Self-adjusting heat dissipation type crosslinked polyethylene cable

Abstract

The invention relates to the technical field of power cables, in particular to a self-adjusting heat dissipation type crosslinked polyethylene cable which comprises a cable core, a filler, a buffer shielding layer and a flame-retardant outer sheath layer. The cable cores are circumferentially distributed in the circumferential direction, a supporting frame is arranged between every two adjacent cable cores, a heat dissipation hollow channel is formed in each supporting frame, an annular heat dissipation cavity is formed in the outer surface of the outer sheath layer, and the cavities are communicated with the heat dissipation hollow channels through radial connecting holes in the supporting frames. A through hole is formed in the outer side wall of the annular heat dissipation cavity, and a temperature control switch assembly for controlling opening and closing of the through hole is installed on the through hole. The thermal expansion liquid in the temperature control switch assembly drives the piston rod and other parts along with the temperature change so as to control the lifting of the valve plug and realize the automatic opening and closing of the through hole so as to adjust the heat dissipation efficiency of the cable. Heat dissipation can be automatically adjusted according to the operating temperature of the cable, the heat dissipation efficiency and safety are improved, and the service life of the cable is prolonged.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power cables, in particular to a self-adjusting heat dissipation type cross-linked polyethylene cable. BACKGROUND

[0002] With the continuous development of power transmission technology, the transmission capacity of the cable is also continuously improved, but the high heat generated thereby also brings challenges to the operation of the cable. The heat dissipation performance of the traditional cable is limited, which is prone to cause temperature rise during high load operation, affecting the insulation performance and service life of the cable, and even causing safety accidents. The heat dissipation methods of the cable on the market at present mainly rely on natural convection and forced air cooling. These methods can improve heat dissipation to some extent, but there are problems such as insufficient intelligent heat dissipation efficiency, slow response speed, high energy consumption, etc. Therefore, it has important practical significance and application value to develop a cable that can automatically adjust heat dissipation according to the temperature change of the cable itself. SUMMARY

[0003] In order to solve the defects existing in the prior art, the present application provides a self-adjusting heat dissipation type cross-linked polyethylene cable, which aims to solve the problems of low heat dissipation efficiency and inflexible adjustment of the cable in the prior art. Through the built-in heat dissipation channel and temperature control switch assembly, active adjustment of cable heat dissipation is realized, heat dissipation efficiency is improved, service life of the cable is prolonged, and safety of power transmission is improved.

[0004] The technical scheme adopted by the present application is as follows: a self-adjusting heat dissipation type cross-linked polyethylene cable, comprising a plurality of cable cores, a filler covering the cable cores, a buffer shielding layer covering the filler, and a flame-retardant outer sheath layer covering the buffer shielding layer, each cable core comprising a conductor, an inner shielding layer covering the conductor, and an inner insulation layer covering the inner shielding layer, the cable cores being distributed in a circumferential circle and tangent to the buffer shielding layer, a support frame being provided between adjacent conductors, a heat dissipation hollow channel being coaxially provided inside the support frame, an annular heat dissipation cavity being provided on the outer surface of the flame-retardant outer sheath layer, the filler being filled between the conductor, the buffer shielding layer and the support frame, the end of the support frame being connected to the inner side of the buffer shielding layer, a plurality of equidistantly distributed radial connection holes being provided at the connection between the support frame and the buffer shielding layer, the heat dissipation hollow channel being in communication with the annular heat dissipation cavity through the radial connection holes, a through hole being provided on the outer side wall of the annular heat dissipation cavity, and a temperature control switch assembly for controlling the opening and closing of the through hole being installed on the inner side of the annular heat dissipation cavity.

[0005] Preferably, the temperature control switch assembly comprises a liquid storage box, a piston rod, a valve rod, a valve plug and a reset mechanism, the liquid storage box is filled with thermal expansion liquid inside, one end of the piston rod is connected to the inside of the liquid storage box in a sliding seal manner, the other end of the piston rod is connected to the valve rod, the valve rod is a hollow structure, the bottom of the valve plug is connected with a lifting rod, the lifting rod is connected to the valve rod in a sliding manner, a jacking spring is sleeved on the valve rod, the two ends of the jacking spring are connected to the bottom of the valve plug and the end of the piston rod respectively, the valve plug is a circular truncated cone structure with a narrow top and a wide bottom, and the bottom of the through hole is formed with a circular truncated cone sealing seat with a narrow top and a wide bottom matched with the valve plug; when the temperature rises, the thermal expansion liquid expands to push the piston rod to extend, drive the valve rod and the valve plug to move, and the valve plug is separated from the sealing seat to open the through hole; when the temperature drops, the piston rod is reset by the reset mechanism, and the jacking spring pushes the valve plug to rise and reset and press the sealing seat to close the through hole.

[0006] Preferably, the reset mechanism comprises a vertical plate fixedly arranged on the inner wall of the annular heat dissipation cavity and a reset spring, the vertical plate is located in front of the extension direction of the piston rod, and the two ends of the reset spring are connected to the vertical plate and the piston rod respectively; when the volume of the thermal expansion liquid decreases due to the temperature drop, the reset spring pushes the piston rod to reset.

[0007] Preferably, the two ends of the heat dissipation hollow channel extend to the cable terminal and are open, a metal heat conduction spiral wire is embedded in the heat dissipation hollow channel, and the position of the heat conduction spiral wire is staggered with the radial connecting holes.

[0008] Preferably, an auxiliary plate is fixedly arranged at the outer port of the through hole, the outer surface of the auxiliary plate is a plane, the through hole penetrates the auxiliary plate, the outer surface of the auxiliary plate is covered with a filter screen corresponding to the through hole, and the upper surface of the filter screen is flush with the outer surface of the auxiliary plate; a rotating shaft is arranged on the auxiliary plate, the rotating shaft is rotatably connected to the auxiliary plate, and a scraper for cleaning the filter screen is fixedly arranged on the rotating shaft.

[0009] Preferably, the rotating shaft penetrates the auxiliary plate and the outer side wall of the annular heat dissipation cavity and extends into the annular heat dissipation cavity, and a gear is fixedly arranged at one end of the rotating shaft in the annular heat dissipation cavity; a rack engaged with the gear is fixedly arranged on the piston rod; when the piston rod moves to extend or reset, the rotating shaft is driven to rotate through the engagement of the rack and the gear, and then the scraper is driven to rotate to clean the filter screen.

[0010] Preferably, the through holes are equidistantly distributed along the circumference of the annular heat dissipation cavity, and one through hole is arranged every two connecting holes.

[0011] Preferably, the thermal expansion liquid is methyl silicone oil with a boiling point of ≥200℃.

[0012] Compared with the prior art, the present invention has the following beneficial effects:

[0013] 1. Through the integrated temperature-controlled switch assembly, the cable's through-holes automatically open or close according to internal temperature changes, thereby regulating air convection and heat dissipation efficiency, achieving intelligent heat dissipation management. Effective heat dissipation lowers the cable's operating temperature and reduces thermal aging of the insulation material, thereby extending the cable's service life and improving its reliability. This prevents insulation degradation or damage due to overheating, reducing the risk of fire and other safety incidents.

[0014] 2. The built-in hollow heat dissipation channel and its connection to the annular heat dissipation cavity provide an effective path for heat dissipation. When the temperature rises, the opening of the heat dissipation channel and cavity significantly increases air circulation, removing more heat.

[0015] 3. The heat dissipation channel and temperature control switch components are integrated inside the cable, with a compact structure that does not affect the installation and laying of the cable.

[0016] 4. The filter design with a scraper can automatically clean the filter when the temperature control switch assembly is activated, reducing maintenance workload. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0018] Figure 1 It is a front view of the present invention;

[0019] Figure 2 It is a schematic diagram of the three-dimensional structure of the present invention;

[0020] Figure 3 This is a schematic diagram of the internal structure of the annular heat dissipation cavity and the heat dissipation hollow channel of the present invention;

[0021] Figure 4 for Figure 3 A schematic diagram of the structure of part A in the middle;

[0022] Figure 5 This is a schematic diagram of the matching structure of the gear, rack and rotating shaft in the temperature control switch assembly.

[0023] In the figure: 1-cable core; 2-support frame; 3-filler; 4-buffering shielding layer; 5-flame-retardant outer sheath layer; 6-heat dissipation hollow channel; 7-annular heat dissipation cavity; 8-temperature control switch assembly; 61-radial connecting hole; 62-heat-conducting spiral wire; 71-sealing seat; 72-through hole; 73-assistant plate; 74-filter screen; 75-rotating shaft; 76-scraping plate; 77-gear; 81-liquid storage box; 82-piston rod; 83-valve rod; 84-valve plug; 85-lifting rod; 86-tightening spring; 87-vertical plate; 88-return spring; 89-rack; 101-conductor; 102-inner shielding layer; 103-inner insulation layer. DETAILED DESCRIPTION

[0024] The preferred embodiments of the present application are described below in conjunction with the accompanying drawings, which should be understood as merely illustrative and explanatory, and not limiting the present application.

[0025] Example 1

[0026] Reference Figures 1 to 3 A self-adjusting heat dissipation type cross-linked polyethylene cable includes a plurality of cable cores 1, a filler 3 covering the cable cores 1, a buffering shielding layer 4 covering the filler 3, and a flame-retardant outer sheath layer 5 covering the buffering shielding layer 4.

[0027] The internal structure of each cable core 1 includes a conductor 101, an inner shielding layer 102 covering the outer layer of the conductor 101, and an inner insulation layer 103 covering the outer layer of the inner shielding layer 102. In this embodiment, the structure of the cross-linked polyethylene cable is a three-phase cable, and the three cable cores 1 are distributed in a circumferential circle and supported by a support frame 2. The inner insulation layer 103 of each cable core 1 is tangent to the buffering shielding layer 4.

[0028] The support frame 2 is provided with a heat dissipation hollow channel 6 coaxially penetrating the inside of the support frame 2. The outer surface of the flame-retardant outer sheath layer 5 is provided with an annular heat dissipation cavity 7. The filler 3 is filled around the outer layer of the conductor 101, the inner layer of the buffering shielding layer 4, and the support frame 2. The end of the support frame 2 is connected to the inner side surface of the buffering shielding layer 4. A plurality of equidistantly distributed radial connecting holes 61 are formed at the connection between the support frame 2 and the buffering shielding layer 4. The heat dissipation hollow channel 6 communicates with the annular heat dissipation cavity 7 through these radial connecting holes 61.

[0029] The outer side wall of the annular heat dissipation cavity 7 is provided with a through hole 72. The inner side wall of the annular heat dissipation cavity 7 is provided with a temperature control switch assembly 8 for controlling the opening and closing of the through hole 72. When the internal temperature of the cable rises, the temperature control switch assembly 8 will act to open the through hole 72, allowing air to enter the annular heat dissipation cavity 7 and be discharged through the heat dissipation hollow channel 6, thereby taking away the heat. When the temperature drops, the temperature control switch assembly 8 closes the through hole 72 to prevent heat loss.

[0030] The through holes 72 are equidistantly distributed along the circumference of the annular heat dissipation cavity 7, and in order to better match the heat dissipation effect of the heat dissipation hollow channel 6, one through hole 72 is arranged every two radial connecting holes 61. Such arrangement can ensure that air can enter or exit uniformly from multiple points during heat dissipation, thereby improving the heat dissipation efficiency.

[0031] Embodiment 2:

[0032] With reference to Figure 3 and Figure 4 , this embodiment describes the temperature control switch assembly 8 and its reset mechanism in detail.

[0033] The temperature control switch assembly 8 includes a liquid storage box 81, a piston rod 82, a valve rod 83, a valve plug 84, and a reset mechanism. The liquid storage box 81 is sealingly fixed in the annular heat dissipation cavity 7 and is filled with a thermal expansion liquid, such as methyl silicone oil with a boiling point ≥ 200℃. One end of the piston rod 82 is slidingly and sealingly connected inside the liquid storage box 81, and the other end is connected to the valve rod 83 through a connecting piece. The valve rod 83 is a hollow structure, and a lifting rod 85 is slidingly connected inside the valve rod 83. The bottom end of the lifting rod 85 is fixedly connected to the valve plug 84. A jacking spring 86 is sleeved outside the valve rod 83, and the two ends of the jacking spring 86 are respectively connected to the bottom of the valve plug 84 and the end of the piston rod 82.

[0034] The valve plug 84 is in the shape of a circular truncated cone with a narrow top and a wide bottom, which can effectively seal with the sealing seat 71 formed at the bottom of the through hole 72.

[0035] When the operating temperature of the cable rises, the thermal expansion liquid in the liquid storage box 81 expands and increases in volume, thereby pushing the piston rod 82 to extend outward. The extension of the piston rod 82 drives the valve rod 83 and the valve plug 84 to move together, and when the valve plug 84 is separated from the sealing seat 71, the through hole 72 is opened.

[0036] When the operating temperature of the cable decreases, the volume of the thermal expansion liquid decreases, and the piston rod 82 retracts. At this time, the reset mechanism will act on the piston rod 82 to push it back to its original position. When the piston rod 82 is reset, the jacking spring 86 will also push the valve rod 83 and the valve plug 84 to rise together until the valve plug 84 re-presses the sealing seat 71 and closes the through hole 72.

[0037] The reset mechanism includes a vertical plate 87 fixedly arranged on the inner wall of the annular heat dissipation cavity 7, and the vertical plate 87 is located in front of the extension direction of the piston rod 82. The two ends of a reset spring 88 are respectively connected to the vertical plate 87 and the piston rod 82. When the temperature decreases and the volume of the thermal expansion liquid decreases, the elastic force of the reset spring 88 will drive the piston rod 82 to reset inward.

[0038] Embodiment 3:

[0039] With reference to Figure 1 andFigure 3 The embodiment describes further optimization of the heat dissipation hollow channel 6. The two ends of the heat dissipation hollow channel 6 extend to the cable terminal and are open to facilitate the entry and exit of air. In order to enhance the heat conduction capacity of the heat dissipation hollow channel 6, a heat conduction spiral wire 62 made of metal is embedded inside the channel. The heat conduction spiral wire 62 is arranged in an interleaved manner with the radial connecting hole 61, so that heat can be efficiently transferred to the air connected with the radial connecting hole 61 through the spiral wire.

[0040] Embodiment 4:

[0041] Referring to Figure 2 and Figure 5 The embodiment describes the filtering and cleaning device of the through hole 72. In order to prevent dust or sundries from entering the heat dissipation system, an auxiliary plate 73 is fixedly arranged at the outer port of the through hole 72. The outer surface of the auxiliary plate 73 is flat, and the through hole 72 penetrates the auxiliary plate 73. The outer surface of the auxiliary plate 73 is covered with a filter screen 74 corresponding to the through hole 72, and the upper surface of the filter screen 74 is flush with the outer surface of the auxiliary plate 73 to maintain the flatness of the outer surface of the cable.

[0042] In order to facilitate the cleaning of the filter screen 74, a rotating shaft 75 is arranged on the auxiliary plate 73, and the rotating shaft 75 is rotatably connected with the auxiliary plate 73. One end of the rotating shaft 75 is fixedly provided with a scraper 76 for scraping off the dust attached to the filter screen 74.

[0043] In the embodiment, the rotating shaft 75 penetrates the auxiliary plate 73 and extends into the annular heat dissipation cavity 7. The end of the rotating shaft 75 in the annular heat dissipation cavity 7 is fixedly provided with a gear 77. A rack 89 engaged with the gear 77 is fixed on a piston rod 82. When the temperature control switch assembly 8 is actuated, the piston rod 82 is pushed out or reset, and through the engagement of the rack 89 and the gear 77, the rotating shaft 75 is rotated, thereby driving the scraper 76 to rotate and cleaning the filter screen 74.

[0044] Working principle:

[0045] Normal operation and low heat dissipation demand:

[0046] When the internal temperature of the cable is within the normal working range, the thermal expansion liquid (such as methyl silicone oil with a boiling point ≥200℃) does not reach the set boiling point or the expansion amount is not enough to overcome the force of the return spring 88. The valve plug 84 in the temperature control switch assembly 8 is tightly pressed on the sealing seat 71 of the through hole 72, closing the through hole. At this time, the annular heat dissipation cavity 7 is blocked from the air flow of the outside world, effectively preventing heat loss and maintaining the internal temperature of the cable within the safe range.

[0047] When the cable load increases and the temperature rises:

[0048] As the cable load increases, the internal heat generation increases, and the temperature of the conductor 101 and the surrounding insulation material begins to rise. The thermal expansion liquid filled in the liquid storage box 81 expands and increases in volume. The expanded thermal expansion liquid pushes the piston rod 82 to extend outward. The extension of the piston rod 82 drives the valve rod 83 and the valve plug 84 to move together. When the piston rod 82 extends to a certain extent, the valve plug 84 is separated from the sealing seat 71 of the through hole 72, and the through hole is opened.

[0049] Once the through hole 72 is opened, air can enter the annular heat dissipation cavity 7 from the through hole. The annular heat dissipation cavity 7 is in communication with the heat dissipation hollow channel 6 inside the support frame 2 through the radial connecting hole 61. Because the internal temperature of the cable is higher than the external air, hot air will flow out of the heat dissipation hollow channel 6, and at the same time, relatively cool external air will flow into the annular heat dissipation cavity 7 through the opened through hole 72, and then enter the heat dissipation hollow channel 6 through the radial connecting hole 61. The heat-conducting spiral wire 62 enhances the heat conduction efficiency in the heat dissipation hollow channel 6, and further transfers heat to the flowing air. This active air convection effectively carries away the heat generated inside the cable, reducing the operating temperature of the cable.

[0050] When the temperature drops, the heat dissipation process ends:

[0051] When the cable load decreases, or the external environmental temperature changes, causing the internal temperature of the cable to drop, the volume of the thermal expansion liquid decreases. The piston rod 82 is retracted inward under the action of the return spring 88. The retracted piston rod 82 drives the valve rod 83 and the valve plug 84 to rise. At the same time, the jacking spring 86 also assists in pushing the valve plug 84 towards the sealing seat 71. The valve plug 84 is re-pressed on the sealing seat 71 of the through hole 72, closing the through hole. The cable is protected from unnecessary heat dissipation and environmental influence.

[0052] During the operation of the temperature control switch assembly 8, the rack 89 on the piston rod 82 engages the gear 77 in the annular heat dissipation cavity 7. The rotation of the gear 77 drives the scraper 76 to scrape and clean the filter screen 74 outside the through hole 72 through the shaft 75, preventing dust accumulation from affecting the heat dissipation efficiency.

[0053] The present application is suitable for various voltage rated cross-linked polyethylene insulated power cables, especially those that generate relatively high heat during operation and have high requirements for heat dissipation performance. The present application provides an innovative self-regulating heat dissipation type cross-linked polyethylene cable, which realizes active regulation of cable heat dissipation through integrated heat dissipation channels and intelligent temperature control switch assemblies. The present application can effectively improve the heat dissipation efficiency of the cable, reduce the operating temperature, prolong the service life, and improve the reliability and safety of power transmission.

Claims

1. A self-regulating heat dissipation cross-linked polyethylene cable, comprising a plurality of cable cores (1), a filler (3) covering the cable cores (1), a buffer shielding layer (4) covering the filler (3), and a flame-retardant outer sheath (5) covering the buffer shielding layer (4), characterized in that: Each cable core (1) comprises a conductor (101), an inner shielding layer (102) covering the conductor (101), and an inner insulating layer (103) covering the inner shielding layer (102); the cable core (1) is circumferentially distributed and tangent to the buffer shielding layer (4); a support frame (2) is provided between adjacent conductors (101); a heat dissipation hollow channel (6) is coaxially provided inside the support frame (2); an annular heat dissipation cavity (7) is provided on the outer surface of the flame-retardant outer sheath layer (5); the filler (3) is filled in the conductor (101), the buffer shielding layer (102), and the heat dissipation hollow channel (6) is provided in the support frame (2); The heat dissipation hollow channel (6) is connected to the annular heat dissipation cavity (7) through the radial connection holes (61). The outer wall of the annular heat dissipation cavity (7) is provided with a through hole (72). The inner side of the annular heat dissipation cavity (7) is provided with a temperature control switch component (8) for controlling the opening and closing of the through hole (72).

2. The self-regulating heat dissipation cross-linked polyethylene cable according to claim 1, characterized in that: The temperature control switch assembly (8) includes a liquid storage box (81), a piston rod (82), a valve stem (83), a valve plug (84) and a reset mechanism. The liquid storage box (81) is filled with thermal expansion liquid. One end of the piston rod (82) is slidably and sealedly connected to the liquid storage box (81). The other end of the piston rod (82) is connected to the valve stem (83). The valve stem (83) is a hollow structure. The bottom of the valve plug (84) is connected to a lifting rod (85). The lifting rod (85) is slidably connected to the inside of the valve stem (83). A tightening spring (86) is sleeved on the valve stem (83). The two ends of the tightening spring (86) are respectively connected to the valve stem (83). The bottom of the plug (84) is connected to the end of the piston rod (82), and the valve plug (84) is a truncated cone-shaped structure that is narrow at the top and wide at the bottom. The bottom of the through hole (72) is formed with a truncated cone-shaped sealing seat (71) that is narrow at the top and wide at the bottom and seals with the valve plug (84); when the temperature rises, the thermal expansion fluid expands and pushes the piston rod (82) to extend, driving the valve stem (83) and the valve plug (84) to move, and the valve plug (84) is separated from the sealing seat (71) to open the through hole (72); when the temperature drops, the piston rod (82) is pushed back to its original position by the reset mechanism, and the tightening spring (86) pushes the valve plug (84) to rise and reset and press the sealing seat (71) to close the through hole (72).

3. The self-regulating heat dissipation cross-linked polyethylene cable according to claim 2, characterized in that: The reset mechanism comprises a vertical plate (87) fixedly arranged on the inner wall of the annular heat dissipation cavity (7) and a reset spring (88); the vertical plate (87) is located in front of the pushing direction of the piston rod (82); the two ends of the reset spring (88) are respectively connected to the vertical plate (87) and the piston rod (82); when the temperature drops and the volume of the thermal expansion fluid decreases, the reset spring (88) pushes the piston rod (82) to reset.

4. The self-regulating heat dissipation cross-linked polyethylene cable according to claim 1, characterized in that: Both ends of the heat dissipation hollow channel (6) extend to the cable terminals and are open. A heat-conducting spiral wire (62) made of a metal material is embedded in the heat dissipation hollow channel (6). The position of the heat-conducting spiral wire (62) is staggered with the radial connection hole (61).

5. The self-regulating heat dissipation cross-linked polyethylene cable according to claim 1, characterized in that: An auxiliary plate (73) is fixedly provided at the outer end of the through hole (72), the outer surface of the auxiliary plate (73) is a plane, the through hole (72) passes through the auxiliary plate (73), the outer surface of the auxiliary plate (73) is covered with a filter screen (74) corresponding to the through hole (72), the upper surface of the filter screen (74) is flush with the outer surface of the auxiliary plate (73); a rotating shaft (75) is provided on the auxiliary plate (73), the rotating shaft (75) is rotatably connected to the auxiliary plate (73), and a scraper (76) for cleaning the filter screen (74) is fixedly provided on the rotating shaft (75).

6. The self-regulating heat dissipation cross-linked polyethylene cable according to claim 5, characterized in that: The rotating shaft (75) passes through the auxiliary plate (73) and the outer wall of the annular heat dissipation cavity (7) and extends into the annular heat dissipation cavity (7); a gear (77) is fixedly provided at one end of the rotating shaft (75) located in the annular heat dissipation cavity (7); a rack (89) meshing with the gear (77) is fixedly provided on the piston rod (82); when the piston rod (82) is pushed out or reset, the rotating shaft (75) is driven to rotate by the meshing of the rack (89) and the gear (77), thereby driving the scraper (76) to rotate to clean the filter (74).

7. The self-regulating heat dissipation cross-linked polyethylene cable according to claim 1, characterized in that: The through holes (72) are distributed at equal intervals along the circumference of the annular heat dissipation cavity (7), and one through hole (72) is provided every two connecting holes (61).

8. The self-regulating heat dissipation cross-linked polyethylene cable according to claim 2, characterized in that: The thermal expansion fluid is methyl silicone oil with a boiling point of ≥200°C.

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