Fireproof plugging device for cable inlet and outlet of transformer box

Abstract

The utility model relates to the field of power equipment fire safety technology discloses a kind of fireproof plugging device for transformer box cable inlet and outlet, comprising: fixed sleeve, be located at the cable inlet and outlet of transformer box, its two ends are respectively connected with extension sleeve, one of the extension sleeve is located inside transformer box, another extension sleeve is located outside transformer box;The utility model is through being provided with fixed sleeve, extension sleeve, annular airbag, liquid ring, connecting pipe, piston and detection part, realize the automatic plugging of transformer box cable inlet and outlet under high-temperature environment such as fire. Annular airbag is expanded by liquid pressure and is attached to cable outer wall, forms efficient fire-retardant seal.

Description

Technical Field

[0001] This utility model relates to the field of fire safety technology for power equipment, specifically to a fireproof sealing device for cable inlets and outlets of a transformer box. Background Technology

[0002] As power equipment develops towards higher voltage and larger capacity, the safety of transformer operation is becoming increasingly important. To connect to external systems, transformers typically have multiple high-voltage cables passing through the inlet and outlet structures of the enclosure. However, gaps exist between the cables and the through-holes, which can easily become channels for external media such as flames, smoke, and water vapor to enter the equipment, potentially leading to short circuits, explosions, and other safety accidents in severe cases.

[0003] Existing fireproof sealing methods mostly use sealant, sealing mud, or rigid modules for filling and sealing. However, these solutions are slow to respond and difficult to cope with sudden high-temperature conditions. Furthermore, rigid structures are not easy to adapt to the thermal expansion and contraction of cables, posing a risk of sealing failure. The safety assurance capability still needs to be improved. Utility Model Content

[0004] In view of the shortcomings of the existing technology, this utility model provides a fireproof sealing device for the cable inlet and outlet of a transformer box, which aims to alleviate the above problems to at least a certain extent.

[0005] The above-mentioned technical objective of this utility model is achieved through the following technical solution: A fireproof sealing device for cable inlets and outlets of a transformer box, comprising: A fixed sleeve is provided at the cable inlet and outlet of the transformer housing, and its two ends are respectively connected to an extension sleeve, one of which is located inside the transformer housing and the other is located outside the transformer housing. An annular airbag is provided in the inner cavity of the extension sleeve, and the annular airbag is filled with liquid, which is used to expand and adhere to the outer wall of the cable to form a seal when pressure is applied. A liquid ring is provided on the outer wall of the fixed sleeve. The liquid ring is filled with the same liquid as the annular airbag, and the liquid ring is in communication with the annular airbag to provide hydraulic fluid replenishment to the annular airbag. A connecting pipe is connected between the two extended sleeves, and both ends extend to the sides of the two extended sleeves respectively. A piston is slidably connected inside the connecting pipe, and the connecting pipe is in communication with the liquid ring. A detection unit located between the piston and the connecting pipe is used to push the piston to slide when the ambient temperature reaches a preset threshold, thereby forcing the liquid in the liquid ring into the annular airbag to achieve sealing around the cable.

[0006] Preferably, the opening of the extension sleeve is connected to a plurality of elastic plates.

[0007] Preferably, the connecting pipe has a connecting channel extending into the liquid ring.

[0008] Preferably, the liquid ring is connected to a connecting pipe, which extends into the extension sleeve and communicates with the annular airbag.

[0009] Preferably, the detection unit includes a connecting ring connected inside the connecting tube, a spring connecting the connecting ring and the piston, a connecting cavity being formed inside the connecting tube, a film being fixed inside the connecting cavity, and the film being bonded to the piston.

[0010] Preferably, the piston includes a push rod and a copper rod, the spring is fixed to the push rod, and the film is adhered to the copper rod.

[0011] Preferably, the film has a ring structure and is fitted onto the inner circumferential wall of the connecting cavity. The inner edge of the film has several serrated weakening parts along the circumferential direction and is bonded to the outer circumferential surface of the copper rod.

[0012] In summary, the present invention has the following main advantages: This invention achieves automatic sealing of transformer box cable inlets and outlets in high-temperature environments such as fires by incorporating a fixed sleeve, an extension sleeve, an annular airbag, a liquid ring, a connecting pipe, a piston, and a detection unit. The annular airbag expands under liquid pressure to adhere to the cable's outer wall, forming a highly efficient flame-retardant seal. An elastic plate at the opening of the extension sleeve assists in cable centering, ensuring uniform airbag coverage and improving sealing effectiveness. The piston structure features a separate copper rod and push rod design, combined with a spring and an annular film to form the detection unit, enabling precise release when the temperature reaches a set threshold, driving the sealing action. The film is an annular structure with serrated weakening sections, allowing for rapid and controllable breakage and preventing uneven fracture. The overall structure is compact, the triggering mechanism is reliable, and it is suitable for various power equipment inlet and outlet protection scenarios, possessing excellent engineering practicality and safety assurance capabilities. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the overall structure of this utility model; Figure 2 This is a cross-sectional schematic diagram of the overall structure of this utility model; Figure 3 yes Figure 2 Enlarged schematic diagram of the local structure at point A; Figure 4 This is a schematic diagram of the film structure of this utility model.

[0014] Figure label: 100. Fixed sleeve; 101. Extending sleeve; 102. Annular airbag; 103. Liquid ring; 104. Connecting tube; 105. Elastic sheet; 106. Connecting channel; 107. Connecting tube; 200. Connecting ring; 201. Spring; 202. Connecting cavity; 203. Film; 204. Weakening part; 300, putter; 301, brass rod. Detailed Implementation

[0015] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0016] refer to Figures 1-4 This embodiment provides a fireproof sealing device for cable inlets and outlets of a transformer box. The device has a compact structure and a rapid response. It is used to automatically seal the cable channel in high-temperature environments, thereby improving the overall fire resistance and operational safety of the equipment.

[0017] Specifically, the fireproof sealing device includes a fixed sleeve 100, which is installed at the cable inlet and outlet of the transformer housing to form a sealed basic structure for the cable to pass through the housing. Extension sleeves 101 are connected to both ends of the fixed sleeve 100, one extension sleeve 101 located inside the transformer housing and the other extension sleeve 101 located outside the transformer housing, allowing the cable to pass through the entire sealing device.

[0018] The inner cavity of the extension sleeve 101 is provided with an annular airbag 102, which covers the outside of the cable and is arranged along the circumference of the extension sleeve 101. The annular airbag 102 is filled with liquid. When the airbag is compressed, the liquid causes the airbag to expand inward and conform to the outer wall of the cable, thereby effectively sealing the annular gap between the cable and the sleeve in the event of a fire, preventing the intrusion and escape of flames and high-temperature gases.

[0019] A liquid ring 103 is provided on the outer wall of the fixed sleeve 100. The liquid ring 103 is fixed to the fixed sleeve 100 to form a closed structure. Its interior is filled with the same liquid as the annular airbag 102. The liquid ring 103 is in fluid communication with the annular airbag 102 through a connecting channel to provide hydraulic replenishment to the airbag. Under the action of the piston, it ensures that the annular airbag 102 can quickly obtain the liquid volume required for expansion.

[0020] The fireproof sealing device also includes a connecting pipe 104, which connects to two extension sleeves 101, with both ends extending to the sides of the two extension sleeves 101, spanning the inside and outside of the transformer tank. A piston is slidably connected inside the connecting pipe 104, sliding along the length of the connecting pipe 104 and capable of applying pressure to the liquid under external temperature changes. The connecting pipe 104 is also connected to the liquid ring 103, so that the pressure generated by the piston's movement can be smoothly transmitted to the liquid ring 103 and the annular airbag 102.

[0021] A detection unit is provided between the piston and the connecting pipe 104 to sense changes in the external ambient temperature. When the temperature reaches a set threshold, the detection unit drives the piston to slide along the connecting pipe 104, thereby compressing the liquid and rapidly pushing it into the annular airbag 102, achieving rapid expansion of the annular airbag 102. The expansion of the airbag tightly covers the outer periphery of the cable, actively sealing the gaps at the cable inlet and outlet, blocking the intrusion and escape paths of high-temperature gases or open flames, thus achieving a good fireproof sealing effect.

[0022] In this embodiment, a plurality of elastic sheets 105 are connected to the opening of the extension sleeve 101. Each elastic sheet 105 is evenly distributed along the circumference of the extension sleeve 101. Each elastic sheet 105 is made of a high-temperature resistant material with elastic recovery properties, such as a stainless steel sheet or a heat-resistant silicone rubber sheet 203, to ensure that it can deform when pressed by an external force.

[0023] During assembly, the cable passes through the opening of the extension sleeve 101 from the outside in. Multiple elastic tabs 105 open sequentially under the action of the cable's outer wall. After the cable is fully inserted into the set position, each elastic tab 105 rebounds and adheres to the outer wall of the cable due to its own elastic recovery. The circumferential distribution of the elastic tabs 105 allows for uniform cable positioning, ensuring that the cable axis and the central axis of the extension sleeve 101 remain as concentric as possible. This ensures that the cable remains stably centered when passing through the fixed sleeve 100 and the extension sleeve 101 on the other side.

[0024] When the device triggers the sealing process due to high temperature, the annular airbag 102 expands inward by being filled with liquid, ensuring that the airbag structure accurately covers the outer wall of the cable, avoiding problems such as misalignment, seal failure, or uneven expansion. Compared to using air as the expansion medium, liquid has stronger incompressibility and more stable volume control capabilities, generating uniform and controllable expansion force within a limited space, ensuring that all parts of the airbag are subjected to force synchronously, thereby achieving stable adhesion to the outer wall of the cable. On the other hand, liquid can also have heat absorption and cooling functions as well as flame retardant and heat insulation functions in high-temperature environments. Even if the airbag is partially damaged, the leaked liquid can still cover the flame, delaying heat conduction and further improving the overall fire resistance reliability and fault tolerance of the device.

[0025] Furthermore, compared to gaseous media such as air, this device preferably uses a liquid with electrical insulating properties as the expansion medium for the annular airbag 102. On one hand, the incompressibility of the liquid allows for a more stable transmission of piston force, achieving synchronous expansion and uniform adhesion of the annular airbag 102. On the other hand, in practical applications, cables are often in a energized or energized standby state. If the expansion medium is gaseous, electrical hazards such as corona discharge or breakdown can easily occur due to poor sealing or temperature fluctuations. Liquid media (such as insulating silicone oil or flame-retardant dielectric oil) have excellent electrical insulation properties, preventing leakage even in direct contact with the cable surface, effectively ensuring the electrical safety of the equipment. In addition, such liquids possess strong heat capacity and flame-retardant properties at high temperatures, enabling rapid expansion and force transmission while also providing multiple safety functions such as thermal barrier, cooling protection, and flame isolation under extreme operating conditions.

[0026] In this embodiment, a connecting channel 106 is provided on the connecting pipe 104. One end of the connecting channel 106 communicates with the interior of the connecting pipe 104, and the other end extends into the internal cavity of the liquid ring 103, forming a liquid passage between the connecting pipe 104 and the liquid ring 103. The connecting channel 106 can be located in the middle of the connecting pipe 104, and its size is reasonably set according to the liquid flow requirements to ensure sensitive pressure response during liquid transmission.

[0027] With the above settings, during the operation of the device, when the detection unit senses that the temperature has reached the set threshold, it drives the piston to slide along the connecting pipe 104. At this time, the piston generates an axial thrust on the liquid inside the connecting pipe 104. This thrust is transmitted to the liquid inside the liquid ring 103 through the connecting channel 106, causing the liquid in the liquid ring 103 to be injected into the cavity of the annular air bladder 102 connected to it.

[0028] Due to the connection channel 106, the pressure applied by the piston sliding is not limited to the local area within the connecting pipe 104, but can quickly and directly act on the liquid ring 103 system, significantly improving liquid transfer efficiency. Through this path, the airbag can obtain sufficient liquid volume in a very short time, achieving rapid and stable expansion and sealing.

[0029] In this embodiment, a connecting pipe 107 is connected to the liquid ring 103. The connecting pipe 107 is led out from one side of the cavity of the liquid ring 103 and extends towards the extension sleeve 101, eventually extending into the inner cavity of the extension sleeve 101 and communicating with the inside of the annular airbag 102 disposed therein.

[0030] The connecting pipe 107 can be a flexible hose or a rigid pipe structure, preferably with high temperature and pressure resistance to ensure the stability and sealing of the liquid transmission process under high temperature environment.

[0031] With the above setup, after the piston moves due to an abnormal temperature rise, the liquid in the liquid ring 103 will be compressed by pressure. At this time, under the action of pressure, the liquid flows into the interior of the extension sleeve 101 through the connecting pipe 107 channel on the liquid ring 103, and is further injected into the cavity of the annular airbag 102 connected thereto.

[0032] Due to the design of this connection structure, the liquid ring 103, connecting pipe 104, and annular airbag 102 form a complete and continuous hydraulic drive path. When the piston pushes the liquid, the liquid can work in conjunction with the connecting pipe 107 through the connecting channel 106 to quickly form a sealing response.

[0033] In this embodiment, the detection unit includes a connecting ring 200 disposed in the connecting pipe 104. The connecting ring 200 is fixedly installed on the inner wall of the connecting pipe 104. The connecting ring 200 is connected to the piston by a spring 201. The spring 201 is in a stretched preloaded state and stores elastic potential energy to drive the piston to move.

[0034] A connecting cavity 202 is provided on the inner wall of the connecting tube 104. A layer of film 203 is fixedly installed inside the connecting cavity 202. The film 203 is made of a heat-sensitive adhesive material that can melt or detach at a set temperature.

[0035] The inner wall of the film 203 is bonded to the piston, and the outer wall is fixed to the cavity wall of the connecting cavity 202, so that the piston is constrained by the film 203 under normal temperature conditions and remains stationary.

[0036] With the above setup, under normal operating conditions, the piston is bonded and fixed to the inner wall of the connecting cavity 202 by the film 203, while the spring 201 is in a stretched state but not released. At this time, the piston remains stationary, the entire liquid system is in a state of static pressure balance, the annular airbag 102 does not inflate, and it does not affect the normal installation and operation of the cable.

[0037] When the external ambient temperature rises to a set threshold (such as 180°C), the film 203 in the connecting cavity 202 undergoes a thermal response, resulting in changes such as melting, debonding, or decreased strength, ultimately leading to the failure of the bond between the film and the piston.

[0038] At this time, the spring 201 releases its elastic potential energy under the traction of the connecting ring 200, pushing the piston to slide along the connecting pipe 104. After the piston moves, it generates axial compression on the liquid in the connecting pipe 104, pushing the liquid into the liquid ring 103 and the air bladder through the connecting channel 106, thereby triggering the subsequent expansion and sealing process.

[0039] In this embodiment, the piston includes a push rod 300 and a copper rod 301 connected in sequence. The push rod 300 is used to slide axially and push liquid during the triggering action, and the copper rod 301 is used to bond and fix to the thermal film 203 to form a detection triggering part.

[0040] The spring 201 is fixedly connected to the push rod 300 and is in a stretched state, so as to push the push rod 300 to slide when the triggering condition is met.

[0041] The film 203 is made of a fusible material, with its inner wall connected to the copper rod 301 and its outer wall fixed to the inner wall of the connecting cavity 202. When the film 203 is intact, the copper rod 301 is constrained by the film 203, thereby keeping the entire piston assembly stationary and preventing malfunction of the piston.

[0042] With the above setup, firstly, the copper rod 301, as the core triggering component of the detection unit, utilizes its excellent thermal conductivity to rapidly conduct heat to the bonding area of ​​the film 203 in a high-temperature environment, thereby achieving precise detachment or melting of the thermal film 203 and improving the response speed and reliability of the device in the early stages of a fire.

[0043] Secondly, the push rod 300, as the main force transmission component of the piston, is made of a high-strength non-copper material, capable of withstanding the mechanical load during the driving process of the spring 201 and smoothly sliding within the pipeline to complete the liquid pressurization task. Compared to an all-copper structure, this design reduces system weight while saving component costs.

[0044] In this embodiment, the film 203 has an annular structure and is attached to the inner peripheral wall of the connecting cavity 202.

[0045] Preferably, the inner edge of the annular film 203 has a plurality of serrated weakening portions 204 formed along the circumferential direction to guide fracture when triggered by high temperature.

[0046] After the annular film 203 is bonded to the copper rod 301 of the piston, it forms an integrated positioning structure, which is used to lock the piston position at room temperature and can provide a more uniform axial constraint force.

[0047] With the above settings, when the ambient temperature in the area where the detection unit is located rises to a set threshold (e.g., 180°C), the annular film 203 gradually softens under the action of heat. The serrated weakened portion 204 on its inner edge melts first, guiding the crack to expand from a specific area to the entire annular film 203. As the adhesive force completely fails, the copper rod 301 detaches from the inner wall of the connecting cavity 202, releasing the constraint on the piston.

[0048] Compared to annular structures without serrated weakening structures, under the same temperature conditions, the film 203 with serrated weakening parts 204 has fewer contact points than a relatively complete annular film, allowing heat to accumulate rapidly at these pointed parts, causing softening and melting to occur first, forming a controllable circumferential pyrolysis path, so that the entire film 203 can completely break in a short time, thereby ensuring the effectiveness of the piston release action.

[0049] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A fireproof sealing device for cable inlets and outlets of a transformer box, characterized in that, include: A fixed sleeve (100) is provided at the cable inlet and outlet of the transformer box, and an extension sleeve (101) is connected to each end of the sleeve. One of the extension sleeves (101) is located inside the transformer box, and the other extension sleeve (101) is located outside the transformer box. An annular airbag (102) is provided in the inner cavity of the extension sleeve (101), and the annular airbag (102) is filled with liquid for expanding and adhering to the outer wall of the cable to form a seal when under pressure; A liquid ring (103) is provided on the outer wall of the fixed sleeve (100). The liquid ring (103) is filled with the same liquid as the annular airbag (102), and the liquid ring (103) is connected to the annular airbag (102) to provide hydraulic fluid replenishment to the annular airbag (102). A connecting pipe (104) is connected between the two extension sleeves (101), and both ends extend to the sides of the two extension sleeves (101), a piston is slidably connected inside the connecting pipe (104), and the connecting pipe (104) is in communication with the liquid ring (103). The detection part located between the piston and the connecting pipe (104) is used to push the piston to slide when the ambient temperature reaches a preset threshold, thereby forcing the liquid in the liquid ring (103) into the annular airbag (102) to achieve sealing around the cable.

2. The fireproof sealing device for cable inlets and outlets of a transformer box according to claim 1, characterized in that, The opening of the extension sleeve (101) is connected to a plurality of elastic plates (105).

3. The fireproof sealing device for cable inlets and outlets of a transformer box according to claim 1, characterized in that, The connecting pipe (104) has a connecting channel (106) extending into the liquid ring (103).

4. The fireproof sealing device for cable inlets and outlets of a transformer box according to claim 1, characterized in that, A connecting pipe (107) is connected to the liquid ring (103), and the connecting pipe (107) extends into the extension sleeve (101) and communicates with the annular airbag (102).

5. A fireproof sealing device for cable inlets and outlets of a transformer box according to claim 1, characterized in that, The detection unit includes a connecting ring (200) connected to the connecting tube (104), a spring (201) connected between the connecting ring (200) and the piston, a connecting cavity (202) is provided in the connecting tube (104), a film (203) is fixed in the connecting cavity (202), and the film (203) is bonded to the piston.

6. A fireproof sealing device for cable inlets and outlets of a transformer box according to claim 5, characterized in that, The piston includes a push rod (300) and a copper rod (301), the spring (201) is fixed on the push rod (300), and the film (203) is bonded to the copper rod (301).

7. A fireproof sealing device for cable inlets and outlets of a transformer box according to claim 6, characterized in that, The film (203) has a ring structure and is fitted to the inner circumferential wall of the connecting cavity (202). The inner edge of the film (203) is provided with a number of serrated weakening parts (204) along the circumferential direction and is bonded to the outer circumferential surface of the copper rod (301).

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