. When the converter transformer heats up due to general faults, the local surface temperature of the converter transformer may reach about 130 °C. This requires that the hot-melt support plate 610 has good mechanical properties under this temperature condition and will not undergo thermal deformation. Therefore, both the heat distortion temperature and the melting peak temperature of the hot-melt support plate 610 should be higher than 135 °C. At the same time, the melting peak temperature of the nylon material is higher than its heat distortion temperature. Therefore, it is necessary to ensure that the heat distortion temperature is higher than 135 °C. Considering a certain safety margin, the heat distortion temperature is determined to be ≥ 180 °C. Within this heat distortion temperature range, the melting peak of the material is generally above 200 °C. In addition, in order to ensure that the hot-melt support plate 610 can quickly melt when a fire occurs in the converter transformer, the melting peak value of the hot-melt support plate 610 cannot be too high, otherwise it will take a long time for the temperature of the hot-melt support plate 610 to rise to the melting peak temperature before it will melt. For the above reasons, the melting peak value range of the hot-melt support plate 610 is determined to be 200 °C - 300 °C, which can not only meet the requirements but also be convenient to purchase. The combustion performance of the hot-melt support plate 610 is determined to be B1 level and above to ensure that the hot-melt support plate 610 will not intensify the fire when a fire occurs in the converter transformer.

[0107] In this embodiment, the blocking block 640 is used to fill between the metal sound absorption and insulation modules 620 and is located above the roof steel structure 500, playing a sealing role for the top cover and preventing sound leakage from the gaps between the metal sound absorption and insulation modules 620.

[0108] In this embodiment, the thickness of the blocking block 640 is thinner than that of the metal sound absorption and insulation module 620, and the thickness is 55 mm - 125 mm to ensure the flatness between the metal sound absorption and insulation modules 620.

[0109] In this embodiment, fasteners are used to fix between the hot-melt support plate 610 and the roof steel structure 500, between the metal sound absorption and insulation module 620, and between the detachable noise reduction plate 630 and the hot-melt support plate 610. In the embodiment, the fasteners are, for example, bolts. Specifically, M12 hot-dip galvanized bolts with a strength of grade 4.8 or 6.8 are used.

[0110] In this embodiment, the metal sound absorption and insulation module 620 and the blocking block 640 are made by fixing the noise reduction plate 700. It can be understood that the fixed noise reduction plate 700 is placed in the detachable area of the roof and combined with the hot-melt support plate 610 to form the metal sound absorption and insulation module 620, and by reducing the size, it forms the blocking block 640. The metal sound absorption and insulation module 620 and the blocking block 640 do not use glass wool, which can avoid the problem of glass wool dusting.

[0111] Please refer to Figure 8 As shown, in an embodiment of the present invention, the design of the second detachable solution is: fixing the detachable noise reduction plate 630 on the roof steel structure 500 through fasteners.

[0112] In this embodiment, when the converter transformer is operating normally, the detachable noise reduction plate 630 acts as a component of the top cover and plays a noise reduction role.

[0113] When a fire occurs in the converter transformer, the adhesive inside the detachable noise reduction plate 630 undergoes molecular chain breakage under the action of high temperature, causing the detachable noise reduction plate 630 to disintegrate or fuse itself, and it falls downward under the action of gravity, and the top cover opens.

[0114] Please refer to Figures 8 to 11 As shown, in an embodiment of the present invention, the detachable noise reduction plate 630 includes: a grid plate 631, a frame 632, a substrate 633, a plastic film 634, an outer surface coating 635, and an inner surface coating 636. The frame 632 is a groove structure frame, and the grid plate 631 is connected to the frame 632. Part of the substrate 633 is embedded in the grid plate 631, and part protrudes from the grid plate 631, and an outer surface coating 635 is provided on the substrate 633 that protrudes from the grid plate 631. After the inner surface coating 636 is sprayed on the plastic film 634, it wraps the frame 632 to form a closed cavity 637 with the grid plate 631 embedded in the substrate 633. And, the inner surface coating 636 is adhered to the plastic film 634, facing the sound source directly, and is adhesively sealed with the outer surface coating 635 to form a closed air layer inside the detachable noise reduction plate 630. When the inner surface coating 636 encounters sound, it forms a resonance system with the air layer to play a role in thin-film resonance sound absorption.

[0115] Please refer to Figure 10As shown, in this embodiment, the grid plate 631 is made by welding flat steel and twisted steel bars. The thickness of the flat steel is 2 - 4 mm, the width is 25 - 50 mm, and the diameter of the twisted steel bar is 2 - 5 mm. The flat steel and the twisted steel bars are welded into a grid shape, and the specifications of the grid are that the length ranges from 120 to 160 mm and the width ranges from 120 to 160 mm. After the grid plate 631 is welded and formed, its surface is treated by hot-dip galvanizing to improve the anti-corrosion performance.

[0116] In this embodiment, the specifications of the grid of the grid plate 631 are 150 mm × 150 mm, which can facilitate the easier fusing of the substrate 633 and can also ensure the support for the operators standing above it, preventing the risk of personnel falling when their feet slip. At the same time, the support structure of the steel grating effectively improves the load-bearing performance of the noise reduction plate, which can meet the uniform load of 4 kN / ㎡, and can meet the concentrated load of 4 kN within the range of 0.1 m wide × 0.25 m long.

[0117] In this embodiment, the frame 632 includes a first groove and a second groove. During production, it is first made of galvanized steel plate, bent into two groove shapes first, and then welded and formed. Among them, the grid plate 631 is fixedly located in the first groove. During welding, full welding is used at the connection parts between the frames 632 and between the frame 632 and the grid plate 631 to ensure airtightness.

[0118] In this embodiment, the substrate 633 is polymerized from about 95% sand grains and about 5% polymer adhesives, with a total thickness of 18 - 22 mm. In this embodiment, the substrate 633 includes a first sand plate 6331 and a second sand plate 6332. Among them, the first sand plate 6331 is embedded in the grid plate 631, and the second sand plate 6332 serves as the outer surface of the detachable noise reduction plate 630, which can ensure a flat surface. The second sand plate 6332 is made of fine sand components, with better compactness and more conducive to sound insulation. The first sand plate 6331 is made of coarse sand components, with more connected pores inside, which can allow sound waves to enter its interior, generate friction, and thus dissipate sound energy, playing a role in sound absorption, as shown in Figure 11 shown.

[0119] In this embodiment, the way of embedding and combining the first sand plate 6331 with the grid plate 631 can make the substrate 633 and the grid plate 631 better combined together, with better integrity. At the same time, since the coefficient of thermal expansion of the grid plate 631 is greater than that of the substrate 633, adopting the design of embedding the first sand plate 6331 into the grid plate 631, under the influence of high temperature, the grid plate 631 undergoes greater high-temperature expansion, which can play a role in stretching and tearing the substrate 633, being more conducive to the fracture and detachment of the substrate. The second sand plate 6332 is higher than the grid plate 631 and serves as the outer surface, which can ensure the flatness of the outer surface of the noise reduction plate.

[0120] In this embodiment, the plastic film 634 is attached to the frame 632, which can play a role in attaching and supporting the inner surface coating 636 before it is cured and formed.

[0121] In this embodiment, the spraying process is adopted to spray polyurea on the plastic film 634 to form the inner surface coating 636, and spray it on the second-layer sand plate 6332 to form the outer surface coating 635. The inner surface coating 636 and the outer surface coating 635 form a closed, water-impermeable and air-impermeable cavity 637 with the frame 632, the grid plate 631 and the substrate 633.

[0122] In this embodiment, the inner surface coating 636 is adhered to the plastic film 634, playing the roles of film sound absorption and protection, preventing the substrate 633 from being affected by water, scratches and collisions on the inner surface. Among them, the combustion performance of the inner surface coating 636 and the outer surface coating 635 is B1 level.

[0123] In this embodiment, on the one hand, the outer surface coating 635 plays a role in protecting the substrate 633, having excellent waterproof, scratch-proof, abrasion-proof, light-aging-proof, etc. At the same time, the dense structure of this coating also has a sound insulation effect, and spraying it on the surface of the substrate 633 can further enhance the sound insulation. In this embodiment, the weighted sound insulation of the detachable noise reduction board 630 of the present invention can reach 35 dB.

[0124] In this embodiment, when sound waves are incident on the inner surface coating 636, the inner surface coating 636 and the inner surface coating 636 vibrate under the excitation of the high-variable pressure of the sound waves, and undergo bending deformation, and frictional losses occur inside them, dissipating sound energy. At the same time, the inner surface coating 636 and the closed air layer at the back end also form a resonance system, which can well dissipate the sound near the resonance frequency. In addition, since the part of the substrate 633 embedded with the grid plate 631 also has certain sound absorption characteristics, it is equivalent to filling a certain amount of sound absorption material in the closed cavity, further promoting the improvement of the sound absorption coefficient. Under the above various effects, in the frequency range of 200 - 1600 Hz in the mid-low frequency, the sound absorption coefficient of the present invention is 0.39 - 0.61, the sound absorption performance is the highest at 400 Hz, reaching 0.61, and the average sound absorption coefficient in the range of 250 Hz - 1000 Hz (low-frequency range) is about 0.55, which is particularly suitable for noise reduction of electrical equipment mainly with low-frequency noise such as converter transformers, improving the overall noise reduction performance.

[0125] Please refer to Figures 9 to 17 As shown, the present invention also provides a preparation method for the substrate 633, including:

[0126] Step 1: Take quartz sand and gravel with a mesh size of 60 - 100, stir it evenly with an adhesive, and pour it into the rectangular mold 10, as shown in Figure 12As shown, after compacting and leveling it in the rectangular mold 10, a roller mold 20 with protrusions is used, as shown in Figure 13 shown, and rolling is carried out to form a concave pit on the leveling surface, as shown in Figure 14 shown. After compacting and forming, it is sent into an oven for the first baking process, baked at a temperature of 80 - 100 °C for 18 - 25 minutes to form the second sand plate 6332.

[0127] In this embodiment, quartz grits of 60 - 70 mesh and 80 - 100 mesh are weighed and mixed respectively, and the mass ratios are 60% and 40% respectively.

[0128] Step two: Take aeolian sand of 20 - 40 mesh and evenly stir it with an adhesive;

[0129] Step three: Align the grid plate 631 and place it on the rectangular mold 10, evenly pour the stirred aeolian sand into the grid plate 631, and use the rolling mold 30 to roll the aeolian sand in each grid until it becomes a flat plate to form the first sand plate 6331, as shown in Figures 15 to 17 shown.

[0130] In this embodiment, the grid plate 631 is placed on the rectangular mold 10. There are protrusions on the outer edge of the rectangular mold 10, which can ensure that the grid plate 631 is exactly placed on the surface of the second sand plate 6332, neither crushing the second sand plate 6332 that has not been shaped in the first step nor forming a gap with the second sand plate 6332. The length of the rollers on the rolling mold 30 matches the length of the squares of the grid plate 631. The distance between two adjacent rollers on the rolling mold 30, when in use, is clamped on the grid plate shared by two squares. The stirred aeolian sand is evenly poured into each square, and the problem of more accumulation at one end of the square and less or no accumulation at the other end is minimized as much as possible.

[0131] Step four: Send it into an oven for the second baking process, bake it in an environment with a temperature of 120 - 170 °C for 50 - 70 minutes to cure and form. After cooling, demold the rectangular mold at room temperature.

[0132] In this embodiment, the baking temperature of the first baking process is low and the baking time is short, which can enable the second sand plate 6332 to have a certain strength after insufficient chemical reaction, and at the same time reserve sufficient reaction conditions for the good fusion after adding the first sand plate 6331. At the same time, concave pits are pressed on the surface of the second sand plate 6332, which can have a good bonding force with the first sand plate 6331 to form an integral plate.

[0133] Please refer to Figures 9 to 17 shown. The present invention also provides a spraying method for an outer surface coating 635 and an inner surface coating 636, including:

[0134] Step 1: Place the assembled grid plate 631, frame 632, and substrate 633 with the second groove facing upward, wrap the outer surface of the entire frame 632 with a plastic film 634 to form a closed cavity 637 with the substrate 633, grid plate 631, and frame 632.

[0135] Step 2: Use a spraying device to spray polyurea on the plastic film 634 to form an inner surface coating 636.

[0136] Step 3: Turn it over so that the second groove faces downward, and spray polyurea on the substrate 633 protruding from the grid plate 631 to form an outer surface coating 635.

[0137] In this embodiment, after adopting the above spraying process, a closed air layer can be formed inside the detachable noise reduction plate 630. When the inner surface coating 636 encounters sound, it can form a resonance system with the air layer in the cavity 637 to play a sound absorption role.

[0138] In this embodiment, since the mass ratio of gravel reaches about 95%, the combustion performance of the substrate 633 can reach B1 level or above, which ensures that the detachable noise reduction plate 630 will not increase the fire when the equipment catches fire, improving safety. At the same time, a high particle mass ratio can also make the detachable noise reduction plate 630 melt into small fragments when it melts at high temperature, eliminating the problem that large pieces may block the fire area after falling off and then continue to block fire extinguishing.

[0139] Please refer to Figure 18 As shown, in an embodiment of the present invention, the third detachment solution is to use the heat-melt support plate 610 of the first detachment solution and the detachable noise reduction plate 630 of the second detachment solution in combination. Since both have the performance of melting at high temperature, using them in combination forms a double insurance for high-temperature detachment, making it easier to open the top cover when the equipment catches fire.

[0140] Please refer to Figure 5 、 Figure 6 、 Figure 19 As shown, in this embodiment, the fixed noise reduction plates 700 are respectively located at the top and front end of the wall steel structure 200. Among them, the fixed noise reduction plate 700 located at the top of the wall steel structure 200 is spliced and fixed around the four edges of the roof steel structure 500. The sound absorption filling material inside the conventional fixed noise reduction plate is glass wool. As the number of years of use increases, the glass wool will become powdered, float in the air, and be adsorbed by the high-voltage DC charged bodies in the converter station, forming a tip discharge phenomenon and generating a relatively high corona noise.

[0141] In this embodiment, to avoid such phenomena, the fixed noise reduction panel 700 in the present invention adopts a sound absorption and insulation structure based on the sound absorption principle of a perforated panel, and the use of glass wool is cancelled. According to theoretical calculations and acoustic tests, the thickness of the fixed noise reduction panel 700 is determined to be 150 mm. The fixed noise reduction panel 700 includes a perforated panel 710 and a steel back plate 720. The steel back plate 720 has an opening in a rectangular shape. The perforated panel 710 is fixedly connected to the steel back plate 720 at the opening to form a noise reduction cavity 730. Inside the noise reduction cavity 730, an aluminum fiber layer 740 is provided on the perforated panel 710. At the same time, based on a comprehensive evaluation of both acoustic performance and processing economy, it is determined that the perforated panel 710 is made of a 3-series aluminum alloy plate with a thickness of 0.8 mm, the opening ratio is 2%, the opening diameter is 1 mm, the thickness of the steel back plate 720 is 2 mm, and the height of the noise reduction cavity 730 is 148 mm.

[0142] In the embodiment, the aluminum fiber layer 740 mainly functions to widen the sound absorption frequency band and improve the overall sound absorption coefficient. In this embodiment, the noise reduction coefficient of the fixed noise reduction panel 700 reaches above 0.6, as shown in Figure 24 shown. The steel back plate 720 mainly functions as sound insulation. A thickness of 2 mm is adopted to ensure that the overall weighted sound insulation quantity Rw ≥ 35 dB, as shown in Figure 25 shown.

[0143] Please refer to Figure 5 、 Figure 6 、 Figures 19 to 23 shown. The flip-type explosion venting module 800 is located at the parts of the top cover that need to release pressure or are prone to explosion, such as the bushing riser area, the tap-changer area, the gas relay area, etc. The flip-type explosion venting module 800 adopts a regular rectangular design without openings, which can make the flip-type explosion venting module 800 have better overall strength, and avoid being shattered and ejected outward during the explosion of the converter transformer, causing secondary damage to the outside world.

[0144] Please refer to Figures 14 to 17 shown. In this embodiment, the flip-type explosion venting module 800 includes a flip cover 810, a cover strengthening frame 820, a spring catch limiter 830, a hinge 840, a waterproof flange 850, an outer frame 860, and a flexible safety cable 870. The outer frame 860 is fixedly connected to the roof steel structure 500. The cover strengthening frame 820 is provided at the rectangular edge of the flip cover 810. The waterproof flange 850 is fixed on the outer frame 860. The flip cover 810 is arranged on the waterproof flange 850 and is movably connected thereto. The hinge 840 is located at one end of the flip cover 810 and is used to install the flip cover 810 on the outer frame 860. The flip cover 810 can rotate along the axis of the hinge 840. The spring catch limiter 830 is located at the other end of the flip cover 810 and is connected to the cover strengthening frame 820, and is used to adjust the ease of opening or closing of the flip cover 810.

[0145] In this embodiment, the flip cover plate 810 is the substrate of a 3-mm thick metal plate or a 20-mm thick detachable noise reduction plate 630. Under normal circumstances, it plays the role of sound insulation and noise reduction. When the equipment explodes, under the action of the explosion shock, it automatically flips open to achieve the purpose of pressure relief inside the sound insulation cover. In this embodiment, the cover plate strengthening frame 820 is made of angle steel L50×5, mainly to strengthen the whole flip cover plate 810, and to prevent the flip cover plate 810 from being shattered and ejected outward under the explosion shock, causing secondary damage to the outside world.

[0146] In this embodiment, the spring catch limiter 830 includes a fixed catch assembly and a movable catch assembly. The movable catch assembly is connected to the cover plate strengthening frame 820 and moves in the same direction as the flip cover plate 810, and includes a first catch 831. The fixed catch assembly includes a second catch 832, an elastic member 833 and a fixed seat 834. The fixed seat 834 is fixed on the outer frame 860. A travel channel 835 is provided on the fixed seat 834. One end of the elastic member 833 located in the travel channel 835 is fixedly connected to the fixed seat 834, and the other end is connected to the second catch 832. And, the first catch 831 touches the second catch 832. Among them, the elastic member 833 is a spring, for example.

[0147] When the converter transformer explodes, under the thrust generated by the explosion shock, the flip cover plate 810 flips upward, causing the first catch 831 to squeeze the second catch 832 and then compress the elastic member 833, realizing the opening of the flip cover plate 810 for explosion relief.

[0148] When the converter transformer is working normally, the elastic force of the elastic member 833 causes the second catch 832 to generate pressure towards the first catch 831, pressing the flip cover plate 810.

[0149] In this embodiment, during the opening and closing actions, the force for compressing the elastic member 833 determines the ease of opening or closing of the flip cover plate 810. In order to meet the different requirements for the opening and closing forces of the flip cover plate 810 in different application scenarios, the relative distance between the fixed catch assembly and the movable catch assembly in the spring catch limiter 830 can be adjusted to make the compression stroke of the elastic member 833 different, so that the compression force is different, and finally the ease of opening and closing of the flip cover plate 810 can be adjusted. The relationship between the clamping force of the spring catch limiter 830 and the wind speed of the strong wind to be prevented is shown in the following formula:

[0150]

[0151] G = Sσg, (2);

[0152] F K1 = F 吸 - G, (3);

[0153] In the formula, F 吸 represents the wind suction force of the environment where the sound insulation cover is located, with the unit of N. α represents the safety factor, which is considered as 1.4 according to the "Load Code for Building Structures". β represents the local shape factor of wind load, and its value is 0.7 according to the "Load Code for Building Structures". V represents the wind speed, with the unit of m / s. S represents the area of the flipping cover plate, with the unit of ㎡. G represents the gravity of the flipping cover plate, with the unit of N. g represents the acceleration due to gravity, and its approximate value is 9.8 m / s 2 or 9.8 N / kg. σ represents the surface density of the flipping cover plate, with the unit of kg / ㎡. F K1 represents the clamping force of the spring catch limiter, with the unit of N. When the actual clamping force when opening the flipping cover plate 810 is greater than the calculated clamping force, it indicates that the flipping cover plate 810 will not be overturned by strong wind, and the safety meets the requirements. The actual clamping force can be obtained through tests during factory production.

[0154] In this embodiment, the above formula gives the calculation process of the wind suction force of the environment where the sound insulation cover is located and the clamping force of the spring catch limiter 830. During actual use, there are also the following requirements for the clamping force of the spring catch limiter 830:

[0155] Requirement 1: The maximum wind suction force of the environment where the sound insulation cover is located < the clamping force of the spring catch limiter 830, ensuring that the flipping explosion venting module 800 will not be overturned and opened by strong wind.

[0156] Requirement 2: The clamping force of the spring catch limiter 830 < the minimum impact force generated by the explosion of extra-high voltage large oil-filled equipment, ensuring that the flipping explosion venting module 800 can be opened for explosion venting when the equipment explodes.

[0157] Combined with Requirement 1, after obtaining the minimum clamping force of the spring catch limiter 830 through formulas (1) to (3), and then combined with Requirement 2, the clamping force of the spring catch limiter 830 is limited. The relative distance between the movable catch component and the fixed catch component is adjusted during factory production to achieve the pre-defined clamping force, ensuring that the flipping explosion venting module 800 will not be overturned and opened by strong wind during normal operation, and at the same time can be quickly opened for explosion venting when the converter transformer explodes.

[0158] In this embodiment, a specific example is given. Suppose the maximum wind speed once in 50 years in a certain area is 35 m / s. According to Equation 1, the wind suction force F 吸 is calculated to be 360 N. The outer dimensions of the flipping cover plate 810 are 0.8 m in length × 0.6 m in width, and it uses a 3-mm-thick steel plate, with its surface density being 23.55 kg / m 2, with a weight of 11.30 kg and a gravity G of 113 N; each flipping cover plate 810 is provided with a spring catch limiter 830. During in-factory production, by adjusting the relative distance between the movable catch assembly and the fixed catch assembly, the clamping force F of the spring catch limiter 830 K1 = 260 N. By comparison, F 吸 - G = 360 - 113 = 247 N, which is less than the clamping force F K1 of 260 N, proving that the once-in-50-year strong wind in this area cannot flip the cover plate.

[0159] At the same time, typical cases of explosion accidents of extra-high voltage large oil-filled equipment and experimental results show that the minimum impact force generated near the noise reduction device at the moment of explosion of extra-high voltage large oil-filled equipment is ≥ 1.5 kPa. In the case of the minimum explosion overpressure intensity of 1.5 kPa, the thrust generated on the flipping cover plate 810 is 1.5 × 1000 × 0.8 × 0.6 = 720 N, which is greater than the sum of the gravity G and the clamping force F K1 of 113 N + 260 N = 373 N, indicating that the impact generated by the equipment explosion can flip it open.

[0160] In this embodiment, the hinge 840 is used to install the flipping cover plate 810 on the outer frame 860, and the flipping cover plate 810 can rotate along the axis of the hinge 840.

[0161] The waterproof flange 850 is arranged at the pressure relief hole corresponding to the flipping cover plate 810 and is made of 4 angle steels of L30. The welding points are arranged outside the four sides of the hole and form a rectangular frame structure. The rectangular frame is larger than the hole size and smaller than the width size of the flipping cover plate 810. When the flipping cover plate 810 is in the normal closed state, the flipping cover plate 810 can completely cover the rectangular frame, preventing rainwater from directly entering the hole, and at the same time preventing the flowing water on the top cover from flowing into the inside of the sound insulation cover along the gap between the flipping cover plate 810 and the outer frame 860, playing a good waterproof role.

[0162] The outer frame 860 is mainly formed by folding galvanized steel plates and is the frame for fixing and supporting the flipping explosion relief module 800.

[0163] The flexible safety cable 870 is connected to the cover plate reinforcement frame 820 and the outer frame 860 and is made of flexible steel wire rope. Its length is greater than the maximum distance between the two connection points when the flipping cover plate 810 is opened, which can reduce the probability of the flipping cover plate 810 being blown off as a whole by excessive explosion impact and reduce the damage caused by the flipping cover plate 810 to the outside.

[0164] Please refer to Figure 5 、 Figure 6As shown in the figure, the sound insulation enclosure further includes an air intake system 310, an air exhaust system 320, and a sound insulation door 330. The air intake system 310 includes an air intake muffler and an aluminum alloy rainproof louver. The air intake system 310 is installed at a lower position on the wall surface of the sound insulation enclosure, which can allow the cold air outside the sound insulation enclosure to enter the interior of the sound insulation enclosure through the air intake system 310, while playing a role in noise reduction, meeting the needs of ventilation, heat dissipation, and noise reduction. The aluminum alloy rainproof louver plays a role in preventing rainwater from entering the interior of the sound insulation enclosure. The air exhaust system 320 includes an air exhaust fan, an air exhaust muffler, and an aluminum alloy rainproof louver. The air exhaust system 320 is installed at an upper position on the wall surface or the top cover of the sound insulation enclosure, which can allow the hot air inside the sound insulation enclosure to be discharged upward through the air exhaust system 320. The air exhaust system 320 mainly promotes the air exhaust inside the sound insulation enclosure, achieving the purpose of natural air intake and mechanical air exhaust. The air exhaust muffler meets the needs of both ventilation and noise reduction, and the aluminum alloy rainproof louver plays a role in preventing rainwater from entering the interior of the sound insulation enclosure. The sound insulation door 330 is installed on the wall surface of the sound insulation enclosure and is fixed by bolts. The thickness of the sound insulation door 330 is 100 mm - 150 mm, and the weighted sound insulation amount Rw ≥ 30 dB, which mainly plays the roles of sound insulation and allowing personnel to pass through.

[0165] Embodiment 2

[0166] Please refer to Figure 4 、 Figure 5 、 Figure 24 and Figure 25 As shown in the figure, the present invention gives the sound absorption and insulation effects of the sound insulation enclosure in Embodiment 1. Among them, the formula of the cenosphere refractory board used in the sound insulation enclosure is: mixing and stirring evenly an inorganic binder and a curing agent with a mass ratio of 70% and 30% respectively. Among them, the gradation ratio of the cenosphere particles is a mixture of 65% by mass of particles with a size of 30 - 40 mesh and 35% by mass of particles with a size of 70 - 100 mesh, to make a 20 - mm - thick cenosphere board. According to the aforementioned structural composition method, it is installed as the firewall of the sound insulation enclosure. The high - temperature oil - fire limit time of the firewall is ≥ 4 h, the noise reduction coefficient is 0.75 - 0.85, and the sound absorption performance curve is as follows Figure 26 shown.

[0167] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above - mentioned exemplary embodiments, and without departing from the spirit or basic characteristics of the present invention, the present invention can be implemented in other specific forms. Therefore, from any point of view, the embodiments should be regarded as exemplary and non - restrictive. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention, and any reference signs in the claims should not be regarded as limiting the claims involved.

[0168] The above-described embodiments merely represent the implementation manners of the invention. The protection scope of the present invention is not limited to the above embodiments. For those skilled in the art, without departing from the concept of the present invention, several modifications and improvements can be made, and these all fall within the protection scope of the present invention.

Claims

1. A noise reduction, fire prevention and sound insulation cover applicable to a converter transformer, characterized in that, It includes a firewall, and the firewall includes a concrete frame structure (110), an intermediate skeleton (120) and a fireproof and sound-absorbing wall panel; Among them, the intermediate skeleton (120) and the fireproof and sound-absorbing wall panel are arranged inside the concrete frame structure (110); a plurality of intermediate skeletons (120) are arranged in a straight line at the middle position between two adjacent concrete frame structures (110), and with the straight line formed by the plurality of intermediate skeletons (120) as the center line, the fireproof and sound-absorbing wall panel is arranged in mirror image on both sides of the plurality of intermediate skeletons (120); and, the space formed by the gap between the plurality of intermediate skeletons (120) and the fireproof and sound-absorbing wall panel is filled with aluminosilicate cotton (140).

2. The noise reduction, fire prevention and sound insulation cover applicable to a converter transformer according to claim 1, wherein The fireproof and sound-absorbing wall panel includes a cenosphere fireproof board (131), a microporous board (132), and a fiber-reinforced silicate board (133) which are connected in sequence; Among them, a first filling interval is formed between the cenosphere fireproof board (131) and the microporous board (132), and a second filling interval is formed between the microporous board (132) and the fiber-reinforced silicate board (133); and, the first filling interval and the second filling interval are filled with aluminosilicate cotton (140); and, the cenosphere fireproof board (131) is the outermost side of the firewall.

3. The noise reduction, fire prevention and sound insulation cover applicable to a converter transformer according to claim 2, characterized in that, A channel steel skeleton (134) is also arranged inside the fireproof and sound-absorbing wall panel, and the channel steel skeleton (134) fixes the cenosphere fireproof board (131), the microporous board (132), and the fiber-reinforced silicate board (133).

4. The noise reduction, fire prevention and sound insulation cover applicable to a converter transformer according to claim 2, wherein The concrete frame structure (110) includes precast concrete frame columns (111) and frame beams (112); and reinforcing bars (101) and through sleeves (102) are reserved at the connection part of the concrete frame columns (111) and the frame beams (112). During use, concrete is injected through the grouting holes (103) of the through sleeves (102) to realize the assembly of the two; And, when the concrete frame columns (111) and the frame beams (112) are precast in the factory, connection fittings are embedded according to the design drawing of the sound insulation cover.

5. The noise reduction, fire prevention and sound insulation cover applicable to a converter transformer according to claim 4, characterized in that, The intermediate skeleton (120) is fixedly connected to the concrete frame structure (110) through the embedded connection fittings, and the fiber-reinforced silicate board (133) is fixedly connected to the intermediate skeleton (120).

6. The noise reduction, fire prevention and sound insulation cover applicable to a converter transformer according to claim 2, characterized in that Pores that communicate with each other and penetrate through the cenosphere fireproof board (131) are formed between the cenosphere particles in the cenosphere fireproof board (131); when sound enters the inside of the cenosphere fireproof board (131), a part of the sound is absorbed by the mutual friction between the pores and the cenosphere particles, and the other part of the sound penetrates through the cenosphere fireproof board (131) and is dissipated by the microporous board (132) and the aluminosilicate cotton (140) after reflecting back and forth between the cenosphere fireproof board (131) and the fiber-reinforced silicate board (133).

7. The noise reduction, fire prevention and sound insulation cover applicable to a converter transformer according to claim 1, characterized in that The sound insulation cover includes a wall steel structure (200), a roof steel structure (500) and a top cover. Among them, the wall steel structure (200) is fixedly connected to the firewall, the roof steel structure (500) is fixedly connected to the top of the wall steel structure (200), and the top cover is fixedly connected to the roof steel structure (500).

8. The noise reduction, fire prevention and sound insulation cover applicable to a converter transformer according to claim 7, characterized in that, The shedding scheme of the top cover includes: applying a detachable noise reduction board (630); fixing the detachable noise reduction board (630) on the roof steel structure (500); When the converter transformer is operating normally, the detachable noise reduction board (630) serves as a component of the top cover; When a fire occurs in the converter transformer, the adhesive inside the detachable noise reduction board (630) undergoes molecular chain breakage under the action of high temperature, causing the detachable noise reduction board (630) to disintegrate or fuse itself, and it drops downward under the action of gravity, and the top cover opens.

9. The noise reduction, fire prevention and sound insulation cover applicable to a converter transformer according to claim 8, characterized in that, The detachable noise reduction board (630) includes: a grid board (631), a frame (632), a substrate (633), a plastic film (634), and also includes an airtight and waterproof outer surface coating (635) and an inner surface coating (636); The frame (632) is a groove-structured frame, and the grid board (631) is connected to the frame 632; The substrate (633) is partially embedded in the grid board (631) and partially protrudes from the grid board (631); and an outer surface coating (635) is provided on the substrate (633) that protrudes from the grid board (631). The plastic film (634) wraps the frame (632) to form a closed cavity (637) with the grid board (631) embedded in the substrate (633); and the inner surface coating (636) is bonded to the plastic film (634), facing the sound source directly, and is adhesively sealed with the outer surface coating (635) to form a closed air layer inside the detachable noise reduction board (630); When the inner surface coating (636) encounters sound, it forms a resonance system with the air layer to play a role in thin-film resonance sound absorption.

10. The noise reduction, fire prevention and sound insulation cover applicable to a converter transformer according to claim 7, characterized in that, The top cover includes fixed noise reduction boards (700), and multiple fixed noise reduction boards (700) are respectively located at the top and front end of the wall steel structure (200); among them, each fixed noise reduction board (700) includes a perforated panel (710) and a steel back plate (720); the steel back plate (720) has an opening in a rectangular shape, and the perforated panel (710) is fixedly connected to the steel back plate (720) at the opening to form a noise reduction cavity (730); and inside the noise reduction cavity (730), an aluminum fiber layer (740) is provided on the perforated panel (710).

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