Self-heating medium voltage cable, laying system and laying method suitable for low temperature environments

Abstract

The application provides a self-heating medium-voltage cable suitable for a low-temperature environment, a laying system and a laying method, and relates to the technical field of cable manufacturing. The self-heating medium-voltage cable suitable for the low-temperature environment comprises a conductor, an insulation layer, an outer sheath and a heating unit. The insulation layer is wrapped around the outer periphery of the conductor. The outer sheath is wrapped around the outer periphery of the insulation layer. The heating unit comprises a heating element, the heating element is longitudinally embedded between the insulation layer and the outer sheath, and is used for heating and warming the insulation layer and the outer sheath. The heating element is provided with a plurality of heating elements, and the plurality of heating elements are uniformly or non-uniformly distributed along the circumferential direction of the insulation layer. Through the insulation layer, the outer sheath and the heating element, the insulation layer and the outer sheath can be heated and warmed conveniently, the cable can be circumferentially heat-compensated conveniently, the heating density can be improved in an easy heat-dissipation area, the stress concentration of the insulation layer and the outer sheath due to a too large temperature difference can be reduced, and the flexibility of the cable can be ensured during the laying, traction, bending and fixing processes of the cable.

Description

Technical Field

[0001] This application relates to the field of wire and cable technology, and in particular to a self-heating medium-voltage cable suitable for low-temperature environments, a laying system and a laying method. Background Technology

[0002] A cable is an electrical energy or signal transmission device consisting of one or more conductors, their insulation layer, and their sheath layer. In the laying and operation of cables in extremely cold regions or specific industrial environments such as polar research stations, power transmission lines in high-altitude and cold mountainous areas, power supply systems for cold storage warehouses, and outdoor industrial equipment in winter, cold-resistant materials, cable structure reinforcement, and external temporary heating are usually used as technical means for cable laying and operation.

[0003] However, under extremely low temperatures or temperature fluctuations, the molecular chain movement of the cable is restricted, which reduces the cable's flexibility and causes stress concentration. This stress concentration can lead to surface cracking or damage during cable laying, affecting the safety of cable laying and the reliability of long-term operation.

[0004] Therefore, how to improve the safety of cable laying and operation and the reliability of long-term operation in low-temperature environments has become an urgent technical problem to be solved. Summary of the Invention

[0005] This application provides a self-heating medium-voltage cable, laying system, and laying method suitable for low-temperature environments, in order to solve the problem of insulation layer cracking or sheath damage caused by mechanical stress concentration, which affects the service life of the cable.

[0006] In a first aspect, embodiments of this application provide a self-heating medium-voltage cable suitable for low-temperature environments, comprising:

[0007] conductor;

[0008] An insulating layer, which wraps around the outer periphery of the conductor;

[0009] The outer sheath wraps around the outer periphery of the insulation layer;

[0010] The heating unit includes a heating element, which is longitudinally embedded between the insulation layer and the outer sheath, and is used to heat the insulation layer and the outer sheath.

[0011] There are multiple heating elements, which are evenly or non-uniformly distributed along the circumferential direction of the insulation layer.

[0012] In one possible embodiment, the heating element is arranged along the axial direction of the conductor.

[0013] In one possible embodiment, multiple heating elements are arranged in parallel.

[0014] In one possible embodiment, the heating elements are non-uniformly distributed along the circumferential direction of the insulation layer, and the distribution density of the heating elements in areas with smaller bending radii is higher than that in areas with straight laying.

[0015] In one possible embodiment, the heating element includes a heating layer and multiple conductive heating wires;

[0016] Multiple conductive heating wires are distributed circumferentially along the insulating layer, and each conductive heating wire is arranged along the axial direction of the conductor.

[0017] The heating layer includes a heating element and a connecting element. The heating element is wrapped around the outer periphery of the conductive heating wire, and the connecting element connects two adjacent heating elements.

[0018] In one possible embodiment, the heating unit further includes a protective layer that wraps around the outer periphery of the heating layer.

[0019] In one possible embodiment, a protective layer is also included, which wraps around the outside of the heating element and is used to fix the heating element and provide thermal insulation.

[0020] In one possible embodiment, a wrapping layer is also included, which is disposed between the insulation layer and the heating unit.

[0021] Secondly, embodiments of this application provide a laying system for a self-heating medium-voltage cable suitable for low-temperature environments, including: an external control power supply, a temperature controller, and the aforementioned self-heating medium-voltage cable suitable for low-temperature environments;

[0022] A temperature controller is installed on the outer sheath surface of a self-heating medium-voltage cable suitable for low-temperature environments to detect the ambient temperature and the surface temperature of the self-heating medium-voltage cable suitable for low-temperature environments.

[0023] An external control power supply and a temperature controller are electrically connected to the heating unit of the self-heating medium-voltage cable suitable for low-temperature environments, and are used to adjust the heating temperature of the heating unit of the self-heating medium-voltage cable suitable for low-temperature environments according to the surface monitoring temperature of the self-heating medium-voltage cable suitable for low-temperature environments.

[0024] Thirdly, embodiments of this application provide a method for laying a self-heating medium-voltage cable suitable for low-temperature environments. The method, employing the aforementioned laying system for a self-heating medium-voltage cable suitable for low-temperature environments, includes the following steps:

[0025] Connect the heating unit of the self-heating medium-voltage cable suitable for low-temperature environments to an external control power supply;

[0026] Turn on the external control power supply to power the heating unit, causing it to heat up;

[0027] The surface temperature of the self-heating medium-voltage cable suitable for low-temperature environments is monitored by a temperature controller, and the heating temperature of the heating unit of the self-heating medium-voltage cable suitable for low-temperature environments is adjusted according to the monitored temperature.

[0028] When the temperature of the self-heating medium-voltage cable suitable for low-temperature environments reaches the preset laying temperature range, the bending, pulling and fixing operations of the self-heating medium-voltage cable suitable for low-temperature environments begin.

[0029] After the installation is completed, the heating process will be adjusted based on the ambient temperature, deciding whether to continue or intermittently.

[0030] The self-heating medium-voltage cable for low-temperature environments provided in this application features an insulation layer around the conductor, an outer sheath around the insulation layer, and a heating element embedded longitudinally between the insulation layer and the outer sheath. This facilitates heating of the insulation layer and outer sheath, enhancing the cable's temperature adaptability and structural flexibility in low-temperature environments. It reduces stress concentration and material performance degradation caused by low temperatures, preventing surface cracking or damage due to stress concentration during cable laying, and improving the safety of cable laying and the reliability of long-term operation. The uniform or non-uniform distribution of the heating element along the circumference of the insulation layer facilitates circumferential thermal compensation, preventing localized hardening caused by unilateral cooling in low-temperature environments. It also increases heating density in areas with high heat dissipation, reducing stress concentration caused by excessive temperature differences between the insulation layer and outer sheath, ensuring cable flexibility during laying, pulling, bending, and fixing. Attached Figure Description

[0031] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0032] Figure 1 A structural schematic diagram of a self-heating medium-voltage cable suitable for low-temperature environments provided in this application;

[0033] Figure 2 A schematic diagram of the heating unit in a self-heating medium-voltage cable suitable for low-temperature environments, provided for this application;

[0034] Figure 3 A schematic diagram of the structure of the self-heating medium-voltage cable laying system for low-temperature environments provided in this application.

[0035] Explanation of reference numerals in the attached figures:

[0036] 1000 - Self-heating medium-voltage cable suitable for low-temperature environments;

[0037] 1100 - Conductor; 1200 - Insulation layer; 1300 - Wrapping layer; 1400 - Heating unit; 1410 - Heating element; 1411 - Heating layer; 1411a - Heating part; 1411b - Connecting part; 1412 - Conductive heating wire; 1420 - Protective layer; 1500 - Sheath; 1600 - Outer sheath;

[0038] 2000 - External control power supply;

[0039] 3000 - Temperature Controller.

[0040] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0041] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0042] This application relates to the field of cable technology, specifically for applications in extremely cold regions, low-temperature industrial environments, and scenarios requiring cable laying and operation under low-temperature conditions. Examples include: power transmission lines in high-latitude regions, winter outdoor projects, power supply systems for low-temperature cold storage facilities, power supply networks for polar research stations, and industrial equipment power supply networks during cold seasons. These scenarios typically require cables to be exposed to sub-zero temperatures, or even tens of degrees below zero Celsius, for extended periods or short periods. The cables must not only meet the demands of power transmission but also maintain sufficient flexibility and structural stability during laying, pulling, bending, and fixing to prevent material performance degradation due to low temperatures, which could compromise cable laying and operational safety.

[0043] In existing cable laying and operation at low temperatures, cold-resistant materials and cable structure reinforcement are typically selected. Alternatively, external temporary heating and insulation covering are used before and after construction to improve the cable's condition. Specifically, relying on the cable material's inherent low-temperature adaptability or external environmental heating, the insulation and sheath layers are maintained within an operable temperature range during construction, thereby reducing bending cracks caused by low-temperature hardening.

[0044] Because cold-resistant materials have a limited applicable temperature range, further temperature decreases will lead to a reduction in cable flexibility and an increase in brittleness. Furthermore, external temporary heating methods rely on on-site arrangements, resulting in slow heating and uneven heat distribution, easily causing excessive localized temperature differences or significant heat loss within the cable, increasing both construction time and energy consumption. Additionally, damage to the insulation and sheathing layers is prone to occur during laying, affecting the safety of cable laying and operation, as well as its long-term reliability. Therefore, improving the temperature adaptability of cables during low-temperature environments, reducing mechanical damage caused by cable material embrittlement, and achieving active heating of the cable have become urgent technical problems to be solved.

[0045] To address the aforementioned issues, a self-heating medium-voltage cable 1000 suitable for low-temperature environments is proposed. The cable includes a conductor 1100, an insulation layer 1200 surrounding the conductor 1100, an outer sheath 1600 surrounding the insulation layer 1200, and a heating unit 1400 disposed between the insulation layer 1200 and the outer sheath 1600. The heating unit 1400 includes heating elements 1410, which are longitudinally embedded between the insulation layer 1200 and the outer sheath 1600 to heat the insulation layer 1200 and the outer sheath 1600. Multiple heating elements 1410 are provided, and these elements are uniformly or non-uniformly distributed along the circumferential direction of the insulation layer 1200. By introducing an active heating unit 1400 inside the cable, the cable maintains structural flexibility in low-temperature environments, thereby providing temperature protection for subsequent cable laying, pulling, fixing, and operation, and thus improving the cable's safety and long-term reliability in low-temperature environments. The heating element 1410 is evenly or non-uniformly distributed along the circumference of the insulation layer 1200, which facilitates circumferential thermal compensation of the cable. This avoids local hardening caused by unilateral cooling of the cable in low-temperature environments, and also increases the heating density in areas with good heat dissipation, reducing stress concentration caused by excessive temperature difference between the insulation layer 1200 and the outer sheath 1600, and ensuring the cable's flexibility during laying, pulling, bending, and fixing.

[0046] This application provides a self-heating medium-voltage cable 1000 suitable for low-temperature environments, referring to... Figure 1 As shown, it includes a conductor 1100, an insulating layer 1200 wrapped around the conductor 1100, an outer sheath 1600 wrapped around the insulating layer 1200, and a heating unit 1400 disposed between the insulating layer 1200 and the outer sheath 1600.

[0047] Among them, conductor 1100 serves as the conductive core and is used to transmit electrical energy; specifically, conductor 1100 is located in the innermost layer of the cable and serves as the internal support body of the outer structure.

[0048] Furthermore, the conductor 1100 can be made of copper, aluminum, copper-clad aluminum composite, or tin-plated copper, as long as it enables the transmission of electrical energy and provides support for the outer structure.

[0049] Furthermore, the conductor 1100 can be a single-core solid conductor 1100 structure or a multi-strand stranded conductor 1100 structure, as long as it realizes the transmission of electrical energy and supports the outer structure to ensure the flexibility and compactness of the cable.

[0050] The insulating layer 1200 is wrapped around the outer periphery of the conductor 1100 and closely adheres to the conductor 1100. It is used to isolate the conductor 1100 from other functional layers, prevent leakage and short circuit, and provide a stable mounting base for the heating unit 1400. Specifically, the insulating layer 1200 is formed by extrusion, covering or co-extrusion.

[0051] The outer sheath 1600 is wrapped around the outer periphery of the insulation layer 1200 and is located on the outermost side of the cable. It is used to protect the internal structure of the cable from mechanical damage, environmental corrosion and low temperature effects, and also serves as an external encapsulation for the heating unit 1400.

[0052] The heating unit 1400 is disposed between the insulating layer 1200 and the outer sheath 1600, and is used to heat the insulating layer 1200 and the outer sheath 1600. The heat generated by the heating unit 1400 is transferred to the insulating layer 1200 and the outer sheath 1600. Specifically, a heat conduction contact interface is formed between the heating unit 1400 and the insulating layer 1200 and the outer sheath 1600.

[0053] Furthermore, the heating unit 1400 can be constructed using heating wire, heating tape, carbon fiber heating wire, metal resistance wire, or composite heating strip, as long as the insulation layer 1200 and the outer sheath 1600 are heated to the desired temperature.

[0054] Specifically, the heating element 1410 is the component that actually performs electrothermal conversion, converting electrical energy into heat energy and transferring it as a heat source to the insulation layer 1200 and the outer sheath 1600 to enhance the structural flexibility of the cable.

[0055] The heating element 1410 is provided in multiple ways, and the multiple heating elements 1410 are evenly or non-uniformly distributed along the circumferential direction of the insulating layer 1200.

[0056] Furthermore, in this embodiment, the heating element 1410 can be two, three, or four, as long as the continuous heat conduction between the insulation layer 1200 and the outer sheath 1600 is ensured, and the insulation layer 1200 and the outer sheath 1600 are rapidly heated.

[0057] Specifically, when multiple heating elements 1410 are evenly distributed along the circumferential direction of the insulation layer 1200, the evenly distributed multiple heating elements 1410 help to ensure that the overall temperature of the cable remains balanced.

[0058] Specifically, when multiple heating elements 1410 are non-uniformly distributed along the circumferential direction of the insulation layer 1200, the non-uniformly distributed multiple heating elements 1410 facilitate the optimization of heat output according to the stress distribution of the cable, thereby improving the heating efficiency of the high-stress area of ​​the cable.

[0059] The self-heating medium-voltage cable 1000 provided in this application embodiment, suitable for low-temperature environments, provides power to the heating unit 1400 when the external control power supply 2000 supplies power. The heating element 1410 in the heating unit 1400 generates heat under the action of current. The heat is continuously diffused to both the inner and outer sides through close contact with the insulation layer 1200 and the outer sheath 1600, so that the insulation layer 1200 and the outer sheath 1600 gradually heat up and restore a suitable flexible state. The external control power supply 2000 adjusts the power supply according to the preset temperature or the detected cable temperature to control the heating state of the heating unit 1400. The heating unit 1400 facilitates heating of the insulation layer 1200 and the outer sheath 1600, improving the cable's temperature adaptability and structural flexibility in low-temperature environments. This reduces stress concentration and material performance degradation caused by low temperatures, and minimizes cracking or damage to the insulation layer 1200 and outer sheath 1600 during laying, pulling, bending, and fixing. This enhances the safety of cable laying and the reliability of long-term operation in frigid regions and low-temperature industrial environments. The heating elements 1410, evenly or non-uniformly distributed along the circumference of the insulation layer 1200, facilitate circumferential thermal compensation of the cable. This avoids localized hardening caused by unilateral cooling in low-temperature environments and increases heating density in areas with high heat dissipation, reducing stress concentration caused by excessive temperature differences between the insulation layer 1200 and the outer sheath 1600. This ensures the cable's flexibility during laying, pulling, bending, and fixing.

[0060] In one possible implementation, refer to Figure 1 As shown, the heating element 1410 is arranged along the axial direction of the conductor 1100.

[0061] The heating element 1410 heats the insulation layer 1200 and the outer sheath 1600 through the electrothermal effect. The heating element 1410 is arranged along the length of the cable so that its extension direction is consistent with the extension direction of the conductor 1100, thereby forming a longitudinally continuous heating path inside the cable. The heating element 1410 can uniformly transfer heat along the length of the cable, so that the insulation layer 1200 and the outer sheath 1600 are heated synchronously along the axial direction and gradually restore their flexibility.

[0062] Furthermore, the heating element 1410 is disposed between the outer peripheral surface of the insulation layer 1200 and the inner peripheral surface of the outer sheath 1600, and is attached, partially attached, or partially covered with the outer wall of the insulation layer 1200.

[0063] Specifically, the heating element 1410 can be a single straight heating wire laid axially around the outer perimeter of the cable, or multiple parallel heating wires can be laid parallel axially, or a heating tape can be continuously extended axially, or a heating tape can be spirally wound axially around the cable, as long as uniform heating of the insulation layer 1200 and the outer sheath 1600 is achieved.

[0064] Specifically, the material of the heating element 1410 can be a metal resistance wire, a carbon-based flexible heating element, or a metal alloy heating element, as long as the insulation layer 1200 and the outer sheath 1600 are heated.

[0065] The self-heating medium-voltage cable 1000 provided in this application embodiment, suitable for low-temperature environments, provides power to the heating element 1410 when the external control power supply 2000 supplies power. The heating element 1410 generates heat under the action of current and continuously heats the insulation layer 1200 and the outer sheath 1600 along its axial extension direction. The heat is transferred segment by segment along the length of the cable and makes the thermal conductivity of the outer sheath 1600 and the insulation layer 1200 tend to be balanced, so that the cable can reach a temperature range suitable for laying and operation in low-temperature environments.

[0066] By arranging the heating element 1410 along the axial direction of the conductor 1100, the heating path is kept consistent with the cable axis, thereby ensuring that the heat on the cable is continuous. This reduces local overheating, local cold spots, and thermal stress concentration in the cable, improves the flexibility and integrity of the insulation layer 1200 and the outer sheath 1600 after being heated, reduces bending cracks or damage to the cable surface caused by low-temperature hardening, and thus improves the cable's low-temperature resistance and long-term reliability.

[0067] In one possible implementation, refer to Figure 1 As shown, multiple heating elements 1410 are arranged in parallel.

[0068] The heating element 1410 is disposed between the insulation layer 1200 and the outer sheath 1600 and is used to convert electrical energy into heat energy, thereby actively heating the insulation layer 1200 and the outer sheath 1600 in a low-temperature environment to reduce the hardening and embrittlement of the cable material caused by low temperature during laying and operation.

[0069] Furthermore, multiple heating elements 1410 are arranged in parallel and laid circumferentially along the insulation layer 1200, thereby forming multiple heating channels, so that heat can be distributed and output circumferentially along the cable, avoiding excessive local temperature rise or uneven heating of the cable.

[0070] The self-heating medium-voltage cable 1000 provided in this application embodiment, suitable for low-temperature environments, has multiple parallel heating elements 1410 that generate heat synchronously or in groups after being energized. The heat diffuses circumferentially through the insulation layer 1200 and the outer sheath 1600, resulting in a uniform temperature rise of the cable. In addition, the heating elements 1410 are uniformly or non-uniformly distributed circumferentially along the insulation layer 1200, which facilitates thermal compensation of the cable in the circumferential direction. This can avoid local hardening caused by unilateral cooling of the cable in low-temperature environments, and can also increase the heating density in areas with good heat dissipation, reducing stress concentration caused by excessive temperature difference between the insulation layer 1200 and the outer sheath 1600, and ensuring the flexibility of the cable during laying, pulling, bending and fixing.

[0071] In one possible implementation, refer to Figure 1 As shown, the heating element 1410 is non-uniformly distributed along the circumferential direction of the insulating layer 1200, and the distribution density of the heating element 1410 in the region with a smaller bending radius is higher than the distribution density in the straight laying region.

[0072] The circumferential non-uniform distribution of the heating element 1410 means that it is not arranged along the outer periphery of the insulation layer 1200 with the same spacing, the same number, or the same coverage. Instead, it is configured differently in different circumferential areas according to the bending, turning, conduit, coiling, or pulling positions of the cable in the actual laying path, so that the cable can obtain higher thermal compensation capability in the parts with large curvature changes.

[0073] The self-heating medium-voltage cable 1000 suitable for low-temperature environments provided in this application embodiment has a heating unit 1400 that operates when powered on. The heating elements 1410 arranged between the insulation layer 1200 and the outer sheath 1600 first heat up the outer periphery of the cable. In areas with a denser circumferential distribution, the heating elements 1410 per unit length have a greater number or smaller spacing, which allows for faster heat transfer to the adjacent insulation layer 1200 and outer sheath 1600. This enables parts with smaller bending radii to reach a suitable flexibility state preferentially in low-temperature environments. In straight-lay areas, the density of heating elements 1410 is correspondingly reduced, thereby reducing the energy consumption of the cable during the insulation and heating process.

[0074] By differentiating the arrangement of heating elements 1410, the temperature recovery efficiency of the cable in high-stress areas is improved, and the number of heating elements 1410 in low-stress areas is reduced, thereby reducing the energy consumption during the cable heating process, improving the heating efficiency of the cable, enabling the cable to heat up quickly in low-temperature environments, and thus improving the cable's laying adaptability and operational reliability under low-temperature conditions.

[0075] In one possible implementation, refer to Figure 1 and Figure 2As shown, the heating element 1410 includes a heating layer 1411 and multiple conductive heating wires 1412; the multiple conductive heating wires 1412 are distributed circumferentially along the insulating layer 1200, and each conductive heating wire 1412 is arranged along the axial direction of the conductor 1100; the heating layer 1411 includes a heating part 1411a and a connecting part 1411b, the heating part 1411a is wrapped around the outer periphery of the conductive heating wire 1412, and the connecting part 1411b connects two adjacent heating parts 1411a.

[0076] The heating layer 1411 is used to fix, cover and diffuse heat from the conductive heating wire 1412.

[0077] Among them, multiple conductive heating wires 1412 serve as the heating carrier.

[0078] Furthermore, the heating layer 1411 includes a heating part 1411a and a connecting part 1411b. The heating part 1411a wraps around the outer periphery of the conductive heating wire 1412, and the connecting part 1411b connects two adjacent heating parts 1411a. It is composed of several heating parts 1411a that partially cover the conductive heating wire 1412 and transition connecting parts 1411b for connecting adjacent heating parts 1411a. Specifically, the connecting part 1411b between two adjacent heating parts 1411a can be one, or it can be two. It can be set to three, as long as the connection between two adjacent heating parts 1411a is achieved; in this embodiment, there are two connecting parts 1411b between two adjacent heating parts 1411a. The two connecting parts 1411b are arranged in parallel, and the two connecting parts 1411b are respectively located near the top and bottom of the heating part 1411a. The plane where the connecting part 1411b is located is tangent to the circumferential sidewall where the heating part 1411a is located, so as to ensure the stable positioning of the conductive heating wire 1412 and form a continuous heat conduction path.

[0079] The self-heating medium-voltage cable 1000 provided in this application embodiment, suitable for low-temperature environments, is powered by an external power source to the heating element 1410. Multiple axially arranged conductive heating wires 1412 simultaneously generate resistance heating. The heat is first transferred outward from the conductive heating wires 1412 to the heating part 1411a covering the outer periphery of the conductive heating wires 1412, and then diffused between adjacent heating parts 1411a via the connecting part 1411b, so that a continuous heating area is formed around the cable.

[0080] The heating layer 1411 limits and protects the conductive heating wire 1412, so that the heating element 1410 remains in a stable position during laying, traction, bending and fixing, thereby improving the structural stability and temperature adaptability of the cable under low temperature conditions and realizing the internal active heating and uniform heat distribution of the cable.

[0081] In one possible implementation, based on the foregoing embodiments, referring to Figure 1 and Figure 2 As shown, the heating unit 1400 also includes a protective layer 1420, which wraps around the outer periphery of the heating layer 1411.

[0082] The protective layer 1420 is used to isolate and protect the heating layer 1411 and the conductive heating wire 1412, and to ensure structural integrity when the cable is subjected to bending, squeezing, friction or low-temperature impact.

[0083] Specifically, the protective layer 1420 is arranged coaxially with the heating layer 1411 and is formed by overmolding, extrusion molding, coating curing or lamination, so that the protective layer 1420 is closely attached to the outer periphery of the heating layer 1411 and forms a stable interlayer bonding interface with the heating layer 1411.

[0084] The self-heating medium-voltage cable 1000 for low-temperature environments provided in this application embodiment, through the protective layer 1420 located between the heating layer 1411 and the outer sheath 1600, can reduce the mechanical action of the outer sheath 1600 on the heating layer 1411, and also prevent the influence of external moisture, corrosive media or low-temperature embrittlement environment on the heating layer 1411. Furthermore, the heating layer 1411 is electrically isolated and thermally diffused, so that the heat is transferred outward more evenly, thereby improving the safety, reliability and service life of the self-heating medium-voltage cable 1000 for low-temperature environments in extremely cold environments.

[0085] In one possible implementation, refer to Figure 1 and Figure 2 As shown, it also includes a protective layer 1500, which wraps around the outside of the heating element 1410 and is used to fix the heating element 1410 and provide heat insulation.

[0086] The sheath 1500 is used to position, protect and manage the heating element 1410 between the insulation layer 1200 and the outer sheath 1600, so that the heating element 1410 is stably maintained in the predetermined laying position, avoiding local stacking, twisting or displacement caused by relative slippage during cable pulling, bending, coiling or long-term thermal cycling, and reducing the heat conduction and heat radiation loss of the heating element 1410 to the external environment, thereby improving the heat utilization efficiency of the heating unit 1400.

[0087] The self-heating medium-voltage cable 1000 for low-temperature environments provided in this application embodiment uses a sheath 1500 to hold and restrict the relative displacement of the heating element 1410, so that it maintains a stable longitudinal and circumferential position during cable bending, laying and operation, reducing the heat conduction and heat radiation loss of the heating element 1410 to the external environment, improving the heat utilization efficiency of the heating unit 1400, and thus improving the stability, durability and low-temperature laying adaptability of the self-heating medium-voltage cable 1000 for low-temperature environments in extremely cold environments.

[0088] In one possible implementation, refer to Figure 1 and Figure 2 As shown, it also includes a wrapping layer 1300, which is disposed between the insulating layer 1200 and the heating unit 1400.

[0089] The wrapping layer 1300 is used to form a buffer, positioning and isolation interface between the outer surface of the insulation layer 1200 and the heating unit 1400, so as to stably support the heating unit 1400 and improve the heat conduction and mechanical bonding effect.

[0090] Furthermore, the wrapping layer 1300 can be formed in a spiral wrapping manner along the cable axis or in a longitudinal wrapping manner along the cable. The wrapping layer 1300 and the insulation layer 1200 are in close or semi-close contact. Moreover, the wrapping layer 1300 and the heating unit 1400 are stably connected through bonding, pressing, or heat fusion. Since the heating unit 1400 will generate thermal expansion and contraction effect when energized and heated, the wrapping layer 1300 can also provide a certain degree of isolation and transition between the insulation layer 1200 and the heating unit 1400, so that the heat is more evenly diffused between the insulation layer 1200 and the heating unit 1400, and the heating element 1410 heats the insulation layer 1200 and the outer sheath 1600 more stably.

[0091] Furthermore, after the wrapping layer 1300 is installed on the outer periphery of the insulation layer 1200, it can be wrapped to form a base layer before winding the heating unit 1400, or it can be synchronously compounded with the heating unit 1400 during continuous production.

[0092] Specifically, the wrapping layer 1300 and the insulation layer 1200 can be fixed together by wrapping tension, surface friction or local bonding, and the wrapping layer 1300 and the heating unit 1400 can be bonded together by pressing, hot melt bonding or adhesive layer, so as to ensure that the heating unit 1400 will not shift, lift or partially detach during cable use.

[0093] The self-heating medium-voltage cable 1000 provided in this application embodiment, suitable for low-temperature environments, first forms a uniform and continuous transition interface on the outer periphery of the insulation layer 1200 by the wrapping layer 1300. Then, the heating unit 1400 is attached to or wrapped around the outside of the wrapping layer 1300. After the cable is energized, the heat generated by the heating element 1410 is transferred to both the inner and outer sides through the heating unit 1400. Furthermore, the wrapping layer 1300 limits and isolates the heating unit 1400, keeping it in a stable position during cable bending, pulling, or low-temperature shrinkage. This makes the heating process of the insulation layer 1200 and the outer sheath 1600 more uniform, improving the laying efficiency, operational reliability, and long-term service life of the cable under severe cold conditions.

[0094] This application also provides a laying system for self-heating medium-voltage cables suitable for low-temperature environments, referring to... Figure 1 and Figure 3 As shown, it includes: an external control power supply 2000, a temperature controller 3000, and the self-heating medium-voltage cable 1000 suitable for low-temperature environments provided above; the temperature controller 3000 is disposed on the surface of the outer sheath 1600 of the self-heating medium-voltage cable 1000 suitable for low-temperature environments, and is used to detect the ambient temperature and the surface temperature of the self-heating medium-voltage cable 1000 suitable for low-temperature environments; the external control power supply 2000 and the temperature controller 3000 are electrically connected to the heating unit 1400 of the self-heating medium-voltage cable 1000 suitable for low-temperature environments, and are used to adjust the heating temperature of the heating unit 1400 of the self-heating medium-voltage cable 1000 suitable for low-temperature environments according to the surface temperature monitoring of the self-heating medium-voltage cable 1000 suitable for low-temperature environments.

[0095] The self-heating medium-voltage cable laying system for low-temperature environments provided in this application embodiment uses a temperature controller 3000 mounted on the surface of the outer sheath 1600 of the self-heating medium-voltage cable 1000. This facilitates the acquisition of ambient temperature and the surface temperature of the self-heating medium-voltage cable 1000, making the temperature information closer to the actual cooling state of the cable and improving the timeliness and accuracy of temperature judgment. Furthermore, the external control power supply 2000, temperature controller 3000, and heating unit 1400 form a linked control system, allowing for dynamic adjustment of the output of the heating unit 1400 based on the monitored surface temperature of the self-heating medium-voltage cable 1000. This ensures that the self-heating medium-voltage cable 1000 maintains a suitable temperature range during low-temperature laying, pulling, and operation, thereby reducing the embrittlement and additional stress on the insulation layer 1200 and outer sheath 1600 caused by low-temperature hardening and shrinkage.

[0096] A method for laying a self-heating medium-voltage cable suitable for low-temperature environments, using the aforementioned laying system for the self-heating medium-voltage cable 1000 suitable for low-temperature environments, includes the following steps: connecting the heating unit 1400 of the self-heating medium-voltage cable 1000 suitable for low-temperature environments to an external control power supply 2000; starting the external control power supply 2000 to supply power to the heating unit 1400, causing it to heat up; monitoring the surface temperature of the self-heating medium-voltage cable 1000 suitable for low-temperature environments through a temperature controller 3000, and adjusting the heating temperature of the heating unit 1400 of the self-heating medium-voltage cable 1000 suitable for low-temperature environments according to the monitored temperature; when the temperature of the self-heating medium-voltage cable 1000 suitable for low-temperature environments reaches a preset laying temperature range, starting the bending, pulling, and fixing operations of the self-heating medium-voltage cable 1000 suitable for low-temperature environments; after laying is completed, determining whether to continue or intermittently heat according to the ambient temperature.

[0097] The method for laying self-heating medium-voltage cables suitable for low-temperature environments provided in this application embodiment first connects the heating unit 1400 to an external control power supply 2000 and energizes it to generate heat, so that the self-heating medium-voltage cable 1000 suitable for low-temperature environments actively heats up from the inside in low-temperature environments, improving the low-temperature hardening state of the insulation layer 1200 and the outer sheath 1600; the surface temperature of the self-heating medium-voltage cable 1000 suitable for low-temperature environments is monitored in real time by the temperature controller 3000, and the heating temperature is adjusted according to the monitoring results, so that the heating process of the self-heating medium-voltage cable 1000 suitable for low-temperature environments is more uniform and the temperature control is more accurate. When the temperature of the self-heating medium-voltage cable 1000 suitable for low-temperature environments reaches the preset laying temperature range, bending, pulling and fixing operations are then carried out. After laying is completed, the heating is continued or intermittently determined according to the ambient temperature, thereby improving the construction safety and long-term reliability of the self-heating medium-voltage cable 1000 suitable for low-temperature environments under low-temperature conditions.

[0098] Finally, it should be noted that other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This invention is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein, and is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

Claims

1. A self-heating medium-voltage cable (1000) suitable for low-temperature environments, characterized in that, include: Conductor (1100); An insulating layer (1200) is wrapped around the outer periphery of the conductor (1100); An outer sheath (1600) is wrapped around the outer periphery of the insulating layer (1200); A heating unit (1400) includes a heating element (1410), which is longitudinally embedded between the insulating layer (1200) and the outer sheath (1600) and is used to heat the insulating layer (1200) and the outer sheath (1600). The heating element (1410) is provided in multiple ways, and the multiple heating elements (1410) are uniformly or non-uniformly distributed along the circumferential direction of the insulating layer (1200).

2. The self-heating medium-voltage cable (1000) suitable for low-temperature environments according to claim 1, characterized in that, The heating element (1410) is arranged along the axial direction of the conductor (1100).

3. The self-heating medium-voltage cable (1000) suitable for low-temperature environments according to claim 2, characterized in that, Multiple heating elements (1410) are arranged in parallel.

4. The self-heating medium-voltage cable (1000) suitable for low-temperature environments according to claim 3, characterized in that, The heating element (1410) is non-uniformly distributed along the circumferential direction of the insulating layer (1200), and the distribution density of the heating element (1410) in the region with a smaller bending radius is higher than the distribution density in the straight laying region.

5. The self-heating medium-voltage cable (1000) suitable for low-temperature environments according to any one of claims 1-4, characterized in that, The heating element (1410) includes a heating layer (1411) and multiple conductive heating wires (1412). Multiple conductive heating wires (1412) are distributed circumferentially along the insulating layer (1200), and each conductive heating wire (1412) is arranged along the axial direction of the conductor (1100). The heating layer (1411) includes a heating part (1411a) and a connecting part (1411b). The heating part (1411a) is wrapped around the outer periphery of the conductive heating wire (1412), and the connecting part (1411b) connects two adjacent heating parts (1411a).

6. The self-heating medium-voltage cable (1000) suitable for low-temperature environments according to claim 5, characterized in that, The heating unit (1400) also includes a protective layer (1420) which wraps around the outer periphery of the heating layer (1411).

7. The self-heating medium-voltage cable (1000) suitable for low-temperature environments according to claim 1, characterized in that, It also includes a protective layer (1500), which is wrapped around the outside of the heating element (1410) and is used to fix the heating element (1410) and provide heat insulation.

8. The self-heating medium-voltage cable (1000) suitable for low-temperature environments according to claim 1, characterized in that, It also includes a wrapping layer (1300) disposed between the insulating layer (1200) and the heating unit (1400).

9. A laying system for self-heating medium-voltage cables suitable for low-temperature environments, characterized in that, include: An external control power supply (2000), a temperature controller (3000), and a self-heating medium-voltage cable (1000) suitable for low-temperature environments as described in any one of claims 1-8. The temperature controller (3000) is disposed on the surface of the outer sheath (1600) of the self-heating medium-voltage cable (1000) suitable for low-temperature environments, and is used to detect the ambient temperature and the surface temperature of the self-heating medium-voltage cable (1000) suitable for low-temperature environments. The external control power supply (2000), the temperature controller (3000), and the heating unit (1400) of the self-heating medium-voltage cable (1000) suitable for low-temperature environments are electrically connected to each other and are used to adjust the heating temperature of the heating unit (1400) of the self-heating medium-voltage cable (1000) suitable for low-temperature environments according to the surface monitoring temperature of the cable.

10. A method for laying self-heating medium-voltage cables suitable for low-temperature environments, characterized in that, The laying system for self-heating medium-voltage cables suitable for low-temperature environments as described in claim 9 includes the following steps: Connect the heating unit (1400) of the self-heating medium-voltage cable (1000) suitable for low-temperature environments to the external control power supply (2000). The external control power supply (2000) is turned on to supply power to the heating unit (1400), causing it to heat up; The surface temperature of the self-heating medium-voltage cable (1000) suitable for low-temperature environments is monitored by the temperature controller (3000), and the heating temperature of the heating unit (1400) of the self-heating medium-voltage cable (1000) suitable for low-temperature environments is adjusted according to the monitored temperature. When the temperature of the self-heating medium-voltage cable (1000) suitable for low-temperature environments reaches the preset laying temperature range, the bending, pulling and fixing operations of the self-heating medium-voltage cable (1000) suitable for low-temperature environments begin. After the installation is completed, the heating process will be adjusted based on the ambient temperature, deciding whether to continue or intermittently.

Images