A fire-resistant and flame-retardant cross-linked polyethylene power cable

Abstract

This invention relates to the field of cross-linked polyethylene (XLPE) power cable technology, and proposes a fire-resistant and flame-retardant XLPE power cable, comprising a conductor, a conductor shielding layer, a XLPE insulation layer, an insulation shielding layer, a metal shielding layer, an inner sheath, an armor layer, and an outer sheath. It also includes a flame-retardant sleeve, a spacer ring, a sealing element, a release tube, and a driving element. The flame-retardant sleeve and the spacer ring are detachably mounted outside the outer sheath. The flame-retardant sleeve has multiple flame-retardant chambers inside, each containing a flame retardant agent. The sealing element communicates with the flame-retardant chambers for sealing them. One end of the release tube is connected to the sealing element via a connecting element, and the other end is detachably connected to the spacer ring. The driving element is located inside the flame-retardant sleeve. This technical solution addresses the problems of difficulty in actively responding to fires and high maintenance costs in existing technologies.

Description

Technical Field

[0001] This invention relates to the field of cross-linked polyethylene power cable technology, specifically to a fire-resistant and flame-retardant cross-linked polyethylene power cable. Background Technology

[0002] Cross-linked polyethylene (XLPE) is a modified polymer material that cross-links polyethylene molecular chains from a linear structure to a three-dimensional network structure through chemical or physical methods. The cross-linked polyethylene forms a thermosetting structure, which, compared with traditional polyethylene, has a higher heat resistance, higher mechanical strength, and excellent insulation and electrical properties. It is a core material for industrial cable manufacturing. The basic structure of cross-linked polyethylene insulated power cables typically includes a conductor, a conductor shielding layer, a cross-linked polyethylene insulation layer, an insulation shielding layer, a metal shielding layer, an inner sheath, an armor layer, and an outer sheath.

[0003] In actual use, cables often face the threat of external fires, high-temperature heat sources or open flames. Although the outer sheath of traditional cross-linked polyethylene insulated power cables has a certain flame retardancy, it is still easy for the outer sheath to melt and burn in continuous flame or high-temperature environments, causing the inner insulation layer to be exposed to high temperatures, which in turn leads to a sharp drop in insulation performance, short circuits or even the spread of fire.

[0004] In the existing technology, some flame-retardant cables improve their flame-retardant rating by adding flame retardants or using flame-retardant materials to the outer sheath. However, such passive flame-retardant methods cannot actively release flame retardants when a fire occurs, and it is difficult to accurately protect the local high-temperature areas of the cable. Furthermore, the outer sheath may be damaged after the cable is subjected to mechanical impact or compression, which further weakens its flame-retardant and heat-insulating capabilities. Once the cable catches fire or is damaged by heat, it is often necessary to replace the entire cable section, which results in high maintenance costs and difficult construction. Summary of the Invention

[0005] This invention proposes a fire-resistant and flame-retardant cross-linked polyethylene power cable to solve the problems of difficulty in actively responding to fires and high maintenance costs in existing technologies.

[0006] The technical solution of the present invention is as follows: A fire-resistant and flame-retardant cross-linked polyethylene power cable includes a conductor, a conductor shielding layer, a cross-linked polyethylene insulation layer, an insulation shielding layer, a metal shielding layer, an inner sheath, an armor layer, and an outer sheath layer, and further includes: Flame-retardant sleeves, wherein multiple flame-retardant sleeves are provided, and the flame-retardant sleeves are detachably disposed outside the outer sheath layer; Spacer rings, wherein multiple spacer rings are provided, and the spacer rings are detachably disposed outside the outer sheath layer, and the spacer rings and the flame-retardant sleeve are spaced apart; The flame-retardant sleeve has multiple flame-retardant chambers inside, and the flame-retardant chambers contain flame retardants. A sealing element, which is connected to the flame-retardant chamber and is used to seal the flame-retardant chamber, the sealing element comprising: A closed cylinder, wherein the closed cylinder and the flame-retardant sleeve are connected, and the closed cylinder is connected to a connecting pipe; A fixing plate is fixedly disposed inside the enclosed cylinder; A sealing plate is fixedly connected to a sliding rod, the sliding rod and the fixed plate are in sliding fit, a compression spring is provided between the fixed plate and the sealing plate, and the end of the sealing plate and the connecting pipe are pressed together to close the sealing cylinder; A release tube, one end of which is connected to the closure via a connecting member, and the other end of which is detachably connected to the spacer ring, wherein the connecting member includes: A connecting seat, wherein the connecting seat and the release pipe are rotatably connected, and the connecting seat and the connecting pipe are threadedly connected; A push rod is fixedly connected inside the connecting seat. When the connecting seat and the connecting pipe are threaded together, the push rod pushes the sealing plate away from the connecting pipe to open the sealing cylinder. A driving component, disposed inside the flame-retardant sleeve, is used to drive the flame retardant from the interior of the flame-retardant chamber to the release pipe after being heated. The driving component includes: A push plate is slidably disposed inside the flame-retardant chamber. A drive chamber is provided in the middle of the flame-retardant sleeve. The drive chamber contains thermally expanding gas and is connected to the flame-retardant chamber.

[0007] To improve the protection effect on the area between the flame-retardant sleeve and the spacer ring, an auxiliary protective component is detachably provided between the flame-retardant sleeve and the spacer ring. This auxiliary protective component is used to shield the area between the flame-retardant sleeve and the spacer ring, and includes: The elastic rings are provided in multiple ways, and a telescopic cover is provided between two adjacent elastic rings. The two ends of the elastic rings abut against each other under the action of elasticity. The elastic rings located at both ends are mounted on the flame-retardant sleeve and the spacer ring via mounting members, the mounting members comprising: An elastic plate, wherein the elastic plate and the elastic ring are fixedly connected; A limiting block is fixedly connected to the outside of the flame-retardant sleeve and the spacer ring, and a limiting hole matching the limiting block is provided on the elastic plate.

[0008] To enable the detachable design of the flame-retardant sleeve, the flame-retardant sleeve includes two flame-retardant half-cylinders. A connecting plate is fixedly connected to the end of each flame-retardant half-cylinder, and the connecting plate is detachably connected to the other flame-retardant half-cylinder via connecting bolts.

[0009] To improve the stability of the flame-retardant half-cylinder connection, a fixing block is provided at one end of the flame-retardant half-cylinder, and a fixing groove matching the fixing block is provided at the other end of the flame-retardant half-cylinder.

[0010] To improve the driving effect of the driving component, a heat-conducting plate is fixedly connected to the flame-retardant sleeve, and the heat-conducting plate extends into the drive chamber to accelerate heat transfer.

[0011] The working principle and beneficial effects of this invention are as follows: 1. In this invention, a flame-retardant chamber containing flame retardant and a drive component driven by thermal expansion gas are provided inside the flame-retardant sleeve. When the temperature around the cable rises, the heat-conducting plate transfers heat to the drive chamber. The gas in the drive chamber expands and pushes the push plate to deliver the flame retardant to the inside of the release tube. When the temperature is too high or combustion occurs, the release tube melts or burns first, and the flame retardant inside is delivered to the area where the spacer ring is located, thereby achieving active and rapid flame retardancy in a fire environment, effectively suppressing the spread of flames and protecting the cable body.

[0012] 2. In this invention, the flame-retardant sleeve adopts two flame-retardant half-cylinders that are detachably connected by connecting bolts, and the spacer ring can also be detachably set outside the outer sheath layer. Multiple flame-retardant sleeves and spacer rings can be flexibly arranged according to the actual protected length of the cable. When a unit is damaged or the flame retardant is consumed, it can be replaced individually without replacing the entire cable, which greatly reduces maintenance costs.

[0013] 3. In this invention, an auxiliary protective component is detachably installed between the flame-retardant sleeve and the spacer ring, which can shield the surface of the outer sheath to prevent the accumulation of dust and debris. At the same time, it can block the flame from directly burning the cable outer sheath in the early stage of a fire, further extending the cable's withstand time. Furthermore, the elastic ring can be quickly installed through the elastic plate and the limiting block, making it easy to disassemble and replace. Attached Figure Description

[0014] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0015] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a side view of the planar structure of the present invention; Figure 3 This is a schematic diagram of the structure of the flame-retardant sleeve and auxiliary protective components of the present invention; Figure 4 This is a schematic diagram of the structure of the spacer ring, release tube, flame-retardant sleeve and auxiliary protection components of the present invention; Figure 5 This is a schematic diagram of the structure of the spacer ring, release tube, flame-retardant sleeve and driving component of the present invention; Figure 6 This is a schematic diagram of the auxiliary protection component of the present invention; Figure 7 This is a schematic diagram of the flame-retardant chamber, flame-retardant half-cylinder, sealing component, and driving component of the present invention. Figure 8 This is a schematic diagram of the structure of the spacer ring, release tube, connecting ring, and connecting member of the present invention; Figure 9 This is a schematic diagram of the structure of the release tube, connector closure, and connecting member of the present invention; Figure 10 For the present invention Figure 1 A magnified schematic diagram of the structure at point A in the middle.

[0016] In the picture: 1. Conductor; 2. Conductor shielding layer; 3. Cross-linked polyethylene insulation layer; 4. Insulating shielding layer; 5. Metal shielding layer; 6. Inner sheath; 7. Armoring layer; 8. Outer sheath layer; 9. Spacer ring; 10. Flame retardant chamber; 11. Release tube; 12. Connector; 13. Connecting ring; 101. Flame-retardant half-cylinder; 102. Connecting plate; 103. Fixing block; 201. Enclosed cylinder; 202. Fixing plate; 203. Enclosed plate; 204. Connecting pipe; 205. Slide rod; 206. Compression spring; 301. Connecting seat; 302. Push rod; 401. Push plate; 402. Heat-conducting plate; 501. Elastic ring; 502. Telescopic cover; 601. Elastic plate; 602. Limiting block. Detailed Implementation

[0017] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0018] like Figure 1 , Figure 2 and Figure 10 As shown, this embodiment proposes a fire-resistant and flame-retardant cross-linked polyethylene power cable, including a conductor 1, a conductor shielding layer 2, a cross-linked polyethylene insulation layer 3, an insulation shielding layer 4, a metal shielding layer 5, an inner sheath 6, an armor layer 7, and an outer sheath layer 8, as well as a flame-retardant sleeve, a spacer ring 9, a sealing component, a release tube 11, and a driving component.

[0019] The conductor shielding layer 2 is located between the conductor 1 and the cross-linked polyethylene insulation layer 3. Its main function is to eliminate the electric field concentration phenomenon on the surface of the conductor 1. The stranded surface of the conductor 1 has irregular protrusions and burrs. If it comes into direct contact with the cross-linked polyethylene insulation layer 3, it will cause local electric field distortion. Under long-term action, it is easy to cause partial discharge and accelerate insulation aging. The conductor shielding layer 2 forms a smooth and equipotential transition interface and uniformly distributes the electric field to prevent partial discharge.

[0020] The cross-linked polyethylene insulation layer 3 is the core functional layer of the cable. Its function is to provide reliable electrical isolation between the conductor 1 and the shield, and to withstand voltage without being broken down. Cross-linked polyethylene is currently the most mainstream insulation material for medium and high voltage cables. Because it forms a three-dimensional network structure through chemical or physical cross-linking, it has significant improvements in heat resistance, mechanical strength and electrical performance compared with traditional polyethylene. It uses low-density polyethylene as the matrix, adds ethylene-vinyl acetate copolymer to improve the flame retardant filling capacity and improve toughness, adds modified magnesium hydroxide as the main flame retardant and has a smoke-suppressing effect, adds aluminum hydroxide for auxiliary flame retardancy and synergistic cooling, adds silane coupling agent to enhance the interface bonding between inorganic filler and resin, and then adds cross-linking agent, antioxidant and lubricant.

[0021] The insulating shielding layer 4 is located outside the cross-linked polyethylene insulation layer 3. Its function is similar to that of the conductor shielding layer 2. It is used to uniformly distribute the electric field on the outer surface of the cross-linked polyethylene insulation layer 3 and prevent partial discharge and electric field distortion caused by the irregular interface between the cross-linked polyethylene insulation layer 3 and the metal shielding layer 5. The main function of the metal shielding layer 5 is to carry fault current, shield external electromagnetic interference, and provide a zero-sequence current path. When a short-circuit fault occurs in the system, the metal shielding layer 5 can serve as a return path for the short-circuit current, protecting the cross-linked polyethylene insulation layer 3 and the conductor 1. The inner sheath 6 is located between the metal shielding layer 5 and the armor layer 7. Its main function is to buffer mechanical stress, prevent direct friction between the metal shielding layer 5 and the armor layer 7, and provide certain waterproof and flame-retardant auxiliary functions. The armor layer 7 is the mechanical protection layer of the cable. Its main function is to withstand external mechanical impact, tension, compression, and rodent bites, protecting the internal structure of the cable from damage. The outer sheath is the outermost structure of the cable and is in direct contact with the external environment. Its main functions are waterproof, moisture-proof, corrosion-proof, UV-resistant, and fire-retardant.

[0022] Multiple flame-retardant sleeves are provided, and the flame-retardant sleeves are detachably installed on the outside of the outer sheath layer 8, such as... Figure 5 and Figure 7As shown, the flame-retardant sleeve includes two flame-retardant half-cylinders 101. A connecting plate 102 is fixedly connected to the end of each flame-retardant half-cylinder 101. The connecting plate 102 is detachably connected to the other flame-retardant half-cylinder 101 by connecting bolts. A fixing block 103 is provided at one end of each flame-retardant half-cylinder 101, and a fixing groove matching the fixing block 103 is provided at the other end. The fit between the fixing block 103 and the fixing groove can improve the positional stability between the two flame-retardant half-cylinders 101. The two flame-retardant half-cylinders 101 can be spliced ​​into a complete flame-retardant sleeve by connecting bolts and fixed to the outside of the outer sheath layer 8. The flame-retardant sleeve is made of high-temperature and corrosion-resistant materials such as ceramicized silicone rubber, which can maintain structural integrity and continue to play a flame-retardant role in the event of a fire.

[0023] like Figure 5 As shown, multiple spacer rings 9 are provided. The spacer rings 9 are detachably installed outside the outer sheath layer 8. The spacer rings 9 and the flame-retardant sleeve are spaced apart. The spacer ring 9 includes two half rings, which are detachably connected by fixing bolts. The spacer rings 9 and the flame-retardant sleeve are made of the same material. The cable can be bent between the spacer rings 9 and the flame-retardant sleeve to adapt to different laying environments.

[0024] like Figure 5 and Figure 7 As shown, the flame-retardant sleeve has multiple flame-retardant chambers 10 inside, each containing a flame retardant. There are two sets of flame-retardant chambers 10, located on both sides of the flame-retardant sleeve. Each set contains multiple flame-retardant chambers 10. The flame retardant can be an organophosphate flame retardant, an inorganic flame retardant, a nitrogen compound, or a bromine compound, etc. It effectively inhibits the spread of flame by absorbing heat, cooling down, and isolating oxygen.

[0025] The closure is connected to the flame-retardant chamber 10 and is used to seal the flame-retardant chamber 10, such as... Figure 5 and Figure 9 As shown, the sealing component includes a sealing cylinder 201, a fixing plate 202, and a sealing plate 203. The sealing cylinder 201 is connected to a flame-retardant sleeve, and a connecting pipe 204 is connected to the sealing cylinder 201. The fixing plate 202 is fixedly installed inside the sealing cylinder 201. A sliding rod 205 is fixedly connected to the sealing plate 203. The sliding rod 205 and the fixing plate 202 are in sliding fit. A compression spring 206 is provided between the fixing plate 202 and the sealing plate 203. The ends of the sealing plate 203 and the connecting pipe 204 are pressed together to seal the sealing cylinder 201. The diameter of the sealing plate 203 is larger than the inner diameter of the connecting pipe 204 and smaller than the inner diameter of the sealing cylinder 201. Under the action of the compression spring 206, the sealing plate 203 seals the connection between the connecting pipe 204 and the sealing cylinder 201 to prevent the leakage of flame retardant.

[0026] like Figure 5 , Figure 8 and Figure 9As shown, one end of the release tube 11 is connected to a connecting member and a closing member, and the other end of the release tube 11 is detachably connected to a spacer ring 9. A connector 12 is fixedly connected to the spacer ring 9, and the connector 12 is provided with an external thread. The end of the release tube 11 away from the connecting member is rotatably connected to a connecting ring 13. The connecting ring 13 has an internal thread that matches the connector 12. The connection and disassembly of the release tube 11 and the spacer ring 9 can be realized through the threaded engagement of the connector 12 and the connecting ring 13. The connecting member includes a connecting seat 301 and a push rod 302. The connecting seat 301 and the release tube 11 are rotatably connected, and the connecting seat 301 and the connecting tube 204 are threadedly connected. The push rod 302 is fixedly connected inside the connecting seat 301. The seat 301 and the connecting tube 204 are threaded together. The push rod 302 pushes the sealing plate 203 away from the connecting tube 204 to open the sealing cylinder 201. The release tube 11 and the sealing element can be connected through the threaded connection between the connecting seat 301 and the connecting tube 204. During the connection process, the push rod 302 is inserted into the interior of the connecting tube 204 and pushes the sealing plate 203 away from the connecting tube 204 as the connecting seat 301 is screwed in, so that the flame retardant can flow into the release tube 11 through the gap between the sealing plate 203 and the sealing cylinder 201. The release tube 11 is made of a material with a low ignition point. When it encounters a fire or high temperature environment, the release tube 11 will melt or burn first, and the flame retardant inside can flow out and cover the surface of the cable to form a flame retardant layer.

[0027] The driving component is located inside the flame-retardant sleeve and is used to drive the flame retardant from the inside of the flame-retardant chamber 10 to the release pipe 11 after being heated, such as... Figure 5 and Figure 7 As shown, the driving component includes a push plate 401, which is slidably and sealed inside the flame-retardant chamber 10. A driving chamber is provided in the middle of the flame-retardant sleeve, and the driving chamber contains thermally expanding gas. The driving chamber and the flame-retardant chamber 10 are connected. To improve the driving effect of the driving component, a heat-conducting plate 402 is fixedly connected to the flame-retardant sleeve. The heat-conducting plate 402 extends into the driving chamber to accelerate heat transfer. When the temperature rises, the heat-conducting plate 402 transfers heat to the interior of the driving chamber, causing the gas to expand due to heat. The pressure inside the driving chamber increases, pushing the push plate 401 outward and pushing the flame retardant in the flame-retardant chamber 10 into the interior of the release pipe 11. This facilitates the timely release of the flame retardant after the release pipe 11 melts, thereby improving the flame-retardant response speed.

[0028] To improve the protection effect on the area between the flame-retardant sleeve and the spacer ring 9, an auxiliary protective component is detachably installed between the flame-retardant sleeve and the spacer ring 9. This auxiliary protective component is used to shield the area between the flame-retardant sleeve and the spacer ring 9, such as... Figure 3 , Figure 4 and Figure 6As shown, the auxiliary protective component includes multiple elastic rings 501. A telescopic cover 502 is provided between adjacent elastic rings 501. Each elastic ring 501 is made of a rod-shaped elastic material bent into a ring shape, with its two ends abutting against each other under elastic action. The elastic rings 501 at both ends are mounted on the flame-retardant sleeve and spacer ring 9 via mounting components. The mounting components include an elastic plate 601 and a limiting block 602. The elastic plate 601 and the elastic rings 501 are fixedly connected, and the limiting block 602 is fixedly connected to the outside of the flame-retardant sleeve and spacer ring 9. The elastic plate 601 has limiting holes that match the limiting block 602. The elastic ring 501 and the elastic plate 601 can be made of iron or elastic plastic and have deformation and reset functions. The elastic ring 501 can be stretched to a certain extent and fitted onto the outside of the flame-retardant sleeve and the spacer ring 9. Under the action of elasticity, the elastic ring 501 and the elastic plate 601 return to the circular shape. The limiting block 602 is pushed into the limiting hole to ensure the stability of the elastic plates 601 at both ends. Thus, the auxiliary protective component is installed between the flame-retardant sleeve and the spacer ring 9 to shield the area between the flame-retardant sleeve and the spacer ring 9 and reduce the intrusion of external dust and moisture. The elastic ring 501 can be stretched to remove it from between the flame-retardant sleeve and the spacer ring 9.

[0029] The working principle or usage process of the fire-resistant and flame-retardant cross-linked polyethylene power cable is as follows: First, according to the length of the cable to be protected, multiple flame-retardant sleeves and spacer rings 9 are installed in sequence outside the outer sheath layer 8. First, two flame-retardant half-sleeves 101 are fastened to the cable and positioned by fixing blocks 103 and fixing grooves. Then, the two flame-retardant half-sleeves 101 are connected by connecting bolts. Finally, the spacer rings 9 are put on the cable and fixed by fixing bolts. Then, one end of the release tube 11 is threaded to the connecting tube 204 through the connecting seat 301. During the connection process, the push rod 302 pushes open the sealing plate to realize the connection between the release tube 11 and the flame-retardant chamber 10. The other end is connected to the spacer ring 9 through the connector 12 and the connecting ring 13. Finally, the elastic plate 601 and the elastic ring 501 are opened so that the limiting hole on the elastic plate 601 is aligned with the limiting block 602. Under the action of elasticity, the two ends of the elastic ring 501 are pressed together. The elastic ring 501 is wrapped between the flame retardant sleeve and the spacer ring 9. The flame retardant chamber 10 is pre-filled with flame retardant, and the drive chamber is filled with thermal expansion gas. In the initial state, the sealing plate 203 is pressed against the end of the connecting pipe 204 under the action of the compression spring 206 to seal it. When a fire occurs in the environment where the cable is located or the local temperature rises sharply, the heat is quickly transferred to the inside of the drive chamber through the heat-conducting plate 402 on the surface of the flame-retardant sleeve. The thermal expansion gas in the drive chamber expands in volume due to the heat, generating pressure to push the push plate 401. The push plate 401 compresses the flame retardant in the flame-retardant chamber 10 and pushes it to the release pipe 11, where it accumulates. When the release pipe 11 is heated and melts or burns, the flame retardant is evenly sprayed on the surface of the cable outer sheath. After the flame retardant covers the surface, it can isolate oxygen, absorb heat, or form an inert protective layer, thereby effectively inhibiting the combustion of the cable outer sheath and protecting the inner cross-linked polyethylene insulation layer 3 from high temperature damage. Meanwhile, the telescopic cover 502 in the auxiliary protection component can block the flame from directly impacting the cable outer sheath and prevent dust and oil from accumulating in the area between the flame-retardant sleeve and the spacer ring 9. When the flame retardant in a certain flame-retardant sleeve is used up or needs to be replaced, the flame-retardant sleeve can be replaced individually by simply disassembling the connecting bolts and connecting parts at the corresponding position, which reduces maintenance costs.

[0030] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A fire-resistant and flame-retardant cross-linked polyethylene power cable, comprising a conductor (1), a conductor shielding layer (2), a cross-linked polyethylene insulation layer (3), an insulation shielding layer (4), a metal shielding layer (5), an inner sheath (6), an armor layer (7), and an outer sheath layer (8), characterized in that, Also includes: Flame-retardant sleeves, wherein multiple flame-retardant sleeves are provided, and the flame-retardant sleeves are detachably disposed outside the outer sheath layer (8); Spacer ring (9), multiple spacer rings (9) are provided, the spacer ring (9) is detachably provided outside the outer sheath layer (8), and the spacer ring (9) and the flame retardant sleeve are spaced apart; The flame-retardant sleeve has multiple flame-retardant chambers (10) inside, and each flame-retardant chamber (10) contains a flame retardant. A sealing element, which is connected to the flame-retardant chamber (10), is used to seal the flame-retardant chamber (10); Release tube (11), one end of the release tube (11) is connected to the closure through a connecting member, and the other end of the release tube (11) is detachably connected to the spacer ring (9); A driving component, disposed inside the flame-retardant sleeve, is used to drive the flame retardant from the inside of the flame-retardant chamber (10) to the release pipe (11) after being heated.

2. The fire-resistant and flame-retardant cross-linked polyethylene power cable according to claim 1, characterized in that, The closure includes: A closed cylinder (201) is connected to the flame-retardant sleeve, and a connecting pipe (204) is connected to the closed cylinder (201). A fixing plate (202) is fixedly disposed inside the closed cylinder (201); A sealing plate (203) is fixedly connected to a sliding rod (205). The sliding rod (205) and the fixed plate (202) are in sliding fit. A compression spring (206) is provided between the fixed plate (202) and the sealing plate (203). The ends of the sealing plate (203) and the connecting pipe (204) are pressed together to close the sealing cylinder (201).

3. The fire-resistant and flame-retardant cross-linked polyethylene power cable according to claim 2, characterized in that, The connecting element includes: Connecting seat (301), the connecting seat (301) and the release tube (11) are rotatably connected, the connecting seat (301) and the connecting tube (204) are threadedly connected; Push rod (302), which is fixedly connected inside the connecting seat (301), when the connecting seat (301) and the connecting pipe (204) are threadedly connected, the push rod (302) pushes the sealing plate (203) away from the connecting pipe (204) to open the sealing cylinder (201).

4. The fire-resistant and flame-retardant cross-linked polyethylene power cable according to claim 1, characterized in that, The driving component includes: Push plate (401) is sealed and slidably disposed inside the flame retardant chamber (10). A drive chamber is provided in the middle position of the flame retardant sleeve. The drive chamber contains thermal expansion gas. The drive chamber and the flame retardant chamber (10) are connected.

5. A fire-resistant and flame-retardant cross-linked polyethylene power cable according to claim 1, characterized in that, An auxiliary protection component is detachably provided between the flame-retardant sleeve and the spacer ring (9), and the auxiliary protection component is used to shield the area between the flame-retardant sleeve and the spacer ring (9).

6. A fire-resistant and flame-retardant cross-linked polyethylene power cable according to claim 5, characterized in that, The auxiliary protection components include: Elastic ring (501), multiple elastic rings (501) are provided, and a telescopic cover (502) is provided between two adjacent elastic rings (501). The two ends of the elastic ring (501) abut against each other under elastic action. The elastic rings (501) located at both ends are mounted on the flame-retardant sleeve and the spacer ring (9) by mounting components.

7. A fire-resistant and flame-retardant cross-linked polyethylene power cable according to claim 6, characterized in that, The mounting component includes: An elastic plate (601) and an elastic ring (501) are fixedly connected; The limiting block (602) is fixedly connected to the outside of the flame-retardant sleeve and the spacer ring (9), and the elastic plate (601) has a limiting hole that matches the limiting block (602).

8. A fire-resistant and flame-retardant cross-linked polyethylene power cable according to claim 1, characterized in that, The flame-retardant sleeve includes two flame-retardant half-cylinders (101), and a connecting plate (102) is fixedly connected to the end of each flame-retardant half-cylinder (101). The connecting plate (102) is detachably connected to the other flame-retardant half-cylinder (101) by connecting bolts.

9. A fire-resistant and flame-retardant cross-linked polyethylene power cable according to claim 8, characterized in that, One end of the flame-retardant semi-cylinder (101) is provided with a fixing block (103), and the other end of the flame-retardant semi-cylinder (101) is provided with a fixing groove that matches the fixing block (103).

10. A fire-resistant and flame-retardant cross-linked polyethylene power cable according to claim 4, characterized in that, A heat-conducting plate (402) is fixedly connected to the flame-retardant sleeve, and the heat-conducting plate (402) extends into the drive chamber to accelerate heat transfer.

Images