Thermally stable medium and high voltage cables suitable for high temperature difference scenarios

Abstract

The present invention relates to the technical field of high-voltage cables, and specifically to a thermally stable medium- and high-voltage cable suitable for high-temperature difference scenarios, comprising a first rib arranged outside an inner sheath layer, a second rib arranged inside an outer sheath layer, and recessed areas of a wavy structure of an insulating layer respectively and alternately accommodating ends of the first rib and the second rib one by one, and the bottoms of the recessed areas respectively fit with the ends of the first rib and the second rib, so that an inner circle heat dissipation cavity is formed between the inner sheath layer and the insulating layer, and an outer circle heat dissipation cavity is formed between the outer sheath layer and the insulating layer, which significantly increases the heat dissipation surface area of ​​the cable and improves the overall heat dissipation performance. The insulating layer is formed into a wavy structure, which increases the heat dissipation surface area, helps to quickly conduct and dissipate heat in the heat dissipation cavity, reduces the internal temperature of the cable, and reduces the thermal aging rate of the material, thereby extending the service life of the cable, effectively preventing overheating of the cable, reducing the risk of fire, and enhancing the operation safety of the cable.

Description

Technical Field

[0001] The present invention relates to the technical field of high-voltage cables, and in particular to a thermally stable medium- and high-voltage cable suitable for high temperature difference scenarios. Background Art

[0002] Medium and high voltage cables suitable for high temperature difference scenarios are power transmission cables designed to cope with high temperature changes and harsh environments. Such cables are widely used in industries, energy, infrastructure and other fields, especially in situations where reliable and stable power supply is required, such as petrochemicals, metallurgy, mining and other fields. Existing products of this type often have the following characteristics:

[0003] The cable material has high temperature resistance and can maintain stable electrical and mechanical properties in high temperature environments. High temperature resistant polymers or cross-linked polyethylene (XLPE) are usually used as insulation materials. The cable structure design fully considers the thermal expansion coefficient to reduce the probability of the cable affecting its performance or causing mechanical damage due to thermal expansion and contraction when the temperature changes drastically.

[0004] Although the current products can meet the existing usage requirements based on the above characteristics, there is no obvious breakthrough in heat dissipation, which limits the improvement of product performance. For example:

[0005] High temperature environment will accelerate the aging of cable materials, especially the insulation layer and sheath materials. Overheating will cause the physical and chemical properties of the materials to deteriorate, such as cracking, hardening and embrittlement, which will in turn affect the insulation performance and mechanical strength of the cable. Frequent temperature fluctuations will aggravate these problems, resulting in a significant shortening of the service life of the cable. The cable may suffer mechanical damage and structural deformation due to thermal expansion and contraction, such as sheath cracking and insulation layer damage. This not only affects the performance of the cable, but may also cause safety accidents. Due to poor heat dissipation, the cable is limited in design and use. For example, the current carrying capacity of the cable needs to be strictly controlled to avoid overheating, which limits the actual transmission capacity of the cable.

[0006] The information disclosed in this background technology section is only intended to deepen the understanding of the overall background technology of the present invention, and should not be regarded as acknowledging or suggesting in any form that the information constitutes the prior art already known to those skilled in the art. Summary of the invention

[0007] The present invention provides a medium- and high-voltage cable with thermal stability suitable for high temperature difference scenarios, thereby effectively solving the problems pointed out in the background technology.

[0008] In order to achieve the above object, the technical solution adopted by the present invention is:

[0009] A thermally stable medium and high voltage cable suitable for high temperature difference scenarios, comprising a plurality of conductors arranged in a central twisted arrangement, a conductor shielding layer, an insulating shielding layer, an inner sheath layer, an insulating layer, an outer sheath layer and a metal layer arranged sequentially on the outer layers of the plurality of conductors;

[0010] A raised first rib is arranged on the outside of the inner sheath layer, and a raised second rib is arranged on the inside of the outer sheath layer. The cross-section of the insulating layer is a wavy structure, and recessed areas are alternately arranged on the inner and outer sides of the wavy structure. The ends of the first rib and the second rib are accommodated alternately one by one corresponding to the recessed areas, and the bottoms of the recessed areas are respectively fitted with the ends of the first rib and the second rib, so that an inner circle heat dissipation cavity separated by the first rib is formed between the inner sheath layer and the insulating layer, and an outer circle heat dissipation cavity separated by the second rib is formed between the outer sheath layer and the insulating layer.

[0011] Furthermore, the distance from the end of the first tendon to the center of the cable is greater than the distance from the end of the second tendon to the center of the cable.

[0012] Furthermore, the inner sheath layer, the insulating layer and the outer sheath layer are all formed by a pultrusion process.

[0013] Furthermore, during the pultrusion molding process of the insulation layer, by controlling the size of the pultrusion die, the insulation layer is made to fit with the end of the first tendon through elastic deformation after molding is completed, and the fitting position of the insulation layer and the end of the first tendon is evenly distributed with a number of through holes along the length direction of the cable.

[0014] Furthermore, the insulating layer is made of a material with high elasticity and high thermal sensitivity.

[0015] Furthermore, the elasticity of the insulating layer is greater than the elasticity of the inner sheath layer and the outer sheath layer.

[0016] Furthermore, the recessed area is spaced apart from both sides of the first rib.

[0017] Furthermore, the recessed area is spaced apart from two sides of the second rib.

[0018] Furthermore, the inner ring heat dissipation cavity space is larger than the outer ring heat dissipation cavity space.

[0019] Furthermore, the metal layer includes an inner metal shielding layer and an outer armor layer, and the heat dissipation effect is ensured by the thermal conductivity of the metal.

[0020] Through the technical scheme of the present invention, the following technical effects can be achieved: by forming an inner ring heat dissipation cavity between the inner sheath layer and the insulating layer, and forming an outer ring heat dissipation cavity between the outer sheath layer and the insulating layer, the heat dissipation surface area of ​​the cable is significantly increased, and the overall heat dissipation performance is improved. The insulating layer is formed into a wavy structure, which increases the heat dissipation surface area, helps to quickly conduct and dissipate the heat in the heat dissipation cavity, and the metal layer outside the outer sheath layer can quickly dissipate the heat from the heat dissipation cavity. Through effective heat dissipation design, the internal temperature of the cable is reduced, and the thermal aging rate of the material is reduced, thereby extending the service life of the cable. The design of the inner ring heat dissipation cavity and the outer ring heat dissipation cavity effectively prevents overheating of the cable, reduces the risk of fire, and enhances the operating safety of the cable. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 A cross-sectional view of a thermally stable medium and high voltage cable suitable for high temperature difference scenarios;

[0023] Figure 2 For Figure 1 A partial enlarged view of the middle A;

[0024] Figure 3 This is a schematic diagram of the end face of a thermally stable medium and high voltage cable suitable for high temperature difference scenarios;

[0025] Figure 4 It is a schematic diagram of the structure of a thermally stable medium and high voltage cable suitable for high temperature difference scenarios;

[0026] Figure 5 is a schematic diagram of the structure of the inner sheath layer;

[0027] Figure 6 is a schematic diagram of the structure of the insulating layer;

[0028] Figure 7 Schematic diagram of the structure of the outer sheath layer.

[0029] Figure numerals: 1. conductor; 2. conductor shielding layer; 3. insulating shielding layer; 4. inner sheath layer; 41. first rib; 42. inner circle heat dissipation cavity; 5. insulating layer; 51. recessed area; 52. through hole; 53. deformation position; 6. outer sheath layer; 61. second rib; 62. outer circle heat dissipation cavity; 7. metal shielding layer; 8. armor layer. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0032] like Figures 1 to 7 As shown: a thermally stable medium and high voltage cable suitable for high temperature difference scenarios, comprising a plurality of conductors 1 arranged in a central twisted arrangement, a conductor shielding layer 2 sequentially arranged on the outer layer of the plurality of conductors 1, an insulating shielding layer 3, an inner sheath layer 4, an insulating layer 5, an outer sheath layer 6 and a metal layer, reference Figure 1 , Figure 4 Specifically, the conductor 1 is made of copper or aluminum with high conductivity, and multiple conductors 1 are twisted to improve flexibility and conductivity; the conductor shielding layer 2 is made of semi-conductive material, such as a semi-conductive tape or a semi-conductive layer, to provide uniform electric field distribution, prevent electric field concentration, and protect the insulating layer 5 of the conductor 1; the insulating shielding layer 3 is made of semi-conductive material to further uniformize the electric field, prevent the electric field from concentrating on the surface of the insulating layer 5, and protect the insulating layer 5; the inner sheath layer 4 is made of polyvinyl chloride (PVC), polyethylene (PE) or other polymer materials, and provides basic mechanical protection and electrical insulation; the insulating layer 5 provides electrical insulation to prevent current leakage; the outer sheath layer 6 provides mechanical protection and environmental protection, such as moisture resistance, corrosion resistance and UV resistance;

[0033] like Figure 5 As shown, the inner sheath layer 4 is provided with a raised first rib 41 on the outside. Figure 7 As shown, a raised second rib 61 is provided inside the outer sheath layer 6. Figure 6 As shown, the cross section of the insulating layer 5 is a wavy structure. Figure 2 As shown, recessed areas 51 are alternately provided on the inner and outer sides of the wavy structure, and the corresponding recessed areas 51 respectively and alternately accommodate the ends of the first rib 41 and the second rib 61 one by one, and the bottoms of the recessed areas 51 are respectively fitted with the ends of the first rib 41 and the second rib 61, so that an inner circle heat dissipation cavity 42 separated by the first rib 41 is formed between the inner sheath layer 4 and the insulating layer 5, and an outer circle heat dissipation cavity 62 separated by the second rib 61 is formed between the outer sheath layer 6 and the insulating layer 5.

[0034] By forming an inner circle heat dissipation cavity 42 between the inner sheath layer 4 and the insulating layer 5, and forming an outer circle heat dissipation cavity 62 between the outer sheath layer 6 and the insulating layer 5, the heat dissipation surface area of ​​the cable is significantly increased, and the overall heat dissipation performance is improved. The insulating layer 5 is formed into a wavy structure, which increases the heat dissipation surface area and helps to quickly conduct and dissipate the heat in the heat dissipation cavity. The metal layer outside the outer sheath layer 6 can quickly dissipate the heat from the heat dissipation cavity. Through effective heat dissipation design, the internal temperature of the cable is reduced, and the thermal aging rate of the material is reduced, thereby extending the service life of the cable. The design of the inner circle heat dissipation cavity 42 and the outer circle heat dissipation cavity 62 effectively prevents the cable from overheating, reduces the risk of fire, and enhances the operating safety of the cable.

[0035] The first rib 41 outside the inner sheath layer 4 and the second rib 61 inside the outer sheath layer 6, by fitting with the recessed area 51 of the wavy structured insulating layer 5, not only enhance the mechanical bonding force between the layers, but also improve the overall structural stability of the cable. The fitting of the recessed area 51 of the wavy structured insulating layer 5 with the ends of the first rib 41 and the second rib 61 ensures the electrical insulation performance of the cable under high voltage, while preventing electric field concentration, further improving the stability of the electrical performance.

[0036] The inner ring heat dissipation cavity 42 and the outer ring heat dissipation cavity 62 provide a buffer space when the cable expands due to heat or contracts due to cooling, thereby reducing the mechanical stress of the material caused by thermal expansion and contraction. This buffering effect can effectively prevent mutual extrusion and stretching between the cable layers, avoid material fatigue and damage caused by mechanical stress, and reduce the risk of material fatigue and cracks by buffering the stress caused by thermal expansion and contraction, thereby extending the overall service life of the cable.

[0037] As a preferred embodiment of the above, refer to Figure 3 , the distance from the end of the first tendon 41 to the center of the cable is greater than the distance from the end of the second tendon 61 to the center of the cable, that is, Figure 3 H2>H1 in the diagram, so when the outer sheath layer 6 rotates circumferentially relative to the inner sheath layer 4, the two can block each other to avoid excessive deformation of the insulating layer 5. Excessive deformation may cause the insulating layer 5 to crack or be damaged, thereby increasing the risk of cable failure. By preventing the insulating layer 5 from excessive deformation, the probability of cable failure can be reduced and the safety of its operation can be improved.

[0038] In this embodiment, the inner sheath layer 4, the insulating layer 5 and the outer sheath layer 5 are all formed by a pultrusion process. On the one hand, the pultrusion process can ensure the purity and density of the insulating layer 5 material, provide excellent electrical insulation performance, reduce the electrical loss of the cable, and improve the power transmission efficiency; on the other hand, the pultrusion process can ensure the uniformity and consistency of the material, reduce product defects, and improve product quality; in addition, the pultrusion process can realize the molding of complex structures, which is suitable for cable designs of different cross-sectional shapes and sizes to meet diverse application needs.

[0039] As a preferred embodiment of the above, refer to Figure 6 During the pultrusion molding process of the insulating layer 5, the size of the pultrusion die is controlled so that after the molding is completed, the insulating layer 5 is fitted with the end of the first tendon 41 through elastic deformation, and the fitting position of the insulating layer 5 and the end of the first tendon 41 is uniformly distributed with a plurality of through holes 52 along the length direction of the cable. For details, refer to Figure 2 In a normal state, the through hole 52 is blocked by the first rib 41 to maintain the isolation of the inner circle heat cavity and the outer circle heat dissipation cavity 62, ensure the insulation effect of the cable, and prevent current leakage; when the temperature of the inner circle heat dissipation cavity 42 is high, the fitting position is deformed due to the expansion of the air in the cavity, that is, the fitting deformation position 53 of the insulating layer 5 and the inner sheath layer 4 is deformed, and the blocking of the through hole 52 by the first rib 41 is released to form a flow channel between the inner and outer heat dissipation cavities. This dynamic heat dissipation management mechanism can automatically adjust the heat dissipation path according to temperature changes to improve the heat dissipation efficiency. Through effective dynamic heat dissipation management, the temperature inside the cable is significantly reduced, the thermal aging rate of the insulating material is reduced, and the service life of the cable is extended. By accurately designing the pultrusion die and controlling the elasticity of the material, the automatic opening and closing of this intelligent heat dissipation channel can be realized, the functionality and intelligence level of the cable can be improved, and dynamic heat dissipation management can be realized.

[0040] Among them, the insulating layer 5 is made of a material with high elasticity and high thermal sensitivity. Specifically, the insulating layer 5 can be cross-linked polyethylene (XLPE) or other materials with high elasticity and high thermal sensitivity to ensure that it can be flexibly deformed under high temperature conditions. By precisely controlling the size and shape of the pultrusion die, it is ensured that the insulating layer 5 can accurately fit the inner sheath layer 4 after molding and form a dynamic heat dissipation channel under high temperature. Of course, elastic deformation is only used to ensure effective fitting. Under the premise of meeting this requirement, it is not necessary to use excessive elastic deformation. The insulating layer 5 made of materials with high elasticity and high thermal sensitivity can respond quickly to temperature changes and adjust its physical properties in time, thereby maintaining stable electrical and mechanical properties in a high temperature environment, and effectively preventing insulation failure caused by overheating.

[0041] In this embodiment, the elasticity of the insulating layer 5 is greater than the elasticity of the inner sheath layer 4 and the outer sheath layer 6. Specifically, the higher elasticity enables the insulating layer 5 to more effectively absorb and buffer external mechanical shocks and vibrations, and protect the inner conductor 1 and other key layers from damage. The highly elastic insulating layer 5 can better relieve the stress caused by thermal expansion and contraction when the temperature changes, and reduce material fatigue and cracks caused by temperature changes. The highly elastic insulating layer 5 can maintain good contact during thermal expansion and contraction, which helps to maintain the stable structure of the heat dissipation cavity and ensure effective heat conduction and heat dissipation.

[0042] As a preferred embodiment of the above embodiment, the recessed area 51 is spaced apart from both sides of the first rib 41 to form a larger airflow area. The larger airflow area ensures that heat can be quickly transferred to the outside, prevents local overheating, and keeps the cable temperature evenly distributed. By reducing the sealing surface other than the above-mentioned fitting position, the cable can adapt to deformation more flexibly in a high temperature environment and maintain structural integrity and stability.

[0043] Among them, the recessed area 51 and the second rib 61 are spaced apart on both sides. Specifically, the recessed area 51 and the first rib 41 are spaced apart on both sides, and the recessed area 51 and the second rib 61 are spaced apart on both sides. Both spacing settings enable the through hole 52 to form a ventilation channel more quickly when the temperature rises, significantly improving the dynamic heat dissipation adjustment capability. Through the optimized airflow channel design, more accurate temperature sensing and heat dissipation adjustment are achieved, which responds quickly when the temperature changes, thereby ensuring the safe operation of the cable.

[0044] In this embodiment, the space of the inner circle heat dissipation cavity 42 is larger than the space of the outer circle heat dissipation cavity 62. Specifically, the inner circle heat dissipation cavity 42 obtains greater expansion sensitivity when the temperature changes due to the larger space, so that the fitting part can quickly respond to temperature changes and quickly open the channel formed by the through hole 52, which significantly improves the heat dissipation efficiency, temperature regulation ability, mechanical protection, electrical performance, service life and safety of the cable, provides an efficient and sensitive heat dissipation solution under high temperature differences and harsh environments, ensures the stability and reliability of the cable, and meets the high performance requirements of industries, energy, infrastructure and other fields.

[0045] As a preferred embodiment of the above, refer to Figure 4 The outer layer of the outer sheath layer 6 is a metal layer, and does not involve other material layers such as rubber. The metal layer includes an inner metal shielding layer 7 and an outer armor layer 8. The heat dissipation effect is ensured by the thermal conductivity of the metal. Specifically, the metal shielding layer 7 can be a copper belt, an aluminum belt or a braided copper mesh, etc., which can shield electromagnetic interference and ensure the stability of the electrical performance of the cable, and serve as a grounding protection; the armor layer 8 can be a steel belt, a steel wire or an aluminum alloy belt to provide additional mechanical protection to prevent the cable from being damaged by external forces. It is suitable for underground cables or occasions that require additional protection.

[0046] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. Thermally stable medium and high voltage cables suitable for high temperature difference scenarios, characterized by: It includes a plurality of conductors arranged in a central twisted arrangement, a conductor shielding layer, an insulating shielding layer, an inner sheath layer, an insulating layer, an outer sheath layer and a metal layer arranged in sequence on the outer layers of the plurality of conductors; The inner jacket layer is provided with a raised first rib on the outside, and the outer jacket layer is provided with a raised second rib on the inside. The cross section of the insulating layer is a wave-shaped structure. Concave areas are alternately provided on the inside and outside of the wave-shaped structure. The ends of the first rib and the second rib are accommodated one by one in correspondence with the concave areas. The bottom of the concave area is respectively fitted with the ends of the first rib and the second rib, so that an inner circle heat dissipation cavity separated by the first rib is formed between the inner jacket layer and the insulating layer, and an outer circle heat dissipation cavity separated by the second rib is formed between the outer jacket layer and the insulating layer. The inner sheath layer, the insulating layer and the outer sheath layer are all formed by pultrusion process; During the pultrusion molding of the insulating layer, by controlling the size of the pultrusion die, the insulating layer is made to fit with the end of the first tendon through elastic deformation after the molding is completed, and a plurality of through holes are evenly distributed along the length direction of the cable at the fitting position of the insulating layer and the end of the first tendon; Under normal conditions, the through hole is blocked by the first rib to maintain the isolation between the inner ring heat dissipation cavity and the outer ring heat dissipation cavity; when the temperature of the inner ring heat dissipation cavity is high, the fitting position is deformed due to the expansion of the air in the cavity, so that the fitting deformation position of the insulating layer and the inner jacket layer is deformed, thereby releasing the blocking of the through hole by the first rib and forming a flow channel between the inner ring heat dissipation cavity and the outer ring heat dissipation cavity.

2. The thermally stable medium and high voltage cable suitable for high temperature difference scenarios according to claim 1, characterized in that: The distance from the end of the first tendon to the center of the cable is greater than the distance from the end of the second tendon to the center of the cable.

3. The thermally stable medium and high voltage cable suitable for high temperature difference scenarios according to claim 1, characterized in that: The insulating layer is made of a material with high elasticity and high thermal sensitivity.

4. The thermally stable medium and high voltage cable suitable for high temperature difference scenarios according to claim 1, characterized in that: The elasticity of the insulating layer is greater than that of the inner sheath layer and the outer sheath layer.

5. The thermally stable medium and high voltage cable suitable for high temperature difference scenarios according to claim 1, characterized in that: The recessed area is spaced apart from both sides of the first rib.

6. The thermally stable medium and high voltage cable suitable for high temperature difference scenarios according to claim 1, characterized in that: The recessed area is spaced apart from both sides of the second rib.

7. The thermally stable medium and high voltage cable suitable for high temperature difference scenarios according to claim 1, characterized in that: The inner ring heat dissipation cavity space is larger than the outer ring heat dissipation cavity space.

8. The thermally stable medium and high voltage cable suitable for high temperature difference scenarios according to claim 1, characterized in that: The metal layer includes an inner metal shielding layer and an outer armor layer, and the heat dissipation effect is ensured by the thermal conductivity of the metal.

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